were all ripe. Furthermore, Christensen (1965) 

 found evidence that checkered puffers from Jupi- 

 ter Inlet, Fla., spawned in low salinity waters dur- 

 ing the fall. He found young fish (s£lO mm SL) 

 from early November through December in waters 

 having salinities generally <20%ii. He also ob- 

 served that young and juveniles were abundant in 

 the upper reaches of the Loxahatchee River ( which 

 flows into Jupiter Inlet ) durmg winter and spring, 

 rarely being found elsewhere. Thus, the checkered 

 puffers leaving the seagrass bed in the present 

 study may have been going to spawn in lower 

 salinity waters found along portions of western 

 Biscayne Bay or in the Miami River. This would 

 explain why no checkered puffers <25 mm SL 

 were captured, except for six in October. Most 

 young likely remain in brackish water areas and 

 move into higher salinity habitats only at larger 

 sizes the following year. The 80-119 mm SL group 

 appearing in August probably composed the 1-yr- 

 old fish moving into the seagrass bed. 



The checkered puffer spawning season, begin- 

 ning in the spring and concentrated during sum- 

 mer and early fall in Biscayne Bay, occurs slightly 

 later than the spring and summer spawning of the 

 southern puffer, S. nephelus, at Cedar Key, Fla. 

 (Reid 1954). The northern puffer in Chesapeake 

 Bay has been reported to spawn during May by 

 Hildebrand and Schroeder ( 19281 and during late 

 May, June, and July by Laroche and Davis (1973). 



Fecundity analysis, using the gravimetric 

 technique, was done on nine checkered puffer 

 females ranging from 127 to 178 mm SL (99-256 

 g). Only yolky eggs, with nuclei obscured, were 

 counted. Regression analyses of fecundity- 

 standard length and fecundity-body weight were 

 done using functional regressions (Ricker 1973). 

 Total fecundity increased exponentially as a func- 

 tion of body length (Figure 4) and linearly as a 

 function of body weight (Fecundity = 1,431.81 

 [Body wt in grams] - 45,704.97; r = 0.96), Over 

 the size range examined, relative fecundity aver- 

 aged 1,146 eggs/g body wt. These fecundity values 

 are greater than those found by Merriner and 

 Laroche ( 1977) for northern puffers in Chesapeake 

 Bay. Of the six checkered puffers <25 mm SL, two 

 (15 and 23 mm SL) were males and the sex of the 

 rest ( 17, 17, 18, and 21 mm SL) was undetermm- 

 able. Thus, it was not possible to estimate the body 

 size at which eggs become discernible. 



The age structure of the checkered puffer popu- 

 lation can be inferred from the monthly length- 

 frequency distributions (Figure 3). The 80-119 



V: 0O48 X 

 r: 88 



50-1 1 1 r 



120 130 140 150 180 



STANDARD LENGTH (mm) 



Flia'RK 4— Tola) fecundity-standard length relationship for 

 nine checkered puffers from Biscayne Bay, Fla. Functional re- 

 gression parameters derived by least squares fit to log trans- 

 formed data, where variance about regression wasSy.,^-0.(X)78. 



mm SL group appearing in August is likely 1-yr- 

 old fish which grow to 1 20- 1 89 mm SL by the end of 

 their second year. A comparison of the growth of 

 checkered puffers in this population with results 

 from the work of Laroche and Davis (1973) on 

 northern puffers from Chesapeake Bay shows that 

 the checkered puffers reach a smaller size at the 

 end of each year of life and are shorter lived than 

 the northern puffers. 



Eggs became discernible, by microscope, in 

 bandtail puffers at 25-30 mm SL. Spawning sea- 

 son, however, was not easily determined. No ripe 

 or nearly ripe bandtail puffers were caught despite 

 the fact that this species was abundant through- 

 out the year and the full size range (to approxi- 

 mately 160 mmTL(Shipp 1974)) was captured. At 

 least one fish <30 mm SL was collected every 

 month except September, November, and De- 

 cember, although most were captured during 

 March through June. This implies that bandtail 

 puffers have a long spawning season, concentrated 

 in the late fall and early winter, and spawn 

 elsewhere with the young moving into the sea- 

 grass bed shortly after hatching. 



Both checkered and bandtail puffers feed 

 mainly on crabs, bivalves, and gastropods (Targett 

 1978). They use their beaklike jaws (paired pre- 

 maxillary and dentary bones) to break the shelled 

 prey. Two specimens of both species were cleared 

 and stained, revealing that they have similar 



294 



