Research Article |
Corresponding author: Boonsatien Boonsoong ( fscibtb@ku.ac.th ) Academic editor: Lyndall Pereira-da-Conceicoa
© 2021 Chanaporn Suttinun, Thomas Kaltenbach, Jean-Luc Gattolliat, Boonsatien Boonsoong.
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:
Suttinun C, Kaltenbach T, Gattolliat J-L, Boonsoong B (2021) A new species and first record of the genus Procerobaetis Kaltenbach & Gattolliat, 2020 (Ephemeroptera, Baetidae) from Thailand. ZooKeys 1023: 13-28. https://doi.org/10.3897/zookeys.1023.61081
|
The genus Procerobaetis Kaltenbach & Gattolliat, 2020 is reported for the first time from Thailand, and Procerobaetis totuspinosus sp. nov. is described as a new species based on larvae. It can be easily distinguished from other known Procerobaetis species by the presence of triangular spines at the posterior margin of tergites VI–IX. COI sequences were obtained from all known species. The genetic distances (Kimura 2-parameter) between the new species and the other species are between 20% and 23%. The morphological characters of the new species and its closely related species are discussed; larval key to all species of the genus Procerobaetis is also provided.
Mayfly, taxonomy, Southeast Asia
The family Baetidae is the most diverse mayfly family at the species level, accounting for about 30% of all mayfly species worldwide (
Recently, the genus Procerobaetis Kaltenbach & Gattolliat, 2020 of Baetidae was discovered from Southeast Asia. It presently contains three species distributed in Indonesia: Sumatra (P. leptobranchius and P. petersorum) and the Philippines (P. freitagi), as described by
The specimens were collected from streams and wadeable rivers from the northern part of Thailand. They were subsequentely preserved in 95% ethanol. Larval dissection was performed in Cellosolve, with subsequent mounting on slides with Euparal. Measurements (given in mm) and photographs were taken using a Visionary LK System (Dun, Inc., USA). All drawings were made with the aid of a camera lucida attached to a compound microscope. For scanning electron microscopy (SEM), specimens (head, legs, tergites, paraproct, caudal firmaments) were dried in a critical point drier (CPD7501) and coated with gold (Sputter Coater SC7620). The SEM photographs were observed with a FEI Quanta 450 SEM. Final plates were prepared with Adobe Photoshop CC 2020.
The DNA was extracted using non-destructive methods, allowing subsequent morphological analysis (see
Species | Locality | GenBank Accession Number (GenSeq Nomenclature) |
---|---|---|
P. totuspinosus sp. nov. | Chiang Mai, Thailand | MW549043 (genseq-2 COI) |
P. leptobranchius | Sumatra, Indonesia | MN453816, MN453817 |
P. petersorum | Sumatra, Indonesia | MN453818, MN453814 |
Procerobaetis sp. C | Sumatra, Indonesia | MN453815 |
P. freitagi | Mindoro, Philippines | MN453819 |
The distribution map was generated with the software SimpleMappr (
The material is deposited in the collection of the Zoological Museum at Kasetsart University in Bangkok, Thailand (ZMKU) and at the Museum of Zoology in Lausanne, Switzerland (
Order Ephemeroptera Hyatt & Arms, 1891
Family Baetidae Leach, 1815
Holotype. 1 larva on slide, deposited in ZMKU, Thailand, Chiang Mai, Mae Chaem district, Mae Chaem wadeable river, 18°30'45.3"N, 98°21'23.8"E, 475 m, 16.02.2020, B. Boonsoong leg.
Paratypes. 1 larva on slide, deposited in ZMKU, same data as holotype; 1 larva in alcohol, GBIFCH00673237, deposited in
6 larvae in alcohol, deposited in ZMKU, same data as holotype. 2 larvae in alcohol, deposited in ZMKU, 1 larva in alcohol, GBIFCH00673238, deposited in
Larva (Figs
Colouration
(Fig.
Head. Antenna (Figs
Labrum
(Fig.
Right mandible
(Fig.
Left mandible
(Fig.
Both mandibles with lateral margins almost straight. Basal half with fine, simple setae scattered over dorsal surface.
