Morphology, Molecules, and Monogenean Parasites: An Example of an Integrative Approach to Cichlid Biodiversity

PLoS One. 2015 Apr 29;10(4):e0124474. doi: 10.1371/journal.pone.0124474. eCollection 2015.

Abstract

The unparalleled biodiversity of Lake Tanganyika (Africa) has fascinated biologists for over a century; its unique cichlid communities are a preferred model for evolutionary research. Although species delineation is, in most cases, relatively straightforward, higher-order classifications were shown not to agree with monophyletic groups. Here, traditional morphological methods meet their limitations. A typical example are the tropheine cichlids currently belonging to Simochromis and Pseudosimochromis. The affiliations of these widespread and abundant cichlids are poorly understood. Molecular work suggested that genus and species boundaries should be revised. Moreover, previous morphological results indicated that intraspecific variation should be considered to delineate species in Lake Tanganyika cichlids. We review the genera Simochromis and Pseudosimochromis using an integrative approach. Besides a morphometric study and a barcoding approach, monogenean Cichlidogyrus (Platyhelminthes: Ancyrocephalidae) gill parasites, often highly species-specific, are used as complementary markers. Six new species are described. Cichlidogyrus raeymaekersi sp. nov., C. muterezii sp. nov. and C. banyankimbonai sp. nov. infect S. diagramma. Cichlidogyrus georgesmertensi sp. nov. was found on S. babaulti and S. pleurospilus, C. franswittei sp. nov. on both S. marginatus and P. curvifrons and C. frankwillemsi sp. nov. only on P. curvifrons. As relatedness between Cichlidogyrus species usually reflects relatedness between hosts, we considered Simochromis monotypic because the three Cichlidogyrus species found on S. diagramma belonged to a different morphotype than those found on the other Simochromis. The transfer of S. babaulti, S. marginatus, S. pleurospilus and S. margaretae to Pseudosimochromis was justified by the similarity of their Cichlidogyrus fauna and the intermediate morphology of S. margaretae. Finally parasite data also supported the synonymy between S. pleurospilus and S. babaulti, a species that contains a large amount of geographical morphological variation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biodiversity*
  • Biological Evolution*
  • Cichlids* / classification
  • Cichlids* / parasitology
  • Female
  • Gills / anatomy & histology
  • Gills / parasitology
  • Host Specificity
  • Lakes / parasitology
  • Male
  • Phylogeny*
  • Platyhelminths / classification*
  • Platyhelminths / physiology
  • Platyhelminths / ultrastructure
  • Principal Component Analysis
  • Species Specificity
  • Tanzania

Grant support

At the time of conducting this research, M.V.S. and M.P.M.V. were Ph.D. fellows, and T.H. a post-doctoral fellow of the Research Foundation – Flanders (FWO-Vlaanderen). Field work was funded by two travel grants from the Research Foundation – Flanders to M.P.M.V. and two grants from the King Leopold III Fund for Nature Exploration and Conservation to M.V.S. and M.P.M.V. Currently, M.P.M.V. is supported by the Czech Science Foundation, Project no. P505/12/G112 (European Centre of Ichthyoparasitology (ECIP) – Centre of excellence). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.