Optimization of Culture Conditions for rearing of Barnacle Nauplii Amphibalanus amphitrite

Abstract

Amphibalanus amphitrite is a ship-fouling species encountered in many water bodies of world. Inspite of its fouling characteristic, these organisms are used in laboratory for many studies like toxic test of chemicals, heavy metals and for antifouling research. Larval culture conditions for barnacle has to be optimized.  The effects of temperature, photoperiod, diet and salinity on the growth and survival of A. amphitrite larvae was studied.  Effect of temperature played a role on development time and survival of the nauplii. At 24˚C the time utilized for the larvae to reach the cyprid stage was longer when compared with that of 28˚C, and above 28°C there was an increase in mortality over 90%.Mid‐range temperatures (25 – 28˚C) increased total survival (20–35%). Diatom diets of Thalasiosirra subtilis, Endomoneis paludosa and green algae Isochrysis galbana did not have significant effect on specific growth rate, but  the proportion of high‐quality healthy cyprids was greatly higher with mixed diet. The development time taken for the larvae to reach the cyprid stage differs depending upon the availability of light (2500 lux). Photoperiod did not play a role on the survival, but specific growth rate was higher at 24:0 and 16:8 L:D. The release and survival of the nauplius depends upon the ranges of salinity (25 and 30 psu).  The survival and growth were got using rearing temperatures of 25 – 27°C, daily feeding with T. subtilis, E. paludosa, I.galbana and a photoperiod of 24:0 L:D along with salinity of 30 psu.