Affiliation:
1. Zoological Institute of the Russian Academy of Sciences, Universitetskaya Emb. 1, 199034 Saint Petersburg, Russia
Abstract
The genus Icelus Krøyer, 1845 includes 18 valid species from shelf and upper slope of the northern Pacific, Arctic and North Atlantic. The taxonomy of the genus is under development. To solve taxonomic problems, there is a need to clarify the diagnostic characters of already known species. As it turned out, information about the composition of the type series of the Okhotsk sculpin I. ochotensis Schmidt, 1927 from different sources is contradictory, and the diagnostic characters in the latest revision of the genus and in the keys for species identification diverge from the original description. The work clarifies the composition of the type series of the Okhotsk sculpin from the ZIN collection (36 specimens), provides a redescription and diagnosis; the Lectotype No. 21898 is designated. Icelus ochotensis, characterized by the presence of only two rows of large scales on the body (dorsal row Dl and lateral line Ll), was included in the group “I. bicornis”, along with I. spatula Gilbert et Burke, 1912, I. uncinalis Gilbert et Burke, 1912 and I. stenosomus Andriashev, 1937. Contrary to results of the latest revision of the genus and modern identifying keys, on the top of its head there is not one pair of spines, but two pairs (parietal and nuchal ones), in the form of blunt tubercles hidden in the skin. The dorsal row of scales (Dl) in front is complete (reaches the head); lateral line begins under scales 3rd–4th of the dorsal row and does not extend posteriorly onto caudal fin; scales Ll below the canal pore are immersed in the skin and usually not serrated (one or two tiny spinules may present); supraorbital cirrus (skin appendage) is simple. The urogenital papilla of males is cylindrical, in contrast to the spatulate one in I. spatula. Vertebrae 37–40, D VII–IX 15–19, A 13–16, P 17–18, Ll 38–40, Dl 29–34; axillary scales 6–13. The distribution of the Okhotsk sculpin requires revision, since modern keys for Icelus identification contain incorrect characters for this species (one pair of spines on the top of the head).
Publisher
Zoological Institute of the Russian Academy of Sciences
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