Wide Variability In Sex Chromosomes Of Some Ophidians From UT Of Jammu And Kashmir

Abstract

Cytogenetic studies were carried out on 11 species of Indian Snakes collected from Jammu region using Air Drying Technique of Gorman et al 1979. Among all E. johni and E. conicus belonging to primitive family Boidae exhibits diploid number, 2n=34 with undifferentiated sex chromosomes in both male and female. In family Colubridae ( an intermediate family) there exist huge variation as far as sex chromosomes are concerned i.e Ptyas mucosus has 2n=34, Oligodon arnensis has 2n=44 with undifferentiated sex chromosomes, Lycodon arnensis and Boiga trigonata both have 2n=36 with differentiated sex chromosomes(as per literature) while Natrix stolata has 2n=36 with distinct ‘ZW’ female. In Family Elapidae Naja naja naja has 2n=38 with undifferentiated sex chromosomes but Bungarus caerulus has 2n=44 with ‘ZW’ female having submetacentric ‘Z’ and largest telocentric ‘ W’ but members of family Viperidae viz. Vipera russelli and Echinis carinatus both have 2n=36 with well differentiated ‘ZW’ where ‘W’ is smaller and ‘ Z’ larger representing final step in the evolution of sex chromosome