Monograph |
Corresponding author: Benoît Dayrat ( bdayrat@gmail.com ) Academic editor: Nathalie Yonow
© 2020 Benoît Dayrat, Tricia C. Goulding, Deepak Apte, Sadar Aslam, Adam Bourke, Joseph Comendador, Munawar Khalil, Xuân Quảng Ngô, Siong Kiat Tan, Shau Hwai Tan.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Dayrat B, Goulding TC, Apte D, Aslam S, Bourke A, Comendador J, Khalil M, Ngô XQ, Tan SK, Tan SH (2020) Systematic revision of the genus Peronia Fleming, 1822 (Gastropoda, Euthyneura, Pulmonata, Onchidiidae). ZooKeys 972: 1-224. https://doi.org/10.3897/zookeys.972.52853
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The genus Peronia Fleming, 1822 includes all the onchidiid slugs with dorsal gills. Its taxonomy is revised for the first time based on a large collection of fresh material from the entire Indo-West Pacific, from South Africa to Hawaii. Nine species are supported by mitochondrial (COI and 16S) and nuclear (ITS2 and 28S) sequences as well as comparative anatomy. All types available were examined and the nomenclatural status of each existing name in the genus is addressed. Of 31 Peronia species-group names available, 27 are regarded as invalid (twenty-one synonyms, sixteen of which are new, five nomina dubia, and one homonym), and four as valid: Peronia peronii (Cuvier, 1804), Peronia verruculata (Cuvier, 1830), Peronia platei (Hoffmann, 1928), and Peronia madagascariensis (Labbé, 1934a). Five new species names are created: P. griffithsi Dayrat & Goulding, sp. nov., P. okinawensis Dayrat & Goulding, sp. nov., P. setoensis Dayrat & Goulding, sp. nov., P. sydneyensis Dayrat & Goulding, sp. nov., and P. willani Dayrat & Goulding, sp. nov. Peronia species are cryptic externally but can be distinguished using internal characters, with the exception of P. platei and P. setoensis. The anatomy of most species is described in detail here for the first time. All the secondary literature is commented on and historical specimens from museum collections were also examined to better establish species distributions. The genus Peronia includes two species that are widespread across the Indo-West Pacific (P. verruculata and P. peronii) as well as endemic species: P. okinawensis and P. setoensis are endemic to Japan, and P. willani is endemic to Northern Territory, Australia. Many new geographical records are provided, as well as a key to the species using morphological traits.
Biodiversity, Coral Triangle, Indo-West Pacific, integrative taxonomy, mangrove, South-East Asia
Onchidiid slugs live in the intertidal, worldwide, except at the poles. Their larvae are released in sea water and, in that sense, onchidiids are truly marine. As adult slugs, however, they breathe air through a lung and die if they are immersed in water for too long. The slugs of the genus Peronia Fleming, 1822a are found across the entire tropical and subtropical Indo-West Pacific, from South Africa to Hawaii. They primarily inhabit rocky shores and coral rubble, can occasionally be found on muddy sand, but are typically not found inside mangrove forests.
The genus Peronia includes all onchidiid slugs with a dorsal notum bearing ramified appendages, or dorsal gills, which are most easily seen when animals are relaxed. Dorsal gills tend to be retracted when live animals are crawling at low tide, and they can be hard to see on specimens preserved without relaxation. In fact, Cuvier did not mention dorsal gills in the original description of Onchidium peronii Cuvier, 1804, the first Peronia species ever recognized. Dorsal gills were first illustrated by
For the past sixty years or so, authors have accepted only two valid Peronia species names for two species broadly distributed across the Indo-West Pacific (e.g.,
All the available types of all onchidiid species were re-examined in the context of our revision of the whole family (
Fresh material was collected across the entire Indo-West Pacific, from South Africa to Japan, Hawaii, and eastern Australia. Special attention was paid to collecting fresh material from type localities. Specimens from which DNA could be extracted were also obtained from museum collections (the first author visited many collections around the world). Old museum specimens from which DNA could not be extracted were also examined, especially in cases of interesting geographical records or when specimens were included in important onchidiid studies (
Because they are notoriously cryptic, Peronia species were first delineated using DNA sequences. Then, the anatomy of the specimens was examined in order to determine diagnostic characters for each species as well as individual variation. As in our previous revisions (
Nine Peronia species are recognized here, five of which are new to science: P. griffithsi Dayrat & Goulding, sp. nov., P. madagascariensis (Labbé, 1934a), P. okinawensis Dayrat & Goulding, sp. nov., P. peronii (Cuvier, 1804), P. platei (Hoffmann, 1928), P. setoensis Dayrat & Goulding, sp. nov., P. sydneyensis Dayrat & Goulding, sp. nov., P. verruculata (Cuvier, 1830), and P. willani Dayrat & Goulding, sp. nov. Both P. madagascariensis and P. platei were only known from the original descriptions and are described anatomically in detail for the first time. Amazingly, the best anatomical description of P. peronii so far is
These nine species cannot be distinguished externally, except for the very large individuals of P. peronii (longer than 100 mm). However, details of the internal anatomy can help separate species, except for P. platei and P. setoensis which are both cryptic externally and internally. Geographic distribution varies greatly among Peronia species. Three species are broadly distributed across the Indo-West Pacific, from the western Indian Ocean to the West Pacific: P. griffithsi, P. peronii, and P. verruculata. The six other species are characterized by much narrower geographic ranges. Three species are even endemic: Peronia okinawensis and P. setoensis are endemic to Japan, and P. willani is endemic to the Northern Territory, Australia.
Of the 31 Peronia species names available, four are valid and 27 are invalid: 21 synonyms (16 of which are new), five nomina dubia, and one junior secondary homonym. The large number of available names in Peronia is explained by a combination of three main factors. First, Peronia slugs have often been collected, because they are common across the Indo-West Pacific and because they mostly live in the rocky intertidal, which is more easily accessible than mangrove forests where most other onchidiids are found. Second, earlier zoologists created new species names without examining the types of existing nominal species and without proper knowledge of individual variation, which resulted in many names being added unnecessarily. Third, Peronia is a genus for which molecular data were critically needed, because species are externally cryptic; also, species could hardly be delineated just based on their internal anatomy because they differ only with respect to minute anatomical details. The fact that five new species names are needed in Peronia even though there already are 31 available names shows that a comprehensive revision was desperately needed.
Establishing a complete list of available names for a taxon often requires an enormous amount of time but it is the keystone of any taxonomic revision, because otherwise it would be impossible to address the nomenclatural status of available names and to determine how many new species names are needed.
All available type specimens were re-examined beyond the taxon of interest (Peronia) because species names often are incorrectly classified when they are first created. For instance, Onchidium durum Labbé, 1934a was originally created for slugs with a smooth notum, but the types of O. durum clearly bear dorsal gills. Ignoring O. durum because it was created for slugs with a smooth notum would have led to an incomplete list of available Peronia species names. Several species names had to be transferred to Peronia, because they refer to slugs with dorsal gills, regardless of whether species were originally described with dorsal gills or not. When type specimens are not located, one needs to go through original species descriptions very carefully, and still beyond the taxon of interest. Reciprocally, not all species names ever classified in Peronia belong to Peronia: for instance, several specific names originally combined with Peronia refer to Onchidella species. Finally, many species names of doubtful application need to be commented upon.
In total, 51 species-group names had to be considered for the revision of Peronia. Of these, only 31 are available Peronia species names (Table
Alphabetic list of the 51 existing species-group names of which the nomenclatural status is addressed in the present work. Details can be found in the text: comments on the four valid Peronia species names, their synonyms, and the junior homonym are in the species remarks; comments on the fifteen nomina dubia and the ten names that must be classified in other genera are in the general discussion.
Species-group names | Type locality | Nomenclatural status |
---|---|---|
Peronia acinosa Gould, 1852 | Fiji | Nomen dubium (onchidiid or not) |
Peronia alderi JE Gray, 1850 | Unknown | Nomen dubium (Peronia) |
Peronia anomala Labbé, 1934a | Red Sea | New junior subjective synonym (P. verruculata, Red Sea) |
Onchidium astridae Labbé, 1934b | West Papua | New junior subjective synonym (P. verruculata, unit #1) |
Onchidium ater Lesson, 1831a | West Papua | Wallaconchis |
Onchidium branchiferum Plate, 1893 | Philippines | New junior subjective synonym (P. verruculata, unit #1) |
Scaphis carbonaria Labbé, 1934a | New Caledonia | New junior subjective synonym (P. verruculata, unit #1) |
Onchidium celticum Cuvier in |
France | Onchidella |
Onchidium cinereum Quoy & Gaimard, 1833 | Tonga | Nomen dubium (Wallaconchis) |
Peronia corpulenta Gould, 1852 | Fiji | Nomen dubium (onchidiid or not) |
Onchidium durum Labbé, 1934a | Red Sea | New junior subjective synonym (P. verruculata, Red Sea) |
Onchidium elberti Simroth, 1920 | Sulawesi | Junior subjective synonym (P. verruculata, unit #1) |
