Field Key to Sharks of North Carolina and Adjacent Waters

Florida Program for Shark Research

Education Selections... South Florida Aquatic Environments About the Different Groups of Fishes About the Anatomy of Fish and Sharks How Fish and Sharks Swim About Fish Adaptations About the Endangered Species Act How to Become a Biologist About Careers In Ichthyology Most Commonly Asked Shark Questions Most Commonly Asked Sawfish Questions Most Commonly Asked Ray and Skate Questions Most Commonly Asked Fish Questions Identification Key to Freshwater Fishes of Peninsular Florida Field Key to Sharks Skates of the Western Gulf of Maine Project Shark Awareness - A Public Outreach Educational Program Shark Fishing in U.S. Territorial Waters Most Commonly Asked Sawfish Questions Sawfish In Peril - PowerPoint file Sawfish Informational Brochure - Acrobat file Sawfish Outreach Boat Ramp/Marina Sign - Acrobat file Sawfish In The News Sawfish References Sawfish Links Smalltooth Sawfish species profile Largetooth Sawfish species profile Green Sawfish species profile Freshwater Sawfish species profile Dwarf Sawfish species profile Knifetooth Sawfish species profile Chondrichthyes Bibliography Search Freshwater Fishes of Florida References General Fish References Shark References Sawfish References Childrens' Shark Books Stingray Reproduction References Biological Profiles Glossary of Terms Shark Games: Test Your Knowlege! 2003 Open House Photos Bigeye thresher (Alopias superciliosus) Biological Profile Bigeye thresher Alopias superciliosus) illustration ©FAO courtesy Species Identification and Biodata Distinguishing Characteristics 1. Eyes are large and directed upward 2. Head has deep grooves along top 3. Caudal fin is sickle-shaped with an extremely long upper lobe (about half the total body length) 4. First dorsal fin originates well behind the free tips of the pectoral fins Bigeye thresher (Alopias superciliosus) Specimen © George Burgess Bigeye thresher (Alopias superciliosus) Specimen: Head with deep grooves © George Burgess Bigeye thresher (Alopias superciliosus) Specimen: Large eyes © George Burgess Bigeye thresher (Alopias superciliosus) Specimen: Ventral view of head © George Burgess Bigeye thresher (Alopias superciliosus) Specimen: Gills © George Burgess Bigeye thresher (Alopias superciliosus) Specimen: Dorsal fin © George Burgess