, 1982, Klein Breteler and Gonzalez, 1986 and Klein Breteler et al., 1990), three different sources of food were used: Isochrysis galbana, Rhodomonas sp. and a mixture of these algae with Oxyrrhis marina. In the laboratory studies of Pseudocalanus elongatus and T. longicornis, Klein Breteler et al. (1990)suggested that the development was not dependent on the type of food used in experiments. Only with I. galbana was the development of T. longicornis clearly retarded (especially during the copepodid stages) (see Figure 2 in Klein Breteler et al. 1990). However, the quality of food

is also closely related to the copepod’s stage of development (Gruzov, 1985 and Klein Breteler et al., 1990). The flagellate O. marina has a low signaling pathway food value for nauplii, owing to its large size, but is the main food for the copepodid stages. For optimal growth, the naupliar and early copepodid stages depend largely on alternative smaller food like Rhodomonas sp. and I. galbana. Additionally,

the growth of the naupliar stages may be slower because of their poorer ability to handle and ingest small food particles ( Fernández 1979), since the only functioning mouthparts are the first and second antennules and mandibles. In the N6, these buds become greatly enlarged, and with the moult to C1, all of the mouthparts unfold ( Peterson 2001). According to recent evidence, the growth and development rates of copepods may also depend on the area of occurrence. buy VX-809 Different populations may develop slightly different survival strategies to adapt to their habitat. Two different populations exhibit different development rates when reared at the same temperature. There are differences in growth Vildagliptin rates between populations too, particularly when reared at high temperatures with the population acclimated to cold temperatures growing faster than the warm acclimated population. Additionally, populations show different ontogenetic responses to temperature shifts (Leandro et al. 2006a). In this paper, the development of individuals in the southern Baltic Sea is manifested

by a change in the total stage duration (N1–C5) as a function of both temperature and food concentration. The impact of the above parameters on the generation time of T. longicornis during the seasons in the upper 10 m layer in the Gdańsk Deep (southern Baltic Sea) is described by equation (2). This approach is possible because T. longicornis is not very sensitive to differences in salinity – like some Acartia species, it is a euryhaline species – but unlike P. elongatus, which is a stenohaline species. The temperature and food composition (equal to 60% of the phytoplankton biomass, 15% of the zooplankton biomass and 25% of the pelagic detritus concentration) used in this paper are mean values from the last 38 years (1965–98) (data from the 1DCEM model – Dzierzbicka-Głowacka et al., 2006 and Dzierzbicka-Głowacka et al., 2010a). For the population of T.