Marine Fish Larviculture in Mexico: Advances and Challenges in Nutrition and Feeding

Resumen

In Mexico, several marine fish species are subject of study as potential candidates for commercial aquaculture. The
controlled production of high quality larvae is essential for completion of the culture cycle in these fish. Therefore,
current efforts are aimed to develop efficient larviculture techniques. To date, successful larval production has been
achieved for spotted sand bass (Paralabrax maculatofasciatus), totoaba (Totoaba macdonaldi), bullseye puffer
(Sphoeroides annulatus), California flounder (Paralichthys californicus), red drum (Sciaenops ocellatus), white sea
bass (Atractoscion nobilis) and red snapper (Lutjanus campechanus). In other fish species some advances in larval
rearing have been reported: Pacific red snapper (L. peru) and spotted rose snapper (L. guttatus). However, high
mortalities are still an obstacle for a successful larviculture in a large number of species, as in the case of common
snook (Centropomus undecimalis), yellow snapper (L. argentiventris), leopard grouper (Mycteroperca rosacea),
pompano (Trachinotus spp.) and hogfish (Lachnolaimus maximus). Because growth and survival in marine fish
larvae are mainly influenced by nutritional aspects, the information on nutritional requirements of fish larvae and
nutritional quality of live food and formulated microdiets food is essential for the establishment of adequate
larviculture techniques. Feeding protocols, digestive capacity of the larvae and the importance of nutritional quality
in live food and microdiets are reviewed for their application in the larviculture of difficult-to-rear species. Feeding
protocols with the use of microalgae, rotifers and Artemia nauplii are currently used for most species. At first
feeding, adequate live food density and particle size are essential for fish larvae. The use of small strain rotifers and
copepods has allowed improvements in fish survival during this critical stage. Once successful first feeding is
achieved, significant higher fish growth and survival have been obtained with the use of live food enriched with
essential fatty acids (i.e. HUFA) when compared to non-enriched rotifers or Artemia. Application of specific
methods for production and storage of live food, such as Artemia cysts decapsulation and live Artemia cold-storage
have improved experimental hatchery outputs. As for weaning microdiets, several formulated microdiets have been
prepared using various manufacturing techniques (i.e. microbound and microencapsulation) and have been tested
with good results in some species. However, the lower ingestion rate of microdiets compared to live food is a major
problem to be tackled. The use of highly digestible protein sources, intact or predigested, has improved microdiet
assimilation.