Karyotypes of Seven Species of Brazilian Bats

Abstract
The chromosome complements of the seven species studied are as follows: Phyllostomus hastatus (2 n=32) has 13 pairs of metacentric or submetacentric and one pair of acrocentric autosomes. The X is a submetacentric and the Y is minute. Phyllostomus discolor (2 n = 32) has all its autosomes metacentric or submetacentric. The X is submetacentric. Chrotopterus auritus (2 n = 28) has all its autosomes metacentric or submetacentric. The X is a me dium submetacentric and the Y is minute. Carolila perspicillata (2 n = 20, 21) has 9 pairs of metacentric or submetacentric autosomes, all distinguishable from each other. The X is submetacentric, the Y1 is a medium acrocentric and the Y2 is a small acrocentric. Artibeus lituratus (2 n = 30, 31) has all its autosomes metacentric or submetacentric. The X is a submetacentric, the Y1 is a acrocentric and the Y2 is a small acrocentric. Desmodus rotundus (2n=28) has all its autosomes metacentric or submetacentric. The X is a submetacentric and the Y is minute. Noctilio leporinus (2 n = 34) has 11 pairs of large metacentric or submetacentric, 2 pairs of medium submetacentric and 3 pairs of small acrocentric autosomes. The X is a submetacentric and the Y is a small acrocentric like the smallest autosomes. The X chromosome in P. hastatus and N. leporinus represents 5% of the haploid complement and is considered as having the original size of the mammalian X. While in Desmodus rotundus and Carollia perspicillata it has duplicate and triplicate size respectively in Artibeus lituratus and Chrotopterus auritus it is about 7% of the haploid set. The origin(s) of the XY1Y2 sex chromosome mechanism cannot be determined with certainty but there are indications that both basic and neo-XY systems occur in the Chiroptera.