Development, growth, and survivorship of the copepod Calanus marshallae in the laboratory

Development times from egg to adult Calanus marshallae (Copepoda, Crustacea) were 36 d at 15 'C, 62 d at 11 "C and 64 d at 10 'C. Stage-by-stage development was not isochronal but followed a sigmoidal pattern. Egg, NI and N2 together took 3.4 d at 10 "C (= 5.3 % of the total development time). N3 had the second longest duration of any stage (6.8 d at 10 "C; 10.7 % of total development). Stage duration decreased from N3 through N6, with N6 having the shortest duration of any stage (2.6 d), then development became progressively slower through each copepodite stage. C5 had the longest duration (20.9 d; 32.8 % of total development time). Body lengths of laboratory-raised stages NI to C3 were the same as of field-collected specimens; C4 and C5 were shorter than in wild copepods, but laboratory-raised females were significantly longer than wild females. This suggests that laboratory growth conditions were probably as good as, if not better than, conditions in the field.