SPAWNING BEHAVIOR IN THE LABRID, HALICHOERES-BIVITTATUS, ON ARTIFICIAL AND NATURAL SUBSTRATES IN ONSLOW BAY, NORTH-CAROLINA, WITH NOTES ON EARLY-LIFE HISTORY

We documented reproductive activity in Halichoeres bivittatus close to the northernmost range of its distribution in the western Atlantic. O bservations were made by means of Scuba at a mean depth of 15 m on a r eef system consisting of a 10-train car artificial reef and adjacent l imestone substrate. The train cars were deployed in 1986 on substrate ranging from limestone colonized by macroalgae to a thin layer of sand over hard substrate. Spawning behavior consisted of the formation of temporary territories defended by terminal phase males. Peak reproduct ive activity occurred at midday during the months of May and June at t emperatures of 21.5-24.5 degrees C. Pair spawning between an initial p hase female and a terminal phase male was observed on artificial and n atural reef substrata, but interference spawning by small initial phas e individuals was observed only on the natural substrate. This differe nce in reproductive strategy may be due to the ability of small initia l phase males to interfere with pair spawnings only on substrates lack ing much vertical relief(<0.5 m) and providing macroalgal cover. Ferti lized eggs were obtained by artificial fertilization in the laboratory . Eggs and larvae were reared in tanks and development up to 5 days af ter fertilization is briefly described.