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Anew minute valvatiform species belonging to the genus Daphniola Radoman, 1973, Daphniola eptalophos sp. n., from mountain Parnassos, Greece is described. The new species has a transparent valvatiform-planispiral shell, wide and open umbilicus, grey-black pigmented soft body and head and a black penis with a small colorless outgrowth on the left side near its base. A comparative table of shell dimensions and a key to the species known for this endemic genus for Greece are provided.
Caenogastropoda, Hydrobiidae, Daphniola eptalophos sp. n., Greece
Greece is a hot spot for hydrobioid gastropods both in terms of species richness and endemism (
The hydrobiid gastropods (family Hydrobiidae) of Greece have been studied by several authors during the 19th, 20th and 21th century (e.g.,
Daphniola Radoman, 1973 (type species Daphniola graeca Radoman, 1973) is an endemic genus from Greece. According to
Two of the three currently known species of this genus, namely Daphniola exigua (A. Schmidt 1856) and Daphniola louisi Falniowski & Szarowska 2000 are included in the category Endangered and Critically Endangered respectively (
Recently, Falniowski and Szarowska (2011) identified a valvatiform hydrobiid gastropod found in the Peloponnisos, Greece as Horatia hadei Gittenberger, 1982, a species, which currently is listed as Islamia hadei (Gittenberger, 1982) according to
The morphology and anatomy of the genus Daphniola have extensively been described by Radoman (1973), Radoman (1983) and Bodonet al. (2001). Morphometric variables, soft body pigmentation, male and female genitalia are widely used for the distinction of species and subspecies of this genus (
Here a new Daphniola species is described from central Greece, i.e. Sterea Ellada, and compared with its congeners.
Materials and methodsSpecimens of a minute valvatoid hydrobiid gastropod from a spring nearby Agoriani (Eptalophos, mountain Parnassos, Sterea Ellada, Greece), were collected alive. Since population abundance of this species seems to be low in the spring where it was found only eighteen specimens were collected. Thirteen of them were stored in 70% ethanol for morphological and anatomical studies and five specimens in deep freezing for future molecular analyses.
Shell morphometric variables (namely shell height and width, aperture height and width) were measured of all specimens collected using the micrometer of a Stemi 2000-C, Zeiss stereomicroscope. The ratios of shell variables were calculated as well.
The structure of protoconch and teleoconch of the shells were studied using scanning electron microscopy (Jeol JSM-35 operating at 25 kV) after being dehydrated in a gradient of ethanol dilution series (10-100%) and finally in pure acetone, critical point dried and spray coated in gold-palladium.
Six randomly chosen specimens were dissected (four of them were found to be mature males, one mature female and one immature female).
Shells and penes were photographed with a Canon Eos 1000D digital camera attached on a stereomicroscope Stemi 2000-C, Zeiss, Germany.
Abbreviations: ZMUA, Zoological Museum, National and Kapodistrian University of Athens.
SystematicsHydrobiidae Troschel, 1857
Genus Daphniola Radoman, 1973
Type species Daphniola graeca Radoman, 1973
urn:lsid:zoobank.org:act:BF2C6C3F-5EF0-4375-802D-37D5529ED3E5
http://species-id.net/wiki/Daphniola_eptalophos
Figs 1-6, 7-10, 11, 14, Tables 1, 2Shell valvatiform to planispiral; operculum circular to ovate without peg, paucispiral with subcentral nucleus; umbilicus open and very wide; male genitalia with a slender black penis having a colorless outgrowth located near its base; female genitalia with a well-developed bursa copulatrix and two rather small receptaculum seminis.
Shell minute (Tab. 1), valvatiform to planispiral, light horn-colored to whitish, transparent, glossy, finely striated (Figs 1, 7, 9).
Protoconch microsculpture composed of a dense net of irregularly shaped pores (Fig. 8), teleoconch with fine pores among the growth lines (Fig. 10).
Spire very low and blunt; 3-3.5 convex whorls, regularly growing, divided by a moderately deep suture, last whorl strongly developed.
Umbilicus open and very wide, the earlier whorls being visible inside.
Aperture prosocline, almost circular with a sharp continuous peristome and thin margins, the upper part of columellar margin slightly leaned against to the shell wall, the outer margin simple.