Onchidium ferrugineum Lesson, 1831a | West Papua | Junior subjective synonym (P. verruculata, unit #1) |
Paraperonia fidjiensis Labbé, 1934a | Fiji | New junior subjective synonym (P. peronii) |
Onchis fruticosa Stimpson, 1855 | Japan | Nomen dubium (Peronia) |
Peronia gaimardi Labbé, 1934a | Vanikoro | New junior subjective synonym (P. verruculata, unit #1) |
Paraperonia gondwanae Labbé, 1934a | Western India | New junior subjective synonym (P. verruculata, unit #4) |
Paraperonia gondwanae hombroni Labbé, 1934a | Torres Strait | Nomen dubium (Peronia) |
Onchidium granulosum Lesson, 1831b | New Ireland | Nomen dubium (onchidiid, Peronia or not) |
Scaphis gravieri Labbé, 1934a | Mayotte | New junior subjective synonym (P. verruculata, unit #5) |
Onchidella griseofusca Tapparone Canefri, 1874 | Singapore | Nomen dubium (onchidiid, Peronia or not) |
Onchidium incisum Quoy & Gaimard, 1832 | Ascension Island | Onchidella |
Quoya indica Labbé, 1934a | Indian Ocean | Nomen dubium (Peronia) |
Peronia indolens Couthouy in Gould 1852 | Brazil | Onchidella |
Peronia irrorata Gould, 1852 | New Zealand | Onchidella |
Paraperonia jousseaumei Labbé, 1934a | Red Sea | New junior subjective synonym (P. madagascariensis) |
Peronia laevis Blainville, 1826 | West Papua | Marmaronchis: junior objective synonym of Marmaronchis vaigiensis (Quoy & Gaimard, 1825) |
Scaphis lata Labbé, 1934a | Vietnam | New junior subjective synonym (P. verruculata, unit #1) |
Paraperonia madagascariensis Labbé, 1934a | Madagascar | Valid (Peronia madagascariensis) |
Peronia mauritiana Blainville, 1824 | Mauritius | Junior objective synonym (P. peronii) |
Peronia marginata Couthouy in Gould 1852 | Tierra del Fuego | Onchidella |
Onchidium melanopneumon Bergh, 1884 | Fiji | Junior subjective synonym (P. peronii) |
Onchidium multiradiatum Semper, 1882 | Unknown | Nomen dubium (onchidiid, Peronia or not) |
Onchidium nebulosum Semper, 1880 | Palau | Nomen dubium (Peronia) |
Onchidium nigricans Quoy & Gaimard, 1832 | New Zealand | Onchidella |
Onchidium oniscoides Blainville, 1816 | Unknown | Nomen dubium (onchidiid, not Peronia) |
Peronia parthenopeia Delle Chiaje, 1841 | Sicily | Onchidella |
Onchidium patelloide Quoy & Gaimard, 1832 | New Zealand | Onchidella |
Onchidium peronii Cuvier, 1804 | Mauritius | Valid (Peronia peronii) |
Peronia persiae |
Iran | New junior subjective synonym (P. verruculata, unit #4) |
Onchidium planatum Quoy & Gaimard, 1825 | Guam | Nomen dubium (onchidiid or not) |
Onchidium platei Hoffmann, 1928 | Tahiti | Valid (Peronia platei) |
Onchidium punctatum Quoy & Gaimard, 1832 | West Papua | New junior subjective synonym (P. peronii) |
Peronia savignii Récluz, 1869 | Red Sea | New junior objective synonym (P. verruculata, Red Sea) |
Onchidium savignyi Semper, 1880 | Philippines | Junior secondary homonym (P. savignii) |
Peronia semituberculata Blainville, 1826 | Guam | Nomen dubium, junior objective synonym of Onchidium planatum Quoy & Gaimard, 1825 (nomen dubium) |
Onchidium straelenii Labbé, 1934b | Aru Islands | Nomen dubium (onchidiid, not Peronia) |
Onchidium tonganum Quoy & Gaimard, 1832 | Tonga | Junior subjective synonym (P. peronii) |
Scaphis tonkinensis Labbé, 1934a | Vietnam | New junior subjective synonym (P. verruculata, unit #1) |
Onchidium verruculatum Cuvier, 1830 | Red Sea | Valid (Peronia verruculata) |
Scaphis viridis Labbé, 1934a | Torres Strait | New junior subjective synonym (P. verruculata, unit #1) |
Many subsequent incorrect spellings are encountered in the onchidiid literature. The subsequent incorrect spelling of a name is not available and, to our knowledge, no subsequent incorrect spelling is in prevailing usage (
UMIZ Universitas Malikussaleh, North Aceh, Sumatra, Indonesia
ZSM Zoologische Staatssammlung München, Munich, Germany
Our molecular analyses and anatomical species descriptions are based on a data set of 179 individuals specifically gathered for the present study. Of those 179 individuals, 112 were collected by the Dayrat lab, of which 91 were deposited in countries or states of origin (Australia, Hawaii, India, Indonesia, Japan, Malaysia, Philippines, Singapore, Vietnam) and 21 (from Madagascar and Mauritius) were deposited at the
Collecting expeditions of the Dayrat lab were led by Benoît Dayrat in the Andaman Islands (India), West Bengal (India), Peninsular Malaysia, the Philippines, Singapore, New South Wales (Australia), and Northern territory (Australia), by Tricia Goulding in Queensland (Australia), Mauritius, Madagascar, Vietnam, and western India, by Munawar Khalil in Indonesia, and by Rebecca Cumming in Japan. Sites were accessed by car or by boat. Although each site was explored for an average of two hours, the exact time spent at each site also depended on the time of the low tide, the weather conditions, etc. Photographs were taken to document the kind of habitat being visited as well as the diverse microhabitats where specimens were collected. Specimens were individually numbered and photographed in their respective habitat. At each site, as much diversity as possible was sampled: even specimens that looked similar were individually numbered so that the presence of cryptic diversity could be tested. Importantly, a piece of tissue was cut for all specimens individually numbered for DNA extraction and the remainder of each specimen was relaxed (using magnesium chloride) and fixed (using 10% formalin or 70% ethanol) for comparative anatomy.
Specimens included in molecular analyses. DNA extraction numbers unique to each individual are indicated in phylogenetic trees as well as in lists of material examined and in figure captions (numbers are between brackets). Our molecular data set includes 190 Peronia individuals, only eleven of which correspond to COI sequences obtained from GenBank or BOLD (Table
All DNA sequences for the eleven outgroups are from our previous studies (
DNA extraction numbers and GenBank accession numbers for all the specimens included in the present study. The letter H next to an extraction number indicates the holotype. Sequences marked with an asterisk (*) are from our former publications (
Species | Individual (DNA #) | Voucher | Locality | GenBank COI | GenBank 16S | GenBank ITS2 | GenBank 28S |
---|---|---|---|---|---|---|---|
Alionchis jailoloensis | 5137 H | UMIZ 00117 | Indonesia, Halmahera | MG953528* | MG953538* | MG953548* | MK122918* |
Laspionchis boucheti | 1688 H |
|
Australia, Northern Territory | MH619249* | MH619310* | MT652862 | MT652995 |
Marmaronchis vaigiensis | 1183 |
|
Singapore | MK122812* | MK122854* | MK122877* | MK122910* |
Melayonchis eloisae | 1011 H |
|
Singapore | KX240026* | KX240050* | MK122904* | MK125515* |
Onchidella celtica | 5013 |
|
France | MG958715* | MG958717* | MK122906* | MK122921* |
Onchidina australis | 1523 |
|
Australia, New South Wales | KX179548* | KX179561* | MG958719* | MG958887* |
Onchidium typhae | 965 |
|
Peninsular Malaysia | KX179509* | KX179525* | MG958720* | MG958885* |
Paromoionchis tumidus | 1732 | UMIZ 00121 | Indonesia, Sumatra | MH054951* | MH055104* | MH055196* | MH055268* |
Peronina tenera | 960 |
|
Peninsular Malaysia | MG958740* | MG958796* | MG958840* | MG958874* |
Platevindex luteus | 1001 |
|
Singapore | MG958714* | MG958716* | MG958718* | MG958888* |
Wallaconchis sinanui | 2740 | UMIZ 00059 | Indonesia, Ambon | MG970713* | MG970881* | MG971093* | MG971161* |
P. verruculata (unit #1) | 1538 |
|
Australia, Queensland (19°S) | MT653148 | MT652693 | MT652863 | MT652996 |
2571 |
|
Australia, Queensland (16°S) | MT653149 | MT652694 | MT652864 | ||
2620 |
|
Australia, Queensland (20°S) | MT653150 | MT652695 | |||
2622 |
|
Australia, Queensland (20°S) | MT653151 | MT652696 | |||
2682 |
|
Australia, Queensland (21°S) | MT653152 | MT652697 | MT652865 | ||
GB | China, Guangdong (21°N) | JN543152* | |||||
GB | China, Fujian (26°N) | JN543153* | |||||
GB | China, Guangxi (21°N) | JN543154* | |||||
GB | China, Hainan (18°N) | JN543165* | |||||
2724 | UMIZ 00162 | Indonesia, Ambon (03°S) | MT653153 | MT652698 | MT652866 | MT652997 | |
P. verruculata (unit #1) | 2729 | UMIZ 00162 | Indonesia, Ambon (03°S) | MT653154 | MT652699 | ||
2856 | UMIZ 00163 | Indonesia, Ambon (03°S) | MT653155 | MT652700 | MT652867 | ||
3080 | UMIZ 00164 | Indonesia, Bali (08°S) | MT653156 | MT652701 | MT652868 | ||
3115 | UMIZ 00165 | Indonesia, Bali (08°S) | MT653157 | MT652702 | MT652869 | ||
5068 | UMIZ 00166 | Indonesia, Halmahera (00°S) | MT653158 | MT652703 | |||
5120 | UMIZ 00167 | Indonesia, Halmahera (01°S) | MT653159 | MT652704 | MT652870 | ||
5124 | UMIZ 00167 | Indonesia, Halmahera (01°S) | MT653160 | MT652705 | |||
5130 | UMIZ 00167 | Indonesia, Halmahera (01°S) | MT653161 | MT652706 | |||
2987 | UMIZ 00168 | Indonesia, Lombok (08°S) | MT653162 | MT652707 | MT652871 | ||
2868 | UMIZ 00169 | Indonesia, Seram (02°S) | MT653163 | MT652708 | |||
2870 | UMIZ 00169 | Indonesia, Seram (02°S) | MT653164 | MT652709 | MT652872 | MT652998 | |
3441 | UMIZ 00169 | Indonesia, Seram (02°S) | MT653165 | MT652710 | |||
731 |
|
Indonesia, Sulawesi | HQ660046* | HQ659914* | |||
2127 | UMIZ 00170 | Indonesia, Sulawesi (01°N) | MT653166 | MT652711 | |||
2150 | UMIZ 00171 | Indonesia, Sulawesi (01°N) | MT653167 | MT652712 | |||
2162 | UMIZ 00171 | Indonesia, Sulawesi (01°N) | MT653168 | MT652713 | MT652873 | ||
1747 | UMIZ 00172 | Indonesia, Sumatra (05°S) | MT653169 | MT652714 | MT652874 | ||
1759 | UMIZ 00173 | Indonesia, Sumatra (05°S) | MT653170 | MT652715 | MT652875 | MT652999 | |
5904 | UMIZ 00174 | Indonesia, Timor (10°S) | MT653171 | MT652716 | MT652876 | ||
5925 | UMIZ 00175 | Indonesia, Timor (10°S) | MT653172 | MT652717 | MT652877 | ||
5927 | UMIZ 00175 | Indonesia, Timor (10°S) | MT653173 | MT652718 | |||
3751 |
|
Japan, Wakayama (33°N) | MT653174 | MT652719 | MT652878 | ||
3752 |
|
Japan, Wakayama (33°N) | MT653175 | MT652720 | MT652879 | MT653000 | |
GB | Japan, Kagoshima (31°N) | LC390389* | |||||
6202 |
|
New Caledonia (22°S) | MT653176 | MT652721 | MT652880 | MT653001 | |
6212 |
|
New Caledonia (22°S) | MT653177 | MT652722 | MT652881 | MT653002 | |
6214 |
|
New Caledonia (21°S) | MT653178 | MT652723 | MT652882 | ||
698 |
