Chaetogammarus, MARTYNOV, 1924

Hou, Zhonge & Sket, Boris, 2016, A review of Gammaridae (Crustacea: Amphipoda): the family extent, its evolutionary history, and taxonomic redefinition of genera, Zoological Journal of the Linnean Society 176 (2), pp. 323-348 : 334

GENUS CHAETOGAMMARUS MARTYNOV, 1924

Type species

Gammarus ischnus Stebbing, 1899 (synonym Gammarus tenellus Sars, 1896 , a homonym).

Aditional species

Molecularly proven ( Hou et al., 2014) members are: Gammarus warpachowskii G.O. Sars, 1894 , Gammarus placidus G.O. Sars, 1895 , and probably Gammarus behningi Martynov, 1919 , Chaetogammarus pauxillus G.O. Sars, 1896 , Sovinskya macrocerus Deržavin, 1948, Chaetogammarus hyrcanus Pjatakova, 1962 , and Gammarus sowinskyi Behning, 1914 .

Distribution

The natural distribution area of Chaetogammarus are the Black and Caspian seas, and their affluents. All known species are present in the Caspian, and most are found in both the Black Sea and the Caspian drainages. Some species are recent strong invaders all over Europe, and even in North America.

Remarks

These species are morphologically very similar to Homoeogammarus (although distinguishable by uropod III setation). As it is deeply nested within the group of Ponto-Caspian genera, we cannot fuse it with the peri-Mediterranean relatives.

Otherwise, the monophyletic Ponto-Caspian group of genera exhibits great diversity, slightly reminiscent of the Baikalian diversity; Chaetogammarus is a branch between other gammaroid and pontogammaroid branches of the Ponto-Caspian group genera, and along with Trichogammarus and the aberrant Derzhavinella the only Ponto-Caspian gammarids without a distoposterior lobe on bases of pereopod VII.