18 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



landed by the shark fishery. The abundance of 

 bull sharks at various locations in the Gulf of 

 Mexico varies seasonally, but from the vicinity 

 of Apalachicola, Fla., westward along the north- 

 ern coast of the Gulf of Mexico and southward 

 along the coasts of Central and South America 

 as far at least as French Guiana, bull sharks fonn 

 the major part of catches of large sharks made by 

 shallow-water setlines in some seasons. Table 4 

 shows the comparative frequence of capture of 

 large sharks during a test-fishing period off the 

 mouth of the Mississippi River. 



Table 4. — Large sharks taken from the Joe Leckich on 

 hMom lines set in 5 to 35 fathoms off the mouth of the 

 Mississippi River, June 25 to July '29, 19^7 



Species ' 



Carctiarhinus leucas TMiiller and Henle), bull shark... 



Fulamia obscura (LeSueur), dusky shark. 



Oaleocerdo cutier fLeSueur), tiger shark. 



Carcliarliinus limbatus (Miiller and Henle), little 



blacktip ' 



Spttyrna sp., great hammerhead 



CaTcharhinus macrilipinnif:, big blacktip . 



Fulamia milherti ( Miiller and Henle), sandbar shark. 



Carcharias tauruf: R;ifincsque, sand shark.. 



Negaprwn brerirofilris d'oey), lemon shark 



Sphyrna tewini GrilTith, southern hammerhead 



Eulamia floridana (Bigelow, Schroeder, and Springer), 



silky shark :^.: 



Eulamia springeri (Bigelow and Schroeder) .U. 



Average 



weight 



of liver 



(lb.) 



38 

 53 

 129 



3 



49 

 13 



U 

 26 

 20 

 12 



16 



4 



' Also taken but not recorded because of small size: several Scoliodon 

 terra-novae (Richardson), Carcharhinus porosus Ranzani, and Mustelus canis 

 (Mitchill), and one young Qiftgtymostoma cirratum (Gmelin). 



2 Continental form— typical of western Gulf of Mexico. 



The eight E. milherti were adult females and 

 five of them were gravid. Since milberti has 

 liver oil of comparatively higher potency than 

 the oil from other species in the area, a special 

 effort was made to catch them in subsequent, 

 larger scale fishing efforts. Nevertheless, catches 

 of milherti were not made later during 1947 and 

 commercial fishermen operating in the area re- 

 ported sandbar sharks absent in 1948 and 1949. 

 JThe few records of E. milherti from offshore 

 Gulf waters would not be important except that 

 they serve to show the species can move into and 

 across deep areas of the ocean. Off the Atlantic 

 States there has been comparatively little long- 

 line fishing beyond the Continental Shelf and 

 there are no records of milherti from deep water. 

 There are, however, records of catches of Eulamia 

 faUifonnis (Miiller and Henle) and E. obscura 

 from longline sets made by the exploratory fish- 

 ing vessel Delaware beyond the limits of the 

 Continental Shelf off the Middle Atlantic States. 



These two species are also reported by Backus 

 ( 1957) from the Atlantic beyond Continental 

 Shelf limits. 



A lot of 51 adult sandbar sharks was taken by 

 Captain B. W. Winkler from off the Caribbean 

 coast of Nicaragua and Costa Rica. This group 

 included all of the sandbar sharks in a collection 

 of 854 sharks of all species which Captain Wink- 

 ler measured and recorded for me from Septem- 

 ber through December, 1948. The most inter- 

 esting feature of this collection of E. milherti 

 was that it was made up of approximately equal 

 numbers of adult males and females (26 males 

 and 25 females). 



The .shark fauna of the area as represented by 

 Captain Winkler's collections included a large 

 number of species that are predatory on sharks 

 of the size of young E. milherti. The following 

 sharks were taken : 



Species: Number 



Carcharhinus, ' chottos or bull sharks 421 



Galeocerdo cuvier (LeSueur), tiger shark 



Eulamia obscura (LeSueur), dusky shark 



Eulamia floridana (Bigelow, Schroeder, and 



Springer), silky shark 



Carcharhinus limbatus (Muller and Henle),* 



little blacktip 



Eulamia milberti (Muller and Henle), sandbar 



shark 



Sphyrna sp. (not determined), hammerhead 



shark 



Eulamia sp.,' reef sharks 



Scoliodon sp., sharpnose shark 



Hexanchus sp.,* cow sharks 



Ginglymostoma cirratum (Gmelin), nurse shark.. 



Eulamia altima Springer, bignose shark 



Negaprion brevirostris (Poey), lemon shark 



Undetermined ' 



85 

 76 



70 



54 



51 



27 



25 



15 



13 



3 



2 



1 



4 



' Either C. leucas (IVIiiller and Henle) or C. nicaraguensis (Gill and Brans- 

 ford) or both. 



2 Continental form. 



s Probably F. springeri (Bigelow and Schroeder) or F. falciformis (Muller 

 and Henle). 



* Includes two species. 



5 Possibly a small species of Oaleorhinus. 



n^. few days' fishing with bottom longlines 

 along the outer edge of the Continental Shelf off 

 northern Nicaragua and on Serrana and Seranilla 

 Banks in February 1949 failed to produce E. 

 7nilherfi or any adult sharks, but moderate num- 

 bers of young E. faridana were taken. 



As a grader and buyer, I examined several lots 

 of dried sliark fins said to have been taken off the 

 coasts of Colombia and Venezuela. E. milherti 

 fins were not noticed althougli it is possible that 



