Osteological development of the vertebral column and of the caudal complex in Dentex dentex

Osteological development of the vertebral column and caudal complex in common dentex was described under extensive larval rearing conditions. Generally, the cartilaginous bones developed prior to the membranous bents. The development of the axial skeleton began with the formation of the hypural 1, the neural arches 2 and 3, as well as the haemal arches 1-8 at 4.8, 4.9 and 5.0 mm total length (L-T, measured in vivo), respectively. By 7.5 mm L-T, all the cartilaginous elements were formed, except for the ventral ribs, which formed between the range of 84-180 mm L-T. The caudal lepidotrichia were the first membranous bones to appear (5.3 mm L-T) and attain their full meristic count (7.4 mm L-T), followed by the vertebral centra, which formed between 6.6 and 9.7 mm L-T. By 25.0 mm L-T, all the elements were fully ossified except for the ventral ribs. The developmental direction and order of all the elements were studied with respect to their formation and ossification. The results were discussed in the contexts of ichthyoplankton, ecology and aquaculture. Compared with other Sparidae species, common dentex followed a pattern of relatively rapid rate of osteological development. (C) 1999 The Fisheries Society of the British Isles.