Great Lakes Water Life Photo Gallery

Zooplankton - Waterfleas

Cladoceran Field Guide

Daphnidae Genera

For morphological terms see: Cladocera Anatomy

The four genera of Great Lakes Daphnidae are easily distinguished by the overall shape of the ventral surface (flat or rounded), head (with or without a rostrum) and tail (slight rounded extension of carapace or shell spine).

Ceriodaphnia spp.
0.4-1.4mm. Head small (1/6th carapace) curved ventrally and without a rostrum, no shell spine (tail) though the posterior carapace may be slightly extended
5 Great Lakes species

Daphnia spp.
<0.5mm-6mm. Rostrum present, Ventral margin convex, shell spine (tail) extending from the midline or dorsal
8 Great Lakes species

1 of 6 Photos of parthenogenetic female Daphnia retrocurva (others are closeups)

1 of 6 photos of parthenogenetic female Daphnia parvula (others are closeups)

Simocephalus spp.
3-4mm. Rostrum present, Ventral margin convex, No shell spine (tail)though the posterior carapace may be slightly extended,
3 Great Lakes species

1 of 3 photos of Simocephalus serrulatus

Scapholeberis spp.
1.0mm. Rostrum present, Ventral margin straight and shell spine (tail) extending from the ventral margin
2 Great Lakes species

1 of 3 Scapholeberis kingi photos in the SMSU collection

Photos courtesy of:
CENTEX Naturalist
The Cladoceran Website - University of Guelph, Canada
Southwest Missouri State University Zooplankton Project

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