Karyological Studies on Three Egyptian Freshwater Species of Order Eulamellibranchiata (Bivalvia-Mollusca).

Abstract

Chromosomal analysis of the three Egyptian species, Unio elongatulus (Family: Unionidae), Mutela rostrata (Family: Mutlelidae) and Corbicula fluminalis (Family: Corbiculidae) have been studied. The diploid chromosome number of these three species are 2n=28, 2n=20 and 2n=26 respectively.Comparative analysis of the karyotypic data of these three species had been discussed. To the best of the author knowledge, these results are reported for the first time in Egypt.

Comparative Karyotyping of Five Marine Species of Genus Cypraea (Mesogastropoda: Prosobranchiata).

“…Our results are in agreement with that reported by Pollister and Pollister (1940), Burch (1960), Lutfy and Demian (1964), Inaba (1965), Janson (1983), Yaseen et al (1991Yaseen et al ( , 1995 and Ebied (1994) in which they reported that the haploid chromosome number of the species of the family Cypraeidae ranged from n=20 to n=60.…”

“…So cytogenetic parameters such as chromosome number and chromosome morphology provide investigatory tools to define phylogenetic patterns and genetic structure of species and population. Several authors, Straiger (1950), Patterson (1970), Abmed (1976), Goldman et al (1980Goldman et al ( , 1984, Nakamura (1985a), Yaseen (1986, 1994, Corni and Trentini (1986), Dixon and Flavell (1986), Thiriot-Quievrreux (1990), and Ebied (1998) described the morphology and chromosome number for several number of mollusca species. Pollister and Pollister (1940), Burch (1960), Lutfy andDemain (1964), Inaba (1965), Janson (1983), Yaseen et al (1991Yaseen et al ( , 1995 and Ebied (1994) reported that the haploid chromosome numbers of order Mesogastropoda ranges from n=7 to n=18, with exception of several species of families Thiaridae and Cypraeidae which have higher haploid chromosome number ranging from n=20 to n=60.…”

Cytotaxonomy of unionid freshwater mussels (Unionoida, Unionidae) from northeastern Thailand with description of a new species

“…However, chromosome number has been, so far, of little used for the taxonomy of unionid mussels. The other recent reports of different diploid number are from Solenaia khwaenoiensis from Thailand with the unusual 37 (2 n ) chromosomes (Deein et al 2003) and from Unio elongatulus from Egypt with 28 (2 n ) (Ebied 1998). However, Unio elongatulus was previously karyotyped from Italy and this Unio species has only been described from the upper Nile in Ethiopia, whereas these were caught in the lower part of this river in Egypt.…”