Carapace dentition patterns, morphometrics and allozyme differentiation amongst two toothed freshwater crab species (Potamonautes warreni and P-unispinus) (Decapoda : Brachyura : Potamonautidae) from river systems in South Africa

Daniels, SR, Stewart, BA, Ridgway, TM and Florence, W (2001) Carapace dentition patterns, morphometrics and allozyme differentiation amongst two toothed freshwater crab species (Potamonautes warreni and P-unispinus) (Decapoda : Brachyura : Potamonautidae) from river systems in South Africa. Journal of Zoology, 255 3: 389-404. doi:10.1017/S0952836901001480


Author Daniels, SR
Stewart, BA
Ridgway, TM
Florence, W
Title Carapace dentition patterns, morphometrics and allozyme differentiation amongst two toothed freshwater crab species (Potamonautes warreni and P-unispinus) (Decapoda : Brachyura : Potamonautidae) from river systems in South Africa
Journal name Journal of Zoology   Check publisher's open access policy
ISSN 0952-8369
Publication date 2001-01-01
Sub-type Article (original research)
DOI 10.1017/S0952836901001480
Volume 255
Issue 3
Start page 389
End page 404
Total pages 16
Editor J. Clutton-Brock
Place of publication Cambridge, UK
Publisher Cambridge University Press
Collection year 2001
Language eng
Subject C1
270203 Population and Ecological Genetics
270501 Animal Systematics, Taxonomy and Phylogeny
780105 Biological sciences
Abstract The taxonomic relationship between two toothed South African river crabs, Potamonautes warreni and P. unispinus, is unclear. The problem stems from the widespread variation in carapace dentition patterns amongst P. warreni individuals over its biogeographic range, where single toothed individuals may appear similar in carapace morphology to P. unispinus. Ten populations of P. warreni and 18 populations of P. unispinus were collected and the morphometric and genetic differentiation between the two taxa quantified. Patterns of morphometric and genetic variation were examined using multivariate statistics and protein gel electrophoresis, respectively. Principal component analyses of carapace characters showed that the two species are morphologically indistinguishable. However, discriminate functions analyses and additional statistical results corroborate the morphological distinction between the two taxa. Allozyme electrophoresis of 17 protein coding loci, indicated a close genetic similarity between the two species (I = 0.92). A fixed allelic difference at one locus (LT-2) and extensive genetic variability at another locus (PGM-1) indicate that two gene pools are present and that the two taxa are genetically isolated. Intraspecific genetic I values for both species were > 0.97 and indicated no apparent genetic structuring on a micro or macro-geographic scale. The variation in carapace dentition among P. warreni populations possesses no genetic basis and may possibly toe the product of ecogenesis. The value of dentition patterns in the systematics of river crabs is discussed. Dentition patterns among river crab species appear to be conserved and reliable as species specific diagnostic markers, but should ideally be used in combination with other morphological data sets and genetic evidence.
Keyword Zoology
Potamonautes
Carapace Dentition
Morphometrics
Allozymes
Systematics
Freshwater Crabs
Sp. Nov. Brachyura
Gulf-of-mexico
Genetic Differentiation
Western-cape
Water Crab
Morphological Variation
Enzyme Polymorphism
Perlatus Decapoda
Populations
Atlantic
Q-Index Code C1

Document type: Journal Article
Sub-type: Article (original research)
Collection: Centre for Marine Studies Publications
 
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Created: Wed, 15 Aug 2007, 02:26:54 EST