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Title: Genetics and ecology of spined loach in England: implications for conservation management
Author: Environment Agency
Document Type: Monograph
Annotation: Environment Agency Project ID:EAPRJOUT_1191, Representation ID: 372, Object ID: 2411
The Environment Agency studied this species in five catchments in England and confirmed for the first time that UK spined loach is the species Cobitis taenia. All the specimens examined in this report had a diploid chromosome number 2n=48 and other cytological features typical of C. taenia. Other morphologically similar species and hybrids commonly encountered in central and middle Europe appeared to be absent from British populations. Generally, spined loach have low levels of genetic variation, probably because of their relatively recent re-colonisation of Europe following the last glacial period. Genetic variation within spined loach populations in the five catchments in which they occur in England was found to be limited. Despite this, there was evidence of genetic population structure. Significant genetic differences were found between the Trent/Witham catchments and the Welland/Nene/Great Ouse catchments, reflecting the lack of connection between these two groups of catchments. The genetic variation within these groups was found to be mainly in inter-population differences in the Trent/Witham group. Both Witham populations (Metheringham Delph and River Witham) differed significantly from both Trent populations (River Mease and Stoke Bardolph). By contrast, the populations within the Welland/Nene/Great Ouse group showed little genetic differentiation. Of all the spined loach examined in this study, those from the rivers Mease (Trent catchment) and Witham (Witham catchment) were the most genetically distinct. Fish from these rivers were found to harbour haplotypes that do not occur anywhere else in Europe, a discovery of some importance given the generally low genetic diversity of the species. This discovery suggests that the Witham and Trent catchments may be potentially important areas for spined loach conservation. The genetic data collected in this study suggests that at least three of the seven UK populations should be managed in distinct units. These are the Witham, the Mease, and one of the rivers from the Welland/Nene/Great Ouse interconnected catchments. The latter two are already included in at least one SAC, but the Witham is not. We recommend that these units should be monitored and managed separately. Finally, the results of the habitat preference experiments carried out in this study suggest that the way populations are currently monitored may need to be rethought, along with the design of habitat management plans. Current understanding of the ecological requirements of spined loach has been largely derived from daytime habitat surveys. However, our results show that nocturnal habitat requirements are often different and perhaps more important, since food foraging occurs at night. Thus, management efforts directed at maintaining daytime habitats may not necessarily be beneficial to the species.
Publisher: Environment Agency
Subject Keywords: GeneticsRiversNature conservationGeneticsGene poolsCytologyHabitatsFreshwater ecology
Geographic Keywords: England
Taxonomic Keywords: Cobitis taenia
Extent: 40
Total file downloads: 37

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