Bostiom el al : Hybridization between two serranids, Ccphalopho/is fulva and Paianthias fu/afei 



655 



sequence divergence was calculated for the mito- 

 chondrial DNA RFLP results by using the equation 

 of Nei and Li ( 1979) for fragment data with weight- 

 ing based on Nei andTajima (1983) as performed by 

 the computer program REAP (McElroy et al., 1992). 

 Genetic distance was not calculated for the nuclear 

 DNA loci owing to an absence of shared restriction 

 fragments between C. fulva and P. furcifer. 



Results 



Morphological analysis 



Of 44 counts and measurements analyzed, mean 

 values of 38 were different between C. fulva and P. 

 furcifer, and the putative hybrids were intermediate 

 in morphology to presumed parents for 33 of these 

 characters (Table 4). The mean value for the puta- 

 tive hybrids exceeded the values of either presumed 

 parent species for four characters (caudal peduncle 

 scales, interorbital width, anal base length, and 

 pectoral length) and was lower than either pre- 

 sumed parent species for two characters (orbit length and 

 depressed dorsal length). In the principal component analy- 

 sis, the first component accounted for 667^ of the variation 

 in the data and the second accounted for 23'^'f . Suborbital 

 width, caudal peduncle length, caudal peduncle to upper fin 

 rays and caudal penduncle to lower fin rays were the char- 

 acters with the highest loadings. In the meristic data, the 

 first principal component accounted for 62% of the varia- 

 tion. Dorsal rays, gill rakers, and transverse scale rows 

 had the highest loadings. A plot of the second principal 



2 



1.5 



1 



0.5 







-0.5 



-1 



-1.5 



-2 



& 



C. fulva 

 P. furcifer 

 Putative Hybrid 



^. 



4* 



— I 1 1 I 1 1 



0.6 -0.4 -0.2 0.2 0.4 0.6 

 Sheared PC 2 



Figure 2 



Graph of principal component 2 for the morphological data and 

 factor 1 for the meristic data for ten Cephalopholis fulva. ten 

 Paranthias furcifer, and ten putative hybrids. The arrow indicates 

 putative hybrid H7, an individual identified as a backcross to C. 

 fulva, according to the genetic data. 



component from the morphological analysis (variation in 

 shape) and the first factor of the correlation matrix of the 

 meristic data shows a discrete difference between the puta- 

 tive parents (Fig. 2). Hybrid individuals were shown to be 

 intermediate between the putative parent species. 



Allozyme analysis 



Sixteen allozyme loci were surveyed in 15 C. fulva and 15 

 P. furcifer to identify those that had different alleles in 



