Chromosome Study Of Some Grasshopper Species From Different Localities In Central Ethiopia

Hitherto, around 200 grasshopper species have been recorded in Ethiopia. Despite therndiversity and economic importance of Ethiopian grasshoppers, the available informationrnon their taxonomy, distribution and ecology is meager, and no report on the karyology ofrnEthiopian grasshoppers is available prior to this study. In this study, the karyotypes of tenrntaxa identified to different taxonomic levels are described. The studied grasshopperrnspecimens were identified to belong to two families – Acrididae and Tetrigidae. UnderrnAcrididae six genera – Acanthacris, Paracinema, Gastrimargus, Acrotylus, Pardalophorarnand Acrida were identified. Specimens of two additional taxa could not be identifiedrnbeyond the family level. The specimens under the family Tetrigidae were found to belongrnto genus Paratettix. The grasshopper specimens were collected from eight localities inrncentral Ethiopia. Chromosome preparations were made from tissues of the whole gut, 6 –rn8 hours after the colchicine injection. The tissue was grinded in hypotonic solutionrn(0.075M KCl). The suspension was centrifuged and the pellet was fixed in 3:1rnmethanol:acetic acid and followed by centrifugation. Air dry slide preparations were madernfrom cell suspension. In some case the testis was used for the preparation of meioticrnchromosomes following the same steps as in mitotic chromosome preparation. Slides werernstained in Giemsa stain. Basically, all the studied species (Acanthacris spp., Paracinemarntricolor, Gastrimargus spp., Acrida spp.-1, Acrida spp.-2, Acrotylus spp., Pardalophorarnspp., and the two unidentified specimens) belonging to the family Acrididae showedrnsimilarity in their karyotype, with all of them having 2n = 23 (22 autosomes + X) and 24rn(22 autosomes + XX) telocentric chromosomes in male and female, respectively.rnParatettix spp. (family Tetrigidae) had a different chromosome number, that is, 2n = 20rntelocentric chromosomes. Furthermore, Acanthacris spp. showed some numericalrninstability of chromosomes in the mitotic and meiotic cells, and B chromosome like bodyrnwas found in the meiotic cells of this specimen. Apart from the gross Karyotypicrnresemblance shown among the studied taxa of family Acrididae, slight variations in theirrnkaryotype have been noted between taxa of acridid grasshoppers. Further studies of thernchromosomes of Ethiopian grasshoppers covering a wider geographic area and employingrnnew cytological techniques were recommended.rnKeywords or phrases: Karyology, Central Ethiopia, Acridid grasshopper, Karyotypicrnconservatism, chromosome

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