Pseudamnicola (Corrosella) astieri (Dupuy, 1851)

Delicado, Diana & Ramos, Marian A., 2012, Morphological and molecular evidence for cryptic species of springsnails [genus Pseudamnicola (Corrosella) (Mollusca, Caenogastropoda, Hydrobiidae)], ZooKeys 190, pp. 55-79 : 58-62

Pseudamnicola (Corrosella) astieri (Dupuy, 1851) Figs 2-4

Hydrobia astierii Dupuy, 1851: 556-557, pl. XXVII, fig. 12, Paris (Type loc. surroundings of Grasse, Alpes-Maritimes, France [shell description]).

Paludinella astieri (Dupuy): Frauenfeld 1865: 575.

Bythinella astieri (Dupuy): Locard 1882: 227; Bérenguier 1882: 83; Locard 1893: 79, fig. 81 (shell description); Berenguier 1902: 378, pl. 16 fig. 6 (1990).

Bythinella anteisensis Bérenguier, 1882: 83, 89-90 (Type loc. Foux de Draguignant, Var, France [shell description]); Bérenguier 1902: 378-379 (shell description) pl. 16 fig. 7 (1990). (Synonymy: Girardi 2009: 56).

Bythinella berenguieri Bourguignat in Bérenguier, 1882: 83, 99-100 (Type loc. Foux de Draguignant, Var, France [shell]); Bérenguier 1902: 379-380 (shell description) pl. 16 fig. 8 (1990) (Synonymy: Girardi 2009: 56).

Bythinella doumeti Bourguignat in Locard, 1893: 91. (Type loc. surroundings of Nimes, Gard, France [shell description]) (Synonymy: Falkner et al. 2002: 81, after revision of two syntypes in the Bourguignat collection, MHNG).

Corrosella anteisensis ( Bérenguier): Boeters, 1970: 64, figs. 2, 4, 7, 9 [(shell, operculum, male and female genital systems of topotypes; Boeters could not find the syntypes)], (= Bythinella berenguieri Bourguignat in Bérenguier). (Synonymy: Girardi 2009: 56).

Pseudamnicola (Corrosella) astierii (Dupuy): Falkner et al. 2002: 29, 80-81; Girardi 2009: 56-61, figs. 1-3 (Var, France: Source d’Argens, Source du Pavillon, Source de la Foux à Draguignan [shell and anatomy]).

Type locality.

Surroundings of Grasse, France (Dupuy, 1851).

Type material.

Boeters (1970) reported the existence of one specimen with the label " Paludinella astieri , typus ex Dupuy" in Paladilhe’s collection at the Faculté des Sciences, Montpellier, France. We tried in vain to confirm the existence of such material at the university mentioned. Consequently, we should consider that the type specimen is presently inaccessible for study. However, some topotypes of Corrosella anteisensis ( Bérenguier) from Foux à Draguignan, Var exist: BOE 261, 285 a-c, 291b Boeters (1970) and Girardi (2009). This author also reported Pseudamnicola (Corrosella) astieri from Source d’Argens, Brue-Aurillac à Seillons, Var and the Source du Pavillon, Ruisseau Fauvery à Pontevès, Var ( Girardi 2009).

Material examined.

A few specimens collected from Source d’Argens, Brue-Aurillac, Var, France after finding the type area and other localities in Alpes-Maritimes and Var practically destroyed by severe storms. A total of two females and four males have been examined for anatomical descriptions.

Localities.

Source d’Argens, Brue-Aurillac, Var, France, 43°30.24'N, 5°54.43'E, D.D., 21 June 2010, MNCN 15.05/60025 (70° ethanol, Figures 2-4) and MNCN/ADN 54949-54951 (absolute ethanol). For more localities, see Girardi 2009.

New diagnosis.

Shell yellowish or whitish with a body whorl occupying 2/3 shell length and a deep suture between whorls; protoconch microsculpture granulated; central radular tooth formula 7-C-7; style sac surrounded by a black pigmented intestine; elongate bursa copulatrix U-shaped; elongate seminal receptacle without duct; penis slender with a black patch of pigmentation and some folds in its middle region; nervous system brown pigmented with supraoesophageal connective about two times longer than suboesophageal.

Description.

Shellovate-conic with 4-4.75 spire whorls, height 2.5-3.5 mm (Figure 2 A–C; Table 2); periostracum yellowish or whitish; protoconch approximately 370 µm wide with 1.5 whorls and a nucleus around 150 µm long (Figure 2D, E); protoconch microsculpture granulated, more intense on apex (Figure 2E); body whorl about 2/3 total length; teleoconch whorls convex with a deep suture; peristome orthocline; aperture complete, oval, with an inner lip thicker than outer lip; peristome margin simple, straight (Figure 2B).

Operculum corneous, yellowish, thin, pliable, ellipsoidal, paucispiral with nucleus submarginal (Figure 3A, B; Table 3); muscle attachment area oval, located near the nucleus.

