726 



Fishei^ Bulletin 98(4) 



Reproduction 



Reproductive analyses were based on gonad weights and 

 a histological examination of gonadal tissue. Fish sampled 

 were put on ice soon after capture, and we sampled fish 

 within 36 hours after their capture by the recreational fish- 

 ery and 10 days after their capture by the commercial fish- 

 ery. Whole gonads were weighed to the nearest 0. 1 g. Some 

 fish were gutted before they were landed. If a portion of 

 gonad was present, it was removed for histological prepa- 

 ration; if none was present, the sex of the fish was listed as 

 unknown. Gonads were fixed in lOVf buffered formalin for 

 approximately one week, rinsed in water, and then trans- 

 ferred to 70';'f ethanol. We removed a sample of tissue from 

 the middle of the preserved gonad and embedded it in 

 paraffin. Several 5.0-pm sections were serially cut from 

 the sample, stained with Harris's haematoxylin, counter- 

 stained with eosin (Humason, 1972), and examined under 

 a compound microscope to determine sex and developmen- 

 tal state of the gonads. For ovaries, we staged oocytes 

 as being primary gi'owth, cortical alveoli, or vitellogenic 

 oocytes, or as mature oocytes by using criteria developed by 

 Moe (1969), Wallace and Selman (1981). and West (1990). 

 The frequency of occurrence of oocyte developmental stages 

 (including atretic bodies and postovulatory follicles) was 

 tabulated for approximately 300 oocytes from each ovary 

 by using a computer-driven data-acquisition software pack- 

 age (Optimas Corp.. 1996). Mature ovaries were distin- 

 guished from immature ovaries by the presence of atretic 

 bodies, advanced oocyte development stages (vitellogenic 

 or mature oocytes), or both. Testes were assigned to devel- 

 opment classes (Table 1) by using a modified classification 

 scheme developed from Hyder ( 1969 ) and Moe ( 1969 ). Tran- 

 sitional males (individuals with gonads in transition from 

 ovaries to testes I were identified according to the criteria of 

 Sadovy and Shapiro ( 1987). 



Sex ratios for all se-\ed fish were compared for signif- 

 icant differences from 1:1 by using the chi-square test 

 (Snedecor and Cochran. 1971). The length and age at 

 which 50'/f of the population consisted of males was esti- 

 mated by fitting a logistic curve to length and age data 

 with sex as a binary response equal to zero for females 

 and to one for males. The curves were fitted to the data by 

 using nonlinear regression (Jandel Corp., 1992). 



Reproductive seasonality was determined by examining 

 the monthly changes in gonad stages, the monthly distri- 

 bution of oocyte stages, and the monthly changes in the 

 gonosomatic index (GSI).The GSI was calculated by using 

 the following equation: 



GSI = gonad wvightliwhole weight -gonad weight). 



Results 



Collections 



We sampled 877 red porgy that ranged from 194 to 489 

 mm in length. Although we did not record the locations 

 where fishermen caught their fisli, most fishing effort was 



Table 1 



Development classes for testes of red porgy. 



Classes 



lestes 



Transitional Massive atresia of oocytes. Spermatogonia, 

 spermatocytes, and (or) spermatids devel- 

 oping in lumen of testicular lumen. Tailed 

 sperm may be present. 



Resting Mostly spermatogonia and spermatocytes 



present in the central lobules. Free sperma- 

 tozoa in the lumen of the lobule, and brown 

 bodies (Grier, 1987) may be present. 



Developing Mostly spermatocytes and spermatids pres- 

 ent in the central lobules, free spermato- 

 zoa in the lumen of the lobule. 



Ripe 



Spent 



Mostly spermatozoa found in the central 

 lobules and in the lumen of the lobule; all 

 or later stages of spermatogenesis occur- 

 ring in the peripheral lobules. 



Few free spermatozoa in the lumen of the 

 lobule; early stages of spermatogenesis in 

 the peripheral lobules. 



directed in the Florida Middle Ground and off west central 

 Florida. Most fish (92%) were in length classes between 

 251 and 400 mm long and had a modal length class 

 of 326-350 mm (Fig. 2). Relationships between lengths, 

 between whole weight and gutted weight, and between TL 

 and weight are shown in Table 2. Male and female data 

 were pooled for the weight-length relationship because 

 sex-specific regression equations were not significantly dif- 

 ferent (ANCOVA, P>0.05). Most of the fish sampled were 

 from the recreational fishery (/;=601), and they ranged 

 in length from 205 to 455 mm (Fig. 2). Fish from the 

 commercial fishery («=276) ranged from 265 to 489 mm 

 (Fig. 2). The mean length of recreationally caught fish 

 (321 mm, SE=40) was significantly less than the mean 

 length of commercially caught fish (350 mm, SE=40; Mest, 

 P<0.001). The length-frequency distributions for commer- 

 cially and recreationally caught fish were significantly 

 different (D=0.287, P<0.001). Males in=S31) ranged in 

 length from 248 to 470 mm and females (/!=456) from 

 205 to 455 mm (Table 3). The mean length of males 

 (341 mm. SE=36.3) was significantly greater than that of 

 females (316.2 mm, SE=40.5; t-test. P<0.001). The length- 

 frequency distributions for males and females were sig- 

 nificantly different (D=0.317, P<0.001). The largest fish 

 examined (489 mm) had been gutted; therefore the sex of 

 the specimen was unknown. 



Age, growth, and mortality 



Under reflected light, alternating opaque (white) and 

 translucent (dark) zones were evident in red porgy oto- 

 liths (Fig. 1). Two readers examined a subsample of 241 

 otoliths, and 50% of their readings were in agreement. 

 Most of the disagreements (71'r) differed by only one 



