Echinogammarus, STEBBING, 1899

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 : 335

( ECHINOGAMMARUS S. STR.)

Type species

Gammarus berilloni Catta, 1878 .

Additional species

Molecularly proven ( Hou et al., 2014) included taxa are: Gammarus calvus Margalef, 1956 , Echinogammarus tarragonensis Pinkster, 1973 , Echinogammarus longisetosus Pinkster, 1973 , Echinogammarus feminatus Pinkster, 1973 , Echinogammarus aquilifer Pinkster, 1969 , Echinogammarus zebrinus Pinkster & Stock, 1971 , and probably all other Echinogammarus berilloni group species sensu Pinkster, 1993 , Stock, 1993.

Distribution

These are freshwater species, inhabiting mainly Atlantic affluents in France and Spain, and with a number of species (also) in the Mediterranean drainages of Spain. Note that large river systems are traversing the Pyreneean peninsula in an east–west direction. In 1920 Echinogammarus berilloni was already found to be in- vading Germany ( Thienemann, 1950), and was found to be invading again recently in Germany and France ( Pinkster, 1993).

Remarks

Echinogammarus s. str. is a distinct clade including only south-west European freshwater species, as defined above. According to Stock (1993), they are morphologically characterized by diverse and extraordinary setosity and/or spinosity of pleonites and urosomites, and peduncle articles of antennae I and II very slender. Surprisingly, in our tree, this clade includes the Caucasian troglobiotic and morphologically very different Zenkevitchia admirabilis Birstein, 1940 , whereas it is in sister relationship with the clade of the Dinaric troglobiotic Typhlogammarus group. The need for redefinition of Echinogammarus s. str. was already expressed by Stock (1993); he left all other Mediterranean, gammariform Ponto-Caspian and marine Atlantic parviramus ‘echinogammarids’ in the genus Chaetogammarus . In our tree ( Fig. 2 ) this clade is very distant from all other would-be ‘ Echinogammarus ’ clades, which appeared to be scattered throughout the phylogenetic tree.

Figures

Figure 2. Maximum-likelihood (ML) phylogeny of Gammaridae with out-groups removed, based on a combined mitochondrial and nuclear data set. Numbers above and below branches are ML bootstrap values and Bayesian posterior probabilities. The major groups are labelled. For details, see Hou et al. (2014: figure S1).