Pseudamnicola (Pseudamnicola) subproducta, Paladilhe, 1869

Delicado, Diana, Machordom, Annie & Ramos, Marian A., 2014, Vicariant versus dispersal processes in the settlement of Pseudamnicola (Caenogastropoda, Hydrobiidae) in the Mediterranean Balearic Islands, Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 171 (1), pp. 38-71 : 60-64

PSEUDAMNICOLA (PSEUDAMNICOLA) SUBPRODUCTA ( PALADILHE, 1869) ( FIGS 13–15 )

Amnicola spirata Paladilhe, 1869 , Nouv. Miscel. Malac., p. 108, pl. v, fig. 10, 11. (Feb. 1869).

Amnicola subproducta Paladilhe, 1869 , Nouv. Miscel. Malac., p. 140; note additionelle (Feb. 1869). nom. nov. pro Amnicola spirata .

Pseudamnicola (Pseudamnicola) spirata (Paladilhe) : Boeters, 1988.

Pseudamnicola (Pseudamnicola) subproducta (Paladilhe) : Soler, Moreno, Araujo & Ramos, 2006. Graellsia , 62: 212. comb. nov.

Type locality

(1) Surrounding areas of Banyoles (Catalonia) and (2) near Salses ( eastern Pyrenees ) ( Paladilhe, 1869) .

According to Boeters (1988), the syntypes from locality (1) Gerona, Banyoles, were collected from a ditch at the north end of the lake, fed by a spring in a brick culvert and a stream that, after about 100 m, flows into Banyoles Lake.

Type material

Not determined. Other populations studied

After several visits to Banyolas Lake, we did not find P. (P.) subproducta but only Potamopyrgus antipodarum . However, a few specimens from a single population found in the area surrounding Salses (Font Estramar, near Perpignan, France) were collected and studied. Based on these specimens, we confirm that these belong to P. (P.) subproducta . In addition, this species was found in several localities in the north-eastern region of the Iberian Peninsula (see Supporting Information Appendix S1).

Specimens examined for morphometry

Shell, anatomical, operculum, and radular measurements (Appendix S2: Tables S1–S 7) were taken from male and female specimens from Baltasar Ullal and Ontígola Lagoon in the provinces of Tarragona and Madrid ( Spain), respectively. These two localities were examined because the species is very abundant, and many specimens per population could be obtained.

New diagnosis

Shell yellowish with a body whorl occupying threequarters of shell length and a deep suture between whorls; protoconch microsculpture grooved or granulated; central radular tooth with five lateral cusps; style sac surrounded by an intestine, usually pigmented; pyriform bursa copulatrix; elongate seminal receptacle without duct; triangular penis with a small black patch of pigmentation in its distal region and folds over the entire surface; nervous system brown pigmented with supraoesophageal connective about seven times longer than suboesophageal.

Description

Shell ovate-conic with 3.25–4.50 spire whorls, with a height of between 2.0 and 3.75 mm ( Fig. 13A–C , Appendix S2: Table S1); periostracum yellowish; protoconch approximately 400 μm wide with 1.5 whorls and a nucleus around 100 μm long ( Fig. 13E, F ); protoconch microsculpture either grooved or granulated, more intense on apex ( Fig. 13G, H ); body whorl about three-quarters of the total length; teleoconch whorls convex with a deep suture; peri- stome orthocline; aperture with an inner lip thicker than outer lip; umbilicus marked; peristome margin simple, straight ( Fig. 13D ).

Operculum with approximately 2.5 whorls on internal side; oval muscular attachment mark is near the nucleus ( Fig. 14A, B , Appendix S2: Table S2).

Radula approximately five times longer than wide ( Fig. 14C , Appendix S2: Table S3) and intermediate in size (17% of total shell length); contains around 35 rows of teeth; central tooth with five pointed lateral cusps on each side of a larger central cusp ( Fig. 14D, E ); lateral teeth contain a tongue-shaped central cusp and three lateral cusps; inner and outer marginal teeth both have 20 cusps each, which become smaller towards the tooth base ( Fig. 14F ).