Hypopharynx
(Fig.
Maxilla
(Fig.
Labium
(Fig.
Thorax. Foreleg (Figs
Middle leg
(Fig.
Hind leg
(Fig.
Abdomen. Tergites (Fig.
Gills
(Fig.
Paraproct
(Figs
Caudal filaments
(Fig.
Larva. The main diagnostic characters are: i) the posterior margin of tergites VI–VIII entirely with triangular spines; ii) the maxillary palp is shorter than in other species, with segment I shorter than galea-lacinia; and iii) all gills present extended points as in P. freitagi, while in P. leptobranchius and P. petersorum only gills I and II are apically strongly produced.
Unknown.
Procerobaetis totuspinosus sp. nov. is a combination of totus (derived from the Latin word meaning entire, whole, complete) and spina (meaning spine), in reference to the remarkable complete row of triangular spines at the posterior margin of tergites VI–VIII.
Chiang Mai province
The specimens were collected in a stream and a wadeable river (Fig.
The Kimura 2-parameter (K2P) analysis revealed interspecific distances (COI) between the new species and the other species of 20–23%. In addition, the interspecific genetic distances of known Procerobaetis species varied between13–20% (Table
Genetic distances (COI) between sequenced specimens, using the Kimura 2-parameter.
1 | 2 | 3 | 4 | ||
---|---|---|---|---|---|
1 | Procerobaetis leptobranchius | ||||
2 | Procerobaetis petersorum | 0.13 | |||
3 | Procerobaetis sp. C | 0.16 | 0.16 | ||
4 | Procerobaetis freitagi | 0.20 | 0.19 | 0.20 | |
5 | Procerobaetis totuspinosus sp. nov. | 0.22 | 0.20 | 0.23 | 0.20 |
The genus Procerobaetis was established in 2020 by Kaltenbach & Gattolliat. This small genus comprises three species: Procerobaetis leptobranchius, P. petersorum and P. freitagi. It shares with Nigrobaetis Kazlauskas in Novikova & Kluge, 1987 and Alainites Waltz & McCafferty, 1994 important morphological characters such as: i) body laterally compressed with hypognathous mouthparts, ii) shape of glossae and paraglossae iii) shape of segments II and III of the labial palp (
Procerobaetis totuspinosus sp.nov. belongs to the genus Procerobaetis based on characters defined by
The molecular analysis clearly supports P. totuspinosus sp. nov. as a valid species. It is clearly differentiated from other species, as the genetic distances between species range from 20% to 23% (K2P; Table
The discovery of Procerobaetis in Thailand is the first report of the genus from continental Asia, as all other specimens were collected on islands. The new type locality is situated between Sumatra and the northern Philippines (Fig.
Larvae of Procerobaetis should not be overlooked, as they are easily recognisable both in the field and in the lab. However, Procerobaetis remains local and rare in Thailand, as in Sumatra and the Philippines, probably due to precise ecological requirements.We may expect a broader distribution including poorly known areas such as continental Malaysia, Laos, Cambodia and Vietnam. Despite intensive field sampling in Brunei and North Kalimantan, allowing recent improvements in the knowledge of the mayfly fauna of Borneo, the genus is still not recorded from this island.
1 | Triangular spines on posterior margin present only on tergite IX, apex of gills III–VII pointed ( |
2 |
– | Triangular spines on posterior margin present on tergites VI–IX or VIII–IX, apex of gills III–VII with long and extended points (Figs |
3 |
2 | Dorsal margin of femur (middle and hind legs) slightly concave | P. leptobranchius |
– | Dorsal margin of femur (middle and hind legs) almost straight | P. petersorum |
3 | Triangular spines on posterior margin present on tergites VIII–IX | P. freitagi |
– | Triangular spines on posterior margin present on tergites VI–IX (Fig. |
P. totuspinosus sp. nov. |
The project was funded by a Science Achievement Scholarship of Thailand (SAST). This research has been supported by the Centre of Excellence on Biodiversity (BDC) Office of Higher Education Commission (BDC-PG2-161004). We are most grateful to our colleagues for assistance during field trips. We are grateful to Marion Podolak (