Classification Success of Species within the<i>Gila robusta</i>Complex Using Morphometric and Meristic Characters—A Reexamination

Carter, Julie Meka; Clement, Matthew J.; Makinster, Andy S.; Crowder, Clayton D.; Hickerson, Brian T.

doi:10.1643/cg-17-614

Cited by 8 publications

(13 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Until recently, the consensus was defined by Minckley and DeMarais (2000) on the basis of morphometric and meristic characters. These have since proven of limited diagnostic capacity in the field, thus provoking numerous attempts to re-define morphological delimitations (Brandenburg et al 2015;Moran et al 2017;Carter et al 2018). Genetic evaluations have to date been inconclusive (Schwemm 2006;Copus et al 2018), leading to a recent taxonomic recommendation that subsequently collapsed the complex into a single polytypic species (Page et al 2016(Page et al , 2017.…”

Section: Huckleberry Andmentioning

confidence: 99%

See 1 more Smart Citation

Taxonomic Uncertainty and the Anomaly Zone: Phylogenomics Disentangle a Rapid Radiation to Resolve Contentious Species (Gila robusta complex) in the Colorado River

Chafin

Douglas

Bangs

et al. 2019

Preprint

View full text Add to dashboard Cite

Disclosure statement:Authors have nothing to disclose.Abstract (242/250) Species are an indisputable unit for biodiversity conservation, yet their delimitation is fraught 2 with both conceptual and methodological difficulties. A classic example is the taxonomic controversy surrounding the Gila robusta complex in the lower Colorado River of southwestern 4 North America. Three species were originally defined according to subtle morphological differences with weak diagnostic power, with traditional genetic analyses failing to support the 6 nominal species. Consequently, the complex was re-defined as a single polytypic unit, with the proposed 'threatened' status of two putative species withdrawn at the federal level. Here, we 8 utilized dense spatial and genomic sampling (N=387 and >22k loci) to re-evaluate the status of the complex, based on SNP-based coalescent and polymorphism-aware phylogenetic models. In 10 doing so, all three species were supported as evolutionarily independent lineages, despite widespread phylogenetic discordance. To understand this discrepancy with past studies, we 12 categorized evolutionary mechanisms driving discordance. We tested (and subsequently rejected) prior hypotheses suggesting that phylogenetic discord in the complex was hybridization-driven. 14 Instead, we found the G. robusta complex to have diverged within the 'anomaly zone' of tree space and, as such, have accumulated inconsistent patterns of diversity which have confounded 16 prior studies. After extending these analyses with phylogeographic modeling, we propose that this is reflective of a rapid radiation promoted by Plio-Pleistocene tectonism. Our results not only 18 support resurrection of the three species as distinct entities, but also offer an empirical example of how phylogenetic discordance can be categorized in other recalcitrant taxa. 20 between G. robusta from the upper and lower basins of the Colorado River ecosystem (Chafin et 130 al. 2019). One species, Gila elegans, is extirpated from the wild, thus samples were provided by the 132 Southwestern Native Aquatic Resources and Recovery Center (Dexter, NM). The genus Ptychocheilus served to root the Gila clade within the broader context of western leuciscids 134 (Schönhuth et al. 2012, 2014, 2018). 8 136 Reduced-representation sequencing Genomic DNA was extracted using either PureGene® or DNeasy® kits (Qiagen Inc.) and 138 quantified via fluorometer (Qubit™; Thermo-Fisher Scientific). Library preparations followed the published ddRAD protocol (Peterson et al. 2012). Restriction enzyme and size-selection 140 ranges were first screened using an in silico procedure (Chafin et al. 2018), with the target fragment sizes further optimized by quantifying digests for 15 representative samples on an 142 Agilent 2200 TapeStation. Final library preparations were double-digested using a high-fidelity PstI (5'-CTGCAG-3') and MspI (5'-CCGG-3') following manufacturer's protocols (New 144 England Biosciences). Digests were purified using bead purification (Ampure XP; Beckman-Coul...

