Systematics of the Oswaldoi Complex (Anopheles, Nyssorhynchus) in South America

Abstract

BackgroundEffective malaria control relies on accurate identification of those Anopheles mosquitoes responsible for the transmission of Plasmodium parasites. Anopheles oswaldoi s.l. has been incriminated as a malaria vector in Colombia and some localities in Brazil, but not ubiquitously throughout its Neotropical range. This evidence together with variable morphological characters and genetic differences supports that An. oswaldoi s.l. compromises a species complex. The recent fully integrated redescription of An. oswaldoi s.s. provides a solid taxonomic foundation from which to molecularly determine other members of the complex.MethodsDNA sequences of the Second Internal Transcribed Spacer (ITS2 - rDNA) (n = 192) and the barcoding region of the Cytochrome Oxidase I gene (COI - mtDNA) (n = 110) were generated from 255 specimens of An. oswaldoi s.l. from 33 localities: Brazil (8 localities, including the lectotype series of An. oswaldoi), Ecuador (4), Colombia (17), Trinidad and Tobago (1), and Peru (3). COI sequences were analyzed employing the Kimura-two-parameter model (K2P), Bayesian analysis (MrBayes), Mixed Yule-Coalescent model (MYC, for delimitation of clusters) and TCS genealogies.ResultsSeparate and combined analysis of the COI and ITS2 data sets unequivocally supported four separate species: two previously determined (An. oswaldoi s.s. and An. oswaldoi B) and two newly designated species in the Oswaldoi Complex (An. oswaldoi A and An. sp. nr. konderi). The COI intra- and inter-specific genetic distances for the four taxa were non-overlapping, averaging 0.012 (0.007 to 0.020) and 0.052 (0.038 to 0.064), respectively. The concurring four clusters delineated by MrBayes and MYC, and four independent TCS networks, strongly confirmed their separate species status. In addition, An. konderi of Sallum should be regarded as unique with respect to the above. Despite initially being included as an outgroup taxon, this species falls well within the examined taxa, suggesting a combined analysis of these taxa would be most appropriate.ConclusionsThrough novel data and retrospective comparison of available COI and ITS2 DNA sequences, evidence is shown to support the separate species status of An. oswaldoi s.s., An. oswaldoi A and An. oswaldoi B, and at least two species in the closely related An. konderi complex (An. sp. nr. konderi, An. konderi of Sallum). Although An. oswaldoi s.s. has never been implicated in malaria transmission, An. oswaldoi B is a confirmed vector and the new species An. oswaldoi A and An. sp. nr. konderi are circumstantially implicated, most likely acting as secondary vectors.

Evidence of new species for malaria vector Anopheles nuneztovari sensu lato in the Brazilian Amazon region

“…and A. halophylus / A. triannulatus C varied from 1.7 to 2.30 % [ 69 ]. As observed, values >2.0 % have consistently been reported between sister taxa of species complexes in the Nyssorhynchus subgenus [ 31 , 36 , 37 , 69 – 71 ], whereas the intra-specific divergence is rarely >2 %. These results suggest that the members of A. nuneztovari complex are of recent evolutionary origin, confirming previous studies [ 18 , 31 ].…”

Mosquitoes of eastern Amazonian Ecuador: biodiversity, bionomics and barcodes

“…konderi and An. oswaldoi ( Ruiz-Lopez et al 2013 ) inadvertently uncovered the presence of more than one species in the specimens listed in the neotype description ( Flores-Mendoza et al 2004 ). Our specimens here correspond to one of the species barcoded from the neotype series, but it remains unclear whether this is “true” An.…”

Geometric morphometrics for the taxonomy of 11 species of Anopheles (Nyssorhynchus) mosquitoes

“…Advanced molecular tools are available to accurately discriminate among sibling species living in sympatry (Matson et al , ; Ruiz‐López et al , , ), but their use is expensive and requires specialized training (Garros & Dujardin, ). Geometric morphometrics does not reach the level of molecular accuracy, but the present findings show that it can be highly informative.…”