CHROMOSOME CHARACTERIZATION OF FOUR CALOPTERYGID DAMSELFLIES WITH CYTOGENETIC REVIEW OF FAMILY CALOPTERYGIDAE (ODONATA: ZYGOPTERA)

Abstract

Taxonomically, in family Calopterygidae, 183 species under 21 genera have been reported worldwide. Out of these, cytogenetic data pertains to only 22 species which is only 12% of the known species. In India, 9 species under 6 genera are present, while only 2 species has been studied cytogenetically. The present study has been conducted to linearly characterize the chromosomes of 4 species (Matrona nigripectus, Neurobasis chinensis, Vestalis apicalis and Vestalis gracilis) of family Calopterygidae by conventional staining, C-banding, silver nitrate staining and sequence-specific staining and also compiled the cytogenetic data of the family. The species were collected from Meghalaya, Goa, Kerala, Himachal Pradesh states of India. All the species possesses 2n=25m as the diploid chromosome number with XO-XX sex determination except Neurobasis chinensis with 2n=23, characterized by the presence of two equal sized large autosomal bivalents originated by the autosome fusion. C-banding and silver nitrate staining results depict the presence of C-bands and NOR’s on the terminal positions of autosomal bivalents, while X chromosome and m bivalent show variation in distribution of C-heterochromatin and NOR’s. Sequence-specific staining represents the complement of all the species as AT-rich due to more DAPI bright signals. All the cytogenetically studied species have been catalogued including the presently studied species and the list has been updated to 23 species