Static-renewal culture of Acartia tonsa (Copepoda: Calanoida) for ecotoxicological testing

Abstract

The calanoid copepod Acartia tonsa has been recommended for standard toxicity tests due to its wide distribution, short life cycle and high reproductive potential. However, relatively high requirements of suitable animals (from 270 to 360 adults) need the development of cost-effective culture systems. In this study we evaluate the efficiency of a static-renewal culture for the calanoid copepod A. tonsa. Density-dependent survival, development and reproduction responses were assessed across three different stocking densities including: 500, 1000 and 2000 individuals l −1. This culture system was developed in order to satisfy the needs for ecotoxicological testing, and thus it differs from large culture programs aimed to fulfil food requirements for fish larval aquaculture. Results showed that culture density had significant effects on copepod development and egg production but not on survival or egg viability. At the highest culture density tested, copepod development was delayed and egg production was low compared to lower culture densities. Relatively low reproduction rates at high stocking densities denoted suboptimal resource availability in terms of quantity and quality of food. Nevertheless, the proposed starting culture system of 1000 individuals l −1 ensured enough animals to carry out single-species toxicity tests and yielded enough eggs to ensure periodical restocking of new cultures