Open AccessCytosystematics of the Simulium tuberosum group (Diptera: Simuliidae) in Thailand
Author(s) -
TANGKAWANIT UBON,
KUVANGKADILOK CHALIOW,
BAIMAI VISUT,
ADLER PETER H.
Publication year - 2009
Publication title -
zoological journal of the linnean society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.148
H-Index - 83
eISSN - 1096-3642
pISSN - 0024-4082
DOI - 10.1111/j.1096-3642.2008.00433.x
Subject(s) - biology , subgenus , polytene chromosome , lineage (genetic) , karyotype , simulium , taxon , black fly , subspecies , evolutionary biology , zoology , chromosome , ecology , larva , genetics , taxonomy (biology) , gene
The polytene chromosomes of 3347 larvae of the Simulium tuberosum group in Asia were analysed, representing the largest ever cytogenetic study of black flies in the Oriental Region. Band‐by‐band comparisons, relative to the established standard chromosome map for the subgenus Simulium , revealed 17 cytogenetically distinct taxa in Thailand, plus an 18th in China. Six of these taxa correspond to morphologically described species ( S. doipuiense , S. rufibasis , S. setsukoae , S. tani , S. yuphae and S. weji ). Recognition of the 18 taxa is based largely on unique inversions, either fixed or sex linked, primarily in the long arm of chromosome III. The greatest cytological diversity was discovered in the S. tani lineage, with ten cytoforms. This marked chromosomal diversification within S. tani is based largely on two inversions that have assumed different roles over evolutionary time, variously functioning in different combinations as fixed inversions, sex‐linked inversions and autosomal polymorphisms. Shared unique chromosomal features, relative to the subgeneric standard chromosome map, allowed evolutionary relationships among the cytotaxa to be inferred. Fluctuations in climate during the Pleistocene might have promoted differentiation of the Southeast Asian S. tuberosum group in isolated refugia such as mountains. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society , 2009, 155 , 289–315.