title: Diet disparity among sympatric herbivorous cichlids in the same ecomorphs in Lake Tanganyika: amplicon pyrosequences on algal farms and stomach contents.
abstract: BACKGROUND
  Lake Tanganyika, an ancient lake in the Great Rift Valley, is famous for the adaptive radiation of cichlids. Five tribes of the Cichlidae family have acquired herbivory, with five ecomorphs: grazers, browsers, scrapers, biters and scoopers. Sixteen species of the herbivorous cichlids coexist on a rocky littoral slope in the lake. Seven of them individually defend feeding territories against intruding herbivores to establish algal farms. We collected epiphyton from these territories at various depths and also gathered fish specimens. Algal and cyanobacteria community structures were analysed using the amplicon-metagenomic method.
  
  
  RESULTS
  Based on 454-pyrosequencing of SSU rRNA gene sequences, we identified 300 phototrophic taxa, including 197 cyanobacteria, 57 bacillariophytes, and 31 chlorophytes. Algal farms differed significantly in their composition among cichlid species, even in the same ecomorph, due in part to their habitat-depth segregation. The algal species composition of the stomach contents and algal farms of each species differed, suggesting that cichlids selectively harvest their farms. The stomach contents were highly diverse, even between species in the same tribe, in the same feeding ecomorph.
  
  
  CONCLUSIONS
  In this study, the amplicon-metagenomic approach revealed food niche separation based on habitat-depth segregation among coexisting herbivorous cichlids in the same ecomorphs in Lake Tanganyika.
authors.affiliation: Graduate School of Science and Engineering, Ehime University, 2-5 Bunkyo, Matsuyama, Ehime, Japan. hata@sci.ehime-u.ac.jp.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Hata
authors.affiliation: Graduate School of Global Environmental Studies, Kyoto University, Sakyo, Kyoto, Japan. akifumi.tanabe@gmail.com.|National Research Institute of Fisheries Science, Fisheries Research Agency, 2-12-4 Fukuura, Kanazawa, Yokohama, Japan. akifumi.tanabe@gmail.com.
authors.forename: Akifumi S
authors.initials: AS
authors.lastname: Tanabe
authors.affiliation: Graduate School of Global Environmental Studies, Kyoto University, Sakyo, Kyoto, Japan. yamamoto@people.kobe-u.ac.jp.|Graduate School of Human and Environmental Studies, Yoshida-Nihonmatsu, Kyoto University, Sakyo, Kyoto, Japan. yamamoto@people.kobe-u.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamamoto
authors.affiliation: Graduate School of Global Environmental Studies, Kyoto University, Sakyo, Kyoto, Japan. toju.hirokazu.4c@kyoto-u.ac.jp.|Graduate School of Human and Environmental Studies, Yoshida-Nihonmatsu, Kyoto University, Sakyo, Kyoto, Japan. toju.hirokazu.4c@kyoto-u.ac.jp.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Toju
authors.affiliation: Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka, Japan. maskohda@sci.osaka-cu.ac.jp.
authors.forename: Masanori
authors.initials: M
authors.lastname: Kohda
authors.affiliation: Kyoto University, Yoshida-Honmachi, Sakyo, Kyoto, Japan. hori@terra.zool.kyoto-u.ac.jp.
authors.forename: Michio
authors.initials: M
authors.lastname: Hori
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D023681:Cichlids / Q000145:classification*; D000458:Cyanobacteria / Q000145:classification / Q000302:isolation & purification; D017377:Diatoms / Q000145:classification / Q000302:isolation & purification; D004032:Diet / Q000662:veterinary*; D017753:Ecosystem; D005766:Gastrointestinal Contents / Q000382:microbiology; D060106:Lakes; D056186:Metagenomics; D013636:Tanzania