Research Product

Topsmelt, Atherinops affinis, were spawned repeatedly in the laboratory during May-July, 1989. A periodic "temperature spike" from the holding temperature of approximately 18°C, up to approximately 20.5°C, introduced at 7 to 9 day intervals, resulted in maximum production of viable embryos on the fourth morning after the spike. Examination of embryonic stages and comparison to known developmental rates for A. affinis embryos revealed that spawning was generally nocturnal, occurring between 1900 and 0500 hrs. Survival of embryonic and larval A. affinis cultured at 21 + or - 1°C and 20 + or - 2 o/oo salinity was excellent (>80%). A larval growth curve was developed for the first 24 days post-hatch.