A new genus and species of cavernicolous Pomatiopsidae (Mollusca, Caenogastropoda) in Bahia, Brazil

A new genus and species of cavernicolous Pomatiopsidae (Mollusca, Caenogastropoda) in Bahia, Brazil

Luiz Ricardo L. Simone

Museu de Zoologia, Universidade de São Paulo. Caixa Postal 42.494, 04218‑970, São Paulo, SP, Brasil. E‑mails: [e-mail]; [e-mail]

ABSTRACT

Spiripockia punctata is a new genus and species of Pomatiopsidae found in a cave from Serra Ramalho, SW Bahia, Brazil. The taxon is troglobiont (restricted to subterranean realm), and is characterized by the shell weakly elongated, fragile, translucent, normally sculptured by pustules with periostracum hair on tip of pustules; peristome highly expanded; umbilicus opened; radular rachidian with 6 apical and 3 pairs of lateral cusps; osphradium short, arched; gill filaments with rounded tip; prostate flattened, with vas deferens inserting subterminally; penis duct narrow and weakly sinuous; pallial oviduct simple anteriorly, possessing convoluted bypass connecting base of bulged portion of transition between visceral and pallial oviducts with base of seminal receptacle; spermathecal duct complete, originated from albumen gland. The description of this endemic species may raise protective environmental actions to that cave and to the Serra Ramalho Karst area.

Key-Words: Pomatiopsidae; Spiripockia punctata gen. nov. et sp. nov.; Brazil; Cave; Troglobiont; Anatomy.

RESUMO

Spiripockia punctata é gênero e espécie novos de Pomatiopsidae encontrado em uma caverna da Serra Ramalho, SW Bahia, Brasil. O táxon é troglóbio (restrito à vida subterrânea), caracterizado pela concha levemente alongada, frágil, translúcida, normalmente esculturada por pústulas contendo pelos do perióstraco no topo das pústulas; perístoma altamente expandido; umbílico aberto; dente raquidiano da rádula com 6 cúspides apicais e 3 pares de basais; osfrádio curto e curvo; filamentos branquiais com topo arredondado; próstata achatada, com vaso deferente inserindo subterminalmente; ducto do pênis fracamente sinuoso; oviduto palial anteriormente simples, possuindo um by-pass convoluto da base da porção bulbosa da porção entre oviduto visceral e palial com a base do receptáculo seminal; ducto da espermateca completo, originado da glândula de albume. A descrição dessa espécie endêmica deve contribuir com ações protetivas do ambiente da caverna e à área da Serra Ramalho.

Palavras-Chave: Pomatiopsidae; Spiripockia punctata gen. nov. et sp. nov.; Brasil; Caverna; Troglóbio; Anatomia.

INTRODUCTION

The family Pomatiopsidae is represented in the Brazilian region by only two species of the genus Idiopyrgus Pilsbry, 1911 (Simone, 2006: 94). However, the taxon is much richer in remaining mainland areas, with both freshwater and semi-terrestrial habits (Ponder & Keyzer, 1998; Kameda & Kato, 2011). Common features of the pomatiopsids are small size (smaller than 15 mm), elongated to short spired, and smooth shell with paucispiral protoconch. The main distinction from other rissooideans is the diaulic pallial oviducts of the females; i.e., the typical pallial oviduct has two separate openings to the pallial cavity (Davis, 1967, 1979; Ponder, 1988).

An enigmatic tiny gastropod has been collected in caves from the Serra Ramalho Kars area, southwestern Bahia state, Brazil. It has a pretty, fragile, translucent shell in such preliminary gross anatomy, which already reveals troglobiont adaptations, i.e., depigmentation, lack of eyes and small size. The sample has been brought by Maria Elina Bichuette, who is specialized in subterranean fauna. Complementary analysis revealed a new pomatiopsid for which no known genus can be attributed. Both genus and species are hereby formally introduced, including a detailed anatomical investigation. The description of this new taxon is not only academically urgent, but the cave is also threatened for economic reasons. The description of an endemic species helps in the argumentation for preserving this fragile location.

