Vol. 40 No. 4, 2001
Early Osteological Development of the Yellow Tail Seriola dumerili (Pisces: Carangidae)
Chen-Hsiang Liu
Department of Fishery Information, Fisheries Research Institute, Council of Agriculture, Keelung, Taiwan 20220
Chen-Hsiang Liu (2001) The osteological development of Seriola dumerili
was studied in a series of 15 cleared-and-stained specimens (6.6-32
mm). The dorsal spine began to ossify by 12.7 mm, and its soft
rays by 27.2 mm, and all elements (VII-I, 32) were completed by 23.5
mm. Ossification of dorsal pterygiophores occurred initially by 15.9
mm. Anal fin ray formation (II-I, 20) was completed by 12.7 mm,
and soft rays began to ossify at 24.5 mm. Ossification of the anal
pterygiophores occurred initially by 15.9 mm. The cartilaginous caudal
complex appeared by 6.6 mm NL, and its ossification was completed by
27.2 mm. The fusing of the 1st and 2nd, and the 3rd and 4th hypurals
occurred by 8.1 mm. The pectoral girdle contained 5 dermal bones which
ossified by 6.6 mm NL, and 3 cartilage replacement bones which ossified
by 27.2 mm. The hyoid arch contained 2 dermal bones, six cartilage
replacement bones, and 7 branchiostegals (dermal bone) which began to
ossify by 15.9 mm. Ossification of the neural and haemal spines was
completed by 23.5 mm. Notochord flexion occurred and formed an
individual centrum by 6.6 mm NL, and all 24 centra had completely
ossified by 12.7 mm. It was previously believed that the hypural
complex fusing at a small size at 16.8 mm was an advanced condition.
There were 2 plesiomorphic characters, i.e., three predorsals of the
back and 3 epurals of the caudal complex, found in S. dumerili.
In addition, there were also 2 apomorphic characters, i.e., a stay on
the proximal radial and a double fin-ray on the last distal radial of
the 2nd dorsal and anal fins, found in S. dumerili.
Key words: Osteological development, Seriola dumerili, Dermal bone.
*Correspondence: Tel: 886-2-24622101. Fax: 886-2-24629388.

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