The genus Mollisquama describes a group of animals known as pocket sharks, so named for a small opening - the “pocket gland” - that lies just above the pectoral fins. While scientists have long presumed that there are multiple species of pocket shark, only a single animal has ever been described! … Read more about Is that a shark in your pocket….?
The reproductive organs of male chondrichthyans (sharks, rays, skates) are called claspers, paired structures that are inserted into the female to achieve internal fertilization. Claspers originate from the medial (inner) surfaces of the pectoral fins of male sharks, and immature claspers are … Read more about How to Make a Boy Shark
I have long been interested in sperm storage in a variety of species, a technique that allows female animals to separate mating and gestation. There is evidence for sperm storage in animals ranging from insects to mammals. This can be advantageous to females in a number of situations, for example … Read more about Long-Term Sperm Storage in Bamboo Sharks
Research into the biology and ecology of the whale shark has increased dramatically over the past 15 years, but our understanding of much of the life cycle of these animals is still lacking. In particular, little is known about their reproduction and the early life of young whale sharks. Mating … Read more about A Rare Find
Sharks don’t get cancer. We’ve all heard this claim, and sadly such beliefs have led to the death of large numbers of sharks for the supposed curative powers of their various body parts. The first ridiculous assumption to dispense with is that even if sharks DIDN’T get cancer, that in no way means … Read more about Taking a Bite Out of Cancer
Geneticists often refer to the “genome” of a species, the DNA sequences that specify the development and physiology of an animal. In reality though, the genome is only a set of instructions for creating that individual, it is the RNAs and proteins within each cell that carry out the DNA’s … Read more about Warm Hearts for White Sharks
Thresher sharks are among the most impressive of elasmobranchs, their scythe-like tails nearly equaling their bodies in length. Many hypotheses have been proposed for the function of these elongated tails. Do they aid in swimming? Attract potential mates? Serve as a warning … Read more about A Slap Upside the Head
Satellite tagging allows both terrestrial and marine animals to be followed remotely over long periods of time. While financial and technological drawbacks to this methodology exist, satellite tags are effectively used to track many different species. For marine animals, among the most … Read more about Sharks and Birds: Showing Off For the Ladies
Electroreception is the ability of certain marine vertebrates to detect minute electrical charges transmitted through the water. The shark electroreceptor system is composed of sensory organs called ampullae of Lorenzini, that lie within small pores across the head of the shark. All … Read more about Future Predators Avoid Becoming Prey
It’s been a while since I wrote on this blog, mostly because I’ve spent the last year on sabbatical visiting whale shark aggregations around the world – Djibouti, Philippines, Mexico.... It’s a rough job but someone has to do it! Seeing so many whale shark aggregations in a short time really lets … Read more about Report from Oslob
Elasmobranchs have highly developed sensory systems that help them find food - a sense of smell that can detect prey at long distances, and the ability to read the minute electrical fields emitted by fish. But what about their vision? Do sharks see in color? Two recent studies use … Read more about Do Sharks See Color?
Sharks strand, or beach themselves, with some frequency in certain coastal areas. This phenomenon is seen in other marine creatures as well, and is particularly common in dolphins and small whales. It’s a frustrating occurrence, as the cause for strandings is rarely known, and most … Read more about Shark Strandings Investigated