MATERIAL AND METHODS

All specimens were fixed in 70% Ethanol. The dissections were performed under a stereomicroscope by standard techniques, with the specimens immersed under fixative. Digital photos of each step of the dissection were obtained, as well as drawings aided by a camera lucida. A scanning electron microscope (SEM) was employed to view details of the shell and radula in the Laboratório de Microscopia Eletrônica of Museu de Zoologia da Universidade de São Paulo.

Anatomical abbreviations in the figures:ag, albumen gland; an, anus; au, auricle; bm, buccal mass; br, subradular membrane; ce, cerebral ganglion; cg, capsule gland; cm, columellar muscle; co, bulged region of oviduct; cv, ctenidial vein; dd, duct to digestive gland; df, dorsal folds of buccal mass; dg, digestive gland; es, esophagus; fe, fecal pellets; fp, female pores; ft, foot; gi, gill; in, intestine; ir, insertion of m4 in subradular cartilage; is, insertion of m5 in subradular cartilage; jw, jaws; ki, kidney; m2‑m12, odontophore muscles; mb, mantle border; mj, jaw and peribuccal muscles; mo, mouth; ne, nephrostome; oc, odontophore cartilage; od, odontophore; of, Spermathecal oviduct; op, opercular pad; os, osphradium; ov, pallial oviduct; oy, ovary; pa, penis aperture; pc, pericardium; pd, penis duct; pe, penis; pg, anterior furrow of pedal glands; pl, pleural ganglion; pn, pedal glanglion; pt, prostate; ra, radula; rm, snout ventral retractor muscle; rn, radular nucleus; rs, radular sac; rt, rectum; sa, salivary gland aperture; sc, subradular cartilage; sd, sperm duct; sg, salivary gland; sn, snout; st, stomach; su, subesophageal ganglion; sv, seminal vesicle; sy, statocyst; te, cephalic tentacle; tg, integument; tn, tentacular nerve; ts, testis; ve, ventricle; vd, vas deferens; vo, visceral oviduct.

Abbreviatons of institutions:MNRJ, Museu Nacional da Universidade Federal do Rio de Janeiro; MZSP, Museu de Zoologia da Universidade de São Paulo; USNM, National Museum of Natural History, Smithsonian Institution.

Systematics

Family Pomatiopsidae Genus Spiripockia new genus

Diagnosis: Turbiform shell with highly expanded peristome. Walls translucent, smooth except for pustules containing hair-like projections of periostracum. Freshwater environment.

Description: Outline turbiform to slightly turriform. Protoconch paucispiral, of single whorl. Outer surface simple, except for small pustules distributed in somewhat spiral alignment, absent in some specimens (surface totally smooth). Peristome highly expanded and sprayed except for implantation on columellar surface. Umbilicus somewhat opened. Operculum thin. Pair of strong ventral retractor muscles of snout. Salivary gland reduced. Gonoducts closed (tubular); oviduct with bypass in posterior region. Spermathecal duct originated from albumen gland.

Type species: S. punctata new species.

List of included taxa: S. punctata new species.

Etymology: The generic epithet is a contraction of Latin words spiri, from spira, and pocillum a little cup. Meaning something like a spiral small cup. This name is also used by my father, Egydio do Carmo de Simone, to designate any female pet in which he does not know the name.

Pronunciation: in English terms the genus must be vocalized as "speereepowqueeah".

Spiripockia puncata new species (Figs. 1‑33)

 

Types: Holotype MZSP 105000. Paratypes: MZSP 104435, 19 specimens, MNRJ 30503, 1 specimen, USNM 2060411, 1 specimen, all from type locality.

Type locality: BRAZIL. Bahia; Serra Ramalho Karst area, Middle São Francisco River basin, Lapa dos Peixes cave, 13°49'21.78"S, 43°57'24.39"W (M.E. Bichuette col., 29/vii/2005).

