Bonnethead sharks, one of the smallest hammerheads, may actually be more than one species

Bonnethead sharks, one of the smallest members of the hammerhead shark family Sphyrnidae, have a special place in my heart. For many years, the avatar I used for science communication efforts, including posts on this blog, was a picture of me with a bonnethead.

Remember this avatar? That’s a bonnethead (on the left).

These sharks, which can grow up to about 5 feet long, are found throughout North, Central, and South America. However, new research by Fields and friends suggests that they may actually be a species complex, not a true species. “A species complex is a group of distinct species that are incorrectly classified as one species because they look very similar to one another,” explained Dr. Demian Chapman, an Associate Professor of Biology at Florida International University and a co-author on this new study. “A great example is the white spotted eagle ray (Aetobatus narinari) that was once thought to be one, globally distributed species, but now has been shown to be a group of very similar-looking species, each of which lives in a particular region.”

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Watch the Sharks International 2014 Keynote Presentations!

logoIn June of 2014, almost 400 of the world’s top shark researchers gathered in Durban, South Africa for the 2nd Sharks International conference.  The four keynote presentations have just been put online.

Beyond Jaws: Rediscovering the “lost sharks” of South Africa

Dave Ebert, Moss Landing Marine Laboratory

daveBiography:Dave Ebert earned his Masters Degree at Moss Landing Marine Labs and his Ph.D. at Rhodes University, Grahamstown, South Africa.  He is currently the Program Director for the Pacific Shark Research Center, a research faculty member at Moss Landing Marine Laboratories, and an honorary research associate for the South African Institute for Aquatic Biodiversity and the California Academy of Sciences Department of Ichthyology.  He has been researching chondrichthyans around the world for nearly three decades, focusing his research on the biology, ecology and systematics of this enigmatic fish group.  He has authored 13 books, including a popular field guide to the sharks of the world and most recently he revised the Food and Agriculture Organization’s Catalogue of Sharks of the World.  He has published over 300 scientific papers and book chapters, and contributed approximately 100 IUCN Shark Specialist Group Red List species assessments.  Dave is regional co-Chair of the IUCN Northeast Pacific Regional Shark Specialist Group, Vice Chair for taxonomy, and a member of the American Elasmobranch Society and Oceania Chondrichthyan Society.  He has supervised more than 30 graduate students, and enjoys mentoring and helping develop aspiring marine biologists.

 

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13 amazing things scientists discovered about sharks in 2013

Other than a certain week in August whose name we shall not speak here, 2013 was a great year for both shark science and the communication of that shark science. There were many important and fascinating discoveries, and many of the world’s top media outlets covered them. Presented here is a list of 13 amazing scientific discoveries made in 2013, in no particular ranking order. To make the list, research must have been published in a peer-reviewed scientific journal in 2013, and someone else other than me must have also thought it was awesome (i.e. it received mainstream media or blog coverage). In the interest of objectivity, I did not include any papers that I or my lab were directly involved with. Whenever possible, I’ve linked to an accessible version of the paper.

 

1) A two-headed bull shark!

From Wagner et al. 2013

From Wagner et al. 2013

 

Citation: Wagner, CM, Rice, PH, and Pease, AP 2013. First record of dicephalia in a bull shark Carcharhinus leucas foetus from the Gulf of Mexico. Journal of Fish Biology 82: 1419-1422.

Brief description: Researchers presented the first case of a bull shark embryo with 2 heads (the mother was caught by a Florida fishermen). In response to the most common question I received about this study, no, this animal would not have survived to adulthood.  While this is a cool discovery, the broader significance is somewhat minimal. As I told science writer Douglas Main in an interview about a similar study, “There have been a number of reports of deformed shark and ray embryos in recent years— two heads, one eye, etc. There’s no evidence to suggest these defects represent a new phenomenon or that they are harmful to shark populations as a whole.”

Media coverage highlights: A figure from this study was named one of the coolest science photos of the year by the International Science Times. It was also covered by National Geographic, the Guardian, and TIME magazine. Read More