EXPANDING PRODUCTION OF COMMON SNOOK THROUGH IMPROVEMENTS IN LARVAL REARING PROTOCOLS

Common snook (Centropomus undecimalis) are a very popular and important sportfish in the coastal waters of the Atlantic ocean.  Population declines in Florida, Texas, Mexico and Brazil have generated interest in developing reliable aquaculture techniques to produce snook for stock enhancement and commercial production.  For more than 10 years, our efforts at Mote Marine Laboratory (Mote) have focused on captive spawning technology and developing larval rearing protocols in experimental recirculating aquaculture systems.  Results from this research developed successful year-round captive spawning of common snook and the production of large volumes of high quality eggs. These eggs have been used to refine larval rearing protocols to meet the environmental and nutritional requirements of common snook.  

Current research is focused on scaling up production using successful larval rearing protocols developed in research trials at Mote and in collaboration with other scientists working on common snook and other Centropomids.  Early protocols developed at Mote had yielded ≤1% survival from egg to first grading (32 ± 3DPH).  The work was conducted in our recirculating larval production systems, consisting of three 3300-L tanks, solids filtration, moving bed bioreactor, protein skimmer, UV sterilizer, LED lighting, and thermal control through a heat-exchange system.  Each larval tank has a removable upwelling egg hatcher and live food delivery system.   In these trials, we standardized key culture variables, identified in earlier experimental trials.  These variables included temperature, salinity, lighting (duration, intensity, spectrum), tank volume, flow rates, shading, probiotic usage, stocking density, live food protocols (enrichments and regime), and weaning strategies.  Though further work is needed, we have already observed a substantial increase in larval survival from egg to first grading (approximately 30 days-post-hatch).  Snook larval survival was as high as 4.2% at first grading, which is 4 times greater than past production-scale trials completed at Mote.