Diagnosis: Shell weakly elongated; walls thin, fragile, translucent, unpigmented. Sculptured by pustules somewhat spirally aligned, possessing periostracum hair on tip of pustules (sometimes absent). Peristome expanded in plane ~90° in relation to last quarter whorl. Umbilicus opened. Strong pair of ventral snout retractor muscles passing through nerve ring. Radular rachidian with 6 apical and 3 pairs of lateral cusps, ~10 terminal cusps in radular lateral and marginal teeth. Eyes absent. Head-foot unpigmented. Osphradium short, arched. Gill filaments with rounded tip. Salivary glands short, small. Odontophore lacking pair of ventral tensor muscles (m11). Genital pallial gonoducts closed (tubular). Prostate flattened, with vas deferens inserting subterminally. Penis duct narrow and weakly sinuous. Pallial oviduct simple anteriorly; posterior region possessing convoluted bypass connecting base of bulged portion of transition between visceral and pallial oviducts with base of seminal receptacle; spermathecal duct complete, opening close to anus level. Nerve ring with well delimited ganglia.

DESCRIPTION

Shell (Figs. 1‑5, 8‑14): Up to 5 mm; about as wide as long, turbiform to slightly turriform. Spire angle ~50°. Color pale beige to white, translucent. Protoconch occupying ~20% of shell width and ~7% of length; globose, smooth, transparent (Figs. 3, 5, 10, 13). Transition protoconch-teleoconch weak, orthocline. Teleoconch up to 4 convex whorls; suture deep, with ~90°; whorls somewhat uniform, except for last whorl in adult specimens, with bluntly pointed projection located approximately in opposed side from aperture (Figs. 2, 5, 11) (more visible in apical or anterior views); projection absent in younger specimens (Figs. 8‑9); being clearly derived from previous aperture. Sculpture minute pustules aligned in spiral lines (Figs. 12, 14), ~6 doted spiral lines, equidistantly spaced, in penultimate whorl; each line with ~40 pustules in penultimate whorl disposed somewhat alternately each line in relation to neighbor lines (Figs. 1‑3, 10‑14); each pustule in form of small, circular convexity, separated from neighbor pustules by smooth distance equivalent to twice pustules width (Fig. 12); pustules somewhat uniformly distributed, and sometimes forming wide angulation on shell surface (Fig. 14); this dotted sculpture absent in ~15% of specimens, possessing completely smooth outer surface (Figs. 4‑5); periostracum possessing 5‑6 axially aligned hair on pustules tip (Figs. 3, 10‑11), looking like flexible scales. Sculpture on younger specimens similar to this above described, but with pustule located closer to each other and with 4 inferior lines located closer to each other and far from subsutural line (Figs. 8‑9); gradually after 2‑3 whorls sculpture changing to adult pattern. Peristome expanding in plane ~90° in relation to terminal region of body whorl (Figs. 1‑5, 10‑11) in mature specimens; expansion edges extremely fragile and somewhat irregular (apparently to fit in substrate), particularly wider in anterior region (Fig. 1) and narrower in columellar implantation; expansion extending ~15 % shell width. Aperture oval, superior angulation blunt; remaining somewhat rounded. Umbilicus opened and relatively wide (Figs. 2, 4, 11), occupying ~15% of shell width (excluding peristome); no callus, except for short and narrow portion of peristome attached to preceding whorl (Figs. 2‑4, 10‑11).

Head-foot (Figs. 19‑21): Relatively small, stubby, unpigmented. Foot thick, as wide as shell aperture. Mesopodium thick, flanked dorsally by shallow lateral furrows (Fig. 21: ft). Anterior furrow of pedal glands (pg) deep, restricted to anterior edge (Figs. 19‑20). Opercular pad (Fig. 21: op) elliptic, terminal, occupying half of posterior foot dorsal surface. Head bulbous, with ~85% of food width; pair of cephalic tentacles lateral positioned (Figs. 19‑20, 23: te), each tentacle simple, thick, with ~twice foot length; no detectable eye. Snout with ~twice tentacles width and ~half tentacles length (sn); anterior end weakly bilobed, mouth oval, wide, subterminal, ventral (Figs. 23: mo). Columellar muscle thick, ~3/4 whorl. Haemocoel elliptical, on central region of head-foot (Fig. 23).

