Chromosomal studies of two spider species of pholcidae (araneae: haplogynae)

Pholcidae (Haplogynae) is the most diverse family which comprises 1,241 taxonomically defined species, of which only 19 have been cytogenetically analyzed. The two pholcids species, Crossopriza lyoni (Blackwall 1867) and Artema atlanta (Walckenaer 1837) are cytogenetically studied following Conventional, and AgNO3 impregnation techniques. The karyotype revealed presence of (2n=23) 22AA+X0♂ and (2n=32) 30AA+X1X2♂ chromosomes in C.lyoni and A. atlanta respectively. In both species, the chromosomes were exclusively biarmed, and the sex chromosomes are the largest elements of the karyotypes. Silver nitrate stained NOR-specifications were noticed in C.lyoni at the telomeric regions of pairs of chromosomes (4 and 6) and sex chromosome in the complement. A. atlanta exhibited the NOR-specifications in 2 pairs of chromosomes in the complement.