Cyclops bicuspidatus
Introduction '''''Cyclops bicuspidatus''''' is a planktonic species of copepod found throughout the world, except Australia, and characteristic of the Great Lakes of North America. It is a deep water species found throughout the year with peak abundance occurring in May or June. Males grow up to  long, while females are larger at .
Distribution and classification ''C. bicuspidatus'' has a cosmopolitan distribution, although several of its subspecies are more restricted, possibly representing cryptic species. For example, most specimens from North America can be ascribed to ''C. b. thomasi'' (= ''Diacyclops thomasi''), while ''C. b. limnoria'' is restricted to Lake Constance. Taxonomy within the group is uncertain, and some subspecies may even belong to different genera.
Ecology In the Great Lakes, ''C. bicuspidatus'' is herbivorous until the fourth instar and omnivorous thereafter. Its prey includes ciliates, rotifers, small cladocera, young copepods and fish larvae. In turn, ''C. bicuspidatus'' is eaten by fish including the alewife, bass, bloaters, ciscoes, carpsuckers, perch, sculpin, shiners, whitefish and walleyes. In Lake Ontario, the population of ''C. bicuspidatus'' declined significantly after the invasive cladoceran ''Cercopagis pengoi'' was introduced.
References