|
Palau (07°N) | MT653179 | MT652724 | MT652883 | MT653003 | |
5467 |
|
PNG, Madang (05°S) | MT653180 | MT652725 | |||
5468 |
|
PNG, Madang (05°S) | MT653181 | MT652726 | MT652884 | MT653004 | |
5469 |
|
PNG, Madang (05°S) | MT653182 | MT652727 | |||
6085 |
|
PNG, New Ireland (02°S) | MT653183 | MT652728 | MT652885 | MT653005 | |
6087 |
|
PNG, New Ireland (02°S) | MT653184 | MT652729 | |||
P. verruculata (unit #1) | 6088 |
|
PNG, New Ireland (02°S) | MT653185 | MT652730 | ||
3379 |
|
Philippines, Bohol (09°N) | MT653186 | MT652731 | |||
3380 |
|
Philippines, Bohol (09°N) | MT653187 | MT652732 | MT652886 | ||
3433 |
|
Philippines, Bohol (09°N) | MT653188 | MT652733 | |||
3437 |
|
Philippines, Bohol (09°N) | MT653189 | MT652734 | |||
712 |
|
Philippines, Cebu (09°N) | HQ660050* | HQ65991* | |||
3160 |
|
Philippines, Luzon (13°N) | MT653190 | MT652735 | MT652887 | ||
3161 |
|
Philippines, Luzon (13°N) | MT653191 | MT652736 | |||
704 |
|
Philippines, Negros (09°N) | MT653192 | MT652737 | |||
991 |
|
Singapore (01°N) | MT653193 | MT652738 | MT652888 | MT653006 | |
GB | Singapore | MH002570* | |||||
5480 |
|
Vanuatu (17°S) | MT653194 | MT652739 | MT652889 | ||
5481 |
|
Vanuatu (17°S) | MT653195 | MT652740 | MT652890 | MT653007 | |
5620 |
|
Vietnam (12°N) | MT653196 | MT652741 | MT652891 | ||
5621 |
|
Vietnam (12°N) | MT653197 | MT652742 | |||
5639 |
|
Vietnam (08°N) | MT653198 | MT652743 | MT652892 | ||
5670 |
|
Vietnam (08°N) | MT653199 | MT652744 | MT652893 | ||
P. verruculata (unit #2) | 1072 |
|
India, Andaman (11°N) | MT653200 | MT652745 | ||
1077 |
|
India, Andaman (11°N) | MT653201 | MT652746 | |||
1079 |
|
India, Andaman (11°N) | MT653202 | MT652747 | |||
1080 |
|
India, Andaman (11°N) | MT653203 | MT652748 | |||
1081 |
|
India, Andaman (11°N) | MT653204 | MT652749 | |||
1084 |
|
India, Andaman (11°N) | MT653205 | MT652750 | |||
1741 | UMIZ 00179 | Indonesia, Sumatra (05°S) | MT653206 | MT652751 | MT652894 | ||
1742 | UMIZ 00179 | Indonesia, Sumatra (05°S) | MT653207 | MT652752 | MT652895 | ||
1746 | UMIZ 00178 | Indonesia, Sumatra (05°S) | MT653208 | MT652753 | MT652896 | MT653008 | |
1795 | UMIZ 00180 | Indonesia, Sumatra (05°S) | MT653209 | MT652754 | MT652897 | ||
1796 | UMIZ 00180 | Indonesia, Sumatra (05°S) | MT653210 | MT652755 | MT652898 | ||
1797 | UMIZ 00180 | Indonesia, Sumatra (05°S) | MT653211 | MT652756 | MT652899 | MT653009 | |
P. verruculata (unit #3) | 974 |
|
Peninsular Malaysia (06°N) | MT653212 | MT652757 | MT652900 | MT653010 |
975 |
|
Peninsular Malaysia (06°N) | MT653213 | MT652758 | MT652901 | ||
976 |
|
Peninsular Malaysia (06°N) | MT653214 | MT652759 | MT652902 | ||
977 |
|
Peninsular Malaysia (06°N) | MT653215 | MT652760 | MT652903 | ||
2546 |
|
Peninsular Malaysia (05°N) | MT653216 | MT652761 | MT652904 | MT653011 | |
2547 |
|
Peninsular Malaysia (05°N) | MT653217 | MT652762 | MT652905 | MT653012 | |
989 |
|
Singapore (01°N) | MT653218 | MT652763 | MT652906 | MT653013 | |
P. verruculata (unit #3) | 990 |
|
Singapore (01°N) | MT653219 | MT652764 | MT652907 | MT653014 |
GB | Singapore | MH002601* | |||||
P. verruculata (unit #4) | 1141 |
|
India, western coast (19°N) | MT653220 | MT652765 | ||
1143 |
|
India, western coast (19°N) | MT653221 | MT652766 | |||
1144 |
|
India, western coast (19°N) | MT653222 | MT652767 | |||
6164 |
|
Pakistan (24°N) | MT653223 | MT652768 | MT652908 | MT653015 | |
6165 |
|
Pakistan (24°N) | MT653224 | MT652769 | MT652909 | MT653016 | |
6166 |
|
Pakistan (24°N) | MT653225 | MT652770 | MT652910 | MT653017 | |
GB | Iran (26°N) | MK993404* | MK993392* | ||||
P. verruculata (unit #5) | 3140 |
|
Madagascar (12°S) | MT653226 | MT652771 | MT652911 | MT653018 |
3142 |
|
Madagascar (12°S) | MT653227 | MT652772 | MT652912 | ||
3143 |
|
Madagascar (12°S) | MT653228 | MT652773 | MT652913 | ||
3144 |
|
Madagascar (12°S) | MT653229 | MT652774 | MT652914 | ||
3146 |
|
Madagascar (12°S) | MT653230 | MT652775 | MT652915 | MT653019 | |
3149 |
|
Madagascar (12°S) | MT653231 | MT652776 | MT652916 | ||
3231 |
|
Madagascar (12°S) | MT653232 | MT652777 | MT652917 | ||
3597 |
|
Madagascar (12°S) | MT653233 | MT652778 | MT652918 | ||
3598 |
|
Madagascar (12°S) | MT653234 | MT652779 | MT652919 | ||
3600 |
|
Madagascar (12°S) | MT653235 | MT652780 | MT652920 | MT653020 | |
730 |
|
Mozambique (12°S) | HQ660045* | HQ659913* | |||
733 |
|
Mozambique (11°S) | HQ660047* | HQ659915* | |||
5507 |
|
Mozambique (26°S) | MT653236 | MT652781 | MT652920 | MT653021 | |
5510 |
|
Mozambique (26°S) | MT653237 | MT652782 | MT652920 | MT653022 | |
P. griffithsi | 2934 | UMIZ 00177 | Indonesia, Kei (05°S) | MT653238 | MT652783 | MT652923 | MT653023 |
2936 | UMIZ 00176 | Indonesia, Kei (05°S) | MT653239 | MT652784 | MT652924 | MT653024 | |
3566 | UMIZ 00177 | Indonesia, Kei (05°S) | MT653240 | MT652785 | MT652925 | ||
3153 |
|
Mauritius (20°S) | MT653241 | MT652786 | MT652926 | MT653025 | |
3154 |
|
Mauritius (20°S) | MT653242 | MT652787 | MT652927 | MT653026 | |
3155 |
|
Mauritius (20°S) | MT653243 | MT652788 | |||
3156 |
|
Mauritius (20°S) | MT653244 | MT652789 | MT652928 | MT653027 | |
3157 H |
|
Mauritius (20°S) | MT653245 | MT652790 | MT652929 | MT653028 | |
3606 |
|
Mauritius (20°S) | MT653246 | MT652791 | MT652930 | ||
3607 |
|
Mauritius (20°S) | MT653247 | MT652792 | |||
3608 |
|
Mauritius (20°S) | MT653248 | MT652793 | MT652931 | ||
6095 |
|
PNG, New Ireland (02°S) | MT653249 | MT652794 | MT652932 | MT653029 | |
P. madagascariensis | BOLD | India, Gujarat, Dwarka (22°N) | LGEN099-14* | ||||
GB | Iran, Persian Gulf | LC027608* | |||||
5500 |
|
Madagascar (25°S) | MT653250 | MT652795 | MT652933 | ||
5501 |
|
Madagascar (25°S) | MT653251 | MT652796 | MT652934 | MT653030 | |
5502 |
|
Madagascar (25°S) | MT653252 | MT652797 | MT652935 | ||
5503 |
|
Madagascar (25°S) | MT653253 | MT652798 | MT652936 | ||
5504 |
|
Madagascar (25°S) | MT653254 | MT652799 | |||
5506 |
|
Madagascar (25°S) | MT653255 | MT652800 | MT652937 | MT653031 | |
735 |
|
Mozambique (12°S) | HQ660042* | HQ659910* | MT652938 | MT653032 | |
703 |
|
Oman (23°N) | MT653256 | HQ659912* | MT652939 | MT653033 | |
5841 |
|
South Africa (29°S) | MT653257 | MT652801 | MT652940 | MT653034 | |
5842 |
|
South Africa (29°S) | MT653258 | MT652802 | MT652941 | MT653035 | |
P. okinawensis | 696-2 |
|
Japan, Okinawa (26°N) | HQ660043* | HQ659911* | MG958871* | MG958883* |
696-3 |
|
Japan, Okinawa (26°N) | MT653259 | MT652803 | MT652942 | MT653036 | |
696-4 H |
|
Japan, Okinawa (26°N) | MT653260 | MT652804 | MT652943 | MT653037 | |
P. peronii | 443 |
|
Guam (13°N) | HQ660041* | HQ659909* | MT652944 | MT653038 |
5840 |
|
Guam (13°N) | MT653261 | MT652805 | MT652945 | MT653039 | |
GB | Japan, Okinawa | LC390402* | |||||
1553 |
|
Mauritius (20°S) | MT653262 | MT652806 | MT652946 | MT653040 | |
3605 |
|
Mauritius (20°S) | MT653263 | MT652807 | MT652947 | MT653041 | |
5872 |
|
Mauritius (20°S) | MT653264 | MT652808 | MT652948 | ||
5874 |
|
Mauritius (20°S) | MT653265 | MT652809 | MT652949 | ||
5471 |
|
PNG, Madang (05°S) | MT653266 | MT652810 | MT652950 | MT653042 | |
5472 |
|
PNG, Madang (05°S) | MT653267 | MT652811 | MT652951 | MT653043 | |
5474 |
|
PNG, Madang (05°S) | MT653268 | MT652812 | MT652952 | ||
5476 |
|
PNG, Madang (05°S) | MT653269 | MT652813 | MT652953 | MT653044 | |
5477 |
|
PNG, Madang (05°S) | MT653270 | MT652814 | MT652954 | MT653045 | |
6086 |
|
PNG, New Ireland (02°S) | MT653271 | MT652815 | MT652955 | MT653046 | |
P. platei | 5405 |
|
PNG, Madang (05°S) | MT653272 | MT652816 | ||
5410 |
|
PNG, Madang (05°S) | MT653273 | MT652817 | MT652956 | ||
5412 |
|
PNG, Madang (05°S) | MT653274 | MT652818 | MT652957 | MT653047 | |
5464 |
|
PNG, Madang (05°S) | MT653275 | MT652819 | MT652958 | MT653048 | |
706 |
|
USA, Hawaii (21°N) | HQ660038* | HQ659906* | MG958722* | MG958884* | |
5380 |
|
USA, Hawaii (21°N) | MT653276 | MT652820 | MT652959 | MT653049 | |
6160 |
|
USA, Hawaii (21°N) | MT653277 | MT652821 | MT652960 | MT653050 | |
6161 |
|
USA, Hawaii (21°N) | MT653278 | MT652822 | MT652961 | MT653051 | |
P. setoensis | 3753 |
|
Japan, Wakayama (33°N) | MT653279 | MT652823 | MT652962 | MT653052 |
3754 |
|
Japan, Wakayama (33°N) | MT653280 | MT652824 | MT652963 | MT653053 | |
5382 |
|
Japan, Wakayama (33°N) | MT653281 | MT652825 | MT652964 | MT653054 | |
5383 H |
|
Japan, Wakayama (33°N) | MT653282 | MT652826 | MT652965 | MT653055 | |
5384 |
|
Japan, Wakayama (33°N) | MT653283 | MT652827 | MT652966 | MT653056 | |
5385 |
|
Japan, Wakayama (33°N) | MT653284 | MT652828 | MT652967 | ||
P. sydneyensis | 1513 |
|
New South Wales (33°S) | MT653285 | MT652829 | MT652968 | MT653057 |
1516 H |
|
New South Wales (33°S) | MT653286 | MT652830 | MT652969 | MT653058 | |
1517 |
|
New South Wales (33°S) | MT653287 | MT652831 | MT652970 | MT653059 | |
734 |
|
Queensland (22°S) | HQ660048* | HQ659916* | |||
1539 |
|
Queensland (22°S) | MT653288 | MT652832 | |||
1540 |
|
Queensland (22°S) | MT653289 | MT652833 | MT652971 | MT653060 | |
2646 |
|
Queensland (20°S) | MT653290 | MT652834 | MT652972 | ||
2653 |
|
Queensland (20°S) | MT653291 | MT652835 | MT652973 | ||
2656 |
|
Queensland (20°S) | MT653292 | MT652836 | MT652974 | ||
2661 |
|
Queensland (20°S) | MT653293 | MT652837 | |||
2662 |
|
Queensland (20°S) | MT653294 | MT652838 | MT652975 | MT653061 | |
2664 |
|
Queensland (20°S) | MT653295 | MT652839 | MT652976 | ||
P. sydneyensis | 2667 |
|
Queensland (20°S) | MT653296 | MT652840 | ||
2680 |
|
Queensland (21°S) | MT653297 | MT652841 | |||
6189 |
|
New Caledonia (22°S) | MT653298 | MT652842 | MT652977 | ||
6195 |
|
New Caledonia (22°S) | MT653299 | MT652843 | MT652978 | MT653062 | |
6209 |
|
New Caledonia (22°S) | MT653300 | MT652844 | MT652979 | ||
6213 |
|
New Caledonia (21°S) | MT653301 | MT652845 | MT652980 | MT653063 | |
6220 |
|
New Caledonia (21°S) | MT653302 | MT652846 | MT652981 | MT653064 | |
6222 |
|
New Caledonia (21°S) | MT653303 | MT652847 | MT652982 | ||
P. willani | 1620 |
|
Northern Territory (12°S) | MT653304 | MT652848 | MT652983 | MT653065 |
1623 |
|
Northern Territory (12°S) | MT653305 | MT652849 | MT652984 | MT653066 | |
1624 |
|
Northern Territory (12°S) | MT653306 | MT652850 | MT652985 | ||
1625 |
|
Northern Territory (12°S) | MT653307 | MT652851 | MT652986 | ||
