Halicmetus Alcock, 1891

Ho, Hsuan-Ching & Last, Peter R., 2018, Review of the batfish genus Halicmetus Alcock, 1891 from Australian waters, with descriptions of two new species (Lophiiformes: Ogcocephalidae), Zootaxa 4508 (2), pp. 179-196 : 180-181

Halicmetus Alcock

Halicmetus Alcock, 1891:27 . Type species: Halicmetus ruber Alcock, 1891 , by monotypy.

Halicmetes: Lindberg et al., 1997:232 (misspelling).

Diagnosis. Head strongly depressed; anterior margin of disk truncate to broadly rounded; rostrum extending anteriorly to or slightly beyond mouth and anterior margin of disk; mouth small; dorsal fin present or absent, if present, minute in size; entire body covered with small bucklers and small dermal tubercles; subopercular buckler moderately developed, usually bearing some short terminal spinules; gill filaments present on 2nd and 3rd gill arches, absent from fourth gill arch; gill rakers present on first to third gill arches; 3–4 gill rakers on outer side of 2nd gill arch; esca triangular and bulbous, fringed on its lower margin and usually bearing a pair of dorsal cirri; teeth on vomer and palate forming three closely adjacent quadrangular patches; tongue teeth (5th ceratobranchial) in two closely attached elongated patches.

Remarks. The taxonomic status of Halicmetus ruber var. marmorata Weber, 1913 has long been a mystery. Weber described marmorata as a new variation of H. ruber , based on 5 syntypes collected from the Madura Sea, Indonesia. The translation of Weber’s (1913: 567) original description is as follows:

Alcock’s H. ruber is described as “uniform light pink” in life, whereas my specimens show several irregularly shaped, brown speckles all over the surface, which often merge into even larger blotches. Moreover the eyes are rather smaller as in H. ruber . The diameter is about one-seventh of the disc and approximately about as wide as half of its anterior distance to one another. The mouth is slightly longer than the eye diameter. But in my specimens the eye diameter is almost one-eighth of the disc’s length, therefore being as long as the anterior distance to one another and only about half as long as the mouth opening. Since my specimens otherwise resemble all other factors in the description of Alcock, I would like to see my specimens only as local variation of the same species, possibly confined to the Indo–Australian Archipelago.

According to Article 45.5.4 of The Code (ICZN, 2018, online version), a taxon “is subspecific if first published before 1961 and its author expressly used one of the terms “variety” or “form” (including use of the terms “var.”, “forma”, “v.” and “f.”)…”. Weber (1913) treated his specimens as a local variation of H. ruber and gave a distribution range of Indo–Australian Archipelago, thus qualifying marmorata as a valid subspecific name.

Weber and de Beaufort (1962), evidently by de Beaufort, synonymized it with H. reticulatus based on the colouration. Bradbury (1967) initially considered the taxon to be a synonym of H. ruber , but later ( Bradbury, 2003) listed it as an incertae sedis in the Ogcocephalidae ( Eschmeyer et al., 2018) . Ho et al. (2008) also treated the taxon as a subspecies of H. ruber .

In 2006 and 2013, the first author examined the syntypes at the Zoölogisch Museum, Amsterdam (ZMA) confirming characters described by Weber, except for the types being colourless. These specimens are similar to H. reticulatus , based on the shared presence of a dorsal fin, simple dermal spinules on the body surface, a small eye and pale peritoneal membrane with scattered melanophores [specimens not dissected, but the colouration still detectable through the semi-transparent skin]. Other species, H. ruber , H. cf. ruber (sensu Ho et al., 2008) and H. niger , with their adults lack dorsal-fin rays, have numerous forked dermal spinules on the body surface, a larger eye, and a brown peritoneal membrane ( Ho et al., 2008).

After examining a large collection of specimens from the Indo–West Pacific, we identified a species with a marbled colour pattern on the dorsal surface, usually with dorsal-fin rays (about one-fifth of examined specimens lacked rays), a small eye, and pale peritoneal membrane, typical of H. ruber var. marmorata . The taxon is elevated as an objective available name of species rank and redescribed below on the basis of newly collected specimens.

Valid species. Halicmetus is represented in the Indo–Pacific by six valid nominal taxa: H. drypus n. sp., H. marmoratus Weber, 1913 , H. niger Ho, Endo & Sakamaki, 2008 , H. reticulatus Smith & Radcliffe, 1912 , H. ruber Alcock, 1891 , and H. westraliensis n. sp., and one undescribed species, H. cf. ruber (sensu Ho et al., 2008).