Spiripockia umbraticola Simone & Salvador 2021, sp. nov.
Creators: name: Simone, Luiz Ricardo L.
name: Salvador, Rodrigo Brincalepe
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Littorinimorpha
Pomatiopsidae
Spiripockia
Spiripockia umbraticola

description: Spiripockia umbraticola sp. nov.   
(Figures 2, 3)  
 ZooBank registration number. urn:lsid:zoobank.org:act: 1B53AA4E-4936-4F76-A1D6 -9D1D98CBD792   
 Type material. Holotype MZSP 151099, spur-coated shell (Figure 2 (a,b,f)). Paratype ♀, MZSP 151100, shell with a hole in penultimate whorl and dissected specimen, from type locality (Figure 2 (c–e,g,h)).   
 Type locality. BRAZIL, Bahia state, Carinhanha municipality, Serra do Ramalho, Gruna do Domingão (Domingão cave), 13°44ʹ40.7”S 43°49ʹ59.7”W [M.E. Bichuette, J.E. Gallão & P.P. Rizatto col. 27 July 2012].   
 Diagnosis. Shell turriform, taller and slenderer than congener; beige to dark brown; whorls with uniform growth; body whorl not expanded towards aperture. Peristome not as flared as in congener. Teleoconch sculpture larger and displaying more pronounced triangular structures than congener; sculpture absent in abapical area of whorl. Aperture (and hence operculum) oval, more elongated than congener. Umbilicus rimate to closed. Presence of well-developed eyes and pigmented areas on head-foot. More conical snout than congener, with wide bifid anterior region; rectum narrower than congener, zigzagging; posterior region of pallial oviduct simpler than congener; visceral oviduct and seminal receptacle inserted directly in posterior region of albumen gland; nerve ring with longer cerebral and pedal commissures than congener.   
 Description. Shell (Figure 2 (a–f,i)). Turriform, circa 5 mm high; ~1.5 times longer than wide; spire angle 45–50°. Colour typically pale beige, translucent (single dark brown specimen was observed in the field – see Figure 2 (c–e,i)). Protoconch of 1¼ whorl, rounded, smooth (Figure 2 (f)). Teleoconch up to 4¼ convex whorls; suture deep; whorls increasing uniformly in height and width, ending in slightly opisthocline and lightly expanded peristome (Figure 2 (a–e)). Teleoconch sculptured with minute pustules arranged in equidistantly spaced spiral rows (Figure 2 (a–b)); initial whorls with 4 rows, increasing to up to 10 rows on body whorl; sculpture absent in abapical area of whorl. Each row composed of ~80 pustules in penultimate whorl. Pustules bearing periostracum hairs, being small on earlier whorls, increasing in size on later whorls, becoming triangular and thorn-like in shape. Peristome white, complete, not covering penultimate whorl; expanded, wider in anterior region, narrower in columellar region (Figure 1 (c)); edges fragile. Aperture oval, adapically and abapically angulate, but with smooth rounded contour. Umbilicus extremely narrow to closed.   
  Measurements (in mm).  Holotype: shell height = 5.2, width = 2.6; paratype: height = 4.8, width = 3.0.   
  Operculum (Figure 2 (g,h)).  Corneous, flexible, thin; paucispiral; translucent, with faint yellow-beige pigmentation. Outline oval, width ~80% of length. Edges thin. Nucleus located in middle region of inner-interior quadrant; ~3 whorls uniformly growing from nucleus; outer surface sculptured with weak growth lines. Inner surface glossy; scar elliptic, occupying circa half of inner surface, located towards (but not touching) internal edge. Occupies almost entire shell aperture.   
  Head-foot (Figure 3 (b)).  Relatively small, stubby. Pale beige, with dark brown spots on exposed areas, mainly on sides of snout. Foot thick, as wide as shell aperture. Mesopodium thick, flanked dorsally by shallow lateral furrows (Figure 3 (b, ft). Anterior furrow of pedal glands (pg) deep, restricted to anterior edge. Opercular pad simple, elliptic, terminal, occupying most of posterior dorsal surface of foot. Head bulbous, ~90% of foot’s width; pair of cephalic tentacles positioned laterally (te), each tentacle simple, stubby, about half foot’s length. Eyes well developed, located on outer region of tentacles’ base. Snout (sn) about twice as wide as tentacles and same length; anterior end bilobed, preceded by narrower region; mouth subterminal, ventral. Columellar muscle (cm) thick, ~3/4 whorl in length. Haemocoel elliptical, on central region of head-foot.   
  Mantle organs (Figure 3 (a)).  Broad, ~3/4 whorl in length. Mantle edge simple, slightly thickened; unpigmented. Osphradium (os) short, almost straight, simple; length ~10% of pallial cavity’s length; located in anterior-left corner of cavity, close and parallel to mantle edge. Gill (gi) elongated-elliptical, broad, ~95% of pallial cavity’s length and ~45% of cavity’s width; anterior end pointed, close to mantle border, slightly bent to left; posterior region rounded, filaments ending on pericardium. Gill filaments approximately triangular, with distal tip rounded; right edge strongly concave. Space between gill and rectum narrow. Hypobranchial gland inconspicuous. Rectum (rt) narrow, zigzagging on right half of cavity; bearing aligned series of elliptical faecal pellets (fe) arranged longitudinally, easily seen due to translucence. Anus (an) simple, shortly siphoned, close to mantle edge. Genital ducts running along right edge, relatively massive, described below.   