Operculum (Figs. 6‑7): Corneous, thin, translucent, yellow-beige, flexible, paucispiral. Outline elliptical-almost circular. Edges thin. Nucleus located in middle region of interior half, weakly dislocated internally (Fig. 6); from nucleus, ~2 whorls uniformly growing, appearing; outer surface also sculptured by weak undulations parallel to outer edge. Inner surface glossy, scar elliptic, occupying ~half of inner surface; location dislocated to internal edge, but not touching internal edge. Occupies entire shell aperture (Figs. 3, 10‑11).

Mantle organs (Figs. 22, 27): Somewhat narrow, with ~1 whorl in length. Mantle edge simple, weakly thick; unpigmented. Osphradium short (os), curved (concavity left), simple; length ~6% pallial cavity length; located in anterior-left corner of cavity, close to mantle border. Gill elongated, narrow, with ~85% of pallial cavity length and ~25% of cavity width; anterior end bluntly pointed, close to mantle border; posterior region narrowing gradually, filaments ending at some distance from pericardium; gill filaments somewhat triangular, with distal tip rounded (Fig. 27: gi). Between gill and rectum a narrow distance equivalent to 10% of pallial cavity width. Hypobranchial gland inconspicuous. Rectum wide, reaching up to half of pallial cavity width in some points; bearing aligned series of elliptical fecal pellets (fe) disposed transversally or weakly oblique, easily seen by translucence (Figs. 1‑3, 10‑11); rectum displaced from right mantle cavity edge by pallial genital ducts. Anus simple, shortly siphoned, distant from mantle border ~10% of cavity length, in anterior-right corner of pallial roof. Genital ducts running along right edge, relatively massive, described below.

Visceral mass (Figs. 22, 31): Length ~3 whorls, keeping ~2 first shell whorls empty in adult specimens (Figs. 2‑3, 10). Color of most structures pale beige to white. Stomach as anterior structure, compressing ventrally small reno-pericardial structures; stomach of ~0.5 whorl and with almost entire adjacent whorl width. Digestive gland of ~2 whorls, mostly posterior to stomach. Gonad running along columellar surface of each whorl when mature, weakly distinct from digestive gland. Other genital and digestive details below.

Circulatory and excretory systems (Fig. 31): Pericardium narrow, located transversely between stomach and pallial cavity (Fig. 22: pc), volume ~1/20 of that of visceral mass; auricle anterior, small, just posterior to posterior end of ctenidial vein; ventricle posterior, simple. Kidney minute, weakly smaller than pericardium, located on right side of pallial cavity posterior end; inner tissue totally solid, white. Nephrostome (ne) small, transverse, located close to pericardium.

Digestive system (Figs. 22‑26, 28): Mouth in antero-ventral end of snout (Fig. 23: mo). Pair of strong ventral retractor muscles of snout and mouth (Figs. 23‑24: rm); originating in middle level of haemocoelic ventral floor; running close to median line towards anterior, flanking ventral surface of buccal mass, passing through nerve ring (Figs. 23, 33); inserting along ventral wall of snout, close to ventral border of mouth. Buccal mass bulged, occupying entire snout inner surface and ~1/3 of haemocoelic volume. Pair of jaw plates (Fig. 25: jw) somewhat separated from each other; each jaw oval and very thin, translucent. Odontophore spherical, with ~half of buccal mass volume. Odontophore muscles (Figs. 24‑26, 28): mj, pair of jaw and peribuccal muscles, working also as odontophore protractors, originating in lateral and ventral region of mouth, running towards posterior as part of oral tube along ~half odontophore length (Fig. 24), inserting in latero-ventral mid region of odontophore cartilages (Fig. 26); m2, pair of posterior retractor muscles of odontophore (Figs. 24‑25), narrow, originating in lateral region of haemocoel inner surface, in its middle level, running towards anterior a distance slightly longer than buccal mass length, inserting in postero-lateral region of odontophore cartilages (Fig. 28); m4, pair of main dorsal tensor muscle of radula (Fig. 28), broad and thick, surrounding outer lateral surface of odontophore cartilages, originating from their ventro-lateral surface, inserting in lateral edges of subradular cartilage in its region in buccal cavity, and also in radular sac region preceding buccal cavity (Fig. 28: ir); m5, pair of secondary dorsal tensor muscles of radula (Figs. 26, 28), narrow and thick, originating in posterior edge of odontophore cartilages, running towards medial and anterior, between cartilages, inserting in ventral side of radular ribbon in its region exposed in buccal cavity (Figs. 28: is); m6, horizontal muscle, thin and wide, connecting ventral edge of both odontophore cartilages along ~75% of their length (Fig. 28); m10, pair of ventral protractor muscle of buccal mass (Figs. 24, 26), relatively wide and thick, originating in ventral edge of mouth, just ventral to retractor muscle (mr) origin, running towards posterior a distance equivalent to odontophore length, inserting in posterior-ventral edge of odontophore cartilages. Subradular cartilage relatively wide in region of buccal cavity (Fig. 25: sc). Odontophore cartilages elliptic, somewhat flattened laterally, anterior edge weakly narrower than posterior edge (Fig. 28: oc). Radular sac with length ~3 times that of odontophore (Figs. 24‑26: rs), and ~1/4 odontophore width; radular nucleus (rn) weakly broader.