Operculum (Fig. 3) ovate, dark orange, thin, thicker and more colored at the nucleus, thinner and colorless at the edges, circular to ovate with weakly convex inner face, paucispiral with subcentral nucleus without any outgrowth on inner face.
In living specimens epithelium of mantle darkly grey-black pigmented, the color being clearly visible under the transparent shell, head grey-black pigmented, large eye spots present and tentacles with a median longitudinal black stripe up to the half of their length.
Penis (Figs 4-6) black pigmented except the apex and the base, long, slender, gradually tapered towards the tip with a prolonged pointed apex, sometimes like an awl (Fig. 5), with a small unpigmented outgrowth on left side near its base (Fig. 6). Occasionally, this outgrowth is not well visible.
Bursa copulatrix ovate and well-developed, renal oviduct developed and unpigmented. Receptaculum seminis rs1 rather small, receptaculum seminis rs2 somewhat vestigial (Fig. 11).
Daphniola eptalophos sp n. photographed in ethanol. Apical view 1, alive specimen carrying egg capsules with an embryo on last body whorl and inside umbilicus (photographed in water) 2 operculum 3 soft body, head with tentacles and penis in situ 4-5 penis 6. A background square represents 1 mm2 in Figs 1, 4, 5. Scale bar 1 mm and 0.5 mm in Figs 2 and 3 respectively. Black arrow points the penis in Figs 4-5 and the outgrowth of penis in Fig. 6.
Daphniola eptalophos sp. n. shell images from SEM Shell habitus 7, 8 protoconch 9 teleoconch 10 Scale bar 0.5 mm in Figs 7, 9 and 0.05 mm in Figs 8, 10.
Female genitalia of Daphniola species.Daphniola eptalophos sp. n. female genitalia drawn from the only one female individual found among dissected specimens 11 Daphniola louisifemale genitalia re-drawn from
Holotype, shell height 0.90 mm, shell width 1.50 mm, aperture height 0.70 mm, aperture width 0.60 mm, collected alive (March 18, 2011), preserved in ethanol and deposited in ZMUA 4087. Paratypes 1-2, 1: shell height 1.00 mm, shell width 1.35 mm, aperture height 0.60 mm, aperture width 0.60 mm, 2: shell height 1.10 mm, shell width 1.40 mm, aperture height 0.65 mm, aperture width 0.65 mm, collected alive (March 18, 2011), preserved in ethanol and deposited in ZMUA 4088.
Agoriani (Eptalophos), mountain Parnassos, Sterea Ellada, Greece, 22°3013.5"N, 38°35'35.5"W, 950 m a.s.l. All the specimens were found on the surface of small stones and dead leaves accumulated on the bottom of a spring covered by a thick snow layer. None other freshwater gastropod species was found to share the same spring.
Known only from Agoriani (Eptalophos), Sterea Ellada, Greece.
The specific name is a noun in apposition taken from the type locality.
The new species collected in the Parnassos Mts. belongs to the genus Daphniola because it has the characteristics of this genus as defined by Radoman (1973),
The macrosculpture of protoconch and teleoconch of Daphniola eptalophos is quite similar to those described by
The shell shape of Daphniola eptalophos resembles that of Daphniola hadei (Figs 14-16, Falniowski and Szarowska 2011, page 133, Fig. 2-7), and its operculum resembles that of Daphniola exigua depicted by
Shells of Daphniola species. a, apical view, b, ventral view, c. frontal view Daphniola eptalophos sp. n. (Agoriani) 14 Daphniola exigua (Marathonas, Attica) 15 Daphniola louisi (Kessariani, Attica) 16 A background square represents 1 mm2.
Several characteristics differentiate Daphniola eptalophos from the other known species of this genus, i.e. Daphniola exigua and Daphniola louisi and Daphniola hadei.
The shell of Daphniola eptalophos is light horn-colored to whitish in contrast to the shell of Daphniola louisi, which is brightly yellowish (
Daphniola eptalophos has a flatter valvatoid shell with lower spire if compared to those of Daphniola exigua and Daphniola louisi (Figs 14-16,
Daphniola eptalophos sp. n. shell morphometry. Measurements in mm. Coefficient of variation (CV) in percent =(SD*100/¯X), ¯X=mean, SD= standard deviation, n=number of specimens measured.
