Results 



The counts of rings within otoliths are summa- 

 rized in Table 1. The average number of rings for 

 each fish has been rounded to the nearest integer. 



On the assumption that one ring is equal to one 

 day's growth (Pannella 1971, 1974; Struhsaker and 

 Uchiyama 1976), the data were fitted to the von 

 Bertalanffy growth equation employing the tech- 

 niques of Allen (1966). This model states: 



/, -L^(l-e 



Kit 



''') 



(1) 



where /, = length at time ^ 



Loo = the average length of a group of fish 



grown for an infinite period of time 

 K =a. growth parameter which describes 

 the rate at which /, is approaching L^ 

 ^0 =the back calculated X intercept or the 

 time at which size was zero. 



120- 



I 100 



60- 



•o 

 c 

 • 40 



20 



I 







r" 

 



I, a 127(1- • 



-00311*301 



200 



T 1 r 



400 

 Days 



600 



800 



Year* 



FiGL'RE 3. -The von Bertalanffy growth curve in length fitted to 

 15 individuals of Chaetadon niiliaris aged by means of otoliths. 



The data are plotted along the calculated von 

 Bertalanffy growth curve in Figure 3. The cal- 

 culated growth equation for the data in this report 

 is: 



/, = 127(1 - e 



,-0.0031(/+30) 



) 



(2) 



when size is expressed as SL in millimeters and 

 time is expressed in days. Alternatively, when 

 time is expressed in years, the equation becomes: 



/, = 127(1 -g-'l^<'+0.08-'))_ 



(3) 



The estimated asymptotic size of 127 mm SL is a 

 reasonable figure. Of 345 C. miliaris examined in 

 another study (Ralston 1975), 4 were larger than 

 this size. Of those, three were 131 mm SL or less. 



Table l.-The number of rings counted in the otoliths of 

 Chaetodon miliaria collected around Oahu, Hawaii, 1974. 



while the fourth was 137 mm SL. Because L^ can 

 be thought of as an average, if sampling is inten- 

 sive enough, one would expect to find individuals 

 of a larger size. Of all the fish sampled in this 

 earlier study, only 1.2% were larger than the 

 estimated growth ceiling of the von Bertalanffy 

 model as determined from the otoliths of the 15 

 individuals reported on here. 



The growth of C. miliaris is very fast. The 

 estimated growth parameter, K, of the von 

 Bertalanffy equation describes how quickly 

 growth proceeds. Large values of K are associated 

 with rapid growth. Beverton and Holt (1959) 

 presented values of K for 57 species of fishes and of 

 those, only 6 species have K values exceeding that 

 of C. miliaris. 



It should also be noted that only fish which were 

 less than 90 mm SL are reported on here. It was 

 found that the otoliths of larger fish became 

 increasingly difficult to read. Not only do the 

 otoliths become thicker, but the peripheral ring 

 increments become smaller with growth. For these 

 reasons, larger fish could not be reliably aged in 

 this study. 



Discussion 



On 2 August 1966, Wass (1967) defaunated a 

 small patch reef in Kaneohe Bay, Hawaii, while 

 studying the repopulation rates of various species 

 of fishes. In so doing, he sampled 476 C. miliaris in 

 1 day. He gave a size-frequency distribution, 



992 



