Macrothricidae Genera

For morphological terms see: Cladocera Anatomy

The Family Macrothricidae includes just 6 occassional to rare Great Lakes genera found most often in littoral and shallow waters. Fine features of the postabdomen, carapace spines, and 2nd antennae are used to distinguish among genera and species - necessitating use of a high-powered light microscope at a minimum.

Convoluted intestine.Without a tail-spine. To 1.8mm
Acantholeberis curvirostris

Simple intestine. Postabdomen with numerous long spines. Antennal setae 0-0-0-3/1-1-3. 0.7-1.0mm

Ilyocryptus (3 Great Lakes species)

Convoluted intestine. Without a tail-spine. Dorsal and posterior margin arched with a conspicuous dorsal tooth. To 0.7mm.

Drepanothrix dentata

Simple intestine. Postabdomen without long spines. Antennal setae 0-0-1-3/1-1-3. 0.5-0.7mm.

Macrothrix laticornis

Convoluted intestine. Spine at the posterior-dorsal angle. To 2mm.

Ophyroxus gracilis