Opinions and declarations Rendered by the International Commission on Zoological Nomenclature

Opinions and declarations Rendered by the International Commission on Zoological Nomenclature

Diplommatinidae from Moti Island, North Moluccas are revised based on material collected in 2010 and

2022. Two species belonging to Diplommatina and a new species of Palaina have been recorded. Diplommatina moluccensis is endemic to the North Moluccas, while Diplommatina radiiformis is endemic to the Moluccan Archipelago. A new species (Palaina motiensis, new species) is described, which is known from a single site, and is most similar with Palaina tanimbarensis from Yamdena Island and Palaina silvicultrix from Waigeo, West Papua

There is hitherto only one species, Amathina tricarinata, of the family Amathinidae that has been previously reported from Singapore (Tan & Low, 2014), and Leucotina casta is now the second. Despite being very similar in shell form, the more coarsely sculptured Monotygma amoena is presently assigned to a different, albeit related, family Pyramidellidae. It is not one of the several pyramidellids recorded from Singapore (e.g., Way & Purchon, 1981; Sanpanich & Tan, 2016). Although both species are herein first records for Singapore, it should be noted that the identifications are somewhat provisional. Several Leucotina species recognised by Japanese authors (e.g., Kuroda & Habe, 1971; Hori & Tsuchida, 1995; Hori, 2000) were synonymised by Beu et al. (2004). We concur with Beu et al.’s (2004) interpretation of Leucotina casta as a variable species, and identify our shells with flat closely spaced spiral ribs as this species. The only specimen herein identified as Monotygma amoena appears to match Leucotina dianae (sensu Kuroda & Habe, 1971), Leucotina digitalis (sensu Hori & Tsuchida, 1995), and Leucotina adamsi (sensu Hori, 2000) well. We follow Beu et al. (2004) in regarding these to be conspecific with Monotygma amoena (see Beu et al., 2004 as Monoptygma amoena). However it may possibly be a different species as the syntype and possible syntype of Monoptygma amoena (= Leucotina amoena), figured in Beu et al. (2004: fig. 25B) and Aartsen & Hori (2006: figs. 1-2), have flatter and more closely spaced spiral ribs with less distinct axial ridges in the interspaces.

Both Lutjanus lutjanus and Lutjanus russelli are known from Singapore waters (Fowler, 1938: 146; Lim & Low, 2008: 108 as Lutjanus madras, 109). Lutjanus lutjanus is distinguished from the similar looking and sympatric Lutjanus madras (Indian snapper) chiefly by its larger eyes and the width of the space between the lower eye margin and the mouth. In Lutjanus lutjanus, this space is much narrower than the eye diameter. In Lutjanus madras, this space is about equal to the eye diameter. The yellow stripe at the level of its eye is twice as wide as the other stripes parallel to it. In Lutjanus madras, the yellow stripe at eye level is only slightly wider than the other stripes. Another species with similar markings, Lutjanus vitta (brownstripe snapper) has a brown mid-lateral stripe and relatively smaller eyes. Both the Indian and brownstripe snappers occur sympatrically with the bigeye snapper (Allen & Erdmann, 2012: 451, 456; Anderson & Allen, 2001: 2882-2883, 2896). The fish illustrated in Lim & Low (2002: 108) as Lutjanus madras seems to be a Lutjanus lutjanus. With a distinct black blotch below the soft dorsal fin, the Russell’s snapper may be mistaken for Lutjanus johnii (John’s snapper), which also occurs in Singapore waters. They can be distinguished by the orientation of the rows of scales on the back above the lateral line. In the John’s snapper, the scale rows on the back run parallel to the lateral line. In the Russell’s snapper, the row rows on the back rise obliquely above the lateral line (Anderson & Allen, 2001: 2878, 2891; Allen & Erdmann, 2012: 454; Lim & Low, 2002: 109). Lutjanus lutjanus is distinguished from the similar looking and sympatric Lutjanus madras (Indian snapper) chiefly by its larger eyes and the width of the space between the lower eye margin and the mouth. In Lutjanus lutjanus, this space is much narrower than the eye diameter. In Lutjanus madras, this space is about equal to the eye diameter. The yellow stripe at the level of its eye is twice as wide as the other stripes parallel to it. In Lutjanus madras, the yellow stripe at eye level is only slightly wider than the other stripes. Another species with similar markings, Lutjanus vitta (brownstripe snapper) has a brown mid-lateral stripe and relatively smaller eyes. Both the Indian and brownstripe snappers occur sympatrically with the bigeye snapper (Allen & Erdmann, 2012: 451, 456; Anderson & Allen, 2001: 2882-2883, 2896). The fish illustrated in Lim & Low (2002: 108) as Lutjanus madras seems to be a Lutjanus lutjanus.

These two venus clam species have not been previously reported from Singapore in the literature (e.g., Morris & Purchon, 1981; Tan & Woo, 2010), and are thus regarded as first records. However it is uncertain if the record of a very similar-looking species, Antigona lamellaris, by Morris & Purchon (1981) could be a previous misidentification of Antigona chemnitzii. Antigona lamellaris can be distinguished by its more strongly frilled lamellae and elongate shell shape with a more pointed anterior (see Lamprell & Whitehead, 1992; Huber, 2010)