Radula intermediate length (20% total shell length) bearing some 50 rows of teeth (Figure 3C, Table 4); central tooth has a tongue-shaped median cusp and seven blunt lateral cusps (Figure 3D, E); lateral teeth with three tapered cusps on each side of a long central tongue-shaped cusp; inner marginal teeth have 18 sharp cusps, shortening towards the tooth base; outer marginal teeth with 19 sharp cusps (Figure 3D, F).

Pigmentation and anatomy: Head dark brown pigmented from snout to neck (Figure 4D); pigmentation clearer on neck; tentacles also brown pigmented except for a narrow band on these and on ocular lobes; snout long as wide, with medial lobation; foot intermediate length and pigmented in dorsal region. Ctenidium in middle region of pallial cavity filling ca. 70% of its length with 17-18 gill filaments; osphradium intermediate width under central gill filaments (Figure 4C, Table 5). Stomach slightly longer than wide with a small posterior caecum; style sac shorter than stomach and surrounded by intestine black pigmented (Figure 4F, Table 5).

Female genitalia with a slender pallial oviduct (Figure 4G; Table 6); capsule gland longer than albumen gland and consisting of two regions, the posterior one being more transparent; elongate bursa copulatrix, long, folded and U-shaped with a duct about 70% of bursa length; renal oviduct straight and less pigmented from the insertion point of the bursal duct to where it begins to fold and black pigmented making one or two loops; elongate seminal receptacle without duct (Figure 4H) joining renal oviduct just before the point where the bursal duct joins the renal oviduct.

Male genitalia bear a bean-shaped prostate gland about three times longer than wide (Figure 4E, Table 6); penis long, slender, with a black patch of pigmentation and some folds in its middle region; attachment area behind right eye (Figure 4D); penial duct scarcely visible running straight close to the outer penis margin.

Nervous system brown pigmented, consisting of disperse points of pigmentation; cerebral ganglia equal in size; supraoesophageal connective more than two times longer than suboesophageal (Figure 4A, B; Table 7). Mean RPG ratio 0.42 (moderately concentrated).

Remarks.

The only available information on the anatomy of this species in the literature corresponded to populations from Foux à Draguignan (figure 2, 4, 7, 9 in Boeters 1970 and figure 2 by M. Bodon in Girardi 2009) and Source du Fauvery in Pontevès (figure 1 by M. Bodon in Girardi 2009). The specimens examined from Source d’Argens (Brue-Aurillac) are similar in shell and gastric complex shapes to specimens from Source du Fauvery though they more resemble specimens from the Foux à Draguignan in terms of pallial oviduct shape and number of gill filaments. However, other important diagnostic characters such as the shape of the penis and bursa copulatrix as well as seminal receptacle shape and its position on the renal oviduct are similar in the three populations. Based on these comparisons we conclude that specimens of the three localities belong to the same taxonomic unit with some inter-population variability shown.

Comparingshell sizes among the Pseudamnicola (Corrosella) species from the northern half of Iberian Peninsula, the shells of Pseudamnicola (Corrosella) astieri are larger (2.5-3.5 mm) than those of Pseudamnicola (Corrosella) hauffei sp. n. (2.20-2.90 mm) (see statistically significant differences in shell measurements in Table 2) and Pseudamnicola (Corrosella) hinzi Boeters, 1986 (2.2-2.7 mm, Boeters 1986) yet similar in size to those of Pseudamnicola (Corrosella) navasiana (Fagot, 1907) (3.0-3.5 mm, Boeters 1988). The only two shell variables resulting no significant between Pseudamnicola (Corrosella) astieri and Pseudamnicola (Corrosella) hauffei sp. n. were the rate SL/SW and NSW. That means that both species share the same ovate-conic shape and around 4 spire whorls, which are common characteristics among all Pseudamnicola (Corrosella) species. Anatomically, Pseudamnicola (Corrosella) astieri bears a similar or higher number of gill filaments (about 17-18) than Pseudamnicola (Corrosella) hinzi (16-17, Boeters 1986), Pseudamnicola (Corrosella) navasiana (15-16, Boeters 1988) and Pseudamnicola (Corrosella) hauffei sp. n. (about 15). The penis in Pseudamnicola (Corrosella) astieri is narrower and more slender than in Pseudamnicola (Corrosella) hauffei sp. n. and Pseudamnicola (Corrosella) navasiana , although it is wider and longer than in Pseudamnicola (Corrosella) hinzi . The copulatory organ is pigmented in its distal region in all four species, but the pigmentation patch is larger in Pseudamnicola (Corrosella) astieri . Although the bursa copulatrix is usually elongate or pyriform shaped among ( Pseudamnicola ) Corrosella species, it is U-shaped and folded in Pseudamnicola (Corrosella) astieri whereas it is J-shaped in Pseudamnicola (Corrosella) hauffei sp. n., Pseudamnicola (Corrosella) hinzi and Pseudamnicola (Corrosella) navasiana . A small seminal receptacle (around 0.15 mm) is a character common to all four species.