Daphniola eptalophos sp. n. n=18 | sh | sw | ah | aw | sh/sw | ah/aw | sh/ah | sw/aw | |
Min | 0.90 | 1.10 | 0.50 | 0.50 | 0.53 | 0.75 | 1.38 | 1.87 | |
Max | 1.25 | 1.90 | 0.80 | 0.75 | 0.91 | 1.33 | 2.00 | 3.17 | |
¯X | 1.09 | 1.46 | 0.66 | 0.65 | 0.75 | 1.03 | 1.65 | 2.28 | |
SD | 0.09 | 0.21 | 0.08 | 0.07 | 0.10 | 0.13 | 0.19 | 0.34 | |
CV | 8.26 | 14.38 | 12.12 | 10.77 | 13.33 | 12.62 | 11.51 | 14.91 |
Shell morphometry of Daphniola species. Measurements in mm.
Daphniola species | sh | sw | ah | aw | |
Daphniola louisi Falniowski and Szarowska (2000), |
Min | 1.09 | 1.17 | 0.59 | 0.59 |
Max | 1.45 | 1.69 | 0.98 | 0.85 | |
Daphniola exigua |
Min | 0.99 | 1.00 | 0.63 | 0.60 |
Max | 1.58 | 1.40 | 0.87 | 0.87 | |
Daphniola hadei Falniowski and Szarowska (2011) | Min | 0.84 | 1.14 | 0.55 | 0.52 |
Max | 0.85 | 1.15 | 0.57 | 0.54 | |
Daphniola eptalophos sp. n. Present study | Min | 0.90 | 1.10 | 0.50 | 0.50 |
Max | 1.25 | 1.90 | 0.80 | 0.75 |
*As Horatia (Horatia) exigua, ** as Horatia (Daphniola) exigua, *** as Daphniola graeca, ****as Horatia (Daphniola) exigua pangaea.
The color of the operculum in Daphniola eptalophos is dark orange while in Daphniola exigua is yellowish brown (
The umbilicus of Daphniola eptalophos is open and wide such as the umbilicus of Daphniola louisi (Falniowski & Szarowska, 2000) and Daphniola hadei (Falniowski and Szarowska, 2011). In contrast, the umbilicus of Daphniola exigua is open but narrow (
Body and head of Daphniola eptalophos are dark pigmented like that of Daphniola exigua (
The eye spots of Daphniola eptalophos are large like in Daphniola louisi (
The penis of Daphniola eptalophos is more slender and elongate than that of Daphniola louisi (
Some of the specimens collected were observed to be carrying a single hemispherical egg capsule inside the umbilicus or attached to the body whorl with an embryo at different stage of maturation (Fig. 2). The attachment of egg capsules to the shells of the same species has not been referred in literature for any other Daphniola species but it has been recorded in some other hydrobiid taxa with wide umbilicus such as Tarraconia gasulli (Boeters, 1981) and Boetersiella wolfi Boeters & Glöer, 2007 (
To date, Daphniola eptalophos sp. n. has been found in only one spring. This fact in combination with its low population density indicates that the new species will be highly sensitive towards any kind of change of its biotope. Obviously, a monitoring of the new species is immediately required and the assessment of its population status and trends is of high priority.
Unfortunately “hydrobioid” localities in Greece, most of them springs, are prone to changes (
Effective conservation measures must be urgently taken to protect “hydrobioid” localities in Greece, among them the spring nearby Agoriani, before their unique gastropod fauna disappears.
Key to the Daphniola species1 | Shell valvatiform or valvatiform to planispiral, umbilicus open and wide, body unpigmented | 2 |
– | Shell valvatiform or valvatiform to planispiral, body and head pigmented | 3 |
2 | Shell valvatiform, penis big and massive with triangular shape and a small blunt outgrowth at the middle of its length | Daphniola louisi |
– | Shell valvatiform to planispiral, penis with long and narrow filament and a small blunt outgrowth at the middle of its length | Daphniola hadei |
3 | Shell valvatiform, umbilicus partly covered by peristome, penis pigmentless, narrow and slender with a long outgrowth at the middle of its length | Daphniola exigua |
– | Shell valvatiform to planispiral penis very dark-colored, narrow, slender with a prolonged pointed apex and a small outgrowth near its base | Daphniola eptalophos |
I am grateful to Dr. K. Triantis for his helpful comments on the manuscript. I deeply thank I. Louvrou for SEM photographs and plates and P. Andriopoulos for helping on the field during material collection and with digital photographs.