Cyclopoid1.mov - Cyclopoid swimming patten (682 KB)

M. edax is widespread throughout eastern and central North America and is also found in the tropics (3).

M. edax exhibits diel vertical migration, however, there is preference for warmer waters and migrations are normally limited to above the thermocline (2).

M. edax feeds on rotifers, cladocera, both calanoid and cyclopoid nauplii and copepodites, as wells as ciliate protozoans (4). This species has been observed eating D. floridanus whole by severing part of the carapace and sucking out the body contents (5).

In southern lakes, females are ovigerous nearly all year round. In colder northern lakes, M. edax completes two to three discrete generations between April and October and then diapause for the winter (3).

M. edax is preyed upon by the planktivorous fish alewife (1).

M. edax swims in a hop-sink fashion (4).

(1) WELLS, L. 1970. Effects of alewife predation on zooplankton populations in Lake Michigan . Limnol. and Oceanogr. 15 (4) : 556-565.

(2) MARARCOGLIESE, D. and G. E. ESCH. 1992. Alterations of vertical distribution and migration of zooplankton in relation to temperature. American Midland Naturalist. 128 (1) : 139-155.

(3) ALLEN, J. D. 1984. Life history variation in a freshwater copepod: Evidence from population crosses. Evolution. 38 (2) : 280-291.

(4) WILLIAMSON, C. E. 1980. The predatory behavior of Mesocyclops edax : Predator preferences, prey defenses, and starvation-induced changes. Limnol. and Oceanogr. 25 (5) : 903-909.

(5 ) CONFER, J. L. 1971. Intrazooplankton predation by Mesocyclops edax at natural prey densities. Limnol. and Oceanogr. 16 (4) : 663-666.

Present in Barbadoes Pond, Madbury, NH