The Autecology of Eudiaptomus cf drieschi (Poppe & Mrazek 1895 ...

duration of naupliar stages from copepodite stages, but a general trend in postembryonic
development across the different temperatures was seen for all treatments. In
many species, nauplii develop somewhat faster than copepodites, however it has been
shown that at optimal temperature and food conditions, stage duration can be very
similar (Fig. 15). The data show a very gradual increase in development time from NII
through NV with a slight drop at NVI. Development time in copepodites is seen to
increase, generally, from CI to CV.
13%
Stage Duration (%)
11%
9%
7%
5%
NI NII NIII NIV NV NVI CI CII CIII CIV CV
Stage
Figure 15: Relative stage duration of E. drieschi.
In Lake Kinneret, average yearly temperature ranges from 14 to 28.5 0 C. At optimal
temperatures, (18-20 0 C) females can produce eggs within 24 hours of mating.
Subsequent clutches are produced within 1-1.5 days (+ 0.45) at 18 0 C. Under low
temperature conditions, females can take up to 2.5 days to produce eggs. At
temperatures >23 0 C, females were not seen to produce eggs. E. drieschi is more
commonly found in waters with temperatures that range from 7-22 0 C (Kiefer, 1968,
Beeton 1981, Gunduz 1998). During the summer months when, water temperatures in
the Kinneret can reach 30 0 C in the epilimnion E. drieschi is absent from the upper
water column and if at all present, found only in the metalimnion (>10 m depth) where
the temperature is less than 20 0 C.