The Karyology of Uraeotyphlus gansi, and Its Implications for the Systematics and Evolution of Uraeotyphlidae (Amphibia: Gymnophiona)

The gross karyotype of the uraeotyphlid caecilian Uraeotyphlus gansi is described as comprising 2n = 42 and fundamental number = 58. These are the first karyotype data for any species of malabaricus-group Uraeotyphlus, and the diploid number is the same as those ichthyophiids thus far studied and differs from the oxyurus-group Uraeotyphlus (2n = 36). These data support the recognition of two species groups within Uraeotyphlus, the monophyly of the oxyurus group, and the understanding that the ancestral diatriatan was more ichthyophiid-than uraeotyphlid-like. Copyright (C) 2010 S. Karger AG, Base

Studies on chromosomal characteristics of Ctenus indicus (Gravely 1931) (Araneae: Ctenidae)

The karyological information gathered for the Indian spiders taxa thus far were cytologically derived from only few species but none for the representatives belonging to the genus Ctenus. Ctenus indicus (Gravely 1931), an Indian ctenid spider was cytogenetically analyzed following conventional, C- and NOR-banding techniques so as to gather substantial data for future course of understanding of karyotypic evolution among spider species. The karyotypic data for Ctenus indicus revealed the complement consisting of (2n = 28) 26AA + X1X2� and (2n = 30) 26AA + X1X1X2X2� acrocentric chromosomes. A closer scrutiny of meiotic progression disclosed many male pachytenic cells displaying the occurrence of �bouquet� formation. The results of C-banding enabled in identifying centromeric constitutive heterochromatin locales, and in some chromosomes also the distal ends of telomeric regions. Silver nitrate stained NOR-specifications were noticed at the distal telomeric regions of two pairs of chromosomes (#8 and #10) in the complement. Cytological evidence procured from the present study not only adds to the ever-growing list of the spider cytogenetic assessments but also offers as a baseline data towards establishing evolutionary relationships within this important group. © 2016, Archana Sharma Foundation of Calcutta

Morphology, biology, and distribution of Ichthyophis kodaguensis (Amphibia:Gymnophiona), a rare caecilian from the Western Ghats, India

Of the amphibian orders, the Gymnophiona (caecilians) have the lowest number of species and are the least known. We report new information on the morphology, biology, range, and distribution of Ichthyophis kodaguensis, a striped ichthyophiid caecilian from the Western Ghats, India that shows the first evidence of possible sexual-dimorphism in this species. Based on the clutch size, limited range, relatively low fecundity, and agricultural practices in their habitats, we consider that I. kodaguensis is highly threatened when compared to other striped ichthyophiids from the Western Ghats, a biodiversity hotspot.

Karyology of three species of Indian Caecilians (Amphibia: Gymnophiona)

Three species of Caecilians, namely I. beddomei, I. ssp. and I. malabarensis were collected from different places of Karnataka and Kerala. Mitotic and meiotic chromosomes were prepared from liver and testis respectively. The karyotypes of 3 species i.e. I. beddomei (2n=42), I. ssp. (2n = 42) and I. malabarensis (2n = 36) are prepared and compared. A probable role of chromosomal rearrangements involved in the evolution of karyotypes of these 3 species is surmised in this paper

Chromosomal characteristics of an Indian tanyponid midge, Anatopynia spp. (Tanypodinae Chironomidae)

The present report describes briefly the mitotic, polyneme and polytene chromosomal karyotype (2n=10) of the newly identified Indian specimen, Anatopynia spp. Based on our observations, cytogenetic implications involved were surmised with respect to the short and stumpy fifth element in the polytene complement

Karyology of two species of Caecilians (Caeciliidae: Gymnophiona): Evolution through tandem fusion and sex chromosome dimorphism

Mitotic and meiotic chromosomal karyotypes have been described for Gegeneophis ramaswamii and G. usp (unspecified species). Based on the available karyological information from among the eight species of Gegeneophis, a tentative scheme is proposed for their karyotypic phylogeny. A closer scrutiny of one of the two in an otherwise homologous chromosomal pair (chromosome number 13) in the complement is suggestive of a XX-XY sex-chromosome differentiation

Chromosomal studies of two species of the genus Gegeneophis (Amphibia: Gymnophiona: Indotyphlidae)

Karyological characteristics in two species of Indian indotyphliid caecilian genus Gegeneophis reveal chromosome variations in morphology of chromosome arms but not in diploid number. In this case, pericentric inversions seem to predominate in karyotype reorganization. This change in chromosome morphology (pairs no. 2, 10 and 13) distinguishes each species karyotype. © 2012 by The Herpetological Society of Japan