title: The post-larval development of lateral musculature in gilthead sea bream Sparus aurata (L.) and sea bass Dicentrarchus labrax (L.).
abstract: Fibre-type differentiation of lateral musculature has been studied in gilthead sea bream Sparus aurata (L.) and sea bass Dicentrarchus labrax (L.) during post-larval development using ultrastructural, histochemical and morphometric techniques. The study showed three muscle layers: red, intermediate (or pink) and white. Initially, most of the red muscle showed low myosin ATPase (m-ATPase) activity fibres, whereas near the transverse septum some small high m-ATPase activity fibres appeared and later acquired a rosette aspect. Afterwards, during adult growth the red muscle showed a histochemical mosaic appearance. The pink muscle in sea bass was observed at the beginning of juvenile development by the oxidative technique (NADH-RT reaction) whereas in gilthead sea bream it was also observed at the end of larval development. The pink layer consists of high m-ATPase activity fibres. However, along the muscle development other low and moderate m-ATPase activity fibres were observed close to the red and white muscles, respectively. The white muscle of juvenile fish showed a histochemical mosaic appearance near the pink muscle. In adult specimens the mosaic white muscle spread out occupying the whole of the myotome. Morphometric analysis shows a significant increase in mean fibre diameter during post-larval development, as shown by the Student's t-test (hypertrophic growth). Skewness and kurtosis values of fibre diameters point to the generation of a new fibres from the myosatellite cells (hyperplastic growth).
authors.affiliation: Departamento de Anatomía y Embriología, Facultad de Veterinaria, Universidad de Murcia, España.
authors.forename: G
authors.initials: G
authors.lastname: Ramírez-Zarzosa
authors.forename: F
authors.initials: F
authors.lastname: Gil
authors.forename: J M
authors.initials: JM
authors.lastname: Vázquez
authors.forename: A
authors.initials: A
authors.lastname: Arencibia
authors.forename: R
authors.initials: R
authors.lastname: Latorre
authors.forename: O
authors.initials: O
authors.lastname: López-Albors
authors.forename: A
authors.initials: A
authors.lastname: Ortega
authors.forename: F
authors.initials: F
authors.lastname: Moreno
mesh_terms: D000818:Animals; D001492:Bass / Q000254:growth & development*; D007814:Larva; D024510:Muscle Development; D018482:Muscle, Skeletal / Q000166:cytology / Q000254:growth & development* / Q000648:ultrastructure; D009218:Myosins / Q000032:analysis; D010473:Perciformes / Q000254:growth & development*
chemical_list: D009218:Myosins