Manickchand-Heileman and Phillip: Age and growth of Epinephelus flavolimbatus and Mycteroperca interstitialis 



293 



TL = 111.40i? - 105.2 



(«=:330, r-'=0.93). 



Number of rings increased with 

 fish length; 3-35 rings were found 

 in yellowedge grouper between 282 

 and 985 mm TL. 



Of the 90 otohths read for the 

 yellowmouth grouper, satisfactory 

 annuH counts were made on 80. 

 A random subsample of 33 oto- 

 hths was read by an independent 

 reader and a 98'7f agreement was 

 found. For this species frequency 

 of otohths with an opaque edge 

 showed significant monthly varia- 

 tion (P<0.001 ), with elevated values 

 occurring from September to Janu- 

 ary (Fig. 3). Growth of the otolith was proportional to 

 growth in length and the relationship between fork 

 length (FL) and otolith radius was 



FL = 162.97 + 90.860/? 



(,7=57, r2=0.811 



The number of rings increased with fish length; 5-41 

 rings were found in yellowmouth grouper between 

 335 and 827 mm FL. 



The monthly sample sizes shown in Figures 2 and 

 3 indicate the seasonal pattern of catches for both 

 species in this study area. At the extremities of the 

 year, catches were low because fishing is restricted 

 to shallow waters owing to rough seas that prevail 

 at this time. 



Age and growth 



For both species, the growth parameters are presented 

 for combined sexes because in some instances oto- 

 liths were obtained from fish that were gutted at sea 

 and thus of unknown sex. The relationship between 

 fish length and otolith radius was used to backcal- 

 culate lengths of fish at earlier ages. Owing to the 

 narrowing of the space between successive annuli in 

 older individuals and the resulting difficulty in making 

 accurate measurements, radii were measured in 231 

 yellowedge grouper with 3 to 15 rings. Mean back- 

 calculated lengths for yellowedge gi-ouper are given 

 in Table 1. Close agreement was found between the 

 observed, backcalculated, and theoretical growth curves 

 for this species, although for some age groups the back- 

 calculated lengths were greater than observed lengths 

 ( Fig. 4 ). The von Bertalanffy growth parameters ( asymp- 

 totic standard error) for observed length and age data for 

 the yellowedge gi'ouper were L^., = 963 mm TL ( 18.8 mm), 

 K= 0.099/yr (0.01 yr), /'„= -0.08 years (0.28 yr). 



Owing to naiTOwing of the space between annuli 

 in older individuals and difficulty in making accurate 

 measurements, it was possible to measure radii in 

 only 20 yellowmouth grouper, with 5 to 19 rings. Mean 

 backcalculated lengths for yellowmouth gi'ouper are 

 given in Table 2. Close agreement was also found 

 between the observed, backcalculated and theoretical 

 growth curves for this species, although some backcal- 

 culated lengths were greater than obsei-ved lengths, 

 particularly for the younger age groups (Fig. 5). For 

 the yellowmouth grouper, the von Bertalanffy growth 

 parameters (asymptotic standard error) for observed 

 length at age data were L„ = 854 mm FL (59.9 mm), 

 K= 0.057/yi- (0.01/yr), 1^= -4.6 years (2.29 yr). 



Length-weight relationship 



For the yellowedge grouper, the relationship between 

 total body weight (Wt) and length (TL) was 



