Allozymic variation in the clam genus Eurhomalea (Bivalvia: Veneridae) in southern South America.

MILTON GALLARDO,; CLAUDIO GONZÁLEZ,; C MENA,; BETINA JUDITH LOMOVASKY; ELBA MORRICONI,; ELENA CLASING,

REVISTA CHILENA DE HISTORIA NATURAL

Sociedad de Biología de Chile

Lugar: Santiago; Año: 2003 vol. 76 p. 501 - 507

0716-078X

The correspondence between allozymic variation and specific differentiation was studied in four populations corresponding to the three nominal, allopatric species of clam genus Eurhomalea (E. rufa, E. lenticularis, E. exalbida) described for southern South America. Allozyme variation scored in 12 loci was high as indicated by heterozygosity levels (15.8-20.7 %) and by the presence of only three monomorphic loci (Hk-2, Icd-2, and by heterozygosity levels (15.8-20.7 %) and by the presence of only three monomorphic loci (Hk-2, Icd-2, and exalbida) described for southern South America. Allozyme variation scored in 12 loci was high as indicated by heterozygosity levels (15.8-20.7 %) and by the presence of only three monomorphic loci (Hk-2, Icd-2, and by heterozygosity levels (15.8-20.7 %) and by the presence of only three monomorphic loci (Hk-2, Icd-2, and Eurhomalea (E. rufa, E. lenticularis, E. exalbida) described for southern South America. Allozyme variation scored in 12 loci was high as indicated by heterozygosity levels (15.8-20.7 %) and by the presence of only three monomorphic loci (Hk-2, Icd-2, and by heterozygosity levels (15.8-20.7 %) and by the presence of only three monomorphic loci (Hk-2, Icd-2, and ) described for southern South America. Allozyme variation scored in 12 loci was high as indicated by heterozygosity levels (15.8-20.7 %) and by the presence of only three monomorphic loci (Hk-2, Icd-2, andHk-2, Icd-2, and Xdh-1). These high estimates of allelic variability were influenced by the low levels of interspecific genetic similarity (I = 0.64) and for the high conspecific values of genetic identity observed. The high estimates of substructuring found at the species level (FST = 0.39) contrasted with the low differentiation (FST = 0.027) and high migration rate (Nm = 9) existing among conspecific samples. Diagnostic allele fixation coinciding with specific recognition was recorded at locus Hk-1 whereas nearly-fixed differences at loci (Adh, á-Gpd, Icd-1, specific recognition was recorded at locus Hk-1 whereas nearly-fixed differences at loci (Adh, á-Gpd, Icd-1, high migration rate (Nm = 9) existing among conspecific samples. Diagnostic allele fixation coinciding with specific recognition was recorded at locus Hk-1 whereas nearly-fixed differences at loci (Adh, á-Gpd, Icd-1, specific recognition was recorded at locus Hk-1 whereas nearly-fixed differences at loci (Adh, á-Gpd, Icd-1, similarity (I = 0.64) and for the high conspecific values of genetic identity observed. The high estimates of substructuring found at the species level (FST = 0.39) contrasted with the low differentiation (FST = 0.027) and high migration rate (Nm = 9) existing among conspecific samples. Diagnostic allele fixation coinciding with specific recognition was recorded at locus Hk-1 whereas nearly-fixed differences at loci (Adh, á-Gpd, Icd-1, specific recognition was recorded at locus Hk-1 whereas nearly-fixed differences at loci (Adh, á-Gpd, Icd-1, high migration rate (Nm = 9) existing among conspecific samples. Diagnostic allele fixation coinciding with specific recognition was recorded at locus Hk-1 whereas nearly-fixed differences at loci (Adh, á-Gpd, Icd-1, specific recognition was recorded at locus Hk-1 whereas nearly-fixed differences at loci (Adh, á-Gpd, Icd-1, ). These high estimates of allelic variability were influenced by the low levels of interspecific genetic similarity (I = 0.64) and for the high conspecific values of genetic identity observed. The high estimates of substructuring found at the species level (FST = 0.39) contrasted with the low differentiation (FST = 0.027) and high migration rate (Nm = 9) existing among conspecific samples. Diagnostic allele fixation coinciding with specific recognition was recorded at locus Hk-1 whereas nearly-fixed differences at loci (Adh, á-Gpd, Icd-1, specific recognition was recorded at locus Hk-1 whereas nearly-fixed differences at loci (Adh, á-Gpd, Icd-1, high migration rate (Nm = 9) existing among conspecific samples. Diagnostic allele fixation coinciding with specific recognition was recorded at locus Hk-1 whereas nearly-fixed differences at loci (Adh, á-Gpd, Icd-1, specific recognition was recorded at locus Hk-1 whereas nearly-fixed differences at loci (Adh, á-Gpd, Icd-1, ST = 0.39) contrasted with the low differentiation (FST = 0.027) and high migration rate (Nm = 9) existing among conspecific samples. Diagnostic allele fixation coinciding with specific recognition was recorded at locus Hk-1 whereas nearly-fixed differences at loci (Adh, á-Gpd, Icd-1, specific recognition was recorded at locus Hk-1 whereas nearly-fixed differences at loci (Adh, á-Gpd, Icd-1, Nm = 9) existing among conspecific samples. Diagnostic allele fixation coinciding with specific recognition was recorded at locus Hk-1 whereas nearly-fixed differences at loci (Adh, á-Gpd, Icd-1,Hk-1 whereas nearly-fixed differences at loci (Adh, á-Gpd, Icd-1, Ldh, Odh, Pgm-3) differed sharply in frequency among species. The Wagner procedure and the neighborjoining algorithm produced a similar tree topology highly related to the geographic distance and to their taxonomic recognition. The lack of coincidence between patterns of allozymic variation and the two distinctive shell morphs (flat and globoid) occurring in E. exalbida from Ushuaia bay do not support their taxonomic recognition. taxonomic recognition. algorithm produced a similar tree topology highly related to the geographic distance and to their taxonomic recognition. The lack of coincidence between patterns of allozymic variation and the two distinctive shell morphs (flat and globoid) occurring in E. exalbida from Ushuaia bay do not support their taxonomic recognition. taxonomic recognition. , Odh, Pgm-3) differed sharply in frequency among species. The Wagner procedure and the neighborjoining algorithm produced a similar tree topology highly related to the geographic distance and to their taxonomic recognition. The lack of coincidence between patterns of allozymic variation and the two distinctive shell morphs (flat and globoid) occurring in E. exalbida from Ushuaia bay do not support their taxonomic recognition. taxonomic recognition. E. exalbida from Ushuaia bay do not support their taxonomic recognition.