The Karyotypes of two Specimens ofLeiopelma HochstetteriFitz. (Amphibia Salientia)

Abstract

The author describes the karyotype of two specimens of the female sex of Leiopelma hochstetteri Fitz., denominated as ♀ 1 (the larger specimen, 46 mm in length) and ♀ 2 (32 mm in length). The chromosome set of ♀ 1 consists of 34 chromosomes, divisible into 5 pairs of large meta- or submetacentric homologues, 6 pairs of medium-small acrocentric homologues (one pair of which is provided with heterochromatic areas) and 6 pairs of microchromosomes, mostly acrocentric. The chromosome set of ♀ 2 consists of 23 chromosomes, divisible into 5 pairs of large meta- or submetacentric homologues, 6 pairs of medium-small acrocentric homologues (corresponding, in shape and dimensions, to the large and medium-small chromosomes of ♀ 1), and one small acrocentric chromosome, without homologue, corresponding morphologically to one of the microchromosomes of ♀ 1. Since the two specimens seem to belong to the same species and appear morphologically quite normal, the author proposes certain theories on the nature of the microchromosomes present in ♀ 1 but absent in ♀ 2.