An Intensive, Large-Scale Batch Culture System to Produce the Calanoid Copepod, \u3ci\u3eAcartia tonsa\u3c/i\u3e

A major obstacle to the development of hatchery production for juveniles of many marine species is the difficulty in successfully feeding early larvae. Copepods contribute to the natural diet of most marine fish larvae and feature characteristics ideal for early larval feeds including small size and suitable nutrient content. However, the use of copepods as larval feeds is limited by the inability to consistently produce them in sufficient quantities to support large-scale fish culture. Here, an innovative design for an intensive, indoor batch culture system to produce the calanoid copepod Acartia tonsa (Dana 1849), a prime candidate for use as a live food item, is described. The system features integrated grow-out and egg-production units that can be operated sequentially by 2.5 full-time employees to produce a predictable daily output of nauplii for use as live feed. The system output was on average 22 million eggs d−1 (21,955,420 ± 8,709,668) with an average hatch rate of 49% (49.1 ± 14.8) over three seasons

Development of a Methodology for Intensive Larviculture of Atlantic Croakers

The Atlantic Croaker Micropogonias undulatus (Sciaenidae) is a candidate species for marine baitfish aquaculture in the southeastern United States because of its high value and common use as live bait by recreational fishers. However, an efficient larviculture procedure has not been reported to date; development of such a procedure was the impetus for this study. Embryos were obtained from captive broodstock that were induced to spawn volitionally by using a single injection of a luteinizing hormone releasing hormone agonist. Larvae were cultured at low density (initial density = 6.4 larvae/L) via intensive culture methods, including the use of recirculating filtration systems and of rotifers, brine shrimp Artemia spp., and micropellets as larval foods. The trial was performed in six 1,100-L tanks at a salinity of 14-29, with average rearing temperatures of 23.6 degrees C and 24.6 degrees C. At the completion of the study (39 d posthatch), mean SLs were 24.7mm (SE = 0.738) for larvae cultured at 24.6 degrees C and 23.0mm (SE = 0.624) for larvae cultured at 23.6 degrees C. Mean survival at 39 d posthatch was 25.9% and did not differ significantly between temperature groups. This work demonstrated a successful methodology for intensive larviculture of Atlantic Croakers and can serve as a platform for the experimentation that will be necessary to develop economically viable procedures for intensive production of this species. Received May 10, 2013; accepted August 24, 201