Di Giacomo and Perier: Reproductive biology of Callorhynchus callorhynchus 



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5 

 4.5 



4 

 3 5 



3 

 2.5 



2 

 1.5 



1 

 0.5 







5 



4 5 



JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV 



5 

 



B 



JAN FEB MAR APR MAr JUN JUL AUG SEP OCT NOV 



JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV 



Figure 5 



Indices of reproductive activity of males of the cockfish, Callorhynchus callorhynchus. (A) Gonadal index (GI) 

 green gland index (GGI); (C) hepatic index (HI). 



(B) 



the green gland index was low) probably remained 

 from copulation during the previous year. After in- 

 semination, the spermatophores were apparently 

 mobilized by the female in coordination with the pro- 

 duction of egg cases in order to fertilize the oocytes. 



Spawning season 



The primary spawning season extended from July 

 to November. The mean size of females with egg cases 

 in formation increased from July to November (Fig. 

 8). Egg cases in an early stage of development were 

 found in bottom trawl catches at 105 m, whereas fe- 

 males with egg cases with embryos almost fully de- 

 veloped were found in bottom dredge catches at 

 depths ranging from 20 to 40 m. 



Discussion 



Morphology 



The morphology of the reproductive system of holo- 

 cephalan fishes has been described for Chimaera 



monstrosa and Callorhynchus antarcticus (Leigh- 

 Sharpe, 1922; Legendre, 1944), and Hydrolagus 

 colliei (Cox, 1963). Species of living holocephalans 

 are generally reported to lack a cloaca (Grasse, 1958; 

 Lagler et al., 1977); Malagrino et al. ( 1981) mentioned 

 the absence of a cloaca in females of Chimaera 

 phantasma as characteristic of the group. This con- 

 trasts with the elasmobranchs, in which the female 

 genital ducts terminate in the cloaca. Stanley ( 1963) 

 noted the presence of a cloaca in newly hatched males 

 and females of//, colliei, which is lost as they grow. 

 Callorhynchus callorhynchus, by contrast, has a 

 cloaca with a seminal receptacle where the spermato- 

 phores are stored. 



Reproductive cycle 



The peak of the male GI indicates the season when 

 testicular activity is at a maximum. The delay be- 

 tween maxima in GGI and GI may reflect a sequence 

 of phenomena: 1) production of spermatozoa in the 

 testes, 2) movement of spermatozoa through the ef- 



