Rocha-Olivares: Age, growth, and mortality of Lutjanus peru 
573 
between sexes. The higher mortality rate of males 
may account for the biased sex ratio. In no other 
lutjanid species has such a large difference in total 
mortality been observed between males and females. 
Whether this difference results from different avail- 
ability to the fishing gear, spatial segregation, or for- 
aging behaviors (F - associated difference), or from dif- 
ferences in predator vulnerability or natural longevity 
(M-associated difference) requires further research. 
In this paper I have compared the merit of scales, 
whole otoliths, and sectioned otoliths to age the Pa- 
cific red snapper, L. peru. As is the case for other tropi- 
cal and semitropical fishes, the usefulness of whole- 
otolith age determination is limited up to a certain 
age, after which, sectioned otoliths are the only reli- 
able method for ageing and scales should be avoided. 
Age determinations from whole and sectioned otoliths 
of fishes covering most of the known size range of L. 
peru were used to determine the VBGF parameters. 
A 31-year-old fish measuring 99.2 cm is reported and 
constitutes a record size and age. Total mortality 
rates were higher for males resulting in a prepon- 
derance of females among the older fishes. 
Acknowledgments 
I am very grateful to Jon Elorduy Garay and Victor 
M. Gomez Munoz for their support and encourage- 
ment. Juan G. Diaz helped in the laborious task of 
reading otoliths. Thanks to Silvia Ramirez and 
Roberto Carmona for their help and enthusiasm. 
Initial drafts of the paper benefited from comments 
by Larry Jacobson, Nancy Lo, Richard Rosenblatt, 
and John Butler, and were prepared while the au- 
thor held a predoctoral fellowship from the Mexican 
Consejo Nacional de Ciencia y Tecnologia (CONACyT). 
Four anonymous reviewers provided insightful com- 
ments and kindly pointed to additional references. 
Financial support was obtained from DGICSA-SEP 
grants C89-01-0191 and C90-01-0406 to Jon Elorduy 
Garay. 
Literature cited 
Aguilar Salazar, F. A. 
1986. Determinacion de la edad y estimacion de la tasa de 
crecimiento del huachinango del Pacifico mexicano 
Lutjanus peru (Nichols y Murphy, 1922), por el metodo de 
lectura de escamas. Tesis profesional, Facultad de 
Ciencias, Universidad Nacional Autonoma de Mexico, 
74 p. 
Beamish, R. J., and D. A. Fournier. 
1981. A method for comparing the precision of a set of age 
determinations. Can. J. Fish. Aquat. Sci. 38:982-983. 
Beamish, R. J., and G. A. McFarlane. 
1987. Current trends in age determination methodology. In 
R. C. Summerfelt and G. E. Hall (eds.), Age and growth of 
fish, p. 15-42. Iowa State Univ. Press, Ames, IA. 
Bernard, D. R. 
1981 Multivariate analysis as a means of comparing 
growth in fish. Can. J. Fish. Aquat. Sci. 38:233-236. 
Bilton, H. T. 
1973. Effects of starvation and feeding on circulus forma- 
tion on scales of young sockeye salmon of four racial ori- 
gins and of one race of young kokanee, coho and chinook 
salmon. In T. B. Bagenal (ed.), The ageing of fish, p. 40- 
70. Unwin Brothers Ltd., Surrey, England. 
Boehlert, G. W. 
1985. Using objective criteria and multiple regression models 
for age determination in fishes. Fish. Bull. 83( 2 ): 103—1 17. 
Castro, F. C. 
1981. Determinacion de la edad y crecimiento ( Lutjanus 
peru). Ciencias del Mar 1:4-8. 
Coggan, R., K. Skora, A. Murray, and M. White. 
1990. A comparison between age determinations of the 
Antarctic fish Notothenia gibberifrons Lonnberg using 
scales and otoliths. Cybium 14(11:43-55. 
Draper, N. R., and H. Smith. 
1981 Applied regression analysis. John Wiley, New York, 
NY, 709 p. 
FAO. 
1982. Metodos de recoleccion y analisis de datos de talla y 
edad para la evaluacion de poblaciones de peces. FAO 
Fisheries Circular 736, FAO, Rome, 101 p. 
Ferreira, B. P., and G. R. Russ. 
1994. Age validation and estimation of growth rate of the 
coral trout, Pleetropomus leopardus , (Lacepede 1802) from 
Lizard Island, Northern Great Barrier Reef. Fish. Bull. 
92(0:46-57. 
Gorelova, T. A. 
1979. Experimental data on the digestion rate in finger- 
lings of the snapper, Lutjanus peru. J. Ichthyol. 19(6): 
161-164. 
Grimes, C. B. 
1987. Reproductive biology of the Lutjanidae: a review. In 
J. J. Polovina and S. Ralston (eds.), Tropical snappers and 
groupers: biology and fisheries management, p. 239- 
294. Westview Press, Inc., Boulder, CO. 
Gutierrez Vargas, R. 
1990 Tasas de crecimiento, mortalidad, reclutamiento, 
rendimiento y biomasa relativos por recluta de Lutjanus 
peru (Perciformes: Lutjanidae) en el Pacifico Noroeste de 
Costa Rica. Rev. Biol. Trop. 38(2B):441-447. 
Hoenig, J. M. 
1983. Empirical use of longevity data to estimate mortal- 
ity rates. Fish. Bull. 82(11:898-903. 
Libby, D. A. 
1985. A comparison of scale and otolith aging methods for the 
alewife, Alosa pseudoharengus. Fish. Bull. 83(41:696-701. 
Lou, D. C. 
1992. Validation of annual growth bands in the otolith of 
tropical parrotfishes Scarus schlegeli (Bleeker). J. Fish 
Biol. 41(5):775-790. 
Loubens, G. 
1980. Biologie de quelques especes de poissons du lagon 
Neo-Caledonian III. Croissance. Cahiers de l’lndo-Pacific- 
que 2:101-153. 
Lowerre-Barbieri, S. K., M. E. Chittenden Jr., and 
C. M. Jones. 
1994. A comparison of a validated otolith method to age 
