Pinfish, continued 



Life Mode 



Eggs that are fertile are semi-buoyant. Although little 

 is known about spawning areas and egg distributions, 

 they are assumed to be planktonic and offshore, based 

 on indirect evidence of their larval distributions (Sabins 

 and Truesdale 1974, Darcy 1985). The pinfish is 

 typically non-schooling, although compact aggrega- 

 tions have been reported (Kloth 1970). Pinfish have a 

 primarily diurnal pattern of activity, but some nocturnal 

 activity has been observed (Sogard et al. 1989). 



Habitat 



Ty pe: Eggs are marine and neritic. Larvae are marine 

 and estuarine. Larval pinfish are known to occur in the 

 Gulf of Mexico October through April, with peak abun- 

 dance Decemberthrough February (Ditty 1 986, Ditty et 

 al. 1 988). Juveniles are marine, estuarine and riverine. 

 Juveniles are common over areas of seagrass, where 

 activity appears to be associated with high tides (Fischer 

 1978, Sogard et al. 1989). Adults are marine to 

 riverine, preferring protected waters and depths of 30 

 to 50 m in the Gulf (Franks et al. 1972, Chittenden and 

 MacEachran 1976), but they have been collected in 

 waters as deep as 92 m (Perry 1 970). Adults probably 

 prefer euhaline (marine) salinities (Wang and Raney 

 1971). 



Substrate : The pinfish is most abundant over veg- 

 etated shallow flats, preferred mainly by juveniles, but 

 also occurs occasionally in other areas that offer some 

 degree of cover such as rocky bottoms, jetties, pilings, 

 and in mangrove areas (Reid 1954, Gunter and Hall 

 1965, Hansen 1970, Fischer 1978, Lee et al. 1980, 

 Coenetal. 1981). 



Physical/Chemical Characteristics : 

 Temperature: Pinfish are eurythermal, tolerating tem- 

 peratures from 3.4° to 37.5° C (Pineda 1 975, Roessler 

 1970, Lee et al. 1980). Water temperature has been 

 suggested as a major factor in the control of emigration 

 to offshore spawning sites. Extremely high and low 

 temperatures cause pinfish to leave shallow areas for 

 nearby deeper waters seasonally, and even daily 

 (Cameron 1969a). Increased water temperatures in- 

 crease the amount of erythrocytes and hemoglobin of 

 pinfish (Cameron 1970, Houston 1973). Tolerance to 

 cold temperatures is strongly influenced by acclimation 

 temperature, and this has led to ambiguous measures 

 of low lethal temperatures in the past (Bennett and 

 Judd 1 992). In a recent study, juveniles were found to 

 have a Critical Thermal Minimum (CTMin) of 3.4° C. 



Salinity: Pinfish are euryhaline, tolerating salinities 

 from to 43.8%o in the Gulf of Mexico (Roessler 1 970, 

 Pineda 1 975, Lee et al. 1 980). Vegetation rather than 

 salinity is thought to have a greater affect on the 

 distribution of pinfish (Weinstein 1979). However, 



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