Alonopsis americana

Alonopsis americana

Phylum	Arthropoda
Subphylum	Crustacea
Class	Branchiopoda
Suborder	Cladocera
Family	Chydoridae

Ecology and Behavior

Characteristics

Postabdominal claw with one basal spine and a secondary tooth in the middle
Dorsal and ventral margins of the postabdomen are relatively parallel
Prominent tooth at inferoposteal angle which is flexed downward
Valves with parallel striae sloping downward with short longitudinal striae in between
3 major head pores

Geographic Distribution

New England, Newfoundland , and Nova Scotia (1)(2).

Reported Habitats

Along rocky lake shores (1)(2).

Reproductive Habits

Male and ephippial female A. americana begin to appear in October and by mid-November reproduction is mainly sexual. Individuals appear not to overwinter since their habitat is frozen over; populations are revived in the spring when the ephippia hatch (2).

Additional Notes

Alonopsis americana may retain old shells upon molting, but not every old shell is kept (2).

Additional Pictures

References

(1) CHENGALATH, R. 1982. A faunistic and ecological survey of the littoral Cladocera of Canada. Can. J. Zool. 60: 2668-2682.

(2) KUBERSKY, E.S. 1977. Worldwide distribution and ecology of Alonopsis (Cladocera: Chydoridae) with a description of Alonopsis americana sp. nov. Int. Revue ges. Hydrobiol. 62: 649-685.