The megamouth is one of the rarest sharks in the world. Surprisingly for an animal that can reach 7 meters in length, it was described only in 1983, and only ~100 specimens have been found. This is largely because it is a deep-water species, spending days at 200 meters or more, but rising close to … Read more about High Connectivity and Low Diversity in Megamouth Sharks
Shark finning continues seemingly unabated, despite some gains in protection for threatened shark species. The scope of the trade is staggering, more than 70 million fins per year are thought to move globally. What species are targeted for these fins? This is a difficult question. Once removed from … Read more about Species Composition of the Shark Fin Trade
Sharks don’t get cancer. That’s the lore we’ve all heard. Some take this claim even farther. Eat a shark and you won’t get cancer, or the cancer you have will be cured. Many sharks are killed for the supposed curative powers of their cartilage, among other health claims. Sharks do, of course, … Read more about Long-term Observation of Cancer in a Shark
Multiple insults to shark populations - fisheries, habitat degradation, the fin trade, climate change - are believed to be interacting to cause steep declines in the numbers of many species. It is difficult, however, to accurately estimate the population size of wide-ranging pelagic sharks. It is … Read more about Fisheries Harvest of Shortfin Mako Sharks
Shark meat consumption is bad for sharks of course, millions of sharks are killed each year for the shark meat and fin trade, but it’s also bad for people. I’ve written before about the way heavy metals and organic pollutants like PCBs concentrate in animals high up on the food chain. Shark meat … Read more about Another Reason (If You Needed One) Not to Eat Shark
The current issue of Ocean Geographic magazine has an article on the CITES CoP17 conference written by SRI Director of Science & Research Dr. Jennifer Schmidt. … Read more about CITES CoP17 Report
We hear so much bad news about sharks – populations of many species have declined to historic lows, finning occurs in numerous countries, bycatch continues to threaten shark species, shark fishing tournaments are conducted for sport here in the US. When a bit of good news about sharks comes along … Read more about Some Good News for Sharks!
A short post today to tell you about the long residency of an individual whale shark at the Ningaloo Reef feeding aggregation in Western Australia. These huge animals require an enormous amount of their planktonic food, and so they travel the seas between sites where rich food sources are … Read more about Stumpy Returns
For many years it was believed that there was a single species of manta ray distributed globally in the oceans, Manta birostris, the Giant manta ray. This was despite the fact that there is a significant range of manta size across different locations, and that some mantas appear to be migratory … Read more about Catching Some Rays in Mexico
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