Karyological studies in Coris julis (Pisces, Labridae).

In the present investigation the diploid number 2n = 48 (NF = 58) has been determined for females, primary males, and secondary males of Coris julis from the Gulf of Palermo. Differentiated sex chromosomes have not been observed in the population under study.

THE KARYOLOGY OF TEREDO UTRICULUS (GMELIN) (MOLLUSCA, PELECYPODA).

By counting spermatocyte and oocyte bivalents and mitotic metaphase chromosomes in cleaving eggs, we have determined both the haploid (n = 19) and the diploid numbers (2n = 38) respectively, for the species Teredo utriculus. An XY and XO sex-determining mechanism is absent in the species under study. chromosomes cannot be grouped into different classes according to length.