Larval morphology and development of Neocalanus tonsus, Calanoides macrocarinatus, and Calanus australis (Copepoda: Calanoida) in the laboratory

Neocalanus tonsus, C. macrocarinatus, and C. australis, three calanids which potentially occur together in New Zealand waters, were raised from eggs and their developmental stages described. All naupliar stages apparently have identical setation. Naupliar stages I—III are very similar. Neocalanus tonsus can be easily identified from naupliar stage IV onwards, whereas C. macrocarinatus and C. australis can be identified with certainty only in the copepodite stages, because their nauplii overlap in size and body proportions. Development at 15 °C from egg to copepodite V took 24 days for N. tonsus, 20.2 days for C. macrocarinatus, and 23.8 days for C. australis. Neocalanus tonsus is the smallest species during early developmental stages but by copepodite III stage is larger than the other two species.