1626 |
|
Northern Territory (12°S) | MT653308 | MT652852 | MT652987 | MT653067 | |
1628 H |
|
Northern Territory (12°S) | MT653309 | MT652853 | MT652988 | MT653068 | |
1629 |
|
Northern Territory (12°S) | MT653310 | MT652854 | |||
1653 |
|
Northern Territory (12°S) | MT653311 | MT652855 | MT652989 | ||
1654 |
|
Northern Territory (12°S) | MT653312 | MT652856 | MT652990 | ||
1655 |
|
Northern Territory (12°S) | MT653313 | MT652857 | MT652991 | MT653069 | |
1667 |
|
Northern Territory (12°S) | MT653314 | MT652858 | MT652992 | MT653070 | |
1668 |
|
Northern Territory (12°S) | MT653315 | MT652859 | MT652993 | ||
1669 |
|
Northern Territory (12°S) | MT653316 | MT652860 | |||
1670 |
|
Northern Territory (12°S) | MT653317 | MT652861 |
COI sequences publicly available. Eleven COI sequences obtained from GenBank (10) and BOLD (1) were added to our own data set (179 COI sequences) for a total of 190 sequences. Four COI sequences are from China (
Vouchers used in
Types of existing species-group names. All type specimens available for all onchidiid species-group names have been examined in context of the revision of the entire family. Comments on many onchidiid types can be found in our previous revisions (
Many type specimens were not labeled as types and were found within the general collections. In most cases, it was easy to determine that specimens were types because the information on the labels would match perfectly to that of the original descriptions. However, finding Labbé’s types was challenging, with the exception of the holotype, by monotypy, of Onchidium astridae Labbé, 1934b, preserved in Bruxelles (
The types of all the other Peronia species (and one subspecies) described by Labbé are preserved at the
For instance, originally, no jar clearly labeled as the type material of Scaphis carbonaria was found at the
Finally, the type material of Peronia persiae, recently described by
Additional material examined (historical museum collections). In addition to the 189 specimens included in the molecular analyses (not including the eleven outgroups) and the 118 type specimens of existing nominal species, 297 old specimens were obtained from museum collections from which no DNA could be extracted. Those specimens correspond to a total of 60 jars. One jar contains 161 specimens. All other jars contain fewer than 15 specimens. These old museum specimens are not included in the anatomical species descriptions, except for the description of Peronia verruculata from the Red Sea. Instead, these additional specimens are commented on in the species remarks. The additional specimens were especially useful to provide geographic records from places which could not be visited, such as the Chagos Archipelago, Nicobar Islands, Persian Gulf, and Socotra. Identifying Peronia species using only anatomical traits is challenging but possible (see below). Finally, some of the historical specimens from museum collections were studied by previous authors, and their re-examination allowed us to confirm or reject many identifications from the literature.
Size (length/width) is indicated in millimeters (mm) for each specimen. Both the external morphology and the internal anatomy were studied. All anatomical observations were made under a dissecting microscope and drawn with a camera lucida. Radulae and male reproductive organs were prepared for scanning electron microscopy (Zeiss SIGMA Field Emission Scanning Electron Microscopy). Radulae were cleaned in 10% NaOH for a week, rinsed in distilled water, briefly cleaned in an ultrasonic water bath (less than a minute), sputter-coated with gold-palladium and examined by SEM. Soft parts (penis, accessory penial gland, etc.) were dehydrated in ethanol and critical point dried before coating.
Anatomical species descriptions are based on those 179 Peronia individuals for which sequences were generated for the present study as well as on the available type material for species with existing names (see below). To avoid unnecessary repetition, the description of anatomical features that are virtually identical between Peronia species (e.g., nervous system, heart, and stomach) is not repeated for each species. However, all the characters that are useful for species comparison (e.g., intestinal loops and male apparatus) are described for every species. Special attention has been given to illustrating the holotype and the type locality of each new species.
Species are being described following a phylogenetic order. The detailed description of Peronia verruculata is based on the mitochondrial unit #1, by far the most widespread (from Peninsular Malaysia to the West Pacific) and most abundant (55 specimens in our study), but variations in the other units are precisely reported and figure captions indicate the unit to which each illustrated individual belongs.
In onchidiids, types of intestinal loops are defined based on the pattern of the intestine on the dorsal aspect of the digestive gland (with the digestive gland still in place).
The intestine first appears dorsally on the right side. In intestinal loops of type I, the intestine starts by forming a clockwise (blue) loop which does not make a complete circle. As a result, the transitional (green) loop is oriented to the right (Fig.
Intestinal types found in Peronia species. A clockwise intestinal loop is colored in blue, a counterclockwise intestinal loop is colored in yellow, and a transitional loop between them is colored in green. The big red arrow indicates the orientation of the transitional loop (A–F) or counterclockwise loop (G–I), and the small black arrows indicates the direction of the intestinal transport A type I, with a transitional loop oriented at 3 o’clock, P. sydneyensis, Australia, New South Wales, [1517] (
DNA was extracted using a phenol-chloroform extraction protocol with cetyltrimethyl-ammonium bromide (CTAB). The mitochondrial cytochrome c oxidase I region (COI) and 16S region were amplified using the following universal primers (all 5’-3’): LCO1490 GGT CAA CAA ATC ATA AAG ATA TTG G, and HCO2198 TAA ACT TCA GGG TGA CCA AAR AAY CA (
Chromatograms were consulted to resolve rare ambiguous base calls. DNA sequences were aligned using Clustal W in MEGA 7 (
Three independent sets of phylogenetic analyses were performed: 1) Maximum Likelihood and Bayesian analyses with concatenated mitochondrial COI and 16S sequences; 2) Maximum Parsimony analyses with concatenated nuclear ITS2 and 28S sequences; 3) Maximum Parsimony analyses with ITS2 haplotype sequences. Maximum Parsimony analyses were conducted in PAUP v 4.0 (
In addition, genetic distances between COI sequences were calculated in MEGA 7 as uncorrected p-distances. COI sequences were also translated into amino acid sequences in MEGA using the invertebrate mitochondrial genetic code to check for the presence of stop codons (no stop codon was found).
The monophyly of Peronia is strongly supported in all analyses except in the mitochondrial ML analyses (bootstrap of 58), which confirms that all onchidiid slugs with dorsal gills belong to the same clade (Figs
Phylogenetic relationships between Peronia species based on concatenated mitochondrial COI and 16S DNA sequences. Numbers by the branches are the bootstrap values (maximum likelihood analysis) and the posterior probabilities (Bayesian analysis). Only the values > 50% (ML) and > 0.9 (Bayesian) are indicated. Numbers for each individual correspond to unique identifiers for DNA extraction. Information on specimens can be found in the lists of material examined and in Table
Seven nodes of higher relationships among Peronia species are well supported. Supports are indicated here in parentheses in the following order: ML bootstrap in mitochondrial analysis, Bayesian posterior probability in mitochondrial analysis, bootstrap in ITS2 analysis, bootstrap in ITS2 and 28S analysis (bootstrap values below 50% and posterior probabilities below 0.90 are replaced by a dash). Most basally, Peronia is always split in clades A and B. Clade A is strongly supported (99, 1.0, 100, 100) and includes P. peronii and P. okinawensis. Clade B is also strongly supported (99, 1, 93, 99) and includes clade C and P. madagascariensis as its most basal species. Clade C, which is consistently recovered but moderately supported (-, -, 90, 87), includes clade D and P. platei as its most basal species. Clade D (98, 1, 99, 86) includes the three clades E, F, and G, of which the relationships are unresolved (Fig.
Maximum parsimony consensus tree within Peronia based on ITS2 sequences (identical sequences are represented as a single haplotype sequence). Numbers by the branches are the bootstrap values. Only the values > 50% are indicated. Numbers for each individual correspond to unique identifiers for DNA extraction. Information on specimens can be found in the lists of material examined and in Table
The monophyly of each species recognized here is strongly supported in all analyses, except for the special case of P. sydneyensis (see below, species delineation). Within four species, some least-inclusive units are supported by the mitochondrial markers but not by comparative anatomy and nuclear markers (Figs
In mitochondrial analyses (Fig.
Maximum parsimony consensus tree within Peronia based on concatenated nuclear ITS2 and 28S sequences. Numbers by the branches are the bootstrap values. Only the values > 50% are indicated. Numbers for each individual correspond to unique identifiers for DNA extraction. Information on specimens can be found in the lists of material examined and in Table
Pairwise genetic distances were calculated for a total of 13 units (Fig.
Diagram to help visualize the data on pairwise genetic distances between COI sequences within and between species and mitochondrial units (P. verruculata) in Peronia (see Table
Pairwise genetic distances between mitochondrial COI sequences in Peronia. Ranges of minimum to maximum distances are indicated (in percentage). For instance, the intra-specific divergences within P. madagascariensis are between 0 and 0.6%, while the inter-specific divergences between P. griffithsi and P. madagascariensis are between 9.3 and 11.3%.
