Colombera D. & Fenaux R.

Italian Journal of Zoology, 1973, 40:3-4, 347-353

Chromosome form and number in the larvacea

“In 10 anaphase plates (fig. 10) a chromosome number of 16 was regularly found. I n another five anaphase plates, presumably because of chromosome losses during the squashing, a lower number mas found.

These chromosomes are exceedingly small, without morphologically differentiated structures. They are rod-shape, with a sharp bend in a medial or submedial position ; of the two arms individuated by the bend, one is often thinner than the other.

As is often the result of squashing, the direction of tlie chromosome movement is clearly altered for some chromosomes. Since none of the chromosomes appears to be homologous we consider such chromosomes to be meiotic and in consequence we mould assign a haploid number of eight to 0. dioica, with the reservation that the above mentioned plates might be mitotic in which case the true haploid number would be four.”

Reports 16 chromosomes in meiotic cells (8 haploid chromosomes).