African Herald snakes, Crotaphopeltis, show population structure for a widespread generalist but deep genetic divergence for forest specialists. (8th January 2020)

• Record Type: Journal Article
• Authors: Engelbrecht, Hanlie M.; Branch, William R.; Greenbaum, Eli; Burger, Marius; Conradie, Werner; Tolley, Krystal A.
• Is Part Of: Journal of zoological systematics and evolutionary research. Volume 58:Number 4(2020)
• Page Start: 1220
• Page End: 1233
• Publication Date: 2020-01-08
• Subjects: Africa -- coalescent species delimitation -- phylogeography; Animals -- Classification -- Periodicals; Zoology -- Periodicals; Evolution -- Periodicals; 578.012
• DOI: 10.1111/jzs.12361
• Languages: English
• ISSNs: 0947-5745

Abstract

Abstract: The African colubrid snake genus Crotaphopeltis currently comprises six species and occurs throughout sub‐Saharan Africa. The most widespread of these, Crotaphopeltis hotamboeia, inhabits most biomes, aside from rainforest and hyper‐arid regions, and its catholic niche has presumably facilitated substantial gene flow. Despite this, the geographical range is large enough that ecological or physical barriers might exist, facilitating allopatric diversification. In contrast, most of the other species are habitat specialists with limited distributions (e.g., Crotaphopeltis tornieri ) and would be expected to show strong genetic structure. We therefore examined species boundaries within Crotaphopeltis in a phylogenetic context using five markers ( 16S, cyt b, ND4, c‐mos, and RAG‐1 ) for four of the six species. Species delimitation methods included two coalescent‐based and one barcoding approach. Widespread geographical sampling of C. hotamboeia allowed examination of genetic structuring across its range. The species status of Crotaphopeltis barotseensis, C. degeni, and C. hotamboeia was confirmed, whereas the Afromontane species C. tornieri comprised two candidate species. Crotaphopeltis hotamboeia did not show cryptic speciation, although its phylogeographic structure corresponded with the spatiotemporal pattern of the African savanna. Our results show how the heterogeneous African environment could influence genetic partitioning of habitat specialist and generalist species at broad geographical scales. Abstract : An investigation of the phylogenetic species boundaries within the African colubrid snake genus, Crotaphopeltis, confirms the species status of Crotaphopeltis barotseensis, C. degeni, and C. hotamboeia and the presence of two candidate species for the Afromontane C. tornieri . Although C. hotamboeia is a single, valid wide‐ranging species, there is considerable phylogeographic structure present across its sub‐Saharan distribution. The genetic partitioning within C. hotamboeia seems to correspond with the spatiotemporal pattern of the African savanna biomes.