A more medial and anterior position of the red aerobic myotomal muscle (RM) and the presence of a vascular counter-current heat exchange system provide the functional elements that facilitate regional RM endothermy in tunas, lamnid sharks and the common thresher shark (Alopias vulpinus). The convergent RM morphology among all species capable of RM endothermy suggests that RM position is a stron...

Current debates about the efficacy of no-take marine reserves (MR) in protecting large pelagic fish such as tuna and sharks have usually not considered the evolutionary dimension of this issue, which emerges because the propensity to swim away from a given place, like any other biological trait, will probably vary in a heritable fashion among individuals. Here, based on spatially explicit simul...

Morphology typically enhances the fidelity of sensory systems. Sharks, skates, and rays have a well-developed electrosense that presents strikingly unique morphologies. Here, we model the dynamics of the peripheral electrosensory system of the skate, a dorsally flattened batoid, moving near an electric dipole source (e.g., a prey organism). We compute the coincident electric signals that develo...

Breaststroke, butterfly, front crawl and back crawl: many of us learnt these swimming styles as kids while splashing around in our local pool. These strokes all involve the swimmer lying on their back or front, much like the way most fish swim. Of course, some people prefer to swim tilted to one side rather than face down even though the side-stroke evokes images of elderly swimmers in bathing ...

AUTONOMOUS TRACKING AND FOLLOWING OF SHARKS WITH AN AUTONOMOUS UNDERWATER VEHICLE

The Saint Peter and Saint Paul Archipelago in the central tropical Atlantic, is an important ground of whale sharks that are commonly sighted throughout the year close to the fishing boats in the adjacencies of the islands. In sightings reported between February 2000 and November 2005, the lengths of the individuals ranged between 1.8 to 14.0 m. The causes of these concentrations in the archipe...

Genomic expansions via regional gene duplications and polyploidization events have been implicated as catalysts for rapid cladogenetic speciation in some fish taxa, but any general relationships between genome sizes and patterns of evolutionary radiation remain poorly characterized. Here we examine empirical correlations between genome size and species richness (number of extant species within ...

This study investigated the birth of a brownbanded bamboo shark Chiloscyllium punctatum at the Steinhart Aquarium. Genetic analyses suggest this is the longest documented case of sperm storage for any species of shark (45 months).

We find an estimate for the blow-up time in terms of the initial data for solutions of the equation ut = (u)xx + u in R × (0, T ) and for solutions of the problem ut = (u)xx in (0,∞)× (0, T ) with −(u)x(0, t) = u(0, t) on (0, T ) with m > 1. To Djairo, ”El Maestro”

Shark conservation has become a focus of current international conservation efforts. However, the misunderstanding of sharks and their negative public portrayal may hinder their conservation. More importantly, the consumption of shark fin, which is very common in Chinese cultures, poses a significant threat to sharks. Hong Kong has long been the world's largest shark fin trading center. Shark c...