Delineating species along shifting shorelines: Tropheus (Teleostei, Cichlidae) from the southern subbasin of Lake Tanganyika

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F18%3A00107239" target="_blank" >RIV/00216224:14310/18:00107239 - isvavai.cz</a>

Result on the web

<a href="https://frontiersinzoology.biomedcentral.com/articles/10.1186/s12983-018-0287-4" target="_blank" >https://frontiersinzoology.biomedcentral.com/articles/10.1186/s12983-018-0287-4</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1186/s12983-018-0287-4" target="_blank" >10.1186/s12983-018-0287-4</a>

Result language

angličtina

Original language name

Delineating species along shifting shorelines: Tropheus (Teleostei, Cichlidae) from the southern subbasin of Lake Tanganyika

Original language description

BackgroundSpecies delineation is particularly challenging in taxa with substantial intra-specific variation. In systematic studies of fishes, meristics and linear measurements that describe shape are often used to delineate species. Yet, little is known about the taxonomic value of these two types of morphological characteristics. Here, we used Tropheus (Teleostei, Cichlidae) from the southern subbasin of Lake Tanganyika to test which of these types of characters best matched genetic lineages that could represent species in this group of stenotypic rock-dwelling cichlids. We further investigated intra-population variation in morphology. By linking this to a proxy of a population's age, we could assess the evolutionary stability of different kinds of morphological markers.ResultsMorphological data was collected from 570 specimens originating from 86 localities. An AFLP approach revealed the presence of five lineages in the southern subbasin: T. moorii, T. brichardi, T. sp. maculatus', T. sp. Mpimbwe' and T. sp. red', which we consider to represent distinct species. Although both types of morphological data supported this classification, a comparison of P-ST-values that describe inter-population morphological differentiation, revealed a better correspondence between the taxon delineation based on AFLP data and the patterns revealed by an analysis of meristics than between the AFLP-based taxon delineation and the patterns revealed by an analysis of shape. However, classifying southern populations of Tropheus was inherently difficult as they contained a large amount of clinal variation, both in genetic and in morphological data, and both within and among species. A scenario is put forward to explain the current-day distribution of the species and colour varieties and the observed clinal variation across the subbasin's shoreline. Additionally, we observed that variation in shape was larger in populations from shallow shores whereas populations from steep shores were more variable in meristics. This difference is explained in terms of the different timescales at which small and large scale lake level fluctuations affected populations of littoral cichlids at steep and shallow shores.ConclusionsOur results showed meristics to be more evolutionary stable, and of higher taxonomic value for species delimitation in Tropheus, than linear measurements that describe shape. These results should be taken into account when interpreting morphological differences between populations of highly stenotypic species, such as littoral cichlids from the Great East African Lakes.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10613 - Zoology

Project

<a href="/en/project/GBP505%2F12%2FG112" target="_blank" >GBP505/12/G112: ECIP - European Centre of Ichtyoparasitology</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Frontiers in Zoology

ISSN

1742-9994

e-ISSN

—

Volume of the periodical

15

Issue of the periodical within the volume

42

Country of publishing house

GB - UNITED KINGDOM

Number of pages

18

Pages from-to

1-18

UT code for WoS article

000450186400002

EID of the result in the Scopus database

2-s2.0-85056645964