Characterisation of the swimming muscles of two Subantarctic notothenoids

• Published in: Scientia Marina
• Main Authors: Daniel Alfredo Fernández, Jorge Calvo, Ian Alistair Johnston
• Format: Article in Journal/Newspaper
• Language: English
• Published: Consejo Superior de Investigaciones Científicas 1999
• Subjects: subantarctic notothenioids; muscle histochemistry; swimming muscles; myosin atpase; Aquaculture. Fisheries. Angling; SH1-691; Antarctic; Antarc*
• Online Access: https://doi.org/10.3989/scimar.1999.63s1477; https://doaj.org/article/d6474cd2825c45b0a52a7be17904af27

The histochemical characteristics and distribution of muscle fibre types have been investigated in the swimming muscles of the róbalo, Eleginops maclovinus and the lorcho, Patagonotothen tessellata, Subantarctic notothenioids that inhabit the Beagle Channel. The fibre types were differentiated on the basis of glycogen and lipid contents and succinate dehydrogenase and myofibrillar ATPase (mATPase) activities. White, red, intermediate and tonic fibres were present in the axial muscle of both species. The same fibre types were identified in the pectoral fin adductor muscles, although the intermediate type was absent. The mATPase technique performed at room temperature (21ºC) allowed a good differentiation of fibre types, overcoming the problems found by previous researchers when applying this technique to Antarctic notothenioids. Four different zones (peripheral, mosaic, main and adjacent to the bone) were found in the adductor profundis muscle. The proportion of the zones varied along the length of the adductor muscle. For both species, the percentage of red fibres found in the axial muscles was less than 5%, indicating that sustained swimming ability is not dependent on these muscles. The pectoral muscle mass/carcase mass ratio was significantly greater in E. maclovinus than in P. tessellata, reflecting a greater capacity for sustained swimming using pectoral fins.