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Aswan University (2010)

Comparative Karyological Studies on Some of Egyptian Snakes

Abd Allah, Amal Abd El-razik.

Titre : Comparative Karyological Studies on Some of Egyptian Snakes

Auteur : Abd Allah, Amal Abd El-razik.

Etablissement de soutenance : Aswan University

Grade : Master of Science in Zoology 2010

Résumé partiel
Fourteen species of Egyptian snakes representing four different families (Colubridae, Elapidae, Viperidae and Boidae), belong to suborder : Serpents, order : Squarnata, class : Reptilia, were morphologically and cytogenetically studied. The results of the chromosomal analysis were compared with those obtained from the classical methods in taxonomy using morphological and anatomical characters alone, the following is a summary of the results. Class : Reptilia order : Squamata. Suborder : Serpentes (Ophidians ; Snakes). 1) Family : colubridae Eight species belong to family colubridae were cytogenetically studied . A.) Two species of genus Psammophis, Psammophis schokari & P. sibilans were studied. The two species of these snakes are living in different habitates . Psammophis schokari is living in sandy habitats, so it is characterized by sandy color from dorsal side and yellowish kvhite from ventral side ; while P. silibans inhibite vegetated labitats, the body color is yellow from the ventral side and triated with yellow and green strands from the dorsal side. Moving very fast with very strong muscle. The chromosomal analysis indicated that, although the two secies have the same diploid number of chromosomes 42 + ZW in females and 42 + ZZ in males. However the fundamental number was different in two species, it is 46 in the first and 60 in the second. Furthermore the karyotypes of the two species were distinctly different. In the case of Psammophis schokarL karyotype is composed of three groups, two pairs of autosomal metacentrics , nine pairs of autosomal telocentrics, ten pairs of micro chromosomes and a single or pair of sex chromosomes I which is ZW in female and ZZ in male respectively, where Z is metacentric and W is telocentric. On the other hand, the ! karyotype of P. silibans was composed of four groups : one pair of autosomal submetacentrics, six pairs of subtelocentric chromosomes, one pair of autosomal telocentrics , ten pairs OB microchromosomes and pair of sex chromosomes, Z is] subtelocentric and W is telocentric. (B) Malpolon monspessulana & M. moilensis They are prefer the north part of Egypt in sandy habitats, East and West desert and Siwa Oasis. The two species arel recognized by moderate size, the head distinct from the necLJ Malpolon monspesssulana is similar to M. moilensis but have green body color and small eyes. While M moilensis appear td be sandy, yellowish brown in body color with yellow spots, ! and orange large eyes . The chromosomal analysis of the two species indicated that, they both have the same haploid chromosome number of n = 20 -j ZW in females and n = 20 + ZZ in males, however the fundamental number was different in the two species (FN = 46 ii the female and FN = 60 in male ). Furthermore the karyotype of Malpolon monspessulanas is composed of four different groups^ two pairs of autosomal metacentrics, two submetacentrics of chromosomes, six pairs of telocentrics, and ten pairs ofj microchromosomes in addition to a single pair of sex chromosomes (ZW) in females and (ZZ) in males, where Z if metacentric and W is telocentric . While they are arranged in four groups in M. moilensis as : Six pairs of metacentric chromosomes, three pairs of submetacentric chromosomes, one pair of telocentrics and ten pairs of microchromosomes in addition to one pair of sex chromosomes Z metacentric and W is submetacentric.

Présentation étendue (EULC)

Page publiée le 23 décembre 2020