Radular tooth (Figs. 15‑18): rachidian tooth triangular, distal tip curved inwards, with ~16% of radular ribbon width, about as tall as wide, base simple, weakly arched, 3 pairs of latero-basal cusps (Figs. 16‑18), each cusp small, triangular, pointed tip; 5‑7 terminal triangular cusps, central cusp larger, cusps weakly diminishing towards lateral, restricted to distal, curved edge; lateral tooth with main region rectangular, with ~double rachidian height and its same width, ~15 cusps similar to those of rachidian, cusps smaller in both ends, being gradually larger towards middle-weakly lateral region (Figs. 16‑17), basal region widening obliquely externally (Figs. 15, 17) along distance equivalent to ~30% radula width, being covered by marginal teeth (Figs. 17‑18); inner and outer lateral tooth similarly shaped, being outer tooth ~30% narrower than inner marginal tooth, ~double length as lateral tooth and ~40% narrower, general form as rod curved inwards at tip, tip flattened, bearing ~13 (inner) and ~10 (outer) terminal cusps of similar characters as lateral tooth cusps.

Salivary gland small (Figs. 23‑24: sg), white, with maximum length ~half buccal mass length, and sometimes smaller; about 3 times longer than wide, tip rounded; salivary aperture in postero-lateral region of oral cavity (Fig. 25: sa). Dorsal folds of buccal mass (Fig. 25: df) smooth, simple, wide, located close to each other. Esophagus simple and sinuous along haemocoel (Figs. 23‑24: es), generally with anterior glandular enlargement (Fig. 24), but sometimes (~30%) with same width along length; most remaining esophageal inner surface simple, lacking folds; posterior esophagus (Fig. 22: es) narrow, inserting in ventral-mid region of stomach. Stomach dimensions and positions above described (visceral mass); possessing main gastric chamber posterior, with rounded posterior surface, and narrow style sac (Figs. 22: ss), with ~half remaining gastric dimensions. Style sac totally separated from intestine; esophagus inserting just ventrally to origins of style sac and intestine, on anterior stomach side; duct to digestive gland as wide as posterior esophagus, originating at short distance posterior to esophageal insertion (Fig. 22: dd), running towards posterior. Intestine originating dorsally and at left from esophageal insertion (Fig. 22: in), with ~double esophagus width, and at left from style sac; running surrounding externally style sac up to dorsal region of kidney, broadening in region preceding pallial cavity. Rectum, fecal pellets and anus above described (pallial cavity). Fecal pellets formed only after renal portion of intestine (Figs. 11, 22).

Genital system: Male (Figs. 19, 29, 31): Testis restricted to posterior half of digestive gland (Fig. 31: ts). Seminal vesicle (sv) weakly convolute, with 3‑4 zigzag loops in columelar region of visceral mass preceding stomach, color pale grey-iridescent; vas deferens relatively straight in gastric and renal region, inserting in prostate subterminally (Fig. 31: vd). Prostate with ~1/4 pallial cavity width, somewhat dorso-ventrally flattened, white, totally closed (tubular); inner lumen simple, flat (Fig. 27: pt). Vas deferens originating subterminally from prostate anterior region (Fig. 31: vd) in level between anterior and mid thirds of pallial cavity; in short distance penetrating in floor of pallial cavity by side of penis base, running immersed in integument (Figs. 19: vd, 29: pd). Penis (Figs. 19‑29: pe) simple, curved, base broad, gradually tapering up to sharp pointed tip. Penis duct seen by translucence, color pale-green-iridescent, performing weak zigzag coils along outer, almost central penial region, up to penis distal tip (Fig. 29: pd); aperture distal, simple, small (pa).

