Development, body length, and feeding of Tigriopus californicus (Copepoda, Harpacticoida) in laboratory and field populations

Development of the harpacticoid copepod Tigriopus californicus was observed under temperature and salinity regimes representative of seasonal conditions in the splashpools of Barkley Sound, Canada. Cultures were maintained in natural sea water representing either summer (18-20 degrees C; 30-32 parts per thousand salinity) or winter (10-15 degrees C; 20-25 parts per thousand salinity) conditions and compared to concurrent samples from field populations. Development of nauplii (stages N-I through N-VI) occurred in 10 days under ''summer'' conditions and 12 days under ''winter'' conditions; copepodite development (stages C-I through C-VI) was similarly delayed from 11 to 18 days at the lower temperature/salinity. Total generation time (egg to adult) was 21 days for the higher temperature/salinity values, and 30 days at the lower values, although no net difference in body length was observed. Clutch size was 17 +/- 4.2 eggs (mean +/- S.E.) at 10-15 degrees C and 15.3 +/- 8.1 eggs at 18-20 degrees C for gravid females in culture; field specimens had a mean clutch size of 17.9 +/- 2.5 eggs at 10-15 degrees C, increasing to 27 +/- 4.2 eggs . clutch(-1) during the summer months (July and August), and possibly indicative of the quality and supply of food available in situ. Non-viable progeny accounted for 10 +/- 8.1% and 10.8 +/- 7.8% of all eggs under ''summer'' and ''winter'' conditions, respectively. A synthesis of these results with several studies using T. californicus and its congeners in evaluations of feeding, fecundity, organism development, and toxicity studies is also provided.