522 



Fishery Bulletin 92|3). 1994 



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Figure 3 



Light micrograph of a section of ovary from a brick soldierfish, Myripristis amaena, showing oocyte 

 development stages: (a) primary growth, (b) perinuclear, (c) early yolk vesicle, (d) late yolk vesicle, (e) 

 yolk granule, and (f) maturation. 



slightly better for power functions than for 

 functions in both cases: 



inear 



F= 5.029 x 10- 20 <SL) 10 - 614 , 

 F= 1.447 x 10- 7 W 5 - 0038 , 



r 



9 



r 



0.75 

 0.86 



(Fig. 6) 



Based on the weight-frequency distribution of the 

 recreational catch sampled at JA (Fig. 7A) and our 

 weight-fecundity expression, in an average year, the 

 reproductive output of the population is distributed 

 as shown in Figure 7C. Thus, for example, about 54% 

 of all eggs are produced by fish of 250 g and larger ( over 

 13 years old) — the oldest 20% of the population. Weight 

 classes between 200 and 250 g (ages of about 10 to 13 

 years) constitute about 38% of the reproductive popu- 

 lation and produce about 35% of all eggs. Smaller fish 

 — over 41% of the reproductive population — produce 

 only about 11% of all eggs. Fishing pressure (all recre- 

 ational) is light at JA, and many large fish remain. 



Discussion 



Feeding 



With the possible exception of some of the larger 

 shrimp and stomatopod specimens, the dominant 



prey found in our M. amaena samples at all three 

 locations were in some sense planktonic. The large 

 number of crab, shrimp, and stomatopod larvae 

 eaten, as well as the presence of prey such as copep- 

 ods and mysids, strongly indicates that M. amaena 

 does much of its feeding in the water column. Hobson 

 ( 1974) found generally the same prey groups domi- 

 nant and concluded that M. amaena, M. berndti, and 

 M. kuntee were planktivores at Kona on Hawaii Is- 

 land. A similar suite of prey items found in M. kuntee 

 at Puako in the present work and at Oahu (Oda and 

 Parrish, 1982) indicated that zooplankton were the 

 dominant food source. Our diet studies of M. berndti 

 at Puako show a similar result. Brecknock (1969) 

 found that M. berndti was primarily zooplanktivorous 

 at Oahu. The results of Harmelin-Vivien (1979) for 

 M. bowditchae in Madagascar and of ter Kuile ( 1989) 

 for M. murdjan in the Flores Sea indicate a large 

 proportion of meroplanktonic prey in the diets. These 

 soldierfishes seem morphologically adapted for pick- 

 ing small prey individuals from the water column 

 (Hobson, 1972, 1974), and they have often been ob- 

 served foraging extensively well above the bottom 

 (Brecknock, 1969; Hobson, 1972, 1974). 



