Clenchiella victoriae Abbott, 1948

Ponder, Winston F., Fukuda, Hiroshi & Hallan, Anders, 2014, A review of the family Clenchiellidae (Mollusca: Caenogastropoda: Truncatelloidea), Zootaxa 3872 (2), pp. 101-153 : 111-114

Clenchiella victoriae Abbott, 1948

Figures 1 , 14

Clenchiella victoriae Abbott, 1948: 76 –78, pl. 5, 1–7.

Types and type locality. Holotype: San Joaquin River, 2 miles (3.2 km) inland, north of Tanauan, eastern side of Leyte Island, Republic of the Philippines. Brackish water, living in ‘black ooze’ under rotting nipa palm fronds, on the banks of a sluggish river, 29 June 1945. Coll. R.T. Abbott (USNM 488534). Paratypes: Same data (USNM 488535; ANSP 183548). Other paratypes were deposited in MCZ (Harvard), MCZ (Michigan) and Carnegie Museum.

Material examined. Paratypes: Estuary SE of Abuyog, eastern side of Leyte Island, Philippines, 14 Aug. 1945. Coll. R. T. Abbott ( USNM 488536). Paratypes: San Joaquin estuary, 3 kms N of Tanauan, eastern Leyte Island, Philippines (Museum of Zoology, University of Michigan 169007).

Distribution. Known only from brackish swamps on Leyte Island, Philippines, but probably has a broader distribution in the Philippines.

Description. (Based on Abbott 1948 and examination of shells using light microscope).

Shell. Small (up to 2.3 mm in maximum diameter; see Table 3 for shell dimensions of all species), spire flat ( Fig. 1 A–C). Protoconch not elevated above spire, of 1.5 ‘smooth’ whorls, last whorl descends slightly just behind aperture. Teleoconch of 2.5–3.0 whorls, rounded except for angulations from two prominent carinae, one middorsal, one mid-basal; whole surface sculptured with fine spiral threads, interspaces about equal to width of threads; finer commarginal growth lines present, becoming more prominent towards thickened external varix. Periphery evenly convex, spiral lirae similar in strength on peripheral area as on dorsal and basal surfaces. Umbilicus wide (over half width of base), spiral sculpture continuous within. Sutures impressed. Aperture near circular, with peristome slightly thickened internally by slight rim, external varix moderately thickened, just behind apertural rim. Periostracum moderately thick, bright translucent red in life ( Abbott 1948), brackish-brown in dry shells; shell white.

Operculum. Horny, near circular, of 4 slowly increasing whorls. Interior with small pimple-like projection in middle part (from Abbott 1948).

Anatomy (Based on the description and figures of Abbott 1948). Head-foot. Snout bilobed distally, cephalic tentacles long and slender, with 6–7 cilial tufts on small raised areas (described as serrations by Abbott 1948) on outer edge of left tentacle. Foot with rounded anterior end, laterally extended, with weak indentation, tapering posteriorly. Mucous slit at anterior edge, anterior mucous gland typical of family. Tentacles with black band near distal end. Light orange cells embedded in tentacles and just above right eye. Snout black other than anterior margin and broken clear streak mid-dorsally. Dorsal head asymmetrically coloured with dark grey to black on left side. Patches of grey on right side of neck and anterior lateral dorsal foot. Sides of foot ‘translucent whitish’ with few yellow or orange cells.

Ctenidium . About 25–27 filaments.

Radula . Typical of family. Cusp formulae 4+1+4, 2+1+3, 18, 20, median cusps of central and lateral teeth a little longer than adjacent cusps, elongate, pointed; other cusps on all teeth triangular, pointed. [Note: Abbott’s figure of the radula (his fig. 7) shows the marginal teeth flattened so that they appear to be broader than the SEM images of those of other species of Clenchiella ].

Gut. Anterior oesophagus and rectum unknown.

Penis. Well behind right tentacle, coiled for half turn when retracted. Long, narrow (in life), expanded distally with two glandular lobes: one adjacent to short distal part of penis, and larger oval outer lobe ( Abbott 1948, fig. 5). Tip narrow, bluntly pointed. Penial duct straight to slightly undulating, narrow throughout. Translucent and unpigmented except for few white cells in largest glandular lobe.

Female reproductive system and nervous system. Not known.

Remarks. This species is readily distinguished by its relatively thick shell which bears a very heavy, sharp keel on the base and a moderately strong keel on the shoulder. Based on Abbott’s description and figure the penis has only two glandular lobes, both located distally.

Abbott figured the aperture as somewhat horizontally elongated and with a very thin peristome, whereas the material inspected in this study appears to possess apertures that are close to perfectly circular and with a slightly thickened peristome. His dimensions are also incorrect giving a size (4 mm) twice that of the actual size of the holotype.

SW SH AH UW TW PW TWN

Clenchiella victoriae

Holotype 2.10 0.86 0.66 1.18 1.75 1.25 3.00 Paratype 2.17 0.95 0.61 1.17 1.75 - - Paratype (USNM 488535) 2.08 0.86 0.56 1.24 - - - Paratype (USNM 488535) 2.01 0.81 0.62 1.09 1.75 1.00 2.75 Clenchiella bicingulata n. sp.

Holotype 1.97 0.74 0.47 0.87 1.5 1.25 2.75 Paratypes 2.16 0.90 0.57 0.95 1.75 1.25 3 2.10 0.79 0.58 1.04 1.5 1.5 3 1.96 0.94 0.57 1.05 1.75 0 0 Clenchiella varicosa n. sp.

Holotype 1.96 0.70 0.57 0.89 1.5 1.25 2.75 Paratype (immature) 1.54 0.56 0.53 0.75 1.75 0 0 Paratype (immature) 1.59 0.65 0.00 0.74 1.75 0 0 Clenchiella iriomotensis n. sp.

Holotype 1.94 0.82 0.53 1.06 2 1.25 3.25 Paratypes 2.32 1.00 0.68 1.23 1.75 0 0 2.05 0.84 0.68 1.03 1.65 1.25 2.9 2.11 0.87 0.65 1.11 2 1.25 3.25 Clenchiella minutissima

Syntype 1.70 0.75 0.60 0.83 1.5 0 0 ANSP 319936 1.77 0.81 0.57 0.74 0 0 0 1.87 0.83 0.61 0.79 0 0 0 1.84 0.91 0.58 0.74 0 0 0 AMS C.412278 (Darwin) 1.29 0.47 0.40 0.59 1.5 1.25 2.75 1.35 0.56 0.40 0.70 1.75 1.12 2.85 1.23 0.49 0.38 0.57 1.5 1.25 2.75 C.412277 (Magnetic Is.) 1.38 0.51 0.42 0.64 1.5 1.35 2.85 1.66 0.56 0.51 0.77 1.5 1.12 2.62 1.52 0.56 0.49 0.82 1.5 1.25 2.75 ......continued on the next page

Figures

FIGURE 1. Holotypes of species of Clenchiella with distinct keels (from left towards right: dorsal, lateral and ventral view respectively). A – C, Clenchiella victoriae (USNM 488534; shell diameter 2.1 mm); D – F, Clenchiella bicingulata n. sp. (AMS C. 462959; shell diameter 1.97 mm); G – I, Clenchiella varicosa n. sp. (AMS C. 460738; shell diameter 1.96 mm); J – L, Clenchiella iriomotensis n. sp. (AMS C. 445413; shell diameter 1.94 mm).

FIGURE 14. Type localities of Clenchiella victoriae, Cl. bicingulata, Cl. varicosa, Cl. iriomotensis, and all recorded localities of Cl. minutissima (type locality Vietnam).