Stomach Contents of Mako Sharks caught off Brazil
Stomach contents analysis of shortfin mako (Isurus oxyrinchus) caught off southern Brazil: A Bayesian analysis.
Gorni, G.R., Loibel, S., Goitein, R. and Amorim, A.F.
SUMMARY:
This study proposes to ascertain the importance of each alimentary category in the Isurus oxyrinchus diet composition, as well, to reinforce the use of the Bayesian approach for analysis of these data. Shortfin mako were collected during fishing cruises carried out by the longline fleet of Santos and Guarujá, São Paulo State, from July 2007 to June 2008. The collection of the stomachs was done on board during evisceration. The stomach contents have been identified to the smallest possible taxa. For Bayesian model formulation, each alimentary item was clustered in four food categories previously defined as: teleost fishes, cephalopod molluscs, crustaceans, and others. After the stomach contents analysis 144 food items were identified, which belonged to 11 taxa. Following the calculation, the most important food category of I. oxyrinchus is comprised of teleost fishes (PM=0.68), followed by cephalopod molluscs (PM = 0.12). Crustaceans and other items were responsible for the posterior mode less than 0.1, indicating low importance in the shortfin mako diet. The Bayesian approach should be useful to analyse the diet of great top predators, which are usually caught in small numbers.
Collect. Vol. Sci. Pap. ICCAT, 68(5): 1933-1937 (2012)