title: rDNA ITS sequences among  morphotypes of Keratell cochlearis, Keratell quadrata and  Brachionus forficula (Rotifera).
abstract: Morphological  variation in rotifers is affected by environmental conditions, making it hard  to identify some rotifer taxa. We examined the rDNA ITS sequences of 10  unspined (KCU1-KCU10) and 17 spined (KCS1-KCS17) Keratell cochlearis clones,  26 two-spined (KQT1-KQT26), 18 single-spined (KQS1-KQS18) and 9 unspined  (KQU1-KQU9) K. quadrata clones, and 17 long-spined (BL1-BL17) and 11  short-spined (BS1-BS11) Brachionus forficula clones collected from Lake  Tingtang in Wuhu city, China. Molecular phylogenetic trees were constructed by  neighbor-joining, maximum-likelihood, maximum parsimony, and Bayesian inference  methods using B. calyciflorus as an outgroup. The K. cochlearis clones  included 20 haplotypes, the K. quadrata clones included 37 haplotypes,  and the B. forficula clones included 25 haplotypes. Different  morphotypes of each rotifer species had shared haplotypes. Sequence divergences  were 0.1-8.9% among different K. cochlearis haplotypes, and 8.1-8.9%  between KCHAP1 (KCU1 and KCU10), KCU3, KCU4 and KCU6, and the other haplotypes.  Sequence divergences were 0.1-14.5% among different K. quadrata haplotypes,  and 11.9-14.5% between KQS17 and the other haplotypes. Sequence divergences  were 0.1-11.7% among different B. forficula haplotypes, 11.0-11.7%  between BL15 and the other haplotypes, 9.3-10.1% between BS3 and the other  haplotypes, and 11.7% between BL15 and BS3. The four phylogenetic trees all  supported that KCHAP1, KCU3, KCU4, KCU6 and the other 16 haplotypes among the  20 K. cochlearis haplotypes, KQS17 and the other 36 haplotypes among the  37 K. quadrata haplotypes, and BL15, BS3 and the other 23 haplotypes  among the 25 B. forficula haplotypes all belonged to their own isolated  clades. The morphological variation of the three rotifer species was attributed  mainly to phenotypic plasticity.
authors.affiliation: Provincial Key Laboratory of Biotic Environment and Ecological Safety in Anhui, College of Life Sciences, Anhui Normal University, Wuhu, Anhui, China.
authors.forename: Y L
authors.initials: YL
authors.lastname: Ge
authors.forename: Y L
authors.initials: YL
authors.lastname: Xi
authors.forename: J
authors.initials: J
authors.lastname: Ma
authors.forename: D D
authors.initials: DD
authors.lastname: Xu
mesh_terms: D000818:Animals; D021903:DNA, Ribosomal Spacer / Q000737:chemistry*; D014644:Genetic Variation; D006239:Haplotypes; D010641:Phenotype; D010802:Phylogeny; D012403:Rotifera / Q000145:classification / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D021903:DNA, Ribosomal Spacer