Simpfendorfer; Growth rates of Carcharhinus obscurus 



819 



12 3 4 5 



Age (years) 



Figure 7 



Comparison of growth rates from three methods used in the current study (open 

 symbols: circle = Fabens 11965) method; square = Francis 11988] method; diamond = 

 length-at-age method! and previous research (solid symbols; circle = length-at-age 

 from vertebrae; square = tag-recapture data from Natanson et al. [1995); triangle = 

 Natanson and Kohler [1996)). 



Table 5 



Results of homogeneity-of-slopes models in which growth rates between male and female, and injected and noninjeeted Carcharhi- 

 nus obscurus were compared. ** indicates significant effects. SS = sum of squares. 



Comparison 



Effect 



SS 



df 



Male with female 



Male 



Injected with noninjeeted 



Female 



Injected with noninjeeted 



' Becau.'ie age  aex interaction is significant, comparisons of injected and noninjeeted groups must be conducted for males and females separately. 



rus. The value of v in the present study (0.24-0.40) was 

 higher than that estimated for Galeoi-hinus galeus (0.06) 

 (Francis and Mulligan, 1998), but lower than for Muste- 

 lus antaixticiis (0.58) (Francis and Francis, 1992). Francis 

 and Mulligan (1998) suggested that their data might not 

 contain enough information to distinguish between mea- 



surement error and growth variability. Francis ( 1997) and 

 Francis et al. ( 1999) reported similar levels of growth vari- 

 ability for elephantfish (Callorhinchus milii) and hapuku 

 (Polypnon oxygeneios), respectively. Growth variability 

 therefore'appears consistently to be relatively high across 

 a range of elasmobranch, chimaerid, and teleost fishes. 



