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Morphology, molecules, and monogenean parasites: an example of an integrative approach to cichlid biodiversity.

Van Steenberge M, Pariselle A, Huyse T, Volckaert FA, Snoeks J, Vanhove MP - PLoS ONE (2015)

Bottom Line: 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.Finally parasite data also supported the synonymy between S. pleurospilus and S. babaulti, a species that contains a large amount of geographical morphological variation.

View Article: PubMed Central - PubMed

Affiliation: Biology Department, Royal Museum for Central Africa, Tervuren, Belgium; Laboratory of Biodiversity and Evolutionary Genomics, Department of Biology, University of Leuven, Leuven, Belgium; Institute of Zoology, University of Graz, Graz, Austria.

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.

No MeSH data available.


PCA on meristics of the inter-specific analysis.PC2 vs. PC1 of a PCA on 16 meristics from 114 specimens belonging to the six Simochromis and Pseudosimochromis species.
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pone.0124474.g002: PCA on meristics of the inter-specific analysis.PC2 vs. PC1 of a PCA on 16 meristics from 114 specimens belonging to the six Simochromis and Pseudosimochromis species.

Mentions: The 16 meristics that contained variation for all 144 specimens were analysed using PCA (Table 1). The number of scales around the caudal peduncle and the number of anal spines were constant (16, resp. 3) and thus omitted from the analysis. A scatter-plot of the second versus the first PC is presented in Fig 2. The first PC, explaining 28.39% of the variance, separated S. diagramma and P. curvifrons from S. babaulti, S. margaretae, S. marginatus and S. pleurospilus, further called the ‘small’ Simochromis. For this axis, values for both S. margaretae paratypes were higher than those for all but one of the S. babaulti and S. pleurospilus specimens. The most important variables in this PC were the number of anal soft rays (ASR), abdominal vertebrae (AV) and lower gill rakers (LGR). The second PC, explaining 14.21% of the variance, allowed for an almost complete separation between S. diagramma and P. curvifrons. This axis also separated S. marginatus from S. margaretae and, albeit with some overlap, from S. pleurospilus and S. babaulti. The main contributors to this axis were the number of bicuspid teeth on the upper and lower jaw (BTU, BTL) and the number of dorsal soft rays (DSR). A separation between P. curvifrons and S. diagramma was also obtained by axis 3 and 4 whereas axis 3 and 5 again separated S. marginatus from S. margaretae (results not shown). None of the PC could distinguish S. pleurospilus from S. babaulti and these species will be hence investigated later (see S. babaulti versus S. pleurospilus).


Morphology, molecules, and monogenean parasites: an example of an integrative approach to cichlid biodiversity.

Van Steenberge M, Pariselle A, Huyse T, Volckaert FA, Snoeks J, Vanhove MP - PLoS ONE (2015)

PCA on meristics of the inter-specific analysis.PC2 vs. PC1 of a PCA on 16 meristics from 114 specimens belonging to the six Simochromis and Pseudosimochromis species.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4414595&req=5

pone.0124474.g002: PCA on meristics of the inter-specific analysis.PC2 vs. PC1 of a PCA on 16 meristics from 114 specimens belonging to the six Simochromis and Pseudosimochromis species.
Mentions: The 16 meristics that contained variation for all 144 specimens were analysed using PCA (Table 1). The number of scales around the caudal peduncle and the number of anal spines were constant (16, resp. 3) and thus omitted from the analysis. A scatter-plot of the second versus the first PC is presented in Fig 2. The first PC, explaining 28.39% of the variance, separated S. diagramma and P. curvifrons from S. babaulti, S. margaretae, S. marginatus and S. pleurospilus, further called the ‘small’ Simochromis. For this axis, values for both S. margaretae paratypes were higher than those for all but one of the S. babaulti and S. pleurospilus specimens. The most important variables in this PC were the number of anal soft rays (ASR), abdominal vertebrae (AV) and lower gill rakers (LGR). The second PC, explaining 14.21% of the variance, allowed for an almost complete separation between S. diagramma and P. curvifrons. This axis also separated S. marginatus from S. margaretae and, albeit with some overlap, from S. pleurospilus and S. babaulti. The main contributors to this axis were the number of bicuspid teeth on the upper and lower jaw (BTU, BTL) and the number of dorsal soft rays (DSR). A separation between P. curvifrons and S. diagramma was also obtained by axis 3 and 4 whereas axis 3 and 5 again separated S. marginatus from S. margaretae (results not shown). None of the PC could distinguish S. pleurospilus from S. babaulti and these species will be hence investigated later (see S. babaulti versus S. pleurospilus).

Bottom Line: 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.Finally parasite data also supported the synonymy between S. pleurospilus and S. babaulti, a species that contains a large amount of geographical morphological variation.

View Article: PubMed Central - PubMed

Affiliation: Biology Department, Royal Museum for Central Africa, Tervuren, Belgium; Laboratory of Biodiversity and Evolutionary Genomics, Department of Biology, University of Leuven, Leuven, Belgium; Institute of Zoology, University of Graz, Graz, Austria.

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.

No MeSH data available.