Osteological development of
the vertebral column and of the fins in Diplodus sargus
(Teleostei: Perciformes: Sparidae)
G. Koumoundouros, D.G. Sfakianakis, E. Maingot, P. Divanach,
M. Kentouri-2001
Marine Biology, 139(5): 817-830
Abstract:
The osteological development of vertebral column and
fins in white sea bream, Diplodus sargus (Linnaeus, 1758) was
studied. Vertebral ontogeny started at 5.7 mm total length (TL,
post-fixation), with the formation of the first cartilaginous neural and
haemal arches, and was completed by the full attainment of dorsal ribs (20.8 mm
TL). The formation of vertebral centra occurred between 7.3 and 9.4 mm
TL, but was fully completed only after the development of post- and
pre-zygapophyses (26.0 mm TL). Pectoral supports were the first fin
elements that started to develop (3.8 mm TL), followed by those of the
caudal fin (5.2 mm TL), dorsal and anal fins (6.7 mm TL), and then
by those of the pelvic fin (9.5 mm TL). The caudal fin of D. sargus
was the first to develop fin rays and attain the full count of lepidotrichia
(5.6-7.8 mm TL), but the last to attain the full count of
dermatotrichia (7.9-16.0 mm TL). The next fins starting to present rays
were the pectoral (6.5 mm TL) and the dorsal and anal fins (7.5 mm
TL), while the pelvic fins were the last (11.5 mm TL). Following the
caudal lepidotrichia (7.8 mm TL), the anal (10.5 mm TL), dorsal
(12.0 mm TL), pectoral (11.4 mm TL) and pelvic fins (12.5 mm
TL) were the next with fully completed ray counts. Finally, fin meristics
were fully developed with the caudal dermatotrichia. The results are
discussed in comparison with the fin and vertebral ontogeny of other
teleosts.