Sunday, April 6, 2014

[Ichthyology • 2014] Complementary Redescription of Anacanthobatis ori (Wallace, 1967) and its assignment to Indobatis n. g. (Elasmobranchii, Anacanthobatidae), with comments on other legskates


Indobatis ori (WALLACE, 1967) Black legskate

Abstract

Anacanthobatis ori is one of the least known species of the family Anacanthobatidae with only four juvenile specimens reported. The species remained assigned to the genus Anacanthobatis sensu lato due to the lack of an adult male as external and skeletal clasper characters are the essential diagnostic features for the differentiation of genera and subgenera within the family Anacanthobatidae. Since an adult male of A. ori became available, along with an adult female and six further juveniles, the authors reinvestigated the species and present its so far unknown diagnostic characters of clasper morphology and skeleton and scapulocoracoid. The clasper turned out to be the most complex one of all known anacanthobatids as the external components flag, slit, pseudosiphon-like cavity, pecten, and two sentinas are not known from any other anacanthobatid species. Furthermore, a dorsal terminal 1 cartilage is present but displaced proximally of the terminal clasper skeleton, the outer edge of dorsal terminal 2 is deeply serrated, the ventral terminal has a very long, curved, strap-like process, and the proximal part of accessory terminal 1 is embedded in the cavity of the baseball-glove-like head of accessory terminal 2. Due to the strong differences in external and internal clasper characters to all other known anacanthobatid species, A. ori is placed in its own, newly erected genus, Indobatis.

Keywords: leg skates, western Indian Ocean, deep water, generic status, clasper features, Crurirajidae


Weigmann, Simon, Matthias F. w. Stehmann & Ralf Thiel. 2014. Complementary Redescription of Anacanthobatis ori (Wallace, 1967) and its assignment to Indobatis n. g. (Elasmobranchii, Anacanthobatidae), with comments on other legskates. Zootaxa. 3779 (2): 101–132