Competition and predation are both important in structuring the distribution of marine organisms; however, little is known about how competition and predation influence the distribution of elasmobranch fishes. We used data collected from shark control programs conducted between 1967 and 1980, throughout the Hawaiian island chain, to examine the distribution and dietary overlap of the 4 most abu...

in a parasitic study on five sharks (carcharhinus macloti) caught from the iranian coasts of persian gulf, two of five sharks appeared to have nematode in their intestine. using light microscopy, the nematode was identified as acanthocheilus rotundatus. a. rotundatus  is characterised by 3.3-4.5 cm in length, semithick cuticle, small lips, semicircular and tri-lobed pseudolabia (not offset from...

Shark nurseries are susceptible to environmental fluctuations in salinity because of their shallow, coastal nature; however, the physiological impacts on resident elasmobranchs are largely unknown. Gummy sharks (Mustelus antarcticus) and school sharks (Galeorhinus galeus) use the same Tasmanian estuary as a nursery ground; however, each species has distinct distribution patterns that are coinci...

To estimate tag retention time, 39 acoustic transmitters were hand-fed to bull sharks Carcharhinus leucas, lemon sharks Negaprion acutidens and tiger sharks Galeocerdo cuvier, in the Shark Reef Marine Reserve, Fiji. Minimum tag retention times ranged from less than 24 h to 34 days, and bull sharks could be tracked for a minimum mean duration of 6.8 days. Feeding acoustic transmitters wrapped in...

Kinematics and critical swimming speed (Ucrit) of juvenile scalloped hammerhead sharks Sphyrna lewini were measured in a Brett-type flume (635 l). Kinematic parameters were also measured in sharks swimming in a large pond for comparison with those of sharks swimming in the flume. Sharks in the flume exhibited a mean Ucrit of 65±11 cm s-1 (± s.d.) or 1.17±0.21 body lengths p...

Although many sharks begin their life confined in nursery habitats, it is unknown how rapidly they disperse away from their natal area once they leave the nursery. We examine this issue in immature lemon sharks (Negaprion brevirostris) from the time they leave the nursery (approximately age 3) at a subtropical island (Bimini, Bahamas), through to the onset of sexual maturity (approximately age ...

In a parasitic study on five Sharks (Carcharhinus macloti) caught from the Iranian coasts of Persian Gulf, two of five sharks appeared to have nematode in their intestine. Using light microscopy, the nematode was identified as Acanthocheilus rotundatus. A. rotundatus  is characterised by 3.3-4.5 cm in length, semithick cuticle, small lips, semicircular and tri-lobed pseudolabia (not offset from...

As apex predators, sharks play an important role shaping their respective marine communities through predation and associated risk effects. Understanding the predatory dynamics of sharks within communities is, therefore, necessary to establish effective ecologically based conservation strategies. We employed non-lethal sampling methods to investigate the feeding ecology of bull sharks (Carcharh...

Sharks are found in association with main Hawaiian Island ocean fish farms more frequently and at higher densities than is typical for coastal Hawaiian waters. Sharks attracted to fish farms could potentially threaten human water users, interact negatively with other fisheries, and seasonal migrations could be disrupted if individuals become entrained around farms throughout the year. We hypoth...