EDAD Y CRECIMIENTO DEL MARLIN RAYADO, Kajikia audax (PHILIPPI, 1887) EN LA COSTA DE MAZATLÁN, SIN., MÉXICO

Abstract

Striped marlin Kajikia audax are distributed throughout tropical, subtropical and temperate waters of the Pacific and Indian Oceans, between 45°N and 35-40°S of latitude. In Mexico it is the most important specie for the recreational fishing, however the knowledge of its biology is scarce. The objective of this study was estimate the age and describe the individual growth of the striped marlin caught by the recreational fishing fleet off Mazatlan coast, Sinaloa. During October 2002 to December 2004, 315 organisms were weighed and measured, and on 310 specimens the 4th dorsal fin spine was collected. The lower jaw-fork length (LJFL) ranged from 148 to 236 cm. The differences in the size by sex were not significant (Kolmogorov-Smirnov; p>0.05). The total weight (TW) ranged from 12 to 77 kg, and a potential model was fitted to the relationship TW-LJFL (TW=4e-5*LJFL3.05) showing allometric growth (b=3); as there were no differences (ANCOVA; p>0.05) in this relationship between sexes. The relationship LJFL-total radius of the spine (RT) was significant (r2=0.93, LJFL=98.71*RT0.39), therefore this structure is adequate to describe growth. Up to twelve growth marks (GM) were observed in the spine sections. The average percent error was 3.3% y the coefficient of variation was 4.3%, which indicates high accuracy in the counting of the GM between readers. Both the monthly percentage of spines with opaque edge as the marginal increment ratio showed that the deposition of the GM is annual. The length at age was backcalculated and the individual growth for sex was described using, the von Bertalanffy growth model. No significant differences were detected in the growth curves by sexes (ARSS; F3,20=0.104; p=0.95). The model growth parameters for pooled data were estimated (L∞=207 cm, k=0.45, t0=-0.17 years). The specie has a rapid growth, reaching over 70% of the asymptotic length at 3 years of age.