Table 3. — Standard lengths of pinfish of age-groups 0, I, and II in the lower Pensacola Estuary at stations I and II, 1963-65 



Date 



ms 



August 30-September 6 



October 29-November 1 



1964 



January 10-15 



FelHuary 28-March3.-. 



May 12-14. 



June29-July 1. 



August 3-5. 



August 31-September 2. 



September 28-30 



October 30-Novemt)er 3 



November 23-25 - 



1965 



January 12.. 



March3 



March 29 



May 6-12.. 



June 1-3 - 



June 25-29- 



August 2-4 . - 



August 30-September 1 



September 22-24 



October 26-27 



December 6-8 



caught at the sampling stations were 14 to l-tfi mm. 

 long.^ 



Pinfisli growth rates computed from changes in 

 lengths between consecutive trawling periods 

 varied with age group and season. Daily increase 

 in length averaged 0.19 mm. for 0-group pinfish 

 and 0.12 mm. for yearlings. Growth of both age 

 groups slowed as the seasons progressed from 

 spring to winter. Daily increase in length of 

 0-group pinfish averaged 0.32 mm. in the spring, 

 0.23 mm. in summer, and 0.01 mm. in fall; yearling 

 pinfish averaged 0.32 mm. in the spring, 0.21 mm. 

 in summer, —0.04 mm. in fall, and —0.02 mm. in 

 winter. Caldwell (1957) also observed maximum 

 growth in the spring and negligible gro\\-th in the 

 fall and winter. 



Annual growth rate of yearling pinfish, esti- 

 mated from increase in length after annulus for- 

 mation, was closely similar to that based on 

 increase in measured lengths, but seasonal growth 

 rates determined by the two methods ditfered. 

 Annual increase in length computed from scale 

 measurements a\'eraged 0.14 mm. per day, and 

 seasonal increases averaged 0.12 mm. per day in 

 tlie spring, 0.14 mm. in the summer, 0.20 mm. in 

 the fall, and O.09 mm. in the winter. 



1 standard length = 0..S5 forit length or 0.7S total length on the 

 basis of measurements of 100 fish, 44 to 101 mm. long. 



MIGRATION AND REPRODUCTION 



Limited data on estuarine movements of pinfish 

 were obtained from recaptures of fin-clipped or 

 tagged fish. Of 2(1,980 pinfish fin-clipped. 234 

 (0.87 percent) were recaptured at the area of orig- 

 inal capture during the trawling period in which 

 they were released and only 47 (0.17 percent) were 

 recovered 1 month or more after marking. There 

 could be several reasons for the low recapture 

 rates. The proportion of the population marked 

 was small, the marking mortality was high, or 

 unmarked fish from other areas were moving in. 

 Of the 47 fish recovered 1 month or more after 

 marking, 39 were caught at tlie station of release, 

 and eight had moved either from station I to 

 station II or from station II to station I (five did 

 .so in tiie 3 principal months of the spawning mi- 

 gration — August, September, and October). Of 

 284 pinfish tagged in April 19(i4, two were recap- 

 tured — one in July about 125 m. from wliere it was | 

 tagged and the other in Octol^er about 3 km. closer] 

 tothe mouth of the bay. 



On the basis of results of trawling and seining,! 

 I believe that most pinfish remain over the grass | 

 flats where they live in the spring until tliey 

 migrate out of the estuary in late summer and I 

 fall. Most appear to move very little in the summer, ! 

 but a few may wander over the grass flats. Fish j 



140 



U.S. FISH AND WILDLIB'E SPmVICE 