Units | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | P. verruculata (unit #1) | 0.0–3.6 | ||||||||||||
2 | P. verruculata (unit #2) | 3.2–6.6 | 0.0–1.4 | |||||||||||
3 | P. verruculata (unit #3) | 3.4–5.4 | 4.7–6.1 | 0.0–0.4 | ||||||||||
4 | P. verruculata (unit #4) | 4.9–8.2 | 6.6–7.3 | 4.9–6.0 | 0.0–1.2 | |||||||||
5 | P. verruculata (unit #5) | 4.0–6.1 | 4.7–6.4 | 4.5–5.4 | 6.5–8–2 | 0.0–0.8 | ||||||||
6 | P. griffithsi | 7.5–10.4 | 8.3–10.0 | 7.5–8.7 | 8.0–9.7 | 7.0–9.0 | 0.0–4.2 | |||||||
7 | P. madagascariensis | 9.3–11.3 | 9.3–10.6 | 9.5–10.3 | 9.2–11.0 | 8.5–10.0 | 9.3–11.3 | 0.0–0.6 | ||||||
8 | P. okinawensis | 12.0–14.0 | 12.8–13.6 | 12.3–13.1 | 13.6–14.2 | 11.5–12.4 | 13.0–14.5 | 12.0–12.8 | 0.0–0.2 | |||||
9 | P. peronii | 11.3–15.4 | 11.5–14.7 | 12.1–14.2 | 12.6–15.2 | 12.0–14.8 | 11.5–15.0 | 12.4–15.3 | 8.6–9.4 | 0.0–4.3 | ||||
10 | P. platei | 9.5–12.5 | 10.5–12.9 | 11.1–13.5 | 11.1–12.9 | 12.1–14.1 | 10.9–13.3 | 14.2–14.8 | 12.8–13.6 | 11.3–13.5 | 0.2–4.7 | |||
11 | P. setoensis | 7.1–8.8 | 8.3–8.6 | 7.0–7.5 | 6.5–7.0 | 8.7–9.5 | 5.4–7.0 | 11.0–11.3 | 13.9–14.2 | 11.3–14.5 | 10.9–12.0 | 0.0–0.0 | ||
12 | P. sydneyensis | 6.8–9.2 | 7.6–9.3 | 6.6–8.0 | 7.0–8.0 | 7.0–8.3 | 5.6–6.8 | 10.0–11.6 | 12.6–13.8 | 14.0–15.7 | 9.8–11.7 | 7.1–7.8 | 0.0–1.6 | |
13 | P. willani | 7.3–9.2 | 8.3–9.1 | 6.1–8.0 | 7.5–8.9 | 7.8–9.3 | 5.9–7.5 | 10.3–11.4 | 13.8–14.6 | 13.8–16.8 | 11.4–12.2 | 6.5–6.6 | 4.3–5.4 | 0.0–1.9 |
All Peronia slugs are characterized by dorsal gills which are not found in other onchidiids. They are also all characterized by a unique combination of internal traits: they are the only onchidiid slugs with intestinal loops of type I or V, an accessory penial gland, and no rectal gland. The fact that any slug with this combination of traits belongs to a Peronia species is helpful to identify specimens with dorsal gills retracted inside the notum.
There are no external differences between Peronia species. In the field, it is not possible to reliably identify any of them, especially because sympatric species are often found together at the exact same sites. Individuals of very large size (longer than 100 mm) are only found in P. peronii, but smaller individuals are impossible to distinguish externally from other species. Also, tall papillae over the entire notum seem to be mostly found in P. peronii and P. madagascariensis, but that may be due to the fact that slugs of both species are the largest, and it remains difficult to define exactly what a tall papilla is because papilla size is highly variable.
Internal differences help identify some species reliably, but not all (Table
Geographical distribution of the Peronia species A distribution of all Peronia species except for P. peronii B distribution of P. peronii. The colors are the same as those used in Figs
Types of intestinal loops are useful for the identification of Peronia species (Fig.
The insertion of the retractor muscle of the penis is not very useful in identification because it mostly matches the distribution of the respective intestinal loop types (Table
The length of the muscular sac of the accessory penial gland varies depending on the size of animals, but it is useful to help identify some species. Indeed, only two species (P. peronii and P. willani) are characterized by a muscular sac which is longer than 20 mm (Table
Summary of traits that can help identify Peronia species, based exclusively on specimens examined for the present revision. Species are arranged in a phylogenetic order (Figs
Species | Max. animal length (mm) | Papillae with dorsal eyes | Intestinal type (transitional loop orientation) | Retractor muscle insertion (near heart or end of visceral cavity) | Muscular sac length (mm) | Accessory penial gland spine length (mm) | Accessory penial gland spine diameter base (μm) | Accessory penial gland spine diameter tip (μm) | Penis hooks length (μm) | Distribution | |
---|---|---|---|---|---|---|---|---|---|---|---|
P. peronii | 140 | 15–20 | I (12–3 o’clock) | heart (exc. vestigial) | >20 | 3.0–5.0 | 400–500 | 160–200 | <50 | Indo-West Pacific (Zanzibar to Okinawa and Tonga) | |
P. okinawensis | 27 | 10–15 | I (12–3 o’clock) | heart | <15 | 1.8–2.3 | 240–300 | 115–150 | <35 | Japan (Okinawa) | |
P. madagascariensis | 80 | 12–18 | V | end of VC | <15 | 2–2.4 | 200–230 | 70–80 | <100 | Western Indian Ocean | |
P. platei | 30 | 7–10 | V | end of VC | <5 | 0.7–1.0 | 65–100 | 20–30 | <60 | Western Pacific (PNG to Hawaii & French Polynesia) | |
P. setoensis | 20 | 8–12 | V | end of VC | <5 | 0.9–1.2 | 80–85 | 15–25 | <25 | Japan (Wakayama) | |
P. griffithsi | 25 | 6–10 | V | end of VC (exc. heart) | <5 | 0.50–0.62 | 60–65 | 15–20 | <25 | Indo-West Pacific (Mauritius to Kei Islands & New Ireland) | |
P. sydneyensis | 50 | 8–16 | I (3–6 o’clock) | end of VC | <10 | 0.6–1.0 | 90–100 | 20–50 | <30 | Queensland, New South Wales & New Caledonia | |
P. willani | 65 | 10–25 | I (3–6 o’clock) | end of VC | <25 | 1.5–1.9 | 240–250 | 80–100 | <37 | Northern Territory | |
P. verruculata | #1 | 60 (exc. 73) | 10–22 | I (3–6 o’clock) | end of VC | <15 | 1.4–2.0 | 100–270 | 35–50 | <50 | Singapore to eastern Australia, New Caledonia & Japan |
#2 | 55 | 14–22 | <10 | 1.4–1.7 | 140–160 | 30–35 | Sumatra & Andaman | ||||
#3 | 40 | 10–18 | 1.8–2.2 | 200–270 | 40–80 | <60 | Malaysia & Singapore | ||||
#4 | 60 | (1.3) 2.2–2.8 | 200 | 50 | Western India, Pakistan & Persian Gulf | ||||||
#5 | 50 | 10–20 | 1.8–2.0 | 150–180 | 45–50 | <55 | Mozambique & Madagascar | ||||
#6 | 40 | 10–18 | <15 | 2.0–2.4 | 140–200 | 55–60 | Red Sea |
The delineation of Peronia species is straightforward. They are all supported by independent data sets: they are reciprocally monophyletic with both mitochondrial and nuclear markers, and their monophyly is strongly supported; they are all separated by a large barcode gap; and they each are characterized by a unique combination of anatomical traits (with the exception of P. setoensis and P. platei, which are cryptic). Only two species need special attention: P. sydneyensis and P. verruculata.
The paraphyly of P. sydneyensis with respect to P. willani in nuclear analyses most likely is the result of incomplete lineage sorting, because lineage sorting progresses more rapidly for mitochondrial alleles than for nuclear alleles (
Despite some genetic structure, Peronia verruculata is regarded as a single species for various reasons. In mitochondrial analyses, P. verruculata is split in five least-inclusive mitochondrial units of which the relationships are basically unresolved due to low support (Fig.
All mitochondrial units of P. verruculata are cryptic anatomically (their anatomical traits display overlapping variation) while P. verruculata is clearly distinct from other Peronia species (Table
Finally, note that Peronia verruculata was described from the Red Sea, from which no fresh material could be obtained. However, the specimens examined from the Red Sea are anatomically indistinguishable from the specimens of the five mitochondrial units of P. verruculata (Table
Geographic distribution is discussed in detail with each species description. The map of species distributions only illustrates the records that are regarded as correct (Fig.
The secondary literature was read with great attention, especially in cases where it could provide geographical records not included in our material. Every record found in the literature is commented on (in the species remarks). Records from the literature are certainly not taken for granted because the secondary literature is plagued with two major issues. First, past authors did not always take the time to examine type specimens. For instance,
Onchis Férussac, 1822: xxxi. Nomen oblitum.
Peronia
Fleming, 1822a: 574;
Peronia Blainville, 1824: 280 [junior homonym of Peronia Fleming, not a reference of Peronia Fleming].
Eudrastus Gistel, 1848: x.
Paraperonia Labbé, 1934a: 196.
Scaphis Labbé, 1934a: 203.
Lessonia Labbé, 1934a: 213 [junior homonym of Lessonia Swainson, 1832, replaced by Lessonina Starobogatov, 1976].
Quoya Labbé, 1934a: 216.
Lessonina Starobogatov, 1976: 211.
Quoyella Starobogatov, 1976: 211 [unnecessary replacement name for Quoya Labbé, 1934a].
Onchis: Onchidium peronii Cuvier, 1804, by monotypy.
Peronia Fleming: Onchidium peronii Cuvier, 1804, by monotypy.
Peronia Blainville: Peronia mauritiana Blainville, 1824, by original designation.
Eudrastus: Onchidium tonganum Quoy & Gaimard, 1832, by subsequent designation (
Paraperonia: Paraperonia gondwanae Labbé, 1934a, by subsequent designation (
Scaphis: Onchidium astridae Labbé, 1934b, by subsequent designation (
Quoya: Quoya indica Labbé, 1934a, by monotypy.
Lessonina: Onchidium ferrugineum Lesson, 1831a, by monotypy.
Quoyella: Quoya indica Labbé, 1934a, by monotypy.
Onchis: After the Greek ὁ ὂγκος, oncos, which means mass, or tumor.
Peronia: After François Péron [1775–1810], zoologist of the Baudin expedition between 1800 and 1803, during which he collected the two slugs (from Mauritius and Timor) which Cuvier described as Onchidium peronii in 1804.
Eudrastus: Likely, although for unclear reasons, from the Greek εὖ, eu, for true, and δραστέoς, drasteos, a verbal adjective which means to be done.
Paraperonia: From the Greek παρα, para, meaning beside, and Peronia.
Scaphis: After the Greek ἡ σκᾰφίs, which means small boat (Labbé, 1934a: 202).
Quoya: After the French naturalist Jean René Constant Quoy [1790–1869], a member of two circumnavigations from 1817 to 1820 with captain Freycinet and from 1826 to 1829 with captain Dumont d’Urville. Quoy and Joseph Paul Gaimard [1793–1858] described several species of onchidiids based on their collections in the southern seas. Quoyella has the same etymology.
