220 



Fishery Bulletin 98(1) 



lengths for females and males were 295 and 245 mm 

 TL respectively (Castro-Aguirre, 1981). The length- 

 weight relationship suggested allometric growth and 

 was described by the following equation 



W = 0.000012 rL2 8-* 



(Fig. lA) 



The b coefficient was not significantly different (i^j 33= 

 2.15) between the sexes. 



Females of this species have two functional ovaries 

 and oviducts. Sixteen (70Vf ) of the females had mature 

 oocytes in their ovaries and a mean oocyte diameter 

 of 10.5 mm (range 2.0-21.8 mm). The relationship 

 of mean oocyte diameter with TL indicated that all 

 females were mature (Fig. IB). The size at first matu- 



•a 



140 

 110 

 80 

 50 

 20 

 -10 



W = 0000012Tl 

 r^ = 0.99 

 n =40 



50 



100 150 200 



Total length (mm) 



250 



300 



40 



80 

 J. I, 60 



I s 



■3 ~ 

 u ?. 20 



^ -e 



220 



90 

 •^ 30 



230 240 250 260 



Female total length (mm) 



270 



J '0 



U 

 -10 



50 100 150 200 250 



Total length (mm) 



300 



Figure 1 



Cephalurus cephalus. (A) Length-weight relationship. 

 (Bl Relationships between oocyte diameter and embr>o 

 total length with female total lengths. (Ci Relationship 

 between total length and clasper length. Data less than 

 75 mm TL are from embryonic material. Data from 

 Castro-Aguirre ( 1981 ) are denoted by solid circles. 



rity has previously been estimated to be 190 mm TL 

 (Compagno, 1984). The large diameter of the oocytes 

 suggested that spawning occurs in early summer. 



Embryonic development of C. cephalus occurs in 

 the uterine tract and is described as aplacental vivi- 

 parity or ovoviviparity (Wourms, 1977, 1981; Com- 

 pagno, 1984). The thin-walled egg cases of C. cephalus, 

 which are retained in the oviducts, were observed in 

 11 individuals. The three largest females had neither 

 eggs in the oviducts nor large oocytes in their ovaries 

 and may have finished their reproductive cycle. 



The mean size of the 19 embryos was 43 mm TL ( size 

 range 21 to 65 mm TL), which is less than the esti- 

 mated size at birth (100 mm; Compagno, 1984), and 

 the sex ratio of embryos (9 males, 10 females) was 

 aproximately equal. The relation between clasper 

 length and total length of adults and embryos is 

 illustrated in Figure IC. 



Parmaturus xaniurus 



Of 51 specimens captured, 22 were female and 29 

 were male. Females measured 108 to 350 mm TL 

 (.v=184 mm TL), males 117 to 380 mm TL (.r=233 mm 

 TL). The largest recorded lengths are 574 mm TL for 

 females and 600 mm TL for males (Springer, 1979). 

 The length-weight relationship of P. xaniurus indi- 

 cated allometric growth (Fig. 2A) and was described 

 by the following equation: 



W= 5.5 X 10-^ TL3 34. 



The analysis by sex (males: W= 6.76 x 10"^ TL^-^i; 

 females: W=9.53 x 10'" TL^-) did not reveal sig- 

 nificant differences in the b coefficient (Fj 45=0.14) 

 as reported by Cross (1988) for specimens from the 

 upper continental slope off southern California. 



All females examined were immature and did not 

 contain mature oocytes. Cross (1988) noted that 

 females first reached maturity at 425-475 mm TL 

 in southern California waters. Parmaturus xaniurus 

 is oviparous, and the egg cases of this species have 

 been described by Cox (1963). Embryonic develop- 

 ment lasts approximately one year (Compagno, 1984; 

 Cross, 1988). The relationship between total length 

 and clasper length suggested that males matured at 

 340 mm TL (Fig. 2B), and this size at first maturity 

 was smaller than that previously recorded (375 to 

 425 mm TL; Cross, 1988). This may reflect latitudinal 

 differences in the reproductive biology of P xaniurus. 



Acknowledgments 



We thank Edgar Amador, Carolina Downton, Dinorah 

 Herrero, M. Angeles Cobarrubias, and Carmifia A. 



