Cyclops bicuspidatus explained

Cyclops bicuspidatus is a planktonic species of copepod found throughout the world, except Australia, and characteristic of the Great Lakes of North America.^[1] It is a deep water species found throughout the year with peak abundance occurring in May or June.^[1] Males grow up to 0.8mm1mm long, while females are larger at 0.9-.^[2]

Distribution and classification

C. bicuspidatus has a cosmopolitan distribution, although several of its subspecies are more restricted, possibly representing cryptic species.^[3] For example, most specimens from North America can be ascribed to C. b. thomasi^[4] (= Diacyclops thomasi), while C. b. limnoria is restricted to Lake Constance.^[5] Taxonomy within the group is uncertain, and some subspecies may even belong to different genera.^[6]

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.

Notes and References

1. Seasonal variations in the relative abundance of Cyclops vernalis Fischer, Cyclops bicuspidatus Claus and Mesocyclops leuckarti (Claus) in western Lake Erie, from July, 1946, to May, 1948 . Ted P. Andrews . . 53 . 2 . 91–100 . 1953 .
2. Web site: Diacyclops bicuspidatus (Claus, 1857) . Norsk institutt for naturforskning . December 30, 2009.
3. Cryptic species in Diacyclops bicuspidatus (Copepoda:Cyclopoida): evidence from crossbreeding studies . . 417 . 1 . 2000 . 10.1023/A:1003811606429 . 101–107 . V. I. Monchenko . 25239892 .
4. The life cycle of Cyclops bicuspidatus thomasi S. A. Forbes in Leavenworth County State Lake, Kansas, U.S.A. (Copepoda) . Kenneth B. Armitage and Jerry C. Tash . . 13 . 1 . 1967 . 94–102 . 20102864 . 10.1163/156854067x00116. 1808/10711 . free .
5. A new cyclopid from groundwater of south Italy: Diacyclops bicuspidatus lucanus n. ssp. (Crustacea: Copepoda) . Giovanni L. Pesce & Diana P. Galassi . Bulletin Zoologisch Museum, Universiteit van Amsterdam . 10 . 8 . 1985 . 41–43 .
6. Web site: Diacyclops Kiefer, 1927, emend. Morton, 1985; Reid et al., 1989 . Giuseppe L. Pesce . January 8, 2009 . Copepod Web Portal.