Pseudamnicola (Pseudamnicola) beckmanni, GLOER & ZETTLER, 2007

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 : 49-53

publication ID	https://doi.org/ 10.1111/zoj.12124
publication LSID	lsid:zoobank.org:pub:9CD3D06C-7D15-4211-9613-D23A67F07938
DOI	https://doi.org/10.5281/zenodo.10541922
persistent identifier	https://treatment.plazi.org/id/03A05C65-2F0D-9553-AA73-FF01E414FB74
treatment provided by	Marcus
scientific name	Pseudamnicola (Pseudamnicola) beckmanni
status

Treatment

PSEUDAMNICOLA (PSEUDAMNICOLA) BECKMANNI GLÖER & ZETTLER, 2007 View in CoL ( FIGS 4–9 View Figure 4 View Figure 5 View Figure 6 View Figure 7 View Figure 8 View Figure 9 )

Pseudamnicola tramuntanae Altaba, 2007: 27 View in CoL .

Type locality

Fountain in Deyá, former washhouse on the outskirts of Deyá, Majorca, 39.746°N, 2.649°E ( Glöer & Zettler, 2007).

Type material

Holotype ( ZMH 51012) and five paratypes ( ZMH 21013) in Zoologischen Museum, Hamburg; nine paratypes in K.-H. Beckmann’s collection, five in Glöer’s collection, and 60 in Zettler’s collection.

Localities

After finding the washhouse in Deyá (type locality) completely dry in 2008, the specimens studied here were collected at El Rentador Spring (type locality of the junior synonym P. tramuntanae ), near the washhouse on the outskirts of Deyá. The species has also been found in other localities on Majorca Island (see Supporting Information Appendix S1).

Material examined for morphometry

Shell, anatomical, operculum, and radular measurements (Appendix S2: Tables S1–S 7) taken from specimens from El Rentador Spring, Majorca. Male and female specimens were collected in April 2008.

New diagnosis

Shell with yellowish periostracum, last body whorl occupying around four-fifths of shell length and aperture slightly longer than wide; protoconch microsculpture with small pits; central tooth of radula with five wide, lateral cusps at each side; black pigmentation on intestine; pyriform bursa copulatrix; elongate seminal receptacle; renal oviduct black pigmented until the base of seminal receptacle; triangular penis with many folds over the entire surface and a small patch of pigmentation on its distal region; nervous system brown pigmented, ganglia darker than connectives; supraoesophageal connective at least eight times longer than suboesophageal; RPG ratio around 0.55.

Description

Shell ovate-conic ( Fig. 4A, D, G View Figure 4 ), yellowish with 3.5– 4.25 spire whorls and around 2–3 mm in height (Appendix S2: Table S1); protoconch approximately 375 μm in width with 1.5 whorls and a nucleus around 150 μm in length ( Fig. 5A View Figure 5 ); protoconch with small pits and some folds near apex ( Fig. 5B View Figure 5 ); last body whorl about four-fifths of total length; convex whorls and deep sutures; inner lip wider than outer; the edge of peristome is simple and straight ( Fig. 4D View Figure 4 ).

Operculum with approximately 2.5 whorls ( Fig. 6A, B View Figure 6 ; Appendix S2: Table S2) and an oval muscle attachment area on the internal side located near the nucleus.

Radula size medium (24%) relative to maximum shell dimension and six times longer than wide ( Fig. 7A View Figure 7 , Appendix S2: Table S3); around 55 rows of teeth; central tooth with a wide median cusp and five small lateral cusps ( Fig. 7D, G View Figure 7 ); basal tongue V-shaped; lateral teeth with three relatively tapered lateral cusps; inner marginal tooth contains approxi- mately 15 cusps of decreasing size; outer marginal tooth with around 20 cusps smaller than inner marginal cusps ( Fig. 7J View Figure 7 ).

Pigmentation and anatomy

Head with uniform brown pigment from snout to base of penis; pigmentation lighter on neck; ocular region lacks pigmentation ( Fig. 8D View Figure 8 ); snout as long as wide with medium distal lobation; foot size intermediate with dorsal pigmentation. Ctenidium with 19–22 well-developed gill filaments situated in the middle of the pallial cavity; osphradium around 30% of ctenidium length, located in the opposite middle of the ctenidium ( Fig. 9A View Figure 9 , Appendix S2: Table S4). Stomach slightly wider than long with a medium- sized gastric caecum (Appendix S2: Table S4); style sac approximately as long as stomach; intestine pigmented ( Fig. 9D View Figure 9 ).