Lessonina: After the French naturalist René Primevère Lesson [1794–1849], a member of a circumnavigation from 1822 to 1825 with captain Duperrey. Lesson described several species of onchidiids based on his collections in the southern seas, such as the type species of Lessonina, Onchidium ferrugineum, which he collected in West Papua, Indonesia. Labbé’s invalid name Lessonia was also dedicated to Lesson.
Onchis: Masculine. Férussac did not specify the gender of Onchis which he did not combine with any specific name, and even the binomen Onchis peronii, which Férussac did not use per se, would not help in that respect. Because Onchis is derived from the masculine Greek noun ὁ ὂγκος, it is considered to be of masculine gender.
Peronia: Feminine. No gender was specified by Fleming, and the combination Peronia peronii does not help to determine it. Because no gender was originally specified or indicated and because Peronia ends in -a, it is treated as a name of feminine gender (
Eudrastus: Masculine. No gender was originally specified or indicated. Eudrastus ends in a word derived from a word of variable gender (a verbal adjective) and should be treated as masculine (
Paraperonia: Feminine. Gender of Peronia.
Scaphis: Feminine. The gender was not specified by Labbé, but his original combinations S. atra, S. carbonaria, S. lata, and S. punctata indicate that he treated Scaphis as a name of feminine gender, which is correct since Scaphis is derived from the feminine Greek noun ἡ σκᾰφίs.
Quoya: Feminine. The gender was not specified by Labbé, but his original combination Q. indica indicates that he treated Quoya as a name of feminine gender, which is assumed to be the gender of Quoyella as well.
Lessonina: Feminine. The gender was not specified by Starobogatov, and no gender was specified for Lessonia by Labbé. Labbé’s original combination Lessonia ferruginea indicates that he treated Lessonia as a name of feminine gender, which is assumed to be the gender of Lessonina as well.
Body not flattened. Dorsal gills present. Dorsal eyes present. No retractable, central papilla present. Eyes at tip of short ocular tentacles. Male opening below right ocular tentacle and to its left. Foot wide. Pneumostome median, on ventral hyponotum. Intestinal loops of types I or V. Rectal gland absent. Accessory penial gland present, with muscular sac. Penis with hooks.
Phylogenetic analyses show that all species of slugs with dorsal gills belong to the same clade (Figs
In his Histoire naturelle générale et particulière des mollusques terrestres et fluviatiles, Férussac (1819: 80–82) agreed with
The two generic names Onchis and Peronia were independently created in 1822 for O. peronii, respectively by Férussac (1822) and
The exact date of publication of Onchis is 13 April 1822 (when the pages xxv–xlvii were published); a collation for
Onchis
is not etymologically rigorous. The latinization of ὂγκος is oncos or oncus, as in the English word oncology. The Greek letter κ is “c” in Latin, while χ becomes “ch.” That Férussac used onchis instead of oncos is not surprising, as naturalists often took liberties with the latinization of Greek words. A famous example being the word taxonomy, created as taxonomie by
The generic name Peronia first appeared in two different venues, both published by Fleming (1822). One venue is
Peronia Fleming, 1822a is an objective junior synonym of Onchis Férussac, 1822, because Férussac’s Onchis was published prior to Fleming’s Peronia and both generic names share the same type species (Onchidium peronii). However, to the best of our knowledge, Onchis has only been used twice in a binomen, and both times before 1899: by
“This genus, which we have named in honor of M. Peron, was referred by Cuvier to the Onchidium of Buchanan (…) and the species termed O. Peronii. It was found creeping upon marine rocks, under water, at the Mauritius, by M. Peron. M. Cuvier conjectures that it breathes free air, and has accordingly inserted it among the Pulmones aquatique [Pulmonés aquatiques, i.e., aquatic pulmonates]. Some doubts, however, may reasonably be entertained about the truth of this supposition. It would certainly be an unexpected occurrence to find a marine gasteropodous mollusca obliged to come to the surface at intervals to respire. It will probably be found that it is truly branchiferous.”
It was
When he created the generic name Peronia,
Like
“The Onchidie thus would have at the same time a pulmonary apparatus and a branchial apparatus; and that structure is in perfect agreement with what we know of the habits of that mollusk: Péron says that it is aquatic; on the contrary M. Cuvier, without the authority of this observer, would have believed it to be terrestrial. (...) We think that the Onchidie, at least the species illustrated here, enjoys the capacity to breathe under water thanks to the help of those ramified tubercles which cover the posterior end of its body, without the necessity of coming up to the surface; which is relatively difficult for an animal that slowly crawls at the bottom underwater. As for the pulmonary opening, it indicates that the onchidie breathes air as well; and we must suppose that several times in its life it finds itself in the condition to do so.”
Audouin supposedly assumed that those slugs were truly aquatic.
Because Peronia was originally used as a genus for all marine onchidiids by both
The name Eudrastus was created by
John Edwards
JE
JE
Then, suddenly, in 1934, the number of onchidiid taxon names for slugs with dorsal gills dramatically increased. Based on the onchidiid collection at the Paris Museum,
The generic name Paraperonia was created by
The generic name Scaphis was created by
Lessonia Labbé, 1934a is objectively invalid because it is the junior homonym of Lessonia Swainson, 1832 [Aves].
Nothing is ever simple in onchidiid taxonomy. Indeed,
Authors completely rejected
Onchidium peronii
Cuvier, 1804: 37–51, pl. 6, figs 1–9;
Peronia peronii
(Cuvier, 1804):
Onchis peronii (Cuvier, 1804): Férussac 1822: xxxi.
Peronia mauritiana Blainville, 1824: 281; Adams and Adams 1855: 235.
Onchidium tonganum
Quoy & Gaimard, 1832: 210–211, pl. 15, figs 17, 18; Semper 1880: 258–260, pl. XIX, figs 2, 9, pl. XXII, figs 1, 2, 10 [in part only];
Peronia tongana
(Quoy & Gaimard, 1832):
Onchidium punctatum Quoy & Gaimard, 1832: 215–216, pl. 15, figs 27, 28. Syn. nov.
Peronia punctata
(Quoy & Gaimard, 1832):
Onchidium melanopneumon
Bergh, 1884a: 129–142, pl. IV, figs 25–27, pl. V, figs 1–27, pl. VI, figs 5–18, 20–21;
Paraperonia fidjiensis Labbé, 1934a: 197–198, figs 9–11. Syn. nov.
Peronia verruculata:
Lectotype and paralectotype (Onchidium peronii). Mauritius • lectotype, hereby designated, by means of
The original description of Onchidium peronii was based on two specimens collected by Péron: the lectotype from Mauritius, of which the internal anatomy was illustrated in detail by
Lectotype
(Peronia mauritiana). Mauritius • lectotype, hereby designated, by means of
Blainville also mentioned the name Peronia mauritiana in his Manuel de Malacologie et de Conchyliologie (Blainville 1825: 490) and in the article “Péronie” of the Dictionnaire des Sciences Naturelles (
Lectotype
(Onchidium tonganum). Tonga • lectotype, hereby designated, 100/60 mm; Panhi-Motou [possibly the small island of Pangaimotu];
Lectotype and paralectotypes (Onchidium punctatum). Indonesia • lectotype, hereby designated, 70/60 mm; dans le port de Dorey [Manokwari harbor, West Papua]; 1829; JRC Quoy and JP Gaimard leg.;
A second jar was found with two paralectotypes (
Holotype
(Onchidium melanopneumon). Fiji • holotype, by monotypy, 65/40 mm; Kandavu [Kadavu]; Aug 1874; HMS Challenger leg.;
Lectotype and paralectotypes (Paraperonia fidjiensis). Fiji • lectotype, hereby designated, 60/50 mm; 1876; Filhol leg.;
Mauritius • 2 specimens 140/100 mm [5872] and 125/75 mm [5874]; La Mivoie; 20°20.659'S, 57°21.763'E; 11 Jun 2014; TC Goulding leg.; st 177, basalt rocks, at night;
Mariana Islands • 1 specimen 115/80 mm [443]; Guam Island, Bile Bay; 13°17.124'N, 144°39.742'E; 23 Mar 2007; C Carlson leg.; reef margin;
Papua New Guinea – Madang • 1 specimen 70/60 mm [5476]; Wonad Island; 05°08.1'S, 145°49.3'E; 29 Nov 2012;
(historical museum collections). Chagos Archipelago • 1 specimen 95/65 mm; Ye Ye, Peros Banhos atoll; 24 Feb 1996; M Spalding (from N Yonow’s personal collection) leg.; exposed on shallow reef flat on rocks;
Fiji • 1 specimen 75/50 mm; Viti Isles; A Garrett leg.;
India • 2 specimens 85/55 mm and 70/50 mm; Nicobar Islands, Pulo Milo, Little Nicobar; Reinhardt, Galathea 305 leg.;
Indonesia – Java • 1 specimen 90/55 mm; Batavia [Jakarta]; 1899; C Aurivillius leg.;
Kiribati • 1 specimen 35/35 mm; Gilbert Islands, Apaiang [Abaiang]; 01°49'N, 172°57'E; 12 Aug 1917; S Bock’s Pacific Expedition 1917–1918 leg.; outer reef;
Madagascar • 1 specimen 65/50 mm; Tulear [Toliara]; 23°22'S, 43°39'E; Feb 1913; K Afzelius leg.; coral reef;
Maldive Islands • 1 specimen 85/55 mm; Tiladummati Atoll, Faro Islet, on reef NW of Fildau Island; 06°55.333'S, 73°11.833'E; 30 & 31 Mar 1964; R Robertson, International Indian Ocean Expedition leg.; st R021, intertidal, on dead coral rubble;
Marshall Islands • 1 specimen 37/30 mm; Jaluit; 06N, 170E; 20 Oct 1917; C Hessle, S Bock’s Pacific Expedition 1917–1918 leg.; west shore southeast of entrance;
Mauritius • 10 specimens up to 90/60 mm; probably Mauritius according to a new label (the original label was destroyed); 1929–1930; T Mortensen leg.;
New Caledonia • 1 specimen 100/60 mm; Touho, NW, Koë Reef, 2 mi. SSE; 16–20 Jan 1961; Kline & Orr leg.; 0–4 feet, live and dead coral, sand, weed;
Palau • 1 specimen 80/65 mm;
Seychelles • 1 specimen 90/70 mm; 1830; Dussumier leg.;
Tanzania • 1 specimen 65/50 mm; Zanzibar; 1902; C Eliot leg.;
One COI sequence was obtained from GenBank (LC390402) for an individual identified as Peronia sp. and collected from Okinawa, Japan (
(Fig.
Interestingly, but for unclear reasons, Peronia peronii seems to be only recorded from relatively small islands, the largest ones being Timor, New Caledonia, and Fiji. Even in Papua New Guinea, it was found on small islands close to the mainland but not on the mainland. Peronia peronii seems to be transported across vast distances from the western Pacific Ocean to the western Indian Ocean, but which does not seem to settle on the coasts of large land masses. We did not find it in any of the many localities we visited in the Philippines, Vietnam, Malaysia, Borneo, Sulawesi, Halmahera, Sumatra, etc. It is possible that we occasionally missed it in a few places (obviously we missed it in Timor and New Caledonia where it is present), but it is unlikely that we missed it everywhere.
