Elaphoidella elaphoides (Chappuis, 1923)

(Figs 14–20)

Location, ecology. Dominant species in groundwater (wells) of Ogrodniczki and Ciasne villages near Białystok city. Only females and copepodites were found.

General distribution and biology. The species is new to the Polish fauna. Elaphoidella elaphoides is considered to be a stygophilic species that recently invaded the subterranean waters (cave, hyporheic and phreatic waters). Widespread in epigean and underground waters of Europe, i.e. Greece, Italy, Turkey (Pesce 1985), Balkan Penisula, Germany (Borutzky 1952), Austria, Czech Republic (Janetzky et al. 1996).

D i s t i n g u i s h i n g f e a t u r e s. Antennule eight-segmented (Fig. 15). Antennal exopodite one-segmented with 4 setae (Fig. 16). Caudal rami short, as long as wide; inner margin convex with row of short hairs (Fig. 17). Two lateral setae inserted midway on outer margin of caudal rami and dorsal seta inserted near posterolateral angle of the ramus (Fig. 17). Exopodite and endopodite of P1 three-segmented with seta formula 0/1/0.2.2 for exopodite (Fig. 18) and 1/1/1.1.1 for endopodite (Fig. 19). Inner lobe of proximal segment of P5 short with 4 setae; distal segment of P5 rounded and as long as wide (Fig. 20).