, 1982 and Klein Breteler & Gonzalez (1986) at the same range of temperature and food concentration. The slight differences in TD were less at higher temperatures than at lower ones under similar food

conditions and were due to the difference in food concentration. On the basis of these results it should be noticed that the development of T. longicornis is not isochronal, even at optimal food concentrations ( Klein Breteler & Gonzalez 1986). Deviations from the isochronal pattern of development have been noted in other species of calanoid copepods too – Acartia spp., Centropages spp. and Eurytemora spp. ( Peterson, 2001, Leandro et al., 2006a and Leandro et al., 2006b). The first naupliar stage PD-166866 has a short duration. Development is prolonged at the N2 stage and at the C4 and C5 stages. Stage durations are approximately equal through the late naupliar

stages and early copepodid stages. The present study has also demonstrated that the mean development time for each of the model stages of T. longicornisKB is a function of both temperature in the 5–20°C range and food concentration from 25 mgC m−3 to excess, rising with decreasing temperature and food level in the studied ranges, except for some developmental stages (naupliar stages, C1, C2 and C4) for which the temperature of ca 15°C was the optimum value. Differences in D at 12.5°C were found between T. longicornisKB and T. longicornisH in similar stage groups. The slight difference in D between the two species at the naupliar stage was from 1 (under conditions of excess food) to 4.7 days and selleck chemicals llc depended on the food concentration. But D of T. longicornisKB was four times and twice as long as that of T. longicornisH for early (C1–C3) and larger (C4–C5) copepodid stages respectively in the 25–200 mgC m−3 range of food concentration. TD of T. longicornisKB was twice as long as TD of T. longicornisH. Benzatropine For example, at Food = 25 mgC m−3, TD was 68.62 days for

T. longicornisKB and 33.705 days for T. longicornisH. In the present study, the generation time N1–C5 for T. longicornisKB at all temperatures was shorter than the values found by other authors, i.e. the difference in TD is ca 12% (4 days) and 25% (9 days) at ca 10°C according to the data given by Hay et al., 1988 and McLaren, 1978 respectively. However, at 20°C, it was 26.2% (5.5 days) when results from the German Bight after Martens (1980) and the experimental data given by Person-Le Ruyet (1975) were included. Fransz et al. (1989) stated that the respective average times required for the development of T. longicornis from the Southern Bight of the North Sea was 45, 35 and 50 days in the 5–10°C, 7–12°C and 12–18°C temperature ranges. The values were obtained on the basis of field samples at different temperatures for three generations. The differences in TD between the generations were caused by different food sources, food concentrations and temperatures.