Naranjia cf. swatowensis ( Yen, 1939 )

Golding, Rosemary E., Ponder, Winston F. & Byrne, Maria, 2007, Taxonomy and anatomy of Amphiboloidea (Gastropoda: Heterobranchia: Archaeopulmonata), Zootaxa 1476, pp. 1-50 : 17-18

Naranjia cf. swatowensis ( Yen, 1939)

Salinator swatowensis Yen, 1939: 65 , pl. V.

Salinator fragilis (not of Lamarck, 1788) Tong 1986: 444, pl. III, figs. D, E.

Type material: Holotype: China, Swatow: Kwangtung (now Guangdong). Location of type material unknown, not examined.

Other material examined: China, Hong Kong New Territory: Tsim Bei Tsui, mangrove soil surface, 10 Apr 1986, L. Tong (AMS C.153259); Tsim Bei Tsui, in mangroves, 15 Apr 1992, W.F. Ponder (AMS C.446511).

Redescription: Shell ( Fig. 2 M): Fragile, spire short, diameter to 7 mm, exterior smooth with faint striae. Last whorl relatively large, spiral line or ridge on shoulder of lower whorls present in some specimens. Exterior brownish-orange, transparent when empty.

Operculum: Corneous, thin, pale yellow, with paucispiral nucleus. Internal surface of operculum lacking elaborations around nucleus.

External morphology: Head-foot white or pale grey in formalin-preserved specimens, lacking pigmentation patterns.

Mantle organs ( Fig. 7 D): As for S. fragilis , with following differences. Opposed ciliary tracts short, restricted to exhalant canal. Hypobranchial gland oval, yellow in formalin-preserved specimens, with large chambers with non-staining contents, presumably mucus.

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

Radula ( Figs. 10 G, H): Central teeth with 13–17 cusps, mesocone enlarged; other cusps on central tooth arranged in undulating pattern forming ‘butterfly’ shaped profile. Single pair of lateral teeth on each row of radula; inner two cusps on lateral teeth separated by deep, u-shaped groove, outer cusp on lateral tooth narrow and reduced. Marginal teeth unicuspid, narrow, elongate, approximately 25 teeth on each side of radula.

Central nervous system ( Fig. 12 E): As for S. fragilis , with following differences. Cerebral-pleural ganglia twice as large as pedal ganglia; cerebral commissure long, thick. Visceral loop moderately long, right parietalvisceral connective shorter than left. Presence of parapedal and subcerebral commissures not confirmed.

Reproductive system ( Fig. 14 G): Proximal reproductive system as for S. fragilis , distal structures differ as follows. Distal spermovipositor fused to spermovipositor sheath forming narrow ridge, folded across aperture of spermoviduct proximally, exterior surface bearing rows of long, unchitinised papillae. Spermovipositor sheath highly folded, relatively thin-walled. Enlarged vaginal pocket (‘accessory bursa’) opening into spermovipositor sheath lumen on left of genital aperture, folded behind spermovipositor. Globular spermatophore present in enlarged vaginal pocket of some animals. Egg mass unknown.

Distribution and habitat ( Fig. 1 ): The type material of N. cf. swatowensis was described from Guangdong on the southern coast of China. The material on which the genus name is based is from mangrove habitat in Hong Kong.

Remarks: Our material is similar to Yen’s (1939) description and figure of S. swatowensis . However, Yen’s (1939) description is based only on shell characters which are relatively uninformative in distinguishing amphibolid taxa. Thus our identification of the Hong Kong material as N. cf. swatowensis is tentative, especially as Hong Kong is a considerable distance southwest of the type locality.

Tong (1986) figured shells of this species from Hong Kong as ‘ S. fragilis ’ (a misidentification) and a second unnamed Salinator species with a spiral ridge on the shell. Anatomical examination of her specimens has failed to reveal any differences between these ‘species’ apart from the presence of a spiral ridge, which is here interpreted as intraspecific variation as there are also intermediate forms with a weak spiral line. It is probably impossible to confirm the identity of the material without anatomical examination of topotypic material of S. swatowensis . It is possible that our Hong Kong specimens represent another new taxon, or they may even prove to be Salinator sanchezi subsp. s purca Yen, 1939 (see Incertae sedis section) from Hainan on the southern coast of China. Despite confusion with species identity, the material examined in this study demonstrates a clear anatomical separation from Salinator based on the colour of the shell, shape of the central radular teeth and the unusual spermovipositor bearing finger-like papillae.

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 7. Morphology of organs in the mantle cavity. A. Amphibola crenata (Martyn, 1786). B. Salinator fragilis (Lamarck, 1822). C. Lactiforis tropicalis sp. nov .. D. Naranjia cf. swatowensis (Yen, 1939). E. Phallomedusa solida (Martens, 1878). F. Maningrida arnhemensis sp. nov .. Scale bar = 1 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.