Juvenile Bluefin Tuna, Thunnus thynnus (Linnaeus), and other Scombrids Taken by Terns in the Dry Tortugas, Florida
Potthoff T and Richards WJ. 1970. Juvenile Bluefin Tuna, Thunnus thynnus (Linnaeus), and other Scombrids Taken by Terns in the Dry Tortugas, Florida. Bulletin of Marine Science. 20(2):389-413
The identification and seasonal distribution of juvenile scombrids in the waters near the Dry Tortugas, Florida, are described. Specimens were collected (1960 through 1967) from regurgitated food of terns. Fishes identified were Thunnus thynnus, Thunnus atlanticus, Euthynnus alletteratus, Auxis spp., and Katsuwonus pelamis; sizes ranged from 24-146 mm. standard length. For the first time, juvenile bluefin tunas are reported in the Dry Tortugas region; their presence may indicate that spawning of the species takes place in the area. Identification methods are discussed, with special emphasis on features of the axial skeleton and the number of gillrakers over the ceratobranchial bone of the first gill arch. A method is presented for estimating the standard length of damaged specimens on the basis of the length of the vertebral column.
- Type
- Journal Article
- Authors
- Potthoff, Thomas; Richards, William
- Units
- DRTO
- Keywords
- Animal Studies, bluefin tuna (Thunnus thynnus), Fish, Juveniles, Predation, terns (Sterninae)