The presence of P. peronii is confirmed in the following locations (Fig.
The following records from the literature are not confirmed here, because authors did not provide enough information supporting the identification: Djibouti (
Onchidium peronii was named after François Péron [1775–1810] who collected the two slugs described by Cuvier during the Baudin expedition [1800–1803]. Peronia mauritiana, Onchidium tonganum, and Paraperonia fidjiensis were named after type localities. Onchidium punctatum was named after the speckled (punctatum in Latin) dorsal notum of live animals. Onchidium melanopneumon was named after the black (melas in Greek) lung (pneumon in Greek) tissue of the holotype.
(Fig.
(Fig.
(Figs
Digestive system, dorsal view, Peronia peronii, type specimens. The arrow indicates the orientation of the transitional loop A paralectotype, Onchidium peronii, Timor (
Digestive system, dorsal view, Peronia peronii. The arrow indicates the orientation of the transitional loop A Mauritius [5874] (
Radula, Peronia peronii A–C Papua New Guinea [5476] (
Radular formulae in Peronia species. Each formula follows the same format: number of rows × number of lateral teeth per left half row - 1 (rachidian tooth) - number of lateral teeth per right half row. Each DNA extraction number corresponds to one individual. The letter H next to an extraction number indicates a holotype.
Species | Radular formula | Spm length (mm) | - | Locality | DNA extraction number |
---|---|---|---|---|---|
P. verruculata (unit #1) | 63 × 70-1-70 | 45 | UMIZ 00170 | Sulawesi | 2127 |
73 × 92-1-92 | 40 |
|
Vietnam | 5621 | |
56 × 60-1-60 | 25 |
|
Queensland | 2622 | |
74 × 75-1-75 | 45 | UMIZ 00166 | Halmahera | 5068 | |
52 × 57-1-57 | 40 | UMIZ 00162 | Ambon | 2729 | |
60 × 60-1-60 | 40 | UMIZ 00168 | Lombok | 2987 | |
70 × 72-1-72 | 50 | UMIZ 00169 | Seram | 2870 | |
70 × 75-1-75 | 35 |
|
Papua New Guinea | 5469 | |
56 × 56-1-56 | 17 |
|
Vanuatu | 5481 | |
P. verruculata (unit #2) | 70 × 75-1-75 | 50 | UMIZ 00178 | Sumatra | 1746 |
70 × 78-1-78 | 50 | UMIZ 00180 | Sumatra | 1797 | |
60 × 68-1-68 | 45 | UMIZ 00180 | Sumatra | 1795 | |
64 × 70-1-70 | 55 | UMIZ 00180 | Sumatra | 1796 | |
P. verruculata (unit #3) | 68 × 78-1-78 | 35 |
|
Peninsular Malaysia | 976 |
70 × 92-1-92 | 40 |
|
Peninsular Malaysia | 2547 | |
65 × 85-1-85 | 25 |
|
Singapore | 990 | |
72 × 86-1-86 | 35 |
|
Peninsular Malaysia | 975 | |
P. verruculata (unit #4) | 73 × 85-1-85 | 50 |
|
Pakistan | 6164 |
75 × 95-1-95 | 50 |
|
Pakistan | 6165 | |
75 × 92-1-92 | 40 |
|
Pakistan | 6166 | |
P. verruculata (unit #5) | 65 × 75-1-75 | 40 |
|
Madagascar | 3231 |
55 × 63-1-63 | 35 |
|
Madagascar | 3144 | |
55 × 65-1-65 | 25 |
|
Mozambique | 5510 | |
P. verruculata (Red Sea) | 66 × 86-1-86 | 35 |
|
Red Sea | #1 |
80 × 95-1-95 | 40 |
|
Red Sea | #2 | |
67 × 80-1-80 | 35 |
|
Red Sea | #3 | |
70 × 80-1-80 | 35 |
|
Red Sea | #4 | |
P. madagascariensis | 85 × 90-1-90 | 40 |
|
Madagascar | 5501 |
78 × 90-1-90 | 40 |
|
Madagascar | 5504 | |
47 × 50-1-50 | 10 |
|
Oman | 703 | |
70 × 72-1-72 | 35 |
|
South Africa | 5841 | |
P. peronii | 90 × 115-1-115 | 110 |
|
Mauritius | 3605 |
90 × 105-1-105 | 140 |
|
Mauritius | 5872 | |
95 × 105-1-105 | 80 |
|
Papua New Guinea | 5472 | |
90 × 100-1-100 | 70 |
|
Papua New Guinea | 5476 | |
100 × 110-1-110 | 85 |
|
Guam | 5840 | |
P. platei | 75 × 75-1-75 | 12 |
|
Hawaii | 706 |
65 × 78-1-78 | 12 |
|
Hawaii | 5380 | |
70 × 90-1-90 | 30 |
|
Hawaii | 6160 | |
70 × 80-1-80 | 30 |
|
Hawaii | 6161 | |
67 × 75-1-75 | 14 |
|
Papua New Guinea | 5405 | |
70 × 72-1-72 | 20 |
|
Papua New Guinea | 5412 | |
P. sydneyensis | 56 × 60-1-60 | 30 |
|
New South Wales | 1516 H |
51 × 60-1-60 | 23 |
|
New South Wales | 1517 | |
47 × 45-1-45 | 6 |
|
Queensland | 2667 | |
58 × 70-1-70 | 50 |
|
Queensland | 2680 | |
35 × 35-1-35 | 12 |
|
New Caledonia | 6189 | |
55 × 70-1-70 | 41 |
|
New Caledonia | 6195 | |
45 × 46-1-46 | 25 |
|
New Caledonia | 6220 | |
P. okinawensis | 60 × 60-1-60 | 20 |
|
Okinawa, Japan | 696-2 |
60 × 60-1-60 | 25 |
|
Okinawa, Japan | 696-3 | |
65 × 65-1-65 | 27 |
|
Okinawa, Japan | 696-4 H | |
P. setoensis | 50 × 50-1-50 | 20 |
|
Wakayama, Japan | 5383 H |
55 × 55-1-55 | 15 |
|
Wakayama, Japan | 3753 | |
50 × 50-1-50 | 15 |
|
Wakayama, Japan | 3754 | |
P. griffithsi | 50 × 45-1-45 | 18 | UMIZ 00177 | Kei | 2934 |
50 × 50-1-50 | 17 | UMIZ 00176 | Kei | 2936 | |
50 × 45-1-45 | 25 | UMIZ 00177 | Kei | 3566 | |
45 × 52-1-52 | 20 |
|
Mauritius | 3153 | |
50 × 52-1-52 | 20 |
|
Mauritius | 3156 | |
50 × 50-1-50 | 15 |
|
Mauritius | 3157 H | |
P. willani | 58 × 80-1-80 | 50 |
|
Northern Territory | 1628 H |
53 × 60-1-60 | 40 |
|
Northern Territory | 1668 | |
65 × 80-1-80 | 60 |
|
Northern Territory | 1626 | |
70 × 90-1-90 | 65 |
|
Northern Territory | 1620 |
(Figs
Posterior, hermaphroditic (female) reproductive system, Peronia peronii A Mauritius [3605] (
Anterior, male, copulatory apparatus, Peronia peronii A Mauritius [3605] (
The retractor muscle is shorter or longer than the penial sheath and inserts near the heart. Exceptionally, the retractor muscle can even be vestigial ([5472]
(Table
Peronia peronii is additionally characterized by a unique combination of anatomical traits: muscular sac longer than 20 mm, intestinal loops of type I (with a transitional loop oriented between 12 and 3 o’clock), retractor muscle inserting near the heart. Also, no individual larger than 80 mm was found in any other Peronia species so far. Animal size can be useful when several Peronia species are found at the same site. For instance, the two individuals of P. verruculata (unit #1) found at the station PM 12 (near Madang, Papua New Guinea) are 35 and 38 mm long while the individual of P. peronii from the same station is 80 mm long. The type I of its intestinal loops (with a transitional loop oriented between 12 and 3 o’clock) is only shared by P. okinawensis, a species endemic to Japan with which it is most closely related.
Accessory penial gland spine, Peronia peronii A, B, F, G Mauritius C, D, H Papua New Guinea E, I Guam A [3605] (
Synonymies.
There is no doubt that
Peronia mauritiana is a junior objective synonym of Onchidium peronii because they share the same name-bearing type.
Onchidium tonganum was described by Quoy and Gaimard (1832: 210–211, pl. 15, figs 17, 18) from “Panhi-Motou,” possibly the small island of Pangaimotu, Tonga, based on an unspecified number of individuals. The illustrations of the dorsal gills by Quoy and Gaimard (1832: pl. 15, figs 17, 18) and their presence on the notum of the lectotype (
Onchidium punctatum is regarded here as a junior synonym of P. peronii because the length (3.7 mm) of the spine of the accessory penial gland of the lectotype (
Secondary literature. Several early authors mentioned Cuvier’s Onchidium peronii without any new material (
In the seventh volume of the second edition of Lamarck’s Histoire naturelle des animaux sans vertèbres, which was revised by
John Edward
Adams and Adams (1855: 235) merely listed Peronia mauritiana, P. peronii, P. punctata, and P. tongana as Peronia species names. Note that for P. peronii, they refer to Savigny’s illustrations of individuals from the Red Sea misidentified as P. peronii by Audouin instead of Cuvier’s original description of P. peronii, which means that Adams and Adams refer to P. verruculata instead of P. peronii (see remarks on P. verruculata). Adams and Adams (1855: pl. LXXXI, fig. 3) also reproduced the original illustration of O. tonganum by Quoy and Gaimard (1832: pl. 15, fig. 17).
The record of Onchidium peronii from Natal, South Africa (
Based on the collections of the Galathea Expedition preserved in Copenhagen,
The record of Onchidium mauritianum from the Red Sea by
The records of Onchidium peronii from Mozambique by
Semper (1880: 258–260, pl. XIX, figs 2, 9, pl. XXII, figs 1, 2, 10) referred to huge onchidiid slugs (from 50 to 105 mm, preserved) as Quoy and Gaimard’s (1832) Onchidium tonganum and merely suggested, with a question mark, that O. peronii could refer to the same species. Semper (1880: 258) listed five geographical records for O. tonganum: Tonga and West Papua (as Port Dorey), from Quoy and Gaimard (1832); Mauritius, based on some material from the Vienna and Kiel museums; Samoa, based on some material from the Museum Godeffroy; and Bohol, Philippines, based on his own collections. Semper (1880: 258) indicated that the specimens he examined were from 50 to 105 mm long, preserved, and that the smallest individual was found in Mauritius. His anatomical description perfectly matches the anatomy of P. peronii. In particular, a spine of an accessory penial gland measuring 4 mm long is only compatible with P. peronii (Table
Semper (1882: 290) thought that
Onchidium punctatum is one of the eight onchidiid species mentioned by
The record of Onchidium peronii from Durban, Natal, South Africa by
According to
It is not possible to determine to what species
Eight large specimens (longer than 65 mm) examined by Hoffmann from Sumatra (
Note that the locality of the specimen from Sumatra (
Two names accepted as valid by
All references cited by Labbé for P. peronii and P. tongana have been commented on above, but
In Japan,
It is not possible to determine whether
Many chemical studies have mentioned P. peronii in the past few decades. However, the name P. peronii was used arbitrarily. The individuals used for the extraction of natural products may not have been properly identified.
