Troglocaris, DORMITZER, 1853

Sket, Boris & Zakšek, Valerija, 2009, European cave shrimp species (Decapoda: Caridea: Atyidae), redefined after a phylogenetic study; redefinition of some taxa, a new genus and four new Troglocaris species, Zoological Journal of the Linnean Society 155 (4), pp. 786-818 : 794-795

GENUS TROGLOCARIS DORMITZER, 1853

Diagnosis: A paratyine genus with supra- and suborbital spines developed or absent, pterygostomian carapace border rounded; pereopods I–III or more with exopodites; pereopods III and IV in mature males differentiated or not; male pleopod-I endopodite ‘9-shaped’ or as an open roll with shortened AI; male pleopod II AM longer than AI, with spines or setae much shorter than appendix diameter. All known species are subterranean and eyeless.

Type species: Palaemon anophthalmus Kollar, 1848 = Troglocaris schmidtii Dormitzer, 1853 .

Remarks: Following the description of the type species, some additional cave shrimps were described as belonging to new (separate) genera. These genera were defined by taxonomically highly unreliable characters, and were therefore later synonymized with Troglocaris . Nevertheless, their names are available, and molecular analysis ultimately showed that each belonged to a distinct clade. The generic names will be used here as subgenera: Troglocaris , Troglocaridella , Spelaeocaris , and Xiphocaridinella .

Distribution: The newly defined genus is distributed throughout the Dinaric karst and in the western Caucasian karst ( Zakšek et al., 2007).

SUBGENUS TROGLOCARIS (TROGLOCARIS) DORMITZER, 1853

Diagnosis: Troglocaris with developed supra- and suborbital spines and well-developed, wide, evenly, and densely serrated rostrum and head region of carapace; male pleopod-I endopodite ( Fig. 3 ) plate-like, with outer border folded to form an open roll, AI short to indistinct, hardly surpassing endopodite lamina distally; male pleopod II ( Fig. 4 Ta) AM shield-like, convex, several times wider and at least twice as long as AI, with numerous small spines on convex surface; maxilliped I with exopodital lobe obliquely to perpendicularly cut distally, with a long narrow flagellum; pereopods III and IV in mature males well differentiated; exopodites on pereopods I–IV well developed (V developed or missing); pereopod-V dactylus comb-like.

Type species: Same as for genus.

Distribution: This group exhibits ( Fig. 13 ) a holodinaric distribution (sensu Sket & Zagmajster, 2006): it is distributed along the Dinaric karst from its northwest border at the lower Isonzo/Soča river in Italy, throughout southern Slovenia, and Croatia, Bosnia and Herzegovina, up to its extreme south-east (but is not found in Montenegro).

Remarks: This clade/subgenus consists of two very distinct subclades; Troglocaris (Troglocaris) bosnica sp. nov. is molecularly and morphologically well defined. The next split within the richer clade is between the molecularly very homogeneous west Slovenian/east Italian group of populations and the molecularly more diversified eastern group, which includes the type population of the species. Some genetic and biogeographical details suggest that this is an aggregate of some independent ‘biological’ species ( Mayr & Ashlock, 1991), but their molecular diversity has yet to be studied in more detail (Zakšek et al., submitted). Unfortunately, the racial morphological variability within some of the subclades may be even higher than the differences between representative (topotype) populations that have been described and named as subspecies. Therefore, they cannot at present be taxonomically well defined, and for a detailed taxonomic analysis, further morphometrical study is needed. Here, we will mainly try to elucidate the position of the taxa (subspecies) that have already been named.

In an eastern Istrian locality, specimens of two clades named by Zakšek et al. (2007) co-occur: one west Slovenian and one related to east Slovenia. The cladistic analysis placed them in separate lineages, and they differ in sequences in two genes simultaneously. This makes it highly improbable that both specimens belong to the same gene pool, and supports the autonomy of the species T. planinensis . Results of an allozyme study ( Cobolli Sbordoni et al., 1990) even suggest a split into a number of intersterile species.

Figures

Figure 3. Endopodites of male pleopods I: Ta, Troglocaris (Troglocaris) anophthalmus from Kompoljska jama, in normal and flattened states; Ta-V, T. (T.) anophthalmus from Vjetrenica. See the Appendix for a list of abbreviations. Scale bars: see Fig. 4: sE for upper images; sG for lower left; sH for lower right.

Figure 4. Endopodite appendices of male pleopods II: Dv, Dugastella valentina from Mijares river; Gi, Gallocaris inermis from Grotte de Cambous; Th, Troglocaris (Troglocaridella) hercegovinensis (jTh, immature male) from Vjetrenica; Sp, Troglocaris (Spelaeocaris) pretneri from Dejanova pećina; Ta, Troglocaris (Troglocaris) anophthalmus from Kompoljska jama, CL 7 mm; jTa, an immature male T. (T.) anophthalmus, CL 6.4 mm. See the Appendix for a list of abbreviations. Scale bars: see Fig. 4: sA-sH scale bars; sE for Sp, Ta, jTa; sG for Dv, Th; sH for Gi, jTh.

Figure 13. Distribution and differerenciation of the subgenus Troglocaris (Troglocaris) Dormitzer, 1853. Solid symbols represent the localities of the sequenced samples. Type localities of species and races: KOM, Kompoljska jama, for Troglocaris (Troglocaris) anophthalmus anophthalmus; MIK, Mikašinovića pećina, for Troglocaris anophthalmus intermedia; PLA, Planinska jama, for Troglocaris planinensis; SUV, Suvaja pećina, for Troglocaris (Troglocaris) bosnica sp. nov.; VJE, Vjetrenica, for Troglocaris (Troglocaris) anophthalmus – Adriatic clade. Dotted lines indicate the supposed smallest possible areas of the named taxa and the Adriatic clade.