  Visceral mass (Figure 3 (a)).  Length ~2.5 whorls, thus not occupying first whorls of shell. Colour of most structures pale beige to white. Kidney (ki) positioned anteriorly; pericardium (pc) located in left-posterior corner of pallial cavity, and partially in visceral mass. Stomach (st) ~0.5 whorls long, occupying ~60% of adjacent whorl width. Digestive gland (dg) ~1.5 whorls long, mostly posterior to stomach, surrounding it. Ovary (oy) small, running along columellar surface of first 2 whorls.   
  Circulatory and excretory systems (Figure 3 (a)).  Pericardium narrow, located longitudinally between stomach and left corner of pallial cavity (pc); volume ~5% that of visceral mass. Kidney large, solid, occupying most of visceral area facing pallial cavity. Nephrostome (ne) small, transverse, located in middle region of kidney.   
  Digestive system (Figure 3 (a,c)).  Mouth on antero-ventral end of snout. Pair of strong ventral retractor muscles of snout and mouth (rm) originating from middle portion of haemocoelic ventral floor, running close to its median line towards anterior portion of body, flanking ventral surface of buccal mass, passing through nerve ring; inserting along ventral wall of snout close to ventral border of mouth. Buccal mass occupying entire inner surface of snout; ~30% of haemocoelic volume. Remaining characters of buccal mass, including jaws and odontophore muscles, similar to those described for S. punctata (Simone 2012, p. 519), except for buccal mass ~30% larger. Radular sac (rs) twice as long as odontophore and ~35% its width; radular nucleus (rn) slightly broader. Salivary gland (sg) small, white, with maximum length ~25% of length of buccal mass; about twice longer than wide; tip rounded. Remaining characters of foregut and midgut similar to those of S. punctata (Simone, 2012). Oesophageal insertion (es) and intestinal origin (in) close to one another, on left base of style sac. Intestine also similar to that of S. punctata, except for a narrower rectum with more zigzagging on pallial cavity roof.   
  Radula (Figure 4).  Rachidian ~1/3 of ribbon width, trapezoid; lateral edges pointed; basal edge concave, with central small convexity; cutting edge bent inwards, with 5 terminal cusps; central cusp larger, lateral cusps succeedingly smaller; 3 pairs of basal cusps, with most central cusps larger, gradually diminishing laterally. Lateral teeth spoonlike, base relatively wide, distal width ~3/4 of rachidian width; 6 subterminal aligned cusps, second cusp larger, remaining cusps ~1/3 of larger cusp. Inner marginal teeth similar to lateral teeth, but ~30% narrower, with 5 aligned cusps, medial cusp slightly larger, cusps gradually diminishing laterally. Outer marginal teeth similar to inner marginal teeth, but ~20% narrower, 11–12 terminal small cusps aligned on cutting edge; medial cusp slightly larger, cusps gradually diminishing laterally.   
  Genital system, female (Figure 3 (a)).  Ovary (oy) restricted to columellar region of first whorls. Visceral oviduct (vo) very narrow, running along middle level of columellar surface of visceral mass, ~1/2 whorl in length. Visceral oviduct zigzagging anteriorly before inserting terminally into left-posterior side of albumen gland (ag). Seminal receptacle balloon-like, small, inserted close to visceral oviduct insertion. Spermathecal oviduct (of) very narrow, originating from posterior-right corner of albumen gland, running straight along ventral-right surface of pallial oviduct towards anterior portion; oviduct aperture very small, located slightly posteriorly from pallial oviduct’s aperture. Capsule gland (cg) occupying ~60% of pallial oviduct’s length; walls thick, glandular, white; lumen flattened; atrium short, terminal, with walls slightly thickened, tapering up to female pore. Female pore shortly siphoned, papilla-like, tilted anteriorly, located close to and posterior to anus.   
  Central nervous system (Figure 3 (c,d)).  Nerve ring essentially like that of S. punctata (Simone, 2012), differing by its slightly longer cerebral commissure, narrower and longer pedal commissure, and bulging ganglionic structure on origin of pedal nerves.   
 Distribution. Only known from type locality.   
 Habitat. Cave surrounded by Caatinga environment (Figure 1), semi-arid climate with a dry season spanning 6–8 months, from mid-autumn to mid-spring (Conti and Furlan 2003; Fernandes et al. 2019). Live specimens were observed attached to hard surfaces such as rocks and logs (Figure 2 (i)), always in the water. All specimens were observed in the aphotic zone of the cavern.   
 Material examined. Types.   
 Etymology. Latin for ‘shade-lover’, a nominative singular noun, in allusion to the aphotic habitat of the species.
description: Published as part of Simone, Luiz Ricardo L. & Salvador, Rodrigo Brincalepe, 2021, A new species of Spiripockia from eastern Brazil and reassignment to Cochliopidae (Gastropoda: Truncatelloidea), pp. 3121-3130 in Journal of Natural History (J. Nat. Hist.) (J. Nat. Hist.) 54 (47 - 48) on pages 3123-3127, DOI: 10.1080/00222933.2021.1890850, http://zenodo.org/record/5406255