show abstract

Section: Huckleberry Andmentioning

confidence: 99%

“…nigra with G. robusta, owing in part to their morphological ambiguity and an imprecise taxonomic key (Carter et al 2018). Given this, a proposal to extend protection to lower basin G.…”

Section: Management Implicationsmentioning

confidence: 99%

Taxonomic Uncertainty and the Anomaly Zone: Phylogenomics Disentangle a Rapid Radiation to Resolve Contentious Species (Gila robusta complex) in the Colorado River

Chafin

Douglas

Bangs

et al. 2019

Preprint

View full text Add to dashboard Cite

show abstract

“…Morphological studies involving Gila in the lower Colorado River basin have varied greatly in their conclusions, with recognition of one to three species in the G. robusta complex (Carter et al 2016). As noted previously in this article, earlier editions of the checklist included only a single species, G. robusta.…”

mentioning

confidence: 92%

Taxonomy of Gila in the Lower Colorado River Basin of Arizona and New Mexico

et al. 2017

View full text Add to dashboard Cite

“…Numerous molecular studies have attempted to resolve the relationships of the Gila robusta complex. Although interpretations of the data vary, there is no clear evidence to date that the three nominal species of Gila in the drainages of the Lower Colorado River basin represent reproductively isolated and distinct evolutionary units ( DeMarais, 1992 ; DeMarais et al, 1992 ; Dowling & DeMarais, 1993 ; Schönhuth et al, 2012 , 2014 ; Dowling et al, 2015 ; Marsh, Clarkson & Dowling, 2017 ), nor has a reliable method (morphological or molecular) of assigning individual fish to species been identified ( Moran et al, 2017 ; Carter et al, 2018 ). The current practice of species identification for managers and researchers working with the G. robusta complex requires identifications based on collection locality as determined by Rinne (1969) and later revised by Minckley & DeMarais (2000) based on mean morphological differences of populations rather than diagnosable morphological or molecular characters of individuals, because no such characters have been identified.…”

Section: Introductionmentioning

confidence: 99%

Geopolitical species revisited: genomic and morphological data indicate that the roundtail chubGila robustaspecies complex (Teleostei, Cyprinidae) is a single species

Copus

Montgomery

Forsman

et al. 2018

PeerJ

View full text Add to dashboard Cite

The Gila robusta species complex in the Lower Colorado River Basin has a complicated taxonomic history. Recent authors have separated this group into three nominal taxa, G. robusta, G. intermedia, and G. nigra, however aside from location, no reliable method of distinguishing individuals of these species currently exists. To assess relationships within this group, we examined morphology of type specimens and fresh material, and used RADseq methods to assess phylogenetic relationship among these nominal species. Maximum likelihood and Bayesian inference tree building methods reveal high concordance between tree topologies based on the mitochondrial and nuclear datasets. Coalescent SNAPP analysis resolved a similar tree topology. Neither morphological nor molecular data reveal diagnostic differences between these species as currently defined. As such, G. intermedia and G. nigra should be considered synonyms of the senior G. robusta. We hypothesize that climate driven wet and dry cycles have led to periodic isolation of population subunits and subsequent local divergence followed by reestablished connectivity and mixing. Management plans should therefore focus on retaining genetic variability and viability of geographic populations to preserve adaptability to changing climate conditions.

show abstract

Classification Success of Species within theGila robustaComplex Using Morphometric and Meristic Characters—A Reexamination

Cited by 8 publications

References 27 publications

Taxonomic Uncertainty and the Anomaly Zone: Phylogenomics Disentangle a Rapid Radiation to Resolve Contentious Species (Gila robusta complex) in the Colorado River

Taxonomic Uncertainty and the Anomaly Zone: Phylogenomics Disentangle a Rapid Radiation to Resolve Contentious Species (Gila robusta complex) in the Colorado River

Taxonomy of Gila in the Lower Colorado River Basin of Arizona and New Mexico

Geopolitical species revisited: genomic and morphological data indicate that the roundtail chubGila robustaspecies complex (Teleostei, Cyprinidae) is a single species

Contact Info

Product

Resources

About