The study of the early life phases of marine fish allows us to know the morphological changes that occur throughout development and make it possible to improve biotechnologies for culturing species of interest. The barred sand bass Paralabrax nebulifer is the most important small-scale commercial fishery along the Pacific coast of Baja California, Mexico making is a considerable species with aquacultural potential. The aim of this work is to contribute to the recognition of main morphological changes during larval development until transformation to juvenile of barred sand bass, through the description of morphometry, meristic, pigmentation and squamation patterns.
During culture, the larvae were fed for 32 days on three diets (rotifers, Artemia nauplii, and microdiets). For the morphometric description, the phases of ontogenetic development were divided into apterolarval phase, pterolarval phase and juvenile, based on the criteria of saltatory ontogeny. The conventional measurements were taken from 219 specimens, corresponding to 112 apterolarval phase, 88 pterolarval phase, and 19 juveniles. To detect allometric growth, the morphometric relationships of each developmental phase were used by the growth coefficient. A series of developments was revealed for the study of meristics. The meristic, pigmentation and squamation patterns were outlined. As for results, the following developmental phases were observed: apterolarval phase, from 1.82-3.79 mm notochordal length (NL) (3-19 days post hatching [DPH]); pterolarval phase (10-25 DPH), with the presence of fin primordia from 3.80-8.05 mm NL; juveniles (23-30 DPH), with full finray complement from 8.06-11.27 mm standard length (SL). The growth of the body parts analyzed throughout the development of the apterolarval phase to the juvenile, behaved with positive or negative allometry, except in the case of the depth of the body, since isometry is present in the apterolarva phase. In the meristic study, it was observed that from the pterolarval phase, the presence of the fin elements were detected starting at 5.05 mm NL, along with the anal fin spine and the vertebral centers; later the rest of the fins were completed, until completing the count in 8.06 mm SL in the juvenile. In addition, the pigmentation and squamation patterns are described until transformation to juvenile. Finally, a feeding schedule from larval development to juvenile of barred sand bass based on their morphological changes is proposed (figure 1).