Calanoid copepod resting eggs can be surface-disinfected

Abstract

Resting eggs of the two calanoid copepods, Eurytemora affinis and Acartia clausi, were exposed to the surface disinfectants Buffodine TM, FAM-30 TM and glutardialdehyde. Eggs were placed individually in wells of multiwell dishes and checked for hatching success and nauplii survival at Day 5 after hatching. To verify sterilization, eggs were incubated individually with two different media for six weeks, allowing bacterial growth to occur. Buffodine had no significant effect on hatching rate and survival, but indications of non-complete disinfection were found. FAM-30 seemed to be harmless to Acartia eggs, but caused very low hatching percentages of Eurytemora eggs and nearly instaneous mortality of the hatched nauplii. Glutardialdehyde treatment of Acartia eggs had no significant effect on hatching rate, but all nauplii died shortly after hatching. This disinfectant had no significant effect on hatching of Eurytemora eggs compared with the control group, although a small negative tendency in hatching rate and survival could be detected. FAM-30 and glutardialdehyde were most successful in obtaining surface-sterile eggs. This study shows that resting eggs collected from sediments can survive disinfection, making them attractive as sterile inoculum for live feed cultures in aquaculture.