Typhlogammarus mrazeki Schäferna 1906

Karaman, Gordan S., 2016, On two new or interesting Amphipoda from Italy and Montenegro (Contribution to the knowledge of the Amphipoda 290, Ecologica Montenegrina 8, pp. 1-16 : 14-15

Typhlogammarus mrazeki Schäferna 1906

Gammarus (Typhlogammarus) mrazeki Schäferna, 1906: 1-24 , fig. 1, Pl. I, figs. 1-35;

Typhlogammarus mrazeki Spandl, 1926: 72 , fig. 47; G. Karaman, 2015: 66, fig. 9 (map). (Other authors omitted).

Material examined: Crna Gora (Montenegro): S-7293= Risan , cave PT 4, between Šaljinovice and Šoljinski Brijeg, 1.8.2010, 3 exp. (leg. M. Labegnović) ; S-7214= Njegoševa pećina Cave, village Njeguši, May 2013, 1 exp 22.5 mm (leg. Miloš Pavičević) ; X-640= Lipska pećina Cave near Cetinje, October, 1965, 3 exp. (leg. G. Karaman) . Herzegovina: Sp. 571= Vjetrenica Cave in Popovo Polje, Donja Vjetrenica , Herzegovina, 19.8.1931, 8 exp. (leg. S. Karaman) .

Remarks

Typhlogammaus mrazeki is one very variable species what is evident from various descriptions and figures of this species (Spandl, 1927; S. Karaman, 1932; G. Karaman, 1972, etc.). Recently G. Karaman (2015) presented the map of distribution of this species. Now I received one sample of this species collected in the cave above Risan in Montenegro, what urged me again to put more attention on taxonomic characters within various samples of T. mrazeki ; some of them are mentioned above.

The specimens from Risan agree with description of this species from type- and other known localities. These specimens from Risan [male 20.2 mm, females of 20.0 and 15.0 mm] are with relatively scarce pilosity of the body: epimeral plates 1-3 along posterior margin with normal row of single short setae, 2-4 single subventral spines appear at subventral face of epimeral plates 2 and 3; basipodit of pereopods 5-7 along posterior margin with row of single short setae, and facial row of spines and setae is very scarce; spines and setae on urosomal segments 1-3 is very reduced; articles 4-6 of pereopods 3-7 along both margins with single setae mixed with spines.

Just opposite situation appear in the specimen from Njegoševa pećina Cave in Njeguši (male, 22.5 mm): Body is very setaceous: epimeral plates 1-3 along posterior margin with densely row of short setae like the brush, and 2-4 bunches of subventral spines mixed with setae appear at subventral face of epimeral plates 2 and 3. Basipodit of pereopods 5-7 along posterior margin with dense row of numerous short setae like the brush, facial row of spines and setae on inner face of basipodites is very numerous; elevated number of setae mixed with single spines are present on urosomal segments 1-3; articles 4-6 of pereopods 3-7 along both margins with bunches of setae mixed with spines.

The various specimens from Lipska pećina Cave near Cetinje and Vjetrenica cave in Herzegovina have mixed combination of characters; densely setose pereopods 5-7, but epimeral plates 2 and 3 with ordinary row of single setae along posterior margin; various degree of pilosity of pereopods and epimeral plates, etc.

Besides these two basic ecological forms, “nudus” [with scarce pilosity of the body parts) and “pilosus” (with densely setose body- parts] exist the various populations with transitive characters between these two forms, sometimes within the same population. At the moment we don`t know the genetic background of these, probably ecological variations.