Female (Figs. 22, 32): Visceral structures similar to those of males; ovary (oy) somewhat broader than testis. Visceral oviduct very narrow, running along middle level of columellar surface of visceral mass ~half whorl (vo). Visceral oviduct inserting terminally in complex posterior region of pallial oviduct (Fig. 32) in bulged region of oviduct (co) with simple glandular walls and hollow inside. This bulged region continuing to albumen gland (ag) strongly curved in ~180°. Spermathecal duct (of) originating in ventral-left side of albumen gland, very narrow but with thick walls, running along right edge of pallial cavity ventral to remaining pallial oviduct ~90% of pallial cavity length; opening simple by side and ventral to main female pore (Figs. 22: fp). Seminal receptacle (rs) bulging subterminally in posterior region of pallial oviduct, possessing two successive bulbs or sometimes horseshoe-shaped; inserting by narrow duct in adjacent left side of posterior end of capsule gland. Sperm duct, or bypass (sd) as convoluted duct connecting anterior region of bulged region of oviduct (co) with base of seminal receptacle (rs); posterior half clearly narrower, gradually broadening in anterior half. Capsule gland (cg) occupying ~80% of pallial oviduct length; walls thick glandular, white, lumen flattened (Fig. 22); short terminal atrium with walls weakly thick, tapering up to female pore. Female pore shortly siphoned, papilla-like, turned anteriorly, located close to and at right of anus. No special female genital structure in head-foot (Figs. 20‑21).

Central nervous system (Figs. 30, 33): Nerve ring located just posterior to buccal mass, with pedal ganglia weakly more anterior (Fig. 23: nr) than remaining ganglia. Each cerebral ganglion (ce) oval, with size equivalent to esophageal section; cerebral commissure narrow, with ~half-length as each ganglion. Pleural ganglia (pl) with ~half size of cerebral ganglia, located just ventral to them. Each pedal ganglion (pn) weakly larger than cerebral ganglion, somewhat spherical, located very close to each other (pedal commissure extremely short). Cerebro-pedal and pleuro-pedal connectives about as long as pedal ganglia (Fig. 30). Subesophageal ganglion (su) with ~half pleural ganglion size, located a distance from right pleural ganglion equivalent to 1.5 times each cerebral ganglion length. Pair of statocysts (sy) located in ventro-posterior side of pedal ganglia; with large, single statolith inside. Single pair of tentacular nerve (tn), lacking optical nerve.

Measurements (in mm): Holotype: 4.6 by 4.3; paratypes: 2♀: 3.3 by 3.1; 4♂: 3.3 by 3.5; 5♀: 3.6 by 3.4.

Distribution: Only known in the type locality (Lapa dos Peixes cave).

Habitat: In a cave surrounded by Caatinga semi-arid environment, attached to rocks inside a small stream.

Material examined: Types.

DISCUSSION

Spiripockia punctata is the second troglobiont gastropod described in Brazilian territory. The first one is a relative taxon, Potamolithus troglobius Simone & Moracchioli, 1994, a Hydrobiidae from Ribeira Valley, southern São Paulo state. Both species share the characters to consider them as troglobiont – the total lack of pigmentation and eyes, and small size – and the freshwater environment. In light of the enormous quantity of caves in the Brazilian region, it is difficult to believe that only 2 troglobiont gastropod species exist. Bichuette & Trajano (2003) cited at least five more troglobiont species, all belonging to Hydrobiidae and probably to the genus Potamolithus Pilsbry, 1911, occurring in Ribeira Velley, SE Brazil. Though, certainly many more studies on this issue and urgent preservation of cave environments are necessary. I can affirm that the MZSP collection already has some samples of troglobiont rissooideans and even pulmonates waiting for study.

