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Muscular system in the pacific bluefin tuna Thunnus orientalis (Teleostei: Scombridae)
Author(s) -
Nakae Masanori,
Sasaki Kunio,
Shinohara Gento,
Okada Tokihiko,
Matsuura Keiichi
Publication year - 2014
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.20210
Subject(s) - thunnus , biology , tuna , scombridae , anatomy , teleostei , fish fin , myology , context (archaeology) , adductor muscles , dorsal fin , dorsum , fishery , fish <actinopterygii> , paleontology
The muscular system in the Pacific bluefin tuna Thunnus orientalis is studied in detail. For the first time, a complete description of the muscular anatomy of a thunnid is provided here. Eighty‐two elements including subdivisions of components of the muscular system are identified. This is less than found in a basal perciform and two other investigated scombrid species, owing mainly to the absence or fusion of pectoral, pelvic and caudal fin muscles. The absence of elements of the basal perciform pattern was most prominent in the caudal fin, which includes only the flexor dorsalis, flexor ventralis, hypochordal longitudinalis, and interradialis. In the caudal fin, the medial fan‐shaped ray was identified as the first dorsal ray, judging from myological and neuroanatomical characters. The highly developed gill filament muscles in Thunnus orientalis and sheet‐like rectus communis control gill ventilation. Long body muscle tendons reduce the metabolic energy needed during rapid and continuous swimming. These characters are interpreted as adaptations in the context of the oceanic life style of the species. J. Morphol. 275:217–229, 2014. © 2013 Wiley Periodicals, Inc.