ABSTRACTS OF THE 52ndANNUAL MEETING OF THE
GULF AND CARIBBEAN FISHERIES INSTITUTE
NOVEMBER 1 - 5, 1999
KEY WEST, FLORIDA USA

Aspects of Reproduction, Age and Growth of the Lane Snapper, Lutjanus synagris, (Linnaeus), 1785 in Jamaican Coastal Waters

KARL AIKEN
Department of Life Sciences
Universtity of the West Indies, Mona Campus
Jamaica, West Indies


The lane snapper, Lutjanus synagris (Linnaeus),1758 is the most important commercial species taken by the large and growing tangle and trammel net fishery on the south shelf of Jamaica. Samples taken from the commercial net fishery between February, 1996 and June, 1999 showed a size range from 150 - 430- mm FL with a mean of 232.1 mm FL (+ 52.4) (N= 1,094), both sexes combined. Most fishes in the samples were encountered already gutted. Mean sizes for male and female fishes were 219.5 (+ 3.72, N=99) and 220.0 mm FL (+ 9.82, N=227), respectively. Weight ranged from 75-1.100 g. Mean size at maturity was 268 mm FL (+ 0.27) and 221 mm FL (+ 1.85) in males and females respectively. Sex ratio (F:M) was 2.6:1.0 from 150-310 mm FL, and above that 100% female. There was prolonged spawning with a maximum in July for both sexes. Sagital otoliths were examined whole and by thin ( 300 micrometers) section and showed a series of opaque and hyaline bands. Whole otolith analysis produced a maximum age of six years, but sections showed a possible maximum age of between 16 and 17 years. Marginal increment analysis showed that one opaque zone was laid down in July and one hyaline in March annually. Otolith studies showed that the relationship between otolith weight and fork length may be described by the regression equation Y = 0.0403X - 1.543 (n= 0.9407) for males and Y = 0.0405 - 1.1716 (n = 0.9711) for females. The high correlation values suggests that the otolith weight changes with fork length may be used to estimate growth. L for females and males differs, with females achieving 460 mm FL, but males only 310 mm FL, ELEFAN produced growth parameters K = 0.19 - yr. L + 460 mm FL, and t0 - 0.001 (females).