Calliax de Saint Laurent, 1973

Hyžný, Matúš, 2020, Revision of the Miocene shrimp Callianassa kerepesiensis Müller, 1976 (Malacostraca, Decapoda), with a description of a new species, Zootaxa 4801 (2), pp. 363-373 : 364-365

Genus Calliax de Saint Laurent, 1973

Type species. Callianassa (Callichirus) lobata de Gaillande & Lagardère, 1966 , by original designation and monotypy.

Remarks. The genus Calliax de Saint Laurent, 1973 , has rather a complex taxonomic history (Hyžný & Gašparič 2014; Ngoc-Ho 2014). Here the concept of the genus presented by Ngoc-Ho (2003, 2014) and Poore et al. (2019) is followed rather than that of Sakai (2011).

It has been argued that at least for some genera the morphology of the major P1 propodus can be diagnostic on the genus level ( Hyžný 2012; Hyžný & Müller 2012). In this respect, the genus Calliax is identifiable based on the following characters (emended from Hyžný & Gašparič 2014): 1) major propodus rectangular, usually longer than high; 2) fixed finger shorter than manus, with a (double) ridge accompanied by a furrow and/or depression extending onto manus; 3) fixed finger with subdistal tooth on the occlusal margin. It should be mentioned that the ridge is well-developed mainly in larger specimens, whereas in smaller individuals it is faint or not present.

Even more diagnostic for Calliax is the morphology of the minor chela (Hyžný & Gašparič 2014; Poore et al. 2019), which, unfortunately, is not observable in the present material. In this respect, Poore et al. (2019: 126) argued that: “the wide gap between the fingers of the minor cheliped, with an intermediate tooth, immediately defines species of Calliax .”