Salinator rhamphidia, Golding, Rosemary E., Ponder, Winston F. & Byrne, Maria, 2007

Golding, Rosemary E., Ponder, Winston F. & Byrne, Maria, 2007, Taxonomy and anatomy of Amphiboloidea (Gastropoda: Heterobranchia: Archaeopulmonata), Zootaxa 1476, pp. 1-50 : 13

Salinator rhamphidia , sp. nov.

Holotype: Australia, New South Wales: Botany Bay, Banksmeadow, sandy, tidal mudflat with small mangroves, 27 Sep 2004, R.E. Golding (AMS C.446516).

Paratypes: Same data as holotype (AMS C.442225), 25 specimens.

Other material examined: Australia, New South Wales: Botany Bay, Banksmeadow, sandy, tidal mudflat with small mangroves, Dec 2003 – Sep 2004, R.E. Golding and M. Hill (AMS C.442226, C.442229, C.442223); Hawkesbury River, Church Point, sandy tidal flat with few large mangroves, 27 Sep 2004, R.E. Golding (AMS C.442222).

Etymology: The species epithet is derived from a Greek word meaning ‘hook shaped’ in reference to the chitinous microsculpture on the spermovipositor.

Description: Shell ( Fig. 2 F): Diameter to 5.5 mm, very thin, spire relatively tall. Whorls evenly convex, lacking shoulder, often with rough patches between axial striae; sinus flattened, indented. Exterior light grey, lacking spiral bands.

Operculum ( Fig. 4 C): Entirely corneous, pale yellow, with paucispiral, eccentric nucleus. Inner surface of operculum with two slightly raised spiral bands encircling nucleus.

External morphology ( Figs. 5 B, 6B): Head and foot cream to yellow in fresh and formalin-preserved specimens. Anterior central snout with diffuse triangular patch of black pigment; lateral stripe of pigment between eyes, around genital aperture and along sides of foot.

Mantle organs: Mantle roof with few blood vessels; opposed ciliary tracts running full length of mantle cavity; hypobranchial gland flat, yellow in fresh and formalin-preserved specimens, circular, at right anterior corner of mantle cavity roof.

Digestive system: As for A. crenata , but proportionally smaller.

Radula ( Figs. 9 E, F): Each row with central tooth, pair of inner and outer lateral teeth and, on each side, approximately 25 marginal teeth. Central tooth with 11 cusps, central cusp elongate, adjacent cusps reduced, other cusps decreasing in length towards outer edge of tooth; inner lateral teeth narrow, bicuspid; outer lateral teeth with three rounded cusps, innermost cusp largest; marginal teeth elongate, narrow, unicsupid, increasing in length towards outer edge of radula.

Central nervous system: As for S. fragilis , but presence of parapedal and subcerebral commissures not confirmed. Visceral loop relatively long. Visceral ganglion closer to right than left parietal ganglion.

Reproductive system ( Figs. 14 C, 17E): Proximal reproductive system as for S. fragilis , with following differences in distal reproductive structures: Spermovipositor short, base very short, aperture simple, flared to form circular plate-like structure; short internal duct opens within curl of aperture plate through slit-like opening; curved projection from base of spermovipositor bearing rows of long, chitinous, hook-shaped microsculpture. Spermovipositor sheath highly folded and relatively thick walled. Egg mass string cylindrical, deposited on surface of sand in semicircle.

Distribution and habitat ( Fig. 1 ): Known from Banksmeadow, Botany Bay and Church Point, Hawkesbury River in Sydney but probably with a wider distribution. Found on open sand flats, with or without sparse mangroves present, rarely on mud or under dense canopy. Often found crawling beneath surface of sand, with raised trail of disturbed sand visible from surface.

Remarks: Salinator rhamphidia sp. nov. occurs sympatrically with S. tecta sp. nov. at the type locality (Banksmeadow, Botany Bay) and, although distinguished by a taller spire, smaller size, different head-foot pigmentation and several features of the reproductive system, it could be mistaken as a juvenile of the latter species. The shape of the spermovipositor is distinct and the hook-shaped microsculpture unique in Salinator .

Figures

FIGURE 1. Distributions of amphiboloidean species determined from the present study and previous reports. Species in bold are examined in this paper.

FIGURE 2. Shell morphology of species in Amphibolidae, Phallomedusidae fam. nov. and Maningrididae fam. nov .. A. Amphibola crenata (Martyn, 1786), (AMS C. 446522). B – D. Salinator fragilis (Lamarck, 1822), B. Lectotype (MHN 1094 / 1), C. Albany, Western Australia (AMS C. 446486), D. Cambridge, Tasmania (AMS C. 442291). E. Salinator tecta sp. nov .. Holotype, Narrabeen Lakes, Sydney (AMS C. 446774). F. Salinator rhamphidia sp. nov .. Holotype, Botany Bay, Sydney (AMS C. 446516). G. Salinator rosacea sp. nov .. Holotype, Elizabeth River, Darwin (AMS C. 446519). H, I. Phallomedusa solida (Martens, 1878), H. Holotype (ZMB 22207), I. Lake Illawarra, New South Wales (AMS C. 442239). J. Phallomedusa austrina sp. nov .. Holotype, Stanley, Tasmania (AMS C. 446510). K. Lactiforis tropicalis sp. nov .. Holotype, Broome, Western Australia (AMS C. 446775). L. Lactiforis takii (Kuroda, 1928). Ariake Sea, Japan (AMS C. 446490). M. Naranjia cf. swatowensis (Yen, 1939). Tsim Bei Tsui, Hong Kong (AMS C. 446511). N. Maningrida arnhemensis sp. nov .. Holotype, Maningrida, Northern Territory (AMS C. 446485). Scale bar = 2 mm.

FIGURE 4. SEM photographs of internal surface of opercula, unless stated otherwise. A. Phallomedusa solida (Martens, 1878). B. Lactiforis tropicalis sp. nov .. C. Salinator rhamphidia sp. nov .. D. Salinator rosacea sp. nov .. E, F. Maningrida arnhemensis sp. nov., E. Exterior surface of operculum, F. Detail of nucleus on internal surface. Scale bar = 500 µm.

FIGURE 5. Photographs of live animals. A. Phallomedusa solida (Martens, 1878). B. Two specimens of Salinator rhamphidia sp. nov .. Scale bar = 5 mm.

FIGURE 9. SEM photographs of radulae of Salinator Hedley, 1900 species, showing half-radula and detail of central and lateral teeth. A, B. Salinator fragilis (Lamarck, 1822). C, D. Salinator tecta sp. nov .. E, F. Salinator rhamphidia sp. nov .. G, H. Salinator rosacea sp. nov .. A, C, E, G. Scale bar = 50 µm, B, D, F, H. Scale bar = 20 µm.

FIGURE 14. Distal reproductive structures of Amphibolidae. Structures orientated with proximal region at top of figure and distal region including genital aperture at base of figure. In all figures the dorsal part of the spermovipositor sheath has been removed, showing the spermovipositor, and in Figs. 13 A – C, E and H the distal portion of the prostatic gland is not shown. A. Salinator fragilis (Lamarck, 1822). B. Salinator tecta sp. nov .. C. Salinator rhamphidia sp. nov .. D. Salinator rosacea sp. nov .. E. Naranjia cf. swatowensis (Yen, 1939). F. Lactiforis tropicalis sp. nov .. G. Lactiforis takii (Kuroda, 1928). H. Amphibola crenata (Martyn, 1786). A, B, C. Scale bar = 1 mm, D, E, F, G, H. Scale bar = 500 µm.