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Fishery Bulletin 91(2), 1993 



Figure 1 



Photomicrographs of whole oocytes of Lutjanus 

 vittus representing (a) yolk granule (YG) stage, in 

 which the oocyte is completely opaque except for 

 the translucent perivitelline border; (b) late-migra- 

 tory nucleus stage, in which parts of the peripheral 

 yolk have coalesced and become translucent 

 (arrowed); and (c) ripe-oocyte stage, in which whole 

 oocyte is translucent, except for the oil droplet. Scale 

 bars 500um. 



identifiable within 12 h after spawning because the folds of the 

 follicle layer are still discrete (Hunter & Goldberg 1980), but 

 they become progressively more compact until they appear as 

 a solid mass of cells. We recorded an early stage where the 

 lumen was open and the wall of the follicle clearly visible 

 (Fig. 2a) and a late stage where the follicle had collapsed and 

 the follicle layer could not be traced around its periphery 

 (Fig. 2b). 



Batch fecundity was determined using the gravimetric 

 method (Hunter et al. 1985) to count numbers of hydrated but 

 unovulated oocytes in weighed subsamples of formalin-fixed 

 ovaries. Each subsample consisted of a wedge of tissue extend- 

 ing from the periphery to the lumen of the ovary. In order to 

 estimate the energetic costs of spawning, the dry weight of 

 hydrated oocytes was determined in nine fish. About 100 oo- 

 cytes were removed from each formalin-fixed ovary. Oocytes 



Figure 2 



Photomicrographs of 

 transverse section of 

 Lutjanus vittus ovary 

 stained with haema- 

 toxylin and eosin, 

 showing (a) early- 

 stage postovulatory 

 follicles, in which the 

 lumen (L) is open 

 and the folds of the 

 follicle layer (FL) are 

 discrete, and (b) late- 

 stage postovulatory 

 follicles, in which the 

 follicle has collapsed 

 and the follicle layer 

 is no longer discrete. 

 FL = follicle layer; 

 L = lumen. Scale 

 bars 100 um. 



