Cytogenetical studies on fishes, IV. Karyotypes of six species in the sparoid fishes

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All six sparoid fish species (Pagrus major, Evynnis japonica, Dentex tumifrons, Acanthopagrus schlegeli, A. latus and Sparus sarba) studied here showed a diploid chromosome number of 48. Although the total numbers of chromosomes in these species were identical, the numbers of the acrocentrics, subtelocentrics and submetacentrics were different from each other. Thus, they had different numbers of chromosome arms such as 50, 52, 58 and 60 (Table 2). Based on the karyotype analysis the sparoid species can be classified roughly into two groups according to the number of biarmed chromosomes; one of them had 2 or 4 biarmed chromosomes as found in P. major, E. japonica and D. tumifrons, and the other one had 10 or 12 biarmed chromosomes as seen in A. schlegeli, A. latus and S. sarba. The secondary constrictions were found in No. 4 chromosomes of two species (A. schlegeli and A. latus). Although a heteromorphic chromosome pair was found in No. 1 chromosomes of P. major and E. japonica, it can not be identified at present whether this heteromorphic pair is sex chromosome or not.