Salinator tecta, 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 : 11-12

Salinator tecta sp. nov.

Holotype ( Fig. 2 E): Australia, New South Wales: South side of Narrabeen Lakes, near stormwater outlet, in shallow permanent pool with Zostera , 27 Sep 2004, R.E. Golding (AMS C.446774).

Paratypes: Same data as holotype (AMS C.440301), 15 specimens.

Other material examined: Australia, Queensland: Moreton Bay, Serpentine Creek, 10 Aug 1972, saltmarsh zone, QLD Museum party (AMS C.446512). Australia, New South Wales: Botany Bay, Banksmeadow, sandy tidal mudflat with small mangroves, Apr–Sep 2004, R.E. Golding and M. Hill (AMS C.440302, C.440303, C.442217); Lake Illawarra, Kully Bay, creek near lake with sparse saltmarsh vegetation, 3 May 2004, R.E. Golding and P.M. Golding (AMS C.440306); North side of Terrigal Lagoon, on mud amongst dense reeds at high tide level, 10 Mar 2004, R.E. Golding, W.F. Ponder and H. Fukuda (AMS C.442216); South side of Narrabeen Lakes, near stormwater outlet, in shallow permanent pool with Zostera , 4 Apr 2004, R.E. Golding and M. Hill (AMS C.442220). Australia, Victoria: Lakes Entrance, Kalimna, saltmarsh, 11 Jan 1970, W.F. Ponder (AMS C.446513). Australia, South Australia: Coorong, Robs Point, 22 Sep 1982, M. Geddes (AMS C.446514). Australia, Tasmania: North of Bicheno, coastal saltmarsh lagoon, date unknown, B. Jenkins and V. Morrissey (AMS C.446515).

Etymology: Tectum (Latin—hidden, sheltered, disguised) is a reference to the cryptic nature of this species’ identity.

Description: Shell ( Fig. 2 E): Globose, spire short, diameter to 11 mm, moderately thin, smaller shells semi-transparent when empty. Last whorl lacking shoulder; sinus flattened, indented. Exterior grey to fawn, with raised striae and dusty appearance in adults. Unbanded or with up to three spiral brown bands present at level of sinus.

Operculum: Entirely corneous, pale yellow, elliptical, with eccentric nucleus and paucispiral striae. Inner surface of operculum lacking elaborations around nucleus.

External morphology ( Fig. 6 A): As for S. fragilis , with following differences: Head cream or pale yellow in fresh and formalin-preserved specimens, with distinctive triangular patch of lateral pigmented stripes on anterior central snout and mottled black pigment covering head and foot. Mantle either solid black or with spots of black pigment.

Mantle organs: Mantle cavity roof with few blood vessels; opposed ciliary tracts run entire length of roof and floor of mantle cavity. Hypobranchial gland at right anterior roof of mantle cavity pale yellow in fresh and formalin-preserved specimens, flat, oval.

Digestive system ( Figs. 8 A, B): As for A. crenata , but proportionally smaller.

Radula ( Figs. 9 C, D): Each row with central tooth, pair of inner and outer lateral teeth and, on each side, approximately 25 marginal teeth. Central tooth with 13 cusps, mesocone enlarged, adjacent cusps reduced, other cusps reducing in length towards outer edges of tooth; inner lateral teeth narrow, bicuspid; outer lateral teeth with five cusps, second innermost cusp slightly reduced; marginal teeth unicuspid, narrow, elongate, slightly curved.

Central nervous system: As for S. fragilis , but presence of parapedal and subcerebral commissures not confirmed.

Reproductive system ( Figs. 13 B, 14B, 17C, D): Proximal reproductive system as for S. fragilis , distal reproductive structures differ as follows: Spermovipositor short, aperture with ‘lily shaped’ plate, flared and pointed towards genital aperture, edge of spermovipositor aperture microsculpture of small, conical projections. Spermovipositor sheath large, thick, highly folded, orange in fresh specimens, pocket beneath central part of base of spermovipositor and two eversible pockets with highly folded interiors proximally on either side of spermovipositor and adjacent to junction with prostatic gland. Some black pigmentation on lateral surfaces of spermovipositor sheath. Possible spermatophore observed in some specimens, white, globular, contains sperm and prostatic fluid. Egg mass deposited on substrate as a semi-circulate string, circular in crosssection.

Distribution and habitat ( Fig. 1 ): Eastern and southern Australian coast, from Adelaide to Brisbane, also northern Tasmania. Found in mangroves and on mudflats, usually associated with permanent pools of water, often found where fresh water mixes with estuarine ( Woolacott 1945, as S. fragilis ).

Remarks: Salinator tecta sp. nov. is separated from S. fragilis primarily by the distinctive mottled pigmentation on the head and the structure of the spermovipositor, which lacks the prominent projection found in S. fragilis .

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 6. Dorsal head-foot morphology. A. Salinator tecta sp. nov .. B. Salinator rhamphidia sp. nov .. C. Phallomedusa solida (Martens, 1878). D. Maningrida arnhemensis sp. nov .. Scale bar = 2 mm.

FIGURE 8. Digestive system of Salinator tecta sp. nov .. A. Complete digestive system. B. Detail of stomach and gizzard, stomach dissected dorsally to show internal structure. Scale bar = 10 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 13. Reproductive systems of Amphibolidae, Phallomedusidae fam. nov. and Maningrididae fam. nov .. These figures show the entire reproductive system and provide an anatomical map for the structures illustrated in Figs. 13 – 15. A. Amphibola crenata (Martyn, 1786), with spermovipositor sheath dissected open to show internal structures. Scale bar = 2 mm. B. Salinator tecta sp. nov., with spermovipositor sheath intact. Scale bar = 1 mm. C. Phallomedusa solida (Martens, 1878), with preputium dissected open to show penis. Scale bar = 2 mm. D. Maningrida arnhemensis sp. nov., with genital atrium dissected open to show internal structure. Parallel shaded lines indicate that ducts are embedded in the body wall. Scale bar = 1 mm.