Karyological studies on fifteen forms of amphisbaenians (Amphisbaenia-Reptilia)

Abstract

The chromosome constitutions of 15 forms (2 acrodonts and 13 pleurodonts) of amphisbaenians belonging to two families and eight genera were studied. The diploid chromosome numbers varied from 30 to 44 with the number of chromosome arms (FN) ranging from 42 to 60. The karyotypes of 12 forms all contained 6 pairs of macrochromosomes with similar morphology and 9 to 12 pairs of microchromosomes. The remaining three species had a higher diploid number (40–44) and a wide variation in chromosome morphology. Karyotype variations were found in the same family, even in the same genus. The lengths of the 6 pairs of macrochromosomes in 5 of the 12 forms were measured and compared. This disclosed similarities in the mean lengths, relative lengths, and arm ratios of those forms. — Chromosome patterns found in the present study support, in general, the classification of amphisbaenians derived from analysis of morphological characters.