Embata parasitica (Giglioli, 1863)

Fontaneto, D., Segers, H. & Melone, G., 2004, Epizoic rotifers (Rotifera: Monogononta, Bdelloidea) from the gill chambers of Potamon fluviatile (Herbst, 1785), Journal of Natural History 38 (10), pp. 1225-1232 : 1230-1231

Embata parasitica (Giglioli, 1863)

( figures 14–16 )

Material examined

Thirty-seven specimens among gills of a male crab; a single specimen near the mouth of a female crab.

Diagnosis and comments

Trophi (n ~8) have two major unci teeth, 19–21 proximal minor teeth and 23–25 distal minor teeth. Rami length is 19.86¡0.24 µ m.

This species is one of the three eyeless and oviparous Embata species. Its external habitus is similar to Macrotrachela cancrophila (Piovanelli, 1903) , also described from the gill chamber of Italian freshwater crabs. These species are easily distinguished by their different number of toes: three in Macrotrachela , and four in Embata . Also, the trophi of E. parasitica are smaller than those of M. cancrophila [rami length of about 20 µ m in E. parasitica , about 27 µ m in M. cancrophila (Piovanelli, 1903a: 346) ].

Embata parasitica is known from Europe and North America (Donner, 1965), living epizoic on various aquatic animals, such as Asellus aquaticus (Linnaeus, 1758) , Gammarus pulex (Linnaeus, 1758) and caddis-fly larvae (May, 1989). We succeeded in maintaining a reproductive population using a feeding suspension of finely ground fish pellets (Friskies ® for goldfish).

As for A. telphusae , we observed fungi on the surface of the body of this species ( figure 16 ).

Figures

FIGS 12–15. Trophi of Anomopus telphusae, SEM pictures. (12) Cephalic. (13) Caudal view. Trophi of Embata parasitica, SEM pictures. (14) Cephalic. (15) Caudal view. Scale bar: 5 µm.

FIG. 16. Foot of Embata parasitica with fungi. Scale bar: 10 µm.