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Fishery Bulletin 92(3). 1994 



frontal 

 tenaculum 



prepelvic 

 claspers 



lasper 



Figure 4 



Male secondary sexual structures of cockfish, Callor- 

 hynchus callorhynchus. (A) Frontal tenaculum; (B) 

 prepelvic and pelvic claspers. 



Gonad and green gland indices were highly vari- 

 able within size classes during the period of maxi- 

 mum activity. There was no relationship between SL 

 and GI (r 2 =0.001;P>0.05; 2V=121), or between SL and 

 GGI (^=0.021; P>0.05;iV=101). Similarly, no relation- 

 ship was found between female SL and GI (r 2 =0.18; 

 P>0.05; N=58) or NGI (r 2 =0.012; P>0.05; N=48). 



Size at sexual maturity 



Immature and mature males could be identified from 

 the relationship between SL and length of the 

 myxopterygia. The myxopterygia did not exceed the 

 posterior margin of the pelvic fin in immature indi- 

 viduals, whereas in mature individuals it consisted 

 of partially calcified structures that exceeded the pos- 



terior margin of the pelvic fin. The length offish mea- 

 sured l./V=123) ranged from 26 cm to 55 cm. Length 

 at first maturity of males was estimated to be 40 cm, 

 corresponding to a length of the myxopterygia of 45 

 mm. No individuals between juvenile and mature 

 stages were observed. Juvenile stages were found in 

 shallow waters (depth range 15-25 m) whereas 

 adults were found in waters deeper than 25 m (Di 

 Giacomo, 1992). Most mature females were larger 

 than 50 cm (SL), whereas all females smaller than 

 48 cm were immature. 



Ovarian maturation 



The percentage of mature oocytes was greatest in 

 August in both ovaries, coinciding with maxima in 

 the indices of reproductive activity. Nevertheless, 

 some mature oocytes were observed throughout the 

 year (Fig. 7A). Mean number of mature oocytes was 

 highest from July to October. There was a signifi- 

 cant difference between the average number of ma- 

 ture oocytes in the right and left ovaries of individual 

 mature females (Wilcoxon test, P<0.05; Fig. 7B). 



Oocyte diameter increased with female size 

 (r 2 =0.083;P<0.01;A^=90). Maximum oocyte diameter 

 (48 mm) was recorded for a female of 71 cm SL. The 

 regression of number of immature oocytes on SL showed 

 a similar trend, indicating that average reproductive 

 potential increases with size (?~=0.024;P<0.01; Af=101). 



Oocytes smaller than 10 mm (diameter) were 

 translucent to lightly whitish. Coloration of oocytes 

 larger than 10 mm changed gradually. Yolk was in- 

 corporated until the oocytes reached complete devel- 

 opment and passed to the nidamental gland. Pro- 

 duction of egg cases began in the nidamental gland, 

 when the oocytes reached maturity. The closed end 

 of the egg case was caudally oriented; the cephalic 

 portion remained open until the case was completely 

 formed. When the egg case was about two-thirds of 

 its final size, ovulation occurred and the egg (with a 

 variable diameter that ranged from 40 to 48 mm ) moved 

 from the ovaries, through the oviduct, to the case. 



Mating season 



Spermatophores were found in the vaginal recep- 

 tacles associated with the female cloaca. Mating oc- 

 curred primarily from July to February, when 

 maxima in the GGI were indicative of active produc- 

 tion of spermatophores. The highest percentage of 

 females with spermatophores in the cloaca was also 

 observed during these months (Fig. 8). In October, 

 recently deposited spermatophores in the female 

 cloaca, characterized macroscopically by an intense 

 green color, resembled green gland products. Yellow- 

 ish spermatophores found in March and May (when 