Female genitalia with a slightly lobulated albumen gland smaller than the capsule gland (Appendix S2: Table S5); bursa copulatrix pyriform with a duct similar or longer in length than bursa copulatrix; renal oviduct lies over bursa copulatrix making one or two loops, it is brown pigmented until insertion of seminal receptacle; elongate seminal receptacle with a short duct; situated on renal oviduct above the insertion of bursal duct ( Fig. 8G View Figure 8 ).

Male genitalia with a prostate gland three times longer than wide (Appendix S2: Table S6); vas efferens entering the medial−posterior region and vas deferens exiting at the anterior ( Fig. 8A View Figure 8 ); triangular penis with a wide base, small pigment patch on distal portion and many folds over the entire surface of internal side ( Fig. 8D View Figure 8 ); attached to central region of head.

Nervous system brown pigmented, darker on ganglia than on connectives and commissures; cerebral ganglia equal in size; supraoesophageal connective approximately nine times longer than suboesophageal ( Fig. 8J View Figure 8 , Appendix S2: Table S7); nervous system elongate (mean RPG ratio 0.55); straight oesophagus running beneath nervous system.

Remarks

This species is mainly distributed along the Tramuntana mountain range in the north of Majorca Island, although it has also been found in a spring in Randa, a village situated in the centre of the island. The specimens from Randa seem to bear minor morphological and molecular differences compared with those from the other mountain localities for this species, which is reflected by the low level of genetic variability: average of 1.2% for COI, 0.53% for 16S, and 0.06% for 28S (Appendix S2: Table S8). The remaining Tramuntana populations show even less genetic divergence amongst them (means of 0.3% for COI, 0.4% for 16S, and 0.1% for 28S).

In 1988, Boeters re-described the species P. (P.) subproducta and cited it not only from sites surrounding Banyolas Lake (type locality 1), an Iberian locality in Gerona province, but also from many sites on the islands of Majorca and Minorca. Moreover, he pointed to the existence of marked anatomical variability in characters of the shell and female and male genitalia. Boeters (1988) erroneously identified the populations in Majorca and Minorca as ‘ P. (P.) spirata ’ when in fact these populations belong to several different species, namely P. (P.) beckmanni (Boeters’ figs 55, 76, 82, 83), P. (P.) granjaensis and P. (P.) artanensis from Majorca, and P. (P.) meloussensis (Boeters’ figs 53, 54, 77, 84) from Minorca (see below). Our results show some discrepancies with Boeters’ drawings. For instance, focusing on the penis drawings of P. (P.) subproducta and P. (P.) beckmanni (numbers 75 and 76, respectively, in Boeters, 1988), the penis of P. (P.) beckmanni seems to be shorter; however, our morphometric study shows the opposite. Moreover, after dissecting some P. (P.) beckmanni females from several localities in Majorca, we observed that the bursa copulatrix is not as large as in Boeters’ drawings (numbers 82, 83, Boeters, 1988), although it is larger and with a longer duct than the bursa copulatrix of P. (P.) subproducta (number 81, Boeters, 1988). Thus, although showing certain similarities in shell habitus (Boeters’ numbers 55 and 56), P. (P.) beckmanni can be differentiated from P. (P.) subproducta by: (1) a shorter penis with a wider base and central attachment area, whereas the narrower base of the P. (P.) subproducta penis is attached behind the right eye; (2) a larger bursa copulatrix with a longer less pigmented duct in P. (P.) beckmanni than in P. (P.) subproducta ; (3) a shorter prostate gland than in P. (P.) subproducta ; and (4) an elongate nervous system ( RPG ratio 0.55), whereas in P. (P.) subproducta , it is moderately concentrated ( RPG ratio 0.45). Furthermore, molecular differences between these two species (7.7, 3, and 0.9% for COI, 16S, and 28S, respectively) confirm that they are different taxa.