Osteological development in the Chinese perch, Siniperca chuatsi (perciformes: Sinipercinae)

Abstract

Herein, the osteological development of the neurocranium, suspensorium, upper and lower jaws, opercular apparatus, hyoid arch, branchial arches, vertebral column, paired and unpaired fins and their supports in the Chinese perch (Siniperca chuatsi) are described from newly hatched larvae to 33.86 mm standard length (SL) post-flexion larvae. Newly hatched larvae had few osteological elements. Some cranial elements were formed in 4.8 mm notochord length (NL) larvae, including the trabecula cartilage and cartilaginous ethmoid plate. Most osteological elements of the upper and lower jaws, suspensorium and pectoral supports developed in 4.8 mm NL or smaller samples, followed by the opercular, hyoid arch, branchial arch (5.2 mm NL), vertebral column elements and caudal supports (6.4 mm NL) and finally by most of the cranial elements and pelvic supports (9.5 mm NL). Notochord flexion started in 9.5 mm NL larvae. The upper and lower jaws, opercular and pectoral supports were completely ossified first. Siniperca chuatsi larvae possessed a large mouth and sharp teeth, vomer teeth, palatine teeth, and pharyngeal teeth. Active feeding behavior was attributed to the early ossification of the feeding apparatus and the majority of teeth. Ossification of the centrum proceeded in a posterior direction. The preural centrum's ossification occurred after that of the urostyle. Parhypural, hypural 1 and hypural 2 fused temporarily at 9.5 mm NL and then became separated at 26.90 mm SL. The details of the osteological development of S. chuatsi in the early stage will increase our comprehension of functional trends and environmental preferences during different developmental stages, and provide important data related to a high growth rate and survival rate of S. chuatsi in the artificial propagation.