We evaluated the survival and growth of 3-d post-hatch Siamese fighting fish, Betta splendens larvae, raised during 15 d in salt-free or salt-added freshwater (5 ppt using common table salt) and fed with a sequence of traditional live diets (Chlorella sp., rotifers, and Artemia) or with one formulated diet complemented with a single or daily additions of Chlorella. The highest survival were those of natural-fed larvae, at 5 and 0 ppt (100 and 96.67 ± 5.77%), and there were no significant differences in final length and weight, although these were more variable in the case of the larvae maintained at 5 ppt. The use of table salt had a negative effect on the trophonts of the external parasitic dinoflagellate Piscinoodinium sp., which colonized the body surface of the larvae raised at 0 ppt and were absent on those kept at 5 ppt.

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Abstract.-The effects of different water temperatures (22, 25, 28 and 31ºC) and salinities between 0 and 60 psu (with intervals of 5 psu) on egg incubation of the bullseye puffer (Sphoeroides annulatus) were evaluated in this study. The embryos could not develop at 22ºC and the highest hatching rate for normal larvae was observed at 28ºC. At 0, 50, 55 and 60 psu larvae were unable to develop. Highest hatching rates were obtained at 25, 30 and 35 psu. It was concluded that water temperature and salinity affects the incubation period, embryo development stage and larval survival of the bullseye puffer.

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Abstract.-The spotted rose snapper (Lutjanus guttatus) is one of the most commercially important fish species inMéxico. As it is considered a suitable candidate for culture, then it is necessary to identify its nutritional requirements in order to succeed. The aim of this study was to evaluate the effects of different protein and lipid levels on growth and survival of juvenile spotted rose snappers. Nine semi-purified diets were formulated with three protein levels (40, 45 and 50%) and three lipid levels (9, 12 and 15%). Hatchery-produced juvenile spotted rose snappers (2.2 ± 0.1 g) were used throughout the eight-week feeding experiment. Body weight, specific growth rate, condition factor, feed consumption, feed conversion rate, and survival were determined in each treatment at the end of the experiment. The highest weight gained and better feed conversion ratio were obtained in fish fed diets with 45 and 50% protein and their three lipids levels. Survival, feed consumption and condition factor were not affected by the treatments. These results indicate that juvenile spotted rose snappers require a minimum of 45% protein and 9% lipid for maximum growth and survival.