Effects of cold storage and salinity on Acartia sinjiensis (Copepoda: Calanoida) egg hatching

Abstract

We determined the combined effects of salinity (10, 15, 20, 25, 27, 30 and 33 psu) and cold storage (4 ± 1°C) for 5, 14, 90 and 180 days for extending the lifespan of subitaneous eggs of the calanoid copepod Acartia sinjiensis. The hatching success rate of the eggs decreased with an increase in the cold storage period. The average proportion of viable A. sinjiensis eggs after 90 days was >40% except at a salinity of 10 psu. Eggs hatched at different times depending on storage and salinity. Specifically, >55% of the eggs stored for 14 days under the salinities of 25 and 30 psu and >45% of those stored for 90 days with salinities of 30 and 33 psu hatched. However, some eggs stored for 180 days hatched which only occurred at salinity 30 psu. These results can help optimize cold storage conditions to improve the viability of stored copepod eggs.

Embryo Development and Effects of Temperature, Salinity, and Light Intensity on Egg Hatching of Calanoid Copepod Bestiolina amoyensis (Calanoida: Paracalanidae)

“…Calanoid copepods are generally well adapted to seasonal fluctuations in temperature and salinity under natural conditions (Miller & Marcus, 1994;Engel & Hirche, 2004;Marcus, 2005). Examples are Eurytemora affinis (Roddie et al, 1984;Nagaraj, 1992;Devreker et al, 2009;Souissi et al, 2016;Karlsson et al, 2018) and a number of Acartia congeners (Gaudy et al, 2000;Castro-Longoria, 2003;Chinnery & Williams, 2004;Milione & Zeng, 2008;Choi et al, 2021;Choi et al, 2022); these estuarine and coastal calanoid copepods are more widely adapted to temperature and salinity than pelagic species, which makes them more suitable for culture as live feed. For most of Paracalanidae species, information about reproduction is still very limited, and the functional response of reproductive success (i.e., egg production and hatching) to salinity and/or temperature only have been studied in a handful species, such as Paracalanus parvus (Jang et al, 2013).…”