434 



Fishery Bulletin 101(2) 



1(K) 

 80 

 60 

 40 

 20 

 



Total length = 300 mm 



D April 1995 

  June 1995 



-J4--t- 



Total length = 400 mm 



D April 1995 

  June 1995 



Oocyte diameter (mm) 



Figure 5 



Oocyte size frequency distributions (0.05-mm intervals) in tautog ovaries. Six fish are 

 represented, two in each length class: (A) 300 mm, (B) 400 mm, (C) 450 mm. Collection 

 dates were 26 April 1995 and 2 June 1995. Fish were staged macroscopically as hydrated 

 or running ripe, and oocytes were hydraulically separated and the diameter of 500 oocytes 

 was measured to the nearest 0.001 mm. 



Oocyte size-frequency distributions measured at the begin- 

 ning and end of the spawning season were also used to classi- 

 fy tautog annual fecundity as determinate or indeterminate. 

 Primary growth and cortical alveoli oocytes were continu- 

 ously yolked, matured, and spawned throughout the spawn- 

 ing season, evidenced by 1 ) lack of hiatus between advanced 

 yolked oocytes and less mature oocytes, and 2) abundance 



of yolked oocytes (size range 0.30-0.55 mm) not decreasing 

 over the spawning season (Fig. 5). This type of development 

 defines tautog as having indeterminate fecundity. 



Two patterns of oocyte development are common among 

 multiple spawning fishes: group synchronous and asyn- 

 chronous oocyte development. Tautog oocyte size-frequency 

 distributions (Fig. 5) show no distinct gaps in develop- 



