Tosana Smith & Pope, 1906

Gill, Anthony C., Pogonoski, John J., Johnson, Jeffrey W. & Tea, Yi-Kai, 2021, Three new species ofAustralian anthiadine fishes, with comments on the monophyly of Pseudanthias Bleeker (Teleostei: Serranidae), Zootaxa 4996 (1), pp. 49-82 : 61-63

Tosana Smith & Pope

Tosana Smith & Pope, 1906: 470 (type species, Tosana niwae Smith & Pope, 1906 , by original designation and monotypy).? Mustelichthys Tanaka, 1917: 201 (type species, Mustelichthys ui Tanaka, 1917, by monotypy).

Diagnosis. Tosana is distinguished from all other anthiadine genera in having variably branched pectoral rays ( Table 4), which we interpret as a synapomorphy of the included species (see below). It is also distinguished by the following combination of characters: dorsal rays usually X,14 (rarely X,13 or X,15); anal rays usually III,7 (rarely III,6); pectoral rays 15–17, usually 16; branched caudal rays usually 7+6; lateral-line complete, consisting of 33–41 tubed scales; gill rakers relatively long, 8–11+22–26=32–37; predorsal formula 0/0/2/1+1; epineurals 11–13; ribs present on vertebrae 3 through 10; vertebrae 10+16, first caudal vertebrae with well-developed parapophyses; predorsal scales extend anteriorly on snout at least to vicinity of nostrils, the remainder of head scaly except for lips, isthmus, and narrow area immediately in front of nostrils; no auxiliary scales on body; scales with peripheral cteni and no ctenial bases.

Remarks. As noted above, monophyly of the genus is supported by a single synapomorphy: variably branched pectoral rays. Unlike other anthiadines, where the pectoral fins have either entirely unbranched rays (e.g., Serranocirrhitus and Tosanoides ) or a few upper and lower unbranched rays with the remaining rays branched (e.g., Pseudanthias ), Tosana species usually have a few unbranched rays dorsally, mostly branched rays on the remaining upper half of the fin, and mostly unbranched rays in the middle and lower part of the fin ( Table 4). Although we record several specimens with mostly branched pectoral rays in Table 4 —which is similar to the condition in Pseudanthias —none of our specimens has entirely unbranched rays. This is contrary to Heemstra & Randall (1999), who, in their key to central West Pacific anthiadines, reported Tosana as only having unbranched pectoral rays. Some of the unbranched rays in Tosana specimens appear to be thickened and misshapen, which, along with the variable nature of branching in the fin, suggests that they may be secondarily unbranched, forming from irregular ontogenetic fusion of ray branches. However, without further study, we cannot rule out the alternative, that unbranched rays are unbranched throughout ontogeny.

We currently include only three species in the genus, T. niwae ( Fig. 5 ), T. longipinnis n. sp. and T. dampieriensis n. sp. In so doing, we follow Gill et al. (2019) in recognising Anthias albofasciatus Fowler & Bean, 1930 , as a junior synonym of T. niwae . They did not discuss additional nominal species placed in the probable synonymy of T. niwae by Katayama (1960): Anthias gracilis Franz (1910) and Mustelichthys ui Tanaka (1917). Type material is lacking for the former species, but Franz’s description and figure appear to agree well with T. niwae . We refrain from commenting on M. ui pending examination of the holotype (ZUMT 9957).

We have not considered reports of T. niwae from outside the vicinity of Japan, Taiwan, the South China Sea, Western Australia, and eastern Australia, some of which may represent additional species. This includes Al-Baharna’s (1986) record from Bahrain. The latter record was repeated by Randall (1995) but was questioned subsequently by Eagderi et al. (2019).

Figures

FIGURE 5. Tosana niwae, KPM-NI 35479 (image KPM-NR 107491B), 106 mm SL, freshly dead male, off Odawara, Honshu, Japan. © Kanagawa Prefectural Museum of Natural History; photo by H. Senou.