Abstract

COMABELLA, Yamilé et al. Allometric growth in cuban gar (Atractosteus tristoechus) larvae. Universidad y ciencia [online]. 2013, vol.29, n.3, pp.301-315. ISSN 0186-2979.

The allometric growth of Cuban gar (Atractosteus tristoechus) was evaluated in larvae reared at a constant temperature (28 ±1 °C), from hatching to 18 days after hatching (DAH). Of the 17 morphometric characters recorded, only six showed isometric growth describing a continuous and gradual change in a very few body characters. From hatching to 14 DAH, the growth in weight presented a slight negative allometry (b = 0.91), but later the growth coefficient increased (b = 2.09) in the exotrophic phase indicating a complete and efficient exogenous feeding thanks to the precocious development of the digestive system. The increase in the length of the head and snout was positively allometric, but their heights and widths were negatively allometric indicating an elongation of the cephalic region that guarantees an efficient food capture. The pectoral and pelvic fins increased in length with a positive allometric growth and biphasic patterns (b = 1.26; b = 2.69, respectively), both with the same inflexion point (8 DAH). The allometries obtained with respect to the head, trunk and tail growth showed a discontinuity and abrupt changes in many of the body sizes and proportions that occur mainly from age 4 (18.6 mm TL) to 8 (23.7 mm TL) DAH. This reflects the priorities of a developing organism, when important organs must first be developed to allow feeding and guarantee a better survival of the juveniles.

Keywords : Fish larvae; allometry; development; growth.

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