NOTE Hazin et a\. Reproduction of Caicharinus acronotus 



145 



sidered a preliminary estimate of size at sexual maturity 

 because few individuals were caught between 95 and 105 

 cm TL and none between 75 and 95 cm TL. Compared with 

 pre-ovulatory females, those in the process of ovulation 

 had slightly wider oviducal glands and heavier ovaries 

 with thicker follicles (2.8-3 cm in diameter) (Fig. 1, A and 

 B, Table 1 ). Ovulation appeared to occur only when MOFD 

 was at least 2.8 cm (Fig IB). The majority of gravid, post- 

 partum, and resting females ranged in size from 111 to 

 131 cm TL and had similar-size oviducal glands (Fig. lA, 

 Table 1 ). Gravid females had undeveloped ovaries with no 

 vitellogenic activity (MOFD was less than 1 cm). Uteri in 

 postpartum females were flaccid and slightly distended 

 (4.2-5.6 cm in width), whereas uteri of resting females 

 were comparable to pre-ovulatory and ovulating individu- 

 als (Fig. IC, Table 1). No mating scars were observed on 

 any of the females. There was no evidence of spermatozoa 

 stored in the oviducal glands of 10 females examined. 



The temporal abundance of females according to stages 

 of reproduction showed that juveniles were present in 

 catches between January and November, but mainly from 

 February to June (Fig. 2A). Pre-ovulatory and ovulating 

 individuals were sampled between February and April 

 and April and May, respectively (Fig. 2A). Except for one 

 gravid female caught during August, all gravid, postpar- 

 tum, and resting females were caught between November 

 and January (Fig. 2A). MOFD of mature females was low- 

 est in August and between November and January, after 

 which it steadily increased to May (Fig. 2B). 



Examination of the uterine contents of the 22 gravid fe- 

 males (Table 2) revealed that individual litter size was al- 

 ways four with both sexes present in varying proportions, 

 although the total pooled ratio of males to females (1:1.25) 

 was not significantly different from 1:1 (x^=1.13, P>0.05). 

 All embryos from individual gravid females were at simi- 

 lar stages of development and showed small variation in 

 TL. ANOVA detected significant differences in mean TLs of 

 embryos among near-term females (F=20.51, P<0.01) and 

 for the main effect of months (F=10.45, P<0.05). ANOVA 

 showed that the mean (±SE) TL of embryos in three near- 

 term females caught on 10 December 1998 (45.96 ±0.38 cm) 

 was significantly longer than in three near-term females 



caught on 11 November 1998 (42.31 ±0.07 cm), suggesting 

 that embryos continued to develop between these periods. 



Male maturation and reproduction 



Of the 45 males examined, 23 were juvenile with thin epi- 

 didymides (Fig. 3A) and filiform ampullae of the ductus 

 deferens without seminal fluid. Juveniles ranging from 49 



