Thermal effects on red muscle contractile performance in deep-diving, large-bodied fishes.

Bigeye thresher sharks (Alopias superciliosus) and swordfish (Xiphias gladius) are large, pelagic fishes, which make long-duration, diurnal foraging dives from warm, surface waters (18-24 °C) to cold waters beneath the thermocline (5-10 °C). In bigeye thresher sharks, the subcutaneous position of the red, aerobic swimming muscles (RM) suggests that RM temperature mirrors ambient during dives (i.e.

Structural adaptations for ram ventilation: gill fusions in scombrids and billfishes.

For ram-gill ventilators such as tunas and mackerels (family Scombridae) and billfishes (families Istiophoridae, Xiphiidae), fusions binding the gill lamellae and filaments prevent gill deformation by a fast and continuous ventilatory stream. This study examines the gills from 28 scombrid and seven billfish species in order to determine how factors such as body size, swimming speed, and the degree of dependence upon ram ventilation influence the site of occurrence and type of fusions. In the family Scombridae there is a progressive increase in the reliance on ram ventilation that correlates with the elaboration of gill fusions.

Effects of temperature on power output and contraction kinetics in the locomotor muscle of the regionally endothermic common thresher shark (Alopias vulpinus).

The common thresher shark (Alopias vulpinus) is a pelagic species with medially positioned red aerobic swimming musculature (RM) and regional RM endothermy. This study tested whether the contractile characteristics of the RM are functionally similar along the length of the body and assessed how the contractile properties of the common thresher shark compare with those of other sharks. Contractile properties of the RM were examined at 8, 16 and 24 °C from anterior and posterior axial positions (0.

Archival tagging of subadult and adult common thresher sharks () off the coast of southern California.

The common thresher shark () is a secondary target species of the California drift gillnet fishery (CA-DGN) and supports a growing recreational fishery in California waters. This study used archival tags to examine the movement patterns and habitat preferences of common threshers of the size range captured in the CA-DGN (>120 cm fork length). Depth and temperature-logging archival tags were deployed on 57 subadult and adult common threshers in the Southern California Bight.

Function of the medial red muscle during sustained swimming in common thresher sharks: contrast and convergence with thunniform swimmers.

Through convergent evolution tunas and lamnid sharks share thunniform swimming and a medial position of the red, aerobic swimming musculature. During continuous cruise swimming these muscles move uniformly out of phase with local body curvature and the surrounding white muscle tissue. This design results in thrust production primarily from the caudal fin rather than causing whole-body undulations.