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SAWFISH IN PERIL © Doug Perrine Orange High School Library Sawfish In Peril •Sawfish Basics •Sawfish Biology •Sawfish Conservation •Sawfish Research © Doug Perrine SAWFISH BASICS © Doug Perrine What is a Sawfish? • Sawfish belong to the family Pristidae • Sawfish are characterized as having an elongate blade-like snout (rostrum or saw) that has laterally placed tooth-like denticles (rostral teeth) How many species of sawfishes are there? © Doug Perrine • There are 6-7 species of sawfishes currently recognized by scientists • Scientists are currently reviewing the taxonomy of sawfishes, some species appear very similar to each other How large can sawfishes grow? © George Burgess • They commonly reach 16.4 feet in length, attaining a maximum length of 24 feet Do sawfishes live off the coast of the U.S.? • The smalltooth sawfish is only found off the Atlantic and Gulf coasts of Florida • The largetooth sawfish is limited to the Gulf of Mexico Why do sawfishes have that remarkable tooth-studded saw? © George Burgess • The rostral “saw” is used for feeding, slashing back and forth in the soft sediments in search of invertebrates and to stun schooling fishes • The “saw” is also used as defense against predators Do sawfishes present a threat to humans? • Sawfishes are harmless to humans if left undisturbed • Care must be taken when handling sawfishes as they may defend themselves with the rostral “saw” SAWFISH BIOLOGY © Don DeMaria Do sawfishes have bones? U.S. Geological Survey • No, sawfishes and other fishes belonging to the class Chondrichthyes lack true bone, but rather have cartilaginous skeletons • Bony fishes (Class Osteichthyes) have true bones as do humans - see photo above How many fins do sawfishes have? Pectoral Fins Pelvic Fins Dorsal Fins Caudal Fin • They have two pectoral fins (fused to the head/trunk), two pelvic fins, two dorsal fins, and a caudal fin • Like the great majority of rays, sawfishes lack an anal fin How long do sawfishes live? • It has been estimated that these animals live up to 25 to 30 years, reaching maturity at 10 years What do sawfishes eat? © Doug Perrine • Sawfishes feed on small fishes and invertebrates that can be ingested whole through the mouth • They only feed on prey that can fit into their small mouths since they are unable to tear chunks off prey items with their toothy saw Do sawfishes have any predators? © Doug Perrine • Adult sawfishes have very few predators • Juvenile sawfishes are preyed upon by crocodiles, large sharks, and even marine mammals such as dolphins Do sawfishes have teeth in their jaws? • Ten to twelve rows of teeth are located in jaws of the smalltooth sawfish • The teeth are rounded anteriorly and have a blunt cutting posterior edge © George Burgess Do sawfishes lay eggs or give live birth to young? • Sawfishes are "ovoviviparous", meaning that young sawfishes grow from eggs retained within the mother • After the embryos are fully developed, the mother sawfish gives live birth with an average litter size of about 8 pups SAWFISH CONSERVATION Are sawfishes listed as threatened or endangered in the U.S.? • On April 1, 2003 the U.S. National Marine Fisheries Service placed the smalltooth sawfish on the Endangered Species List, making it the first marine fish species to receive protection under the Endangered Species Act What are some threats to sawfishes? U.S. Geological Survey • Entanglement in fishing gear and marine debris • Indirect take as by-catch in other directed fisheries • Loss of habitat, coastal development and marine pollution • Use of saws as curios and the fins for soup What should you do if you encounter a sawfish in its natural habitat? © Doug Perrine • Sawfish are listed under the Endangered Species Act which makes it illegal to harm, harass, or handle them in any way • If you do see a sawfish, enjoy the moment and feel extremely lucky! Are sawfishes ever accidentally caught? © Doug Perrine • Sawfish are sometimes accidentally caught on fishing hooks and in fishing nets • If a sawfish is accidentally caught, it should be released immediately to ensure its survival Is it difficult to safely release a captured sawfish? • Sawfish are sometimes accidentally caught on fishing lines and in fishing nets • Guidelines are available on what to do if a sawfish is hooked or if a sawfish is tangled in a net • Encounters should be reported to assist with ongoing scientific research Did fishermen catch sawfishes prior to their protection in the U.S.? • Sawfish were often caught by fishermen who would sometimes eat the flesh and keep the trophy “saw” • Very large sawfishes were often captured in past decades SAWFISH RESEARCH What do scientists still need to learn about sawfish? • Scientists are researching age and growth, reproduction, movement patterns, and habitat use of the smalltooth sawfish to assist in management and recovery of this endangered species. What is the Sawfish Recovery Team? • This team consists of researchers, managers, and representatives from constituent groups working to develop a recovery plan for the smalltooth sawfish • http://www.flmnh.ufl.edu/fish/sharks/sawfish/srt/srt.htm What are some good resources to learn more about sawfishes? • There are some good web sites to learn more about sawfishes • You can also read more about sawfishes in scientific journals and books Questions/Answers?