Five gray snapper sampled by spear fishing from Bear Cut, Biscayne Bay (fork lengths 
387 to 480 mm.) ranged in age from four to seven years. Gray snapper four years of 
age and older appear only infrequently in the sport fishery catch in the Everglades 
National Park. Gray snapper average 7.1 in fork length at two years of age, and are 
recruited into the sport fishery at this time. The age at maturity of gray snapper in 
south Florida is not known, although it is greater than three years. There is no 
consistent difference in the mean fork lengths of male and female gray snapper of the 
same age for first four years of life. Mean fork lengths of gray snapper for the first 
four years of life, sexes are combined, are: 3.2, 7.1, 9.5, and 11.6 in. Mean fork 
lengths of gray snapper for the first four years of life, sexes combined, are: 3.2, 7.1, 
9.5, and 11.6 in. Growth of gray snapper from the Everglades National Park is rapid to 
the second year, followed by a moderate decrease to the third year, and almost similar 
growth to four years of age. Continued growth of gray snapper in south Florida beyond 
the age of four years is evident from the examination of scales from fish five to seven 
years of age taken from Biscayne Bay. The gonads of 790 gray snapper were examined 
for macroscopic appearance between July 1959, and April 1960. With the exception of 
five fish from Biscayne Bay, all fish were assigned to one of two initial maturity 
stages. Nearly ripe, ripe, and spent fish were not observed during this study. Gray 
snapper in the Everglades National Park, therefore, appear to pass through two 
immature gonad stages. Gonad studies have shown the sport fishery catch for gray 
snapper in the Everglades National Park to consist of immature fish. The five fish 
examined from Biscayne Bay, fork lengths 387 to 480 mm. and four to seven years of 
age, could conceivably be assigned to a third stage of gonad maturation. The specific 
time, duration, and place of spawning of gray snapper in south Florida is not known. 
Several factors point to a possible early summer spawning period. Collections of 
juvenile gray snapper from central Florida and the Florida Keys report the smallest fish 
collected during the late summer and early fall. Sizes of these fish when compared with 
mean fork lengths of gray snapper at first annulus formation during the period 
December to February, give evidence of a possible early summer spawning period. Gray 
snapper from the Everglades National Park may not be one year old at first annulus 
formation, but six- to eight-months of age. The Everglades National Park waters are 
important nursery grounds for young gray snapper one to three years of age. There is 
no significant difference in the length-weight relationship of male and female gray 
snapper sampled during the study. Gray snapper caught in the sport fishery in the 
Everglades National Park average one-half pound. The stomachs of 200 gray snapper 
were examined during this study. One hundred ninety-five were from the Everglades 
National Park specimens, and five were from Biscayne Bay. The fish ranged from 135 
to 480 mm fork length. Fifty four, or 27%, of the stomachs were empty. All five of the 
Biscayne Bay stomachs were empty. No significant difference in food preference was 
noted from month to month, or for snappers of different sizes. L. griseus preys largely 
on Crustacea; 79% of the stomachs contained at least one type of Crustacea. 
Crustaceans made up 61.6% of food items by number, and 76.7% by volume. When bait 
shrimp were separated from naturally occurring shrimp, shrimp still held prominence 
over any other food item, occurring in 42% of the stomachs containing food. Fish and 
crabs occurred in 34 and 27% of the stomachs respectively. Gray snapper feed near 
rocky and mangrove shore-lines in addition to foraging further out onto grassy and 
sandy flats, and into nearby channels. 
959 - 1960 
Croker, R. A. (1962) Growth and food of the gray snapper, Lutjanus griseus in Everglades 
National Park. Trans. Amer. Fish Soc. . 91 (4):379-83. 
A study of the biology of the gray snapper was based on the examination of 849 fish 
collected primarily from the sport fishery of Everglades National Park. Gray snappers 
