Morphoecology in larval
fin-fish: a new candidate species for aquaculture, Diplodus puntazzo
(Sparidae)
C. Boglione, M. Giganti, C. Selmo, S. Cataudella-2003
Aquaculture
International, 11
(1-2): 17-41
Abstract:
This study was aimed to acquire information on
trophic behavior of Diplodus puntazzo larvae and juveniles, by
studing the ontogenetic sensory development, except vision. D. puntazzo
specimens were observed using a scanning electron (n = 67) and a
light microscope (n = 7). The results concerned four ontogenetical
stages of sharpsnout seabream: larval, post-larval, transitional, and
juvenile stages. The yolk-sac larval stage was not detected as the smallest
larvae at our disposal (3.1 mm TL; 2nd day from hatching) showed no external
appearance of the yolk. During the larval stage (3.1–4.7
mm TL), sharpsnout seabream is equipped with free neuromasts and olfactory
ciliated receptor cells. In the post-larval stage (5–28.6
mm TL), mechano- and chemo-reception is implemented: the inner and outer
taste buds differentiation, the nasal formation, the lateral line system
canalization occur. The precocious differentiation of chemo-receptors makes
post-larvae particularly sensitive to the organoleptic properties of
administered preys. D. puntazzo, at the end of this phase, could be
considered a juvenile (complete squamation is acquired), except for the
mouth and pharyngeal teeth. During the subsequent phase (`transitional'), in
fact, eight chisel-type and two lateral series of molar-like teeth
progressively substituted the conical ones on each jaw, and three different
types of teeth on the upper and lower pharynx differentiated. So, the
juvenile phase is reached in individuals longer than 58 mm TL.
(Laboratory of
Experimental Ecology and Aquaculture, Biology Dept., University of Rome `Tor
Vergata', Italy, e-mail: boglione@uniroma2.it)