Lactiforis takii ( Kuroda, 1928 )

Golding, Rosemary E., Ponder, Winston F. & Byrne, Maria, 2007, Taxonomy and anatomy of Amphiboloidea (Gastropoda: Heterobranchia: Archaeopulmonata), Zootaxa 1476, pp. 1-50 : 16-17

Lactiforis takii ( Kuroda, 1928)

Salinator takii Kuroda, 1928: 11 , pl. I; Tanaka 1959: 354, figs. 1–11; Kosuge 2000: 19; Fukuda & Kosuge 2000: 140, fig. 6.1.

Type material: Japan, Kyushu: Fukuoka Prefecture, on the coast of Kurosaki, Ariake Inland Sea, muddy bottom, collector unknown. Holotype deposited in Faculty of Science, Kyoto University, not examined.

Other material examined: Japan, Kyushu: Fukuoka prefecture, estuary of the Okihata River (flowing into the Ariake Inland Sea), very soft mud tidal-flat, 1 May 2004, T. Ishibashi (AMS C.446490); Oita prefecture, estuary of the Kakise River (flowing into Seto Inland Sea), soft mud tidal-flat, 28 Dec 2003, T. Wada (AMS C.446491).

Redescription: Shell ( Fig. 2 L): Fragile, opaque, spire very short, conical, diameter to 7 mm. Exterior pale grey to brown, unbanded or sometimes with one to three dark brown spiral bands, lacking differentiated colouring at umbilicus.

Operculum: Thin, pale yellow, corneous with fan-shaped white deposit on interior surface around nucleus and along outer edge, visible from exterior. Columellar edge of operculum concave; nucleus eccentric, paucispiral.

External morphology: Head-foot dark grey in formalin-preserved specimens, with diffuse stripe of black pigment on central snout and around genital aperture; mantle solid black.

Mantle organs: As for L. tropicalis sp. nov.

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

Radula ( Figs. 10 E, F): Central and lateral teeth absent, marginal teeth continuous across radula with approximately 25 on each side; unicuspid, elongate, narrow, with recurved tips.

Central nervous system ( Fig. 12 D): As for L. tropicalis sp. nov. but visceral ganglion adjacent to right parietal ganglion, with connective not visible.

Reproductive system ( Fig. 14 G): As for L. tropicalis sp. nov., but with following differences: Prostatic gland uniform colour for entire length, crimson tissue at proximal base absent. Spermovipositor short, thickened tube. Muscular ridge on left side of spermovipositor sheath.

Distribution and habitat ( Fig. 1 ): Ariake Inland Sea, Kyushu, Japan. Also found in the Seto Inland Sea, Kyushu, though this population may be introduced (H. Fukuda, personal communication). Found on very soft mud on tidal-flats.

Remarks: Although the development ( Tanaka 1959) and ecology (Kosuge 2000) of L. takii have been studied, the large anatomical differences between this genus and other amphibolids have not been addressed. Fukuda & Kosuge (2000) cited earlier reports that the radula of L. takii lacks central teeth, recognising that this probably merited generic (or even subfamilial) distinction—but in the absence of comparable data for other amphibolids no name was proposed. Lactiforis takii is separated from L. tropicalis sp. nov. by the uniformly coloured prostatic gland and grey shell. It has a very limited distribution in the Ariake Sea, Japan and is considered critically endangered ( Fukuda & Kosuge 2000).

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 10. SEM photographs of radulae of Amphibola Schumacher, 1817, Lactiforis gen. nov. and Naranjia gen. nov. species, showing half-radula and detail of central and lateral teeth. A, B. Amphibola crenata (Martyn, 1786). C, D. Lactiforis tropicalis sp. nov .. E, F. Lactiforis takii (Kuroda, 1928). G, H. Naranjia cf. swatowensis (Yen, 1939). A, C, E, G. Scale bar = 50 µm, B, D, F, H. Scale bar = 20 µm.

FIGURE 12. Central nervous systems. A. Amphibola crenata (Martyn, 1786). B. Salinator fragilis (Lamarck, 1822). C. Lactiforis tropicalis sp. nov .. D. Lactiforis takii (Kuroda, 1928). E. Naranjia cf. swatowensis (Yen, 1939). F. Phallomedusa solida (Martens, 1878). G. Maningrida arnhemensis sp. nov .. Scale bar = 500 µm. Subcerebral and parapedal commissures are indicated on the figures for A. crenata, S. fragilis and P. s o l i d a, but not on the figures for other species as the presence of these structures is unconfirmed.

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.