Early growth of some marine harpacticoid species in laboratory condition

Abstract

This study was conducted to compare the growth of three harpacticoid species which are Schizopera knabeni, Paradactylopodia oculata, and Robertsonia knoxi cultured in laboratory condition and also to observe their generation time and morphology changes (nauplii, copepodite, and adult). These harpacticoid copepods were obtained from seagrass patch at Merchang estuaries and cultured under laboratory controlled with temperature ranging between 24-27 °c and salinity around 16-26 ppt for 40 days. Copepods cultures were fed with 0.1 ml of baker's yeast (0.02 g/ L) daily. For population growth, P. oculata showed the highest population growth and the growth was more stable, while, S. knabeni showed the lowest population growth. The duration in their morphology changes was different for each species where S. knabeni showed the shorter generation time of life cycle that was 7 - 14 days than R. knoxi and P. oculata. The generation time for morphology changes of R. knoxi was between 9 - 19 days. Meanwhile, generation time of P. oculata was longer compared to two other species that was 14 - 21 days. Thus, high population growths of harpacticoid species are not strongly depending on the generation time of their life cycle.