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Three new species of saddled hypostomine loricariids are described. According to a recent phylogenetic analysis, these species are members of the genus Peckoltia. The species differ from all described Peckoltia except Peckoltia furcata and Peckoltia sabaji by having the dentaries meet at an angle greater than 90°. The species also have similarities to Hemiancistrus, and can be separated from all described species by having dorsal saddles. We discuss the taxonomy of Peckoltia, Hemiancistrus, and allied genera and recognize Ancistomus as valid for Peckoltia feldbergae, Hemiancistrus micrommatos, Ancistrus snethlageae, Hemiancistrus spilomma, and Hemiancistrus spinosissimus. We recommend descriptions of genera for several clades of Hemiancistrus and restriction of Hemiancistrus to the type species of the genus, Hemiancistrus medians. Chaetostomus macrops is transferred to Pseudancistrus and recognized as a junior synonym of Pseudancistrus megacephalus. The Hemiancistrus annectens group of species (Hemiancistrus annectens, Hemiancistrus argus, Hypostomus aspidolepