NEWSLETTER 3/2010 14. March 2010


Shark Specialist Group (IUCN) (Homepage)

Maldives Whale Shark Research Programme (MWSRP) (Homepage)

Dr. Richard Pillans, CSIRO Marine and Atmospheric Research, Brisbane, Australia

Umberto Scacco, I.C.R.A.M (Istituto Centrale per la Ricerca scientifica e tecnologica Applicata al Mare) Roma, Italy

Dr. David Rowat, Chairman, Marine Conservation Society, Victoria, Seychelles (Homepage)

Dr. Giuseppe Notarbartolo di Sciara, Honorary President, Tethys Research Institute, Milano, Italy (Homepage)

Feodor Litvinov, Atlantic Scientific Research Institute of Marine Fisheries and Oceanography, Kaliningrad, Russia

Dr. Jenny Ovenden, Molecular Fisheries Laboratory, St. Lucia, Australia (Homepage)

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27.02.2010: 197 new data, 235 new analysed papers

14.03.2010: 241 new data, 248 new analysed papers


Sunday, 28. March 2010


Currently this database contains 6.937 papers (4.524 about recent sharks, rays and chimaeras, 2.413 about fossil sharks, rays and chimaeras). Out of this 6.937 papers, 3.088 papers had been evaluated , and there is the possibility of free downloading 706 papers.


ICES Annual Science Conference 2010
20-24 September
Nantes, France
Session E:
Elasmobranch Fisheries: Developments in stock assessment, technical mitigation and management measures

All abstracts must be received on or before Thursday 15 April 20

Early registration opens March 2010

Early registration deadline Tuesday 31 August 2010

The II Colombian Meeting on Chondrichthyans

16-20 August 2010

Cali (Colombia)

The deadline for abstracts is May 14, 2010.

Further information on the Meeting is on the SQUALUS FOUNDATION website (



BECKER, M.A. & WELLNER, R.W. & MALLERY, C.S. & CHAMBERLAIN, J.A. (2010); Chondrichthyans from the Lower Ferron Sandstone Member of the Mancos Shale (upper Cretaceous: Middle Turonian) of Emery and Carbon Counties, Utah, USA.; Journal of Paleontology, 84 (2): 248-266

LANE, J.A. (2010); Morphology of the Braincase in the Cretaceous Hybodont Shark Tribodus limae (Chondrichthyes: Elasmobranchii), Based on CT Scanning.; American Museum Novitates, 3681: 1-70

WHITENACK, L.B. & GOTTFRIED, M.D. (2010); A Morphometric Approach for Addressing Tooth-Based Species Delimitation in Fossil Mako Sharks, Isurus (Elasmobranchii: Lamniformes).; Journal of Vertebrate Paleontology, 30 (1): 17-25

VISAGGI, C.C. & GODFREY, S.J. (2010); Variation in Composition and Abundance of Miocene Shark Teeth from Calvert Cliffs, Maryland.; Journal of Vertebrate Paleontology, 30 (1): 26-35

SHIMADA, K. & EVERHART, M.J. & DECKER, R. & DECKER, P.D. (2010); A new skeletal remain of the durophagous shark, Ptychodus mortoni, from the Upper Cretaceous of North America: an indication of gigantic body size.; Cretaceous Research, 31 (2): 249-254


PÉREZ-JIMÉNEZ, J.C. & SOSA-NISHIZAKI, O. (2010); Determining reproductive parameters for population assessments of two smoothhounds (Mustelus californicus and Mustelus lunulatus) from the northern Gulf of California, Mexico.; Bulletin of Marine Science, 86 (1): 1-11

BALLANTYNE, J.S. & ROBINSON, J.W. (2010); Freshwater elasmobranchs: a review of their physiology and biochemistry.; Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology, xxx: 19p

STEVENS, J.D. & BRADFORD, R.W. & WEST, G.J. (2010); Satellite tagging of blue sharks (Prionace glauca) and other pelagic sharks oV eastern Australia: depth behaviour, temperature experience and movements.; Marine Biology, 157 (3): 575-591

McCOMB, D.M. & FRANK, T.M. & HUETER, R.E. & KAJIURA, S.M. (2010); Temporal Resolution and Spectral Sensitivity of the Visual System of Three Coastal Shark Species from Different Light Environments.; Physiological and Biochemical Zoology, 83 (2): 299-307

FELDHEIM, K.A. & CHAPMAN, D.D. & SIMPFENDORFER, C.A. & RICHARDS, V.P. & SHIVJI, M.S. & WILEY, T.R. & POULAKIS, G.R. & CARLSON, J.K. & ENG, R. & SAGARESE, S. (2010); Genetic tools to support the conservation of the endangered smalltooth sawfish, Pristis pectinata.; Conservation Genetics Resources. In Press.

FELDHEIM, K.A. & CHAPMAN, D.D. & SWEET, D. & FITZPATRICK, S. & PRODOHL, P.A. & SHIVJI, M.S. & SNOWDEN, B. (2010); Shark virgin birth produces multiple, viable offspring.; Journal of Heredity. In Press.

SCACCO, U. & LA MESA, G. & VACCHI, M. (2010); Body morphometrics, swimming diversity and niche in demersal sharks: a comparative case study from the Mediterranean Sea.; Scientia Marina, 74 (1): 37-51

CONRATH, C.L. & MUSICK, J.A. (2010); Residency, space use and movement patterns of juvenile sandbar sharks (Carcharhinus plumbeus) within a Virginia summer nursery area.; Marine and Freshwater Research, 61 (2): 223-235

OVENDEN, J.R. & MORGAN, J.A.T. & KASHIWAGI, T. & BRODERICK, D. & SALINI, J. (2010); Towards better management of Australia’s shark fishery: genetic analyses reveal unexpected ratios of cryptic blacktip species Carcharhinus tilstoni and C. limbatus.; Marine and Freshwater Research, 61 (2): 253-262

VIGNON, M. & SASAL, P. & JOHNSON, R.L. & GALZIN, R. (2010); Impact of shark-feeding tourism on surrounding fish populations off Moorea Island (French Polynesia).; Marine and Freshwater Research, 61 (2): 163-169

MØLLER, P.R. & NIELSEN, J.G. & KNUDSEN, S.W. & POULSEN, J.Y. & SÜNKSEN, K. & JØRGENSEN, O.A. (2010); A checklist of the fish fauna of Greenland waters.; Zootaxa, 2378: 1-84


Ancient shark was a shell-crushing giant

Category: PaleontologySharks
Posted on: February 22, 2010 7:49 AM, by Brian Switek

A restoration of the giant, durophagous shark Ptychodus, courtesy paleo-artist Matt Celeskey.

The study of prehistoric sharks is no easy task. Specialists in other branches of vertebrate paleontology at least have the reasonable hope of discovering complete skeletons of their subjects; except in instances of exceptional preservation the scientists who study sharks typically only have teeth and a few vertebrae to work with. Still, you can tell a lot about a shark by its teeth, and a new study published in Cretaceous Research suggests that one peculiar form was a shell-crushing giant.

Thanks to Jaws, "Shark Week", and other sensationalist films the word "shark" most immediately conjures up images of streamlined predators with triangular, razor-sharp teeth. For much of the public the great white shark (Carcharodon carcharias) is the epitome of "sharkiness", but there is a much wider variety of shark types. The largest fish in the sea, the whale shark (Rhincodon typus) is a filter feeder with teeth smaller than your fingernails, while the much smaller Port Jackson shark (Heterodontus portusjacksoni) has differentiated teeth adapted for crushing mollusks. And, just like today, there was a diversity of shark types in the past. One of the most enigmatic was the Late Cretaceous form Ptychodus mortoni.

The largest tooth recovered for the new Ptychodus mortoni specimen. (From Shimada et al., 2010)

Like many other kinds of prehistoric sharks Ptychodus is primarily known from bits and pieces. A tooth here, a vertebrae there, but altogether the scraps add up. In fact, last year a team led by Kenshu Shimada used what was known about the shark to suggest that it was enormous, perhaps in excess of 11 meters in length, and the new paper builds upon this hypothesis.

The new specimen comes from Jewell Country, Kansas, and is little more than a portion of the upper jaw associated with a total of 19 teeth. Smack in the middle of the continental United States the county is about as land-locked as it is possible to get, but in the time of Ptychodus (about 89 million years ago) there was a great sea that stretched from Canada down to the modern Gulf of Mexico. This was the Western Interior Seaway, the home of plesiosaurs, mosasaurs, and, of course, enormous sharks.

Four views of the jaws of two species of Ptychodus. A) Lower jaw of Ptychodus decurrens as viewed from above, B) Upper tooth plate of Ptychodus occidentalis as viewed from below, C) Lower jaw of Ptychodus occidentalis as viewed from above, D) Lower jaw of Ptychodus occidentalis as viewed from below. (From Shimada et al., 2009)

But the teeth of Ptychodus did not look very much like those of its living relatives. The largest tooth from the jaw fragment, measuring 33.5 by 41 mm, looks like a flat garbage-can lid. It is not a tooth for stabbing or slicing but for crushing, as were the rest of the recovered teeth. In life these would have been arrayed in a set of opposing plates in the upper and lower jaws containing about 500 teeth each; vast, knobbly surfaces perfect for crushing large clam-like organisms and barnacles. This made Ptychodus a "durophage", or an organism that primarily consumed hard-shelled prey.

An outline of the upper jaw of Ptychodus mortoni showing the position of the new fragment, and a comparison of the size of the shark next to an adult human. (From Shimada et al., 2010)

But what did Ptychodus look like? Several interpretations have been put forward. Some think that it had a flattened body like a stingray, while others have suggested that it had a more streamlined shark shape. The authors behind the new study split the difference by suggesting that it was something like a nurse shark (Ginglymostoma cirratum), a shark well-adapted to cruising over the bottom in search of hard-shelled prey to consume.

Ptychodus would have been much larger than any nurse shark, though. Based upon the fragments of the upper and lower jaws recently recovered and what is known about the relationship between jaw size and body length the researchers proposed that Ptychodus mortoni was over 11 meters long. This is in the range of modern basking sharks (Cetorhinus maximus) and whale sharks, and a few isolated teeth hint that there may have been individuals (or even a different species) even larger in size. Along with the shell-crunching mosasaur Globidens and the even more ancient placodonts, Ptychodus mortoni was one of the largest shellfish-eating animals ever.

[This post was inspired by Carl Zimmer's post on the enormous filter-feeding fish Bonnerichthys published last week.]

Shimada, K., Everhart, M., Decker, R., & Decker, P. (2010). A new skeletal remain of the durophagous shark, Ptychodus mortoni, from the Upper Cretaceous of North America: an indication of gigantic body size Cretaceous Research, 31 (2), 249-254 DOI: 10.1016/j.cretres.2009.11.005

Great white shark is more endangered than tiger, claims scientist

Recent research suggests there are more tigers left in the wild than there are great white sharks

Their poor public image may mean great white sharks go extinct before the tiger. Photograph: Brandon Cole/Getty

Great white sharks may be more endangered than tigers, with only a few thousand left in the world's oceans, according to a leading marine biologist.

The grim assessment suggests that fishing and collisions with shipping vessels have taken a devastating toll on the ancient predators.

The World Conservation Union, which operates the red list of endangered species, lists great white sharks as vulnerable but has no official estimate of their global population. But a recent survey suggests that great whites have fallen below 3,500 individuals, the number of tigers conservationists believe are left in the wild.

A team led by Barbara Block, a marine biologist at Stanford University, used radio transmitters to track more than 150 great white sharks off the coast of southern California.

"The estimated total population of great white sharks in the world's oceans is actually less than the number of tigers," said Ronald O'Dor, a senior scientist at the Census of Marine Life, an international collaboration that is cataloguing marine life.

"We hear an awful lot about how endangered tigers are, but apparently great white sharks are pretty close to the same level. Some people say 'I don't care, they eat people,' but I think we have to give them a little space to live in," O'Dor told the American Association for the Advancement of Science meeting in San Diego yesterday.

"The Australians have now got a system where they put tags on great white sharks and they have receivers on the beaches so when a great white comes into the bay the receiver automatically makes a cell phone call and tells the guy in charge to close the beach. So we can co-exist with marine life," he added.

In 2007, marine biologists at Dalhousie University in Canada analysed records from fisheries and research vessels dating from the 1970s to 2005 and found evidence for a dramatic fall in shark populations. Tiger sharks and scalloped hammerheads had declined more than 97% since the mid-1980s, while numbers of smooth hammerheads and bull sharks fell 99% off the east coast of the US.

SUV-Sized Fish Were Earliest Filter-Feeders

By Jennifer Viegas | Thu Feb 18, 2010 02:00 PM ET

Giant whales are known for their open-mouthed filter feeding, but the technique was likely devised by humongous fish that lived during the Mesozoic.

Whales include the world's largest animals, but newly identified fossils reveal they were preceded by SUV-sized filter-feeding fishes that emerged during the Jurassic Period, 170 million years ago, and lived until the extinction event that wiped out dinosaurs and numerous other species.

Although the now-extinct fishes, called pachycormiforms, were not closely related to whales, their demise left an ecological niche void that whales, sharks and rays filled starting around 56 million years ago, helping to explain the top portion of today's marine food chain.

The fish fossils, described in the latest issue of Science, also prove that filter feeding emerged long before the first whales. For this method of eating, the diner suspends itself in the water, mouth agape. Water escapes through gill slits, leaving behind the filtered food.

It can help to have a big mouth, which many of these enormous fishes must have had.

Co-author Kenshu Shimada, a research associate in paleontology at the Sternberg Museum of Natural History, told Discovery News that one of the fish he and his colleagues identified, Bonnerichthys, grew to around 20 feet in length and swam through a seaway covering what is today the state of Kansas.

"A previously described species, Leedsichthys, from the Jurassic of Europe that belongs to the same lineage that includes Bonnerichthys was even larger, likely reaching up to about 30 feet, which is the most massive bony fish of all time," added Shimada, who is also an associate professor in the Environmental Science Program and Department of Biological Sciences at DePaul University.

For the study, led by University of Oxford scientist Matt Friedman, the researchers analyzed both old and new fish fossils found in England, the U.S. and Japan. The Kansas fish was previously thought to have been like a gigantic swordfish, bearing fang-like teeth on its jawbones.

"However, our close examination of the specimen showed that such a long snout and fang-like teeth were not present in the fish," Shimada said. "Rather, with a blunt massive head, the fish had long toothless jawbones and long gill-supporting bones that are characteristic of plankton-feeding fishes."

While this fish, and the other Dinosaur-Era filter feeders, enjoyed a long existence on the planet, they were no match for the K-T extinction event that killed off 70 percent of all species then living on Earth.

"The filter-feeding pachycormiforms, relying for food on small organisms low in the trophic chain, had the perfect profile of a victim and became extinct," wrote Lionel Cavin in a commentary that also appears in Science. Cavin is a curator in the Department of Geology and Paleontology at the Natural History Museum in Geneva.

Cavin added, "The tropical niche was later refilled, first with sharks and rays from around 56 million years ago and then with modern cetaceans (whales, dolphins and porpoises) from 34 million years ago."

Yet another paper in the latest Science, authored by the University of Otago's Felix Marx and George Mason University's Mark Uhen, found that diatoms, a common type of phytoplankton, along with climatic events, influenced the evolution of cetaceans once they headed into the water.

Marx and Uhen believe that "a great increase in diatom-based productivity, possibly by increasing the bioavailability of silica and other nutrients in the Southern Ocean and coastal upwelling zones around the world through deep-mixing occurring around Antarctica" drove the evolution of baleen whales, in particular.

The research sheds light on why marine mammals that can weigh over 190 short tons and grow to 108 feet in length may subsist on minuscule diatoms and other tiny, yet prevalent, water dwellers, such as krill.

Shark Alliance urges international trade restrictions for threatened sharks

Coalition supporting proposals to add eight shark species to CITES Appendix II

10 March 20

Qatar: Whether to protect eight shark species – spiny dogfish, porbeagle, oceanic whitetip, scalloped hammerhead, great hammerhead, smooth hammerhead, dusky and sandbar sharks – that are vulnerable to international trade will be a question debated at the 15th Conference of the Parties to the Convention on International Trade in Endangered Species (CITES).

The Shark Alliance is calling on delegates from the 175 governments that will attend the meeting to list these threatened shark species under CITES Appendix II. Such action would require export permits for all international trade and a determination that trade is legal and not detrimental to the species’ survival.

Most sharks are exceptionally susceptible to overfishing because they grow slowly, mature late, and produce few young. For example, spiny dogfish are pregnant for nearly two years, and porbeagles only give birth to about four young per brood.

"Sharks are exceptionally vulnerable animals and the species proposed for CITES listing have been hit especially hard by international trade," said Heike Zidowitz, chair of Germany's shark science society, who will head the Shark Alliance delegation to the CITES meeting. "It's high time to view sharks not just as commodities, but as wildlife, and to use this wildlife treaty to control the lucrative shark trade.”

Spearheaded by Germany, proposals to list porbeagle and spiny dogfish have been formally introduced by Sweden, supported by the other Member States of the European Community, and co-sponsored by the Pacific island nation of Palau.

Porbeagle and spiny dogfish, classified by the International Union for Conservation of Nature (IUCN) as Endangered in the Northwest Atlantic and globally as Vulnerable, are at risk primarily due to demand for their meat, which drives international trade. In Europe, porbeagle meat is among the most valuable shark meat, particularly in France; spiny dogfish meat is more widely popular, found regularly in UK fish and chip shops.

The United States and Palau are proposing CITES listing for the oceanic whitetip shark, categorized by IUCN as globally Vulnerable and the scalloped hammerhead, listed as globally Endangered. The great hammerhead, smooth hammerhead, sandbar and dusky shark have been added to the latter proposal because the fins of these species closely resemble those of scalloped hammerheads.

Hammerhead shark fins are highly sought for use in the traditional, Asian delicacy “shark fin soup.” Because their meat is generally considered unpalatable, hammerhead sharks too often fall victim to “finning” (slicing off a shark’s fins and discarding the body at sea). Strong demand for fins is also a driving force behind the depletion of oceanic whitetip sharks.

"We congratulate Palau, the United States and Sweden for championing strong proposals to list commercially valuable sharks under CITES Appendix II," said Matt Rand, coordinator of the Shark Alliance and director of Global Shark Conservation for the Pew Environment Group, "We call on all other CITES parties to support the proposed Appendix II listings for these 8 shark species before it's too late."

For the Shark Alliance position paper and more information on the sharks proposals go to

For further information or to arrange media interviews or B roll contact:

Sophie Hulme,, c: +44 7973 712 869

Dan Klotz, Communications Officer, Pew Environment Group,, c: +1 347-307-2866