Finally, a few last words on P. peronii in phylogenetic studies.
Holotype. Japan • holotype, hereby designated, 27/25 mm [696-4 H]; Okinawa, Kunigami, Bay just SE of Cape Hedo; 26°51.803'N, 128°15.863'E; 3 Jul 2004; G Paulay, J Jeller, M Malay & Y Hiratsuka leg.; reef flat;
Japan • 2 specimens 25/20 mm [696-3] and 20/17 mm [696-2]; same collection data as for the holotype;
(Fig.
Peronia okinawensis is named after its type locality: okinawensis is a latinized adjective that agrees in gender (feminine) with the generic name (
The only specimens known were found on a reef flat. Peronia okinawensis seems to be rare compared to P. verruculata (unit #1) but may be more abundant at some other sites in Okinawa. It would be interesting, in the future, to map in detail at what exact sites the three Peronia species that are sympatric in Okinawa (P. okinawensis, P. peronii, and P. verruculata) overlap or not, in Okinawa and possibly in the rest of the Ryukyu Islands.
No picture of live animals is available. The color of preserved specimens is beige mottled with darker areas dorsally and whitish ventrally. The dorsal notum of live animals is covered by dozens of papillae of various sizes. Some papillae bear black dorsal eyes at their tip. The number of papillae with dorsal eyes is variable (8–15). The largest specimens are 27 mm long.
(Figs
Peronia okinawensis, Japan, Okinawa, holotype [696-4 H] (
Radula, Peronia okinawensis, Japan, Okinawa A, B holotype [696-4 H] (
(Figs
(Table
A new species name is needed because no existing name applies to the species described here. The specimen [696-2] was tentatively identified as Peronia cf. verruculata by
Paraperonia madagascariensis Labbé, 1934a: 199, fig. 15.
Paraperonia jousseaumei Labbé, 1934a: 198, figs 12–14. Syn. nov.
Holotype
(Paraperonia madagascariensis). Madagascar • holotype, by monotypy, 40/40 mm; Fort Dauphin [Taolagnaro]; 1932; Décary leg.;
Peronia madagascariensis A–D digestive system, dorsal view, with intestinal loops of type V E posterior, hermaphroditic (female) reproductive system A holotype, Paraperonia madagascariensis, Madagascar (
Syntypes
(Paraperonia jousseaumei). The type material of Paraperonia jousseaumei could not be located at the
South Africa • 2 specimens 35/23 mm [5841] and 18/13 mm [5842]; KwaZulu-Natal, Durban, Treasure Beach; 29°57.294'S, 30°59.514'E; 18 Nov 2010; D Herbert and L Davis leg.; rocky intertidal zone;
Mozambique • 1 specimen 42/37 mm [735]; Cabo Delgado Province, Pemba, Wimbi Beach, Pemba Beach Hotel; 12°58'S, 40°32'E; 14 Jul 2006; DG Reid leg.; on shady rock at base of limestone cliff, in upper eulittoral behind intertidal platform;
Madagascar • 1 specimen 55/40 mm [5500]; Ambatobe, près Soamanitse; 25°27.4'S, 44°57.4'E; 24 May & 7 Jun 2010;
Oman • 1 specimen 10/7 [703]; Muscat, Cemetery Bay; 23°37.250'N, 58°36.016'E; 9 Feb 2004; G Paulay & M Claereboudt leg.; coral community, reef slope, on ophiolitic bedrock and rubble;
(historical museum collections). Oman • 3 specimens 80/60 mm; Qurm Beach, near Muscat; 23°37.56'N, 58°28.86'E; 26 Jan 2005; V Bonito, M Claereboudt & G Paulay leg.; intertidal rocky shore;
Iran • 3 specimens 80/65 mm to 75/65 mm; Persian Gulf, Strait of Hormuz, Qeshm Island; 18 Apr 1937; G Thorson leg.; st 69;
Yemen • 1 specimen 55/55 mm; Socotra, off Quadub; 12°39.015'N, 53°55.730'E; 18 Mar 1999; Salim Al-Moghrabi (from N Yonow’s personal collection) leg.; intertidal, ST-064 SAM-1;
South Africa • 1 specimen 70/45 mm; Port Natal, Durban; 30S, 31E; Wahlberg leg.; littoral rocky bottom;
One COI sequence was obtained from BOLD (LGEN099-14) for an individual identified as Onchidium verruculatum and collected from Dwarka, Gujarat, on the western coast of India (ca. 22°N), which is the easternmost known locality for P. madagascariensis. A second COI sequence was obtained from GenBank (LC027608) for an individual identified as Peronia sp. and collected from the coast of Iran in the Persian Gulf. Both sequences were unpublished.
(Fig.
Peronia madagascariensis was named after its type locality, Madagascar. Peronia jousseaumei was named after Félix Pierre Jousseaume [1835–1921], a medical doctor and malacologist who collected many specimens from the Red Sea preserved at the
Peronia madagascariensis is found in the rocky intertidal, like most other Peronia slugs.
No picture of live animals was available. The color of preserved specimens is not different from other species (greyish brown and mottled with darker and lighter areas dorsally, and light brown greyish ventrally). The dorsal notum of live animals is covered by dozens of papillae of various sizes. In large individuals, dorsal papillae can be particularly tall (easily up to 4 mm), even in preserved specimens, and are evenly distributed over the entire notum. Preserved, they are very difficult to distinguish from retracted dorsal gills in the posterior half of the notum, but they are regular papillae with or without eyes. Some papillae bear black dorsal eyes at their tip. The number of papillae with dorsal eyes is variable (from 12 to 18). Dorsal gills seem taller and denser than in other species. The largest specimens in our fresh material are 55 mm long but two additional museum specimens are much longer (80 mm).
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Radula, Peronia madagascariensis, South Africa, [5841] (
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Anterior, male, copulatory apparatus, Peronia madagascariensis A Madagascar, [5501] (
(Table
The name Paraperonia madagascariensis clearly applies to a Peronia species because of the dorsal gills on the notum of the holotype. The holotype was entirely dissected by Labbé. The radula, the posterior (hermaphroditic) reproductive parts, and the anterior copulatory apparatus are missing. The intestinal loops are of type V (Fig.
Additional, non-type specimens were found in historical museum collections which could be identified as P. madagascariensis due to the presence of intestinal loops of type V, from Oman (
Peronia slugs with intestinal loops of type V are without doubt present in the Red Sea. For instance, one of the “c” paralectotypes of
Even though the names Peronia madagascariensis and Peronia jousseaumei were never used prior to the present contribution, they are not regarded as new combinations because Paraperonia has already been regarded as a synonym of Peronia by
The specimen [703] from Oman was tentatively identified as Peronia sp. 2 by
A specimen from Durban (30°S), South Africa, preserved in Stockholm (
Onchidium platei Hoffmann, 1928: 51–53, figs 9, 10, pl. 3, figs 11, 12.
Lectotype and paralectotypes. French Polynesia • lectotype, hereby designated, 18/10 mm; Eimeo [Moorea], Tahiti; 1851–1853; Eugenie Expedition leg.; st 1245–9, in the barrier reef;
Hawaii • 2 specimens 12/10 mm [706] and 12/12 mm [5380]; Molokai, Puko’o; 21°04.313'N, 156°48.001'W; 27 Jan 2003; V Bonito leg.; on rocks;
Papua New Guinea – Madang • 1 specimen 14/12 mm [5405]; Rempi Area, SW Hargun Island; 05°01.6'S, 145°47.9'E; 15 & 20 Nov 2012;
(historical museum collections). French Polynesia • 2 specimens 15/10 mm and 13/8 mm; Tuamotu Archipelago, NE side, Anaa Atoll; 17°20'S, 145°30'W; 27 Oct 1967; NGS-SBM Marquesa Expedition MV “Pele” 1967 leg.;
Hawaii • 15 specimens from 18/15 mm to 8/8 mm; Oahu, Kailua Bay, Mokapu Point; 21°28.02'N, 157°43.98'E; WF Ponder and EA Kay leg.; 7 Apr 1974; on rocks, semi-sheltered and exposed platforms;
Kiribati • 8 specimens from 10/9 mm to 3/3 mm; Gilbert Islands, Apamama [Abemama]; 00S, 173E; 1917–1918; S Bock’s Pacific Expedition leg.; sand, inside lagoon;
(Fig.
Peronia platei was named after German zoologist Ludwig Hermann Plate [1862–1937], professor of zoology at the University of Jena and author of a monograph on onchidiids (
Peronia platei is found primarily in the rocky intertidal. According to the label, specimens from Kiribati were collected on sand inside a lagoon (P. sydneyensis and P. willani are also known to be found on sand).
(Fig.
(Figs
Digestive system, dorsal view, Peronia platei, with intestinal loops of type V A lectotype, French Polynesia, Moorea (
Radula, Peronia platei A Papua New Guinea, Madang [5405] (
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Posterior, hermaphroditic (female) reproductive system, Peronia platei A Papua New Guinea, Madang [5412] (
Anterior, male, copulatory apparatus, Peronia platei A lectotype, French Polynesia, Moorea (
(Table
Onchidium platei applies to the species described here because the anatomy of the lectotype is identical to the anatomy of our material (Table
Additional specimens were found in historical museum collections which could be identified as P. platei mostly based on the intestinal loops of type V, the specimen size, and their geographic origin. Specimens from Kiribati (
Accessory penial gland spine, Peronia platei A–C, F, G Hawaii, Oahu D, E, H, I Papua New Guinea, Madang A [706] (
No Peronia slug from Hawaii was positively demonstrated to belong to P. verruculata (unit #1), which is characterized by intestinal loops of type I. Therefore,
Onchidella evelinae Marcus & Burch, 1965 was described based on small specimens (average length 6 mm) from Eniwetok Atoll, Marshall Islands (ca. 11°N, 162°E). The type material was deposited at the Museum of Zoology, University of Michigan, but could not be located there (personal communication from the collection manager, Dr. Taehwan Lee). Onchidella evelinae is a misidentification for one of the onchidiid species present in the Marshall Islands: it cannot refer to Onchidella slugs because an accessory penial gland is mentioned in the original description and because Onchidella is not present in the middle of the West Pacific. The Marshall Islands are within the distribution range of P. platei (Fig.
Holotype. Japan • holotype, hereby designated, 20/15 mm [5383]; Honshu, Wakayama, Nishimuro, near Seto Marine Biological Laboratory; 33°41.504'N, 135°20.179'E; 30 Aug 2014; R. Cumming leg.; exposed rock wall and platform;
Japan • 3 specimens 13/8 mm [5382], 10/5 mm [5384], and 12/10 mm [5385]; same collection data as for the holotype;
(historical museum collections). Japan • 1 specimen 23/20 mm; Sagami Bay, Misaki; 1930–1931; Gislén’s Pacific Expedition 1930–1931 leg.; littoral rocky bottom;
(Fig.
Peronia setoensis is named after its type locality, near the Seto Marine Biological Laboratory: setoensis is a latinized adjective that agrees in gender (feminine) with the generic name (
(Fig.