Spiripockia punctata has no South American species with which it can be confused. The set of conchological features are so far exclusive and sufficiently distinctive to erect a new genus. From the family Pomatiopsidae, the only two species hitherto described belong to the genus Idiopyrgus – I. rudolphi Haas, 1838 and I. souleyetianus Pilsbry, 1911 (Simone, 2006), from which S. punctata differs in having a shorter and wider shell, fewer whorls, peristome more expanded, umbilicus wider, and the sculpture of most specimens of pustules with periostracum hair in them (Figs. 1‑3, 10‑11). The radula and genital part of the anatomy of I. souleyetianus has been investigated (Rey, 1959; Malek, 1983), which permits some extra-shell comparison. The operculum of S. punctata has a more central nucleus. Its osphradium is much shorter and curved. Spiripockia punctata also has the insertion and pallial origin of the vas deferens in the prostate gland in a subterminal manner (Fig. 31: vd), however, that of I. souleyetianus is inserted and originated at mid-level of that gland. The penis is somewhat similar, with totally closed (tubular) duct, but the penis duct of S. punctata appears to be more convolute. The contrary happens in the seminal vesicle, such as in the case of I. souleyetianus whose seminal vesicle is apparently much more coiled. Related to the pallial oviduct, S. punctata lacks a clear separation between albumen and capsule glands (Fig. 32), as happens in I. souleyetianus; the bypass duct (sd) is much more coiled in S. punctata, and its seminal receptacle is connected directly to the pallial oviduct, while that of I. souleyetianus is connected to the visceral oviduct; S. punctata lacks a small secondary receptacle, which is present in I. souleyetianus; the spermathecal duct (of) has its origin in the end of the albumen gland, close to insertion of the visceral oviduct in S. punctata, while that of I. souleyetianus is originated from the receptacle (also known, in rissooideans, as spermatheca or bursa copulatrix). Actually, the arrangement of the posterior region of the pallial oviduct of I. souleyetianus looks more like the pattern of the family (Davis, 1967, 1979; Ponder, 1988; Davis et al., 1992) than that of S. punctata, with the spermathecal duct connected to the pallial oviduct instead to the receptacle. In this point of view, the name "spermathecal duct" is not totally accurate; however the name was maintained in order to permit further comparisons and to suggest homology. This singularity of S. punctata is another indication of generic separation, beyond those features of the shell.

With respect to the radula, Spiripockia punctata possesses the normal pattern of the family (Ponder & Keyzer, 1998), which includes the lateral cusps in the rachidian and the basal lateral expansion of the lateral toot base. It differs in number and form of the cusps, as normally found amongst closely related species.

It is expected that with the description of this new endemic taxon, further argumentation for the conservation of the cave type locality for the present species and others can be instituted. Some pomatiopsids have been considered as endangered species on the IUCN Red Lists. One example is Tomichia cawstoni Connolly, 1939, from South Africa (Kristensen et al., 2010). According to the IUCN terms, S. punctata is already considered threatened based on its endemicity, as well as on its troglomorphic features, such as depigmentation and being eyeless.

ACKNOWLEDGMENTS

The material was collected under IBAMA license 027/00‑DIFAS/DIREC by Maria Elina Bichuette, Universidade Federal de São Carlos. I am deeply grateful to her for donation of the specimens, location description, and for reviewing the paper. I am also grateful to Winston Ponder, Australian Museum, for suggestions on systematics in the early phase of this study. I further acknowledge FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo) for financial support in the field activities of E. Trajano's project (process 2003/0794‑5).

Aceito em: 26.10.2012

Publicado em: 20.12.2012

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• Simone, L.R.L. & Moracchioli, N. 1994. Hydrobiidae (Gastropoda: Hydrobioidea) from the Ribeira Valley, S.E. Brazil, with descriptions of two new cavernicolous species. Journal of Molluscan Studies, 60:445‑459.

Publication Dates

• Publication in this collection
  27 Nov 2012
• Date of issue
  2012

History

• Received
  26 Oct 2012
• Accepted
  20 Dec 2012