MORPHOMETRICAL STUDY ON THE CHROMOSOMES OF 3 SPECIES OF MULLET (TELEOSTEI, MUGILIDAE)

An intensely morphometrical study of the chromosomes of Liza aurata, Liza ramada and Chelon labrosus is presented in this paper. We have found a very homogeneous karyotype for these three species formed by 2n = 48 chromosomes and 50 distinguishable arms, i.e. 46 acrocentric chromosomes and two biarmed ones. We have analyzed statistically the real lengths and the haploid relative lengths of the chromosome pairs of these species, the latter in order to neutralize the effect of the metaphase state on the variable variance. Using these data we have made a comparison between the chromosome complements of these three species, by mean of a fixed simple linear model of analysis of variance. This comparison supports the modern systematics of these species, and upholds the last evolutive criteria, observing both Liza as being very near, and Ch. labrosus showing a certain distance. The specific study on the biarmed pair 24 has revealed these chromosomes as being submetacentric, with great differences between species for their lengths but with a strong homogeneity with respect to their arm ratio.