Pigmentation and anatomy

Head and tentacles pigmented dark brown, but pigment absent in ocular lobe regions, edge of snout, and along a longitudinal stripe on tentacles ( Fig. 15F ); foot intermediate in size with dark brown pigmentation on its dorsal side. Ctenidium in the middle of the pallial cavity and contains around 20 gill filaments that are longer than wide; osphradium opposite middle section of ctenidium ( Fig. 15C , Appendix S2: Table S4). Stomach and style sac slightly longer than wide (Appendix S2: Table S4); anterior region of the style sac surrounded by a pigmented intestine ( Fig. 15E ); rectum slightly S-shaped in pallial cavity.

Female genitalia with a pallial oviduct containing a capsule gland approximately as long as the albumen gland ( Fig. 15G , Appendix S2: Table S5); pyriform bursa copulatrix with a duct usually longer than bursa length; renal oviduct black pigmented until loop; elongate seminal receptacle with a short duct inserted slightly above the point where the bursal duct joins the renal oviduct ( Fig. 15H ).

Male genitalia bear a prostate gland about three times longer than wide ( Fig. 15D , Appendix S2: Table S6); penis triangular with rounded tip and a patch of brown pigment, which varies in size, on its distal region; folds present over its entire surface; the base is attached to central area of the head ( Fig. 15F ).

Nervous system brown pigmented, but ganglia darker than connectives and commissures; cerebral ganglia equal in size; supraoesophageal connective approximately seven times longer than suboesophageal ( Fig. 15A, B ; Appendix S2: Table S7). Mean RPG ratio 0.45 (moderately concentrated).

Remarks

The species P. (P.) subproducta has been cited for the Iberian Peninsula, southern France, and the islands of Majorca and Minorca ( Boeters, 1988). However, after studying populations from these three regions, we conclude that the species occurs only in the Iberian Peninsula and southern France, and that the populations from the islands actually belong to the species P. (P.) beckmanni , P. (P.) granjaensis , P. (P.) artanensis , and P. (P.) meloussensis . Although all of these species share features with P. (P.) subproducta , such as an ovate-conic shell, a triangular penis, a pyriform bursa copulatrix, and an elongate seminal receptacle, P. (P.) subproducta can be differentiated from the others by its smaller bursa copulatrix, shorter bursal duct, and moderately concentrated nervous system (RPG ratio around 0.45), and, in most of the examined specimens, an oesophagus that moves from side to side underneath the nervous system.

Within the Iberian Peninsula, this species has a wide, but noncontiguous, distribution range, and therefore, some populations are isolated. This fragmented distribution may lend itself to intraspecific variation and account for the observation that individuals from Font Estramar show a more depressed shell ( Fig. 13B ) and smaller penis, whereas those from Baltasar Ullal have larger shells yet most of their internal organs are smaller than in specimens from Ontígola Lagoon. Furthermore, protoconch microsculpture is grooved in Baltasar Ullal shells and granulated in Ontígola Lagoon ones ( Fig. 13G, H ). Genetically, the greatest divergences exist between a spring in Les Borges (Catalonia) and Ontígola Lagoon localities, reaching as high as 3.2% for COI.

Figures

Figure 13. Shells of Pseudamnicola (Pseudamnicola) subproducta. A, D, shells from Baltasar Ullal, Tarragona, Spain. B, shell from Font Estramar, Perpignan, France. C, shell from Ontígola Lagoon, Madrid, Spain. E, F, H, protoconch and microsculpture of shell from Baltasar Ullal, Tarragona, Spain. G, microsculpture of shell from Ontígola Lagoon, Madrid, Spain.

Figure 14. Operculum and radula of Pseudamnicola (Pseudamnicola) subproducta from Baltasar Ullal, Tarragona, Spain. A, internal side of the operculum. B, external side of the operculum. C, radula. D, rows of teeth of the radula. E, central teeth. F, details of outer marginal teeth.

Figure 15. Anatomy of Pseudamnicola (Pseudamnicola) subproducta from Baltasar Ullal, Tarragona, Spain. A, B, partial nervous system. C, ctenidium and osphradium. D, prostate gland. E, stomach. F, head and penis of a male. G, female genitalia. H, bursa copulatrix and seminal receptacle.