Dexamine spinosa (Montagu, 1813)

Krapp-Schickel, T., 2013, New or amended data on Mediterranean Amphipoda: genera Dexamine, Ericthonius and Stenothoe, Zootaxa 3613 (2), pp. 125-145 : 126

Dexamine spinosa (Montagu, 1813)

Fig. 1

Cancer (Gammarus) spinosus Montagu, 1813:3 , pl. 2, fig. 1

Dexamine spinosa Della Valle, 1893 (partim): 573; Sars, 1895:475, pl. 166, fig. 2; pl. 167; Stebbing, 1906: 515; Chevreux & Fage, 1925: 264, fig. 264, fig. 274; Gurjanova, 1951: 789, fig. 550; Lincoln, 1979: 450, fig. 214 a–h.

non Bellan-Santini, 1982: 222–224, fig. 151–152.

As already visible in the rich citation list, this species is among the very early described amphipods, and is cited from the NE Atlantic, English Channel, North Africa to Senegal, Mediterranean and Black Sea. Some authors mention the type locality as "unknown", others indicate at least "Devonshire". The depth range is from low intertidal to about 60 m. The body length of adult specimens is reported in Sars, 1895 as 11–13 mm, in Chevreux & Fage, 1925 as 9–12 mm, in Lincoln, 1979 as about 14 mm.

When Angelo Libertini and I wanted to collect ovigerous females for studying the chromosome number and their morphology, we were extremely astonished to find among large ones also a few very small and clearly mature females with eggs. Looking better at the morphology of the appendages, I fortunately could find some very small but constant differences. Sadly enough, the material from the Venice lagoon got lost. But within the rich collection of the Verona Museum I found other material of this new species.

Figures

FIGURE 1. Dexamine spinosa (Montagu, 1814) habitus of live specimen from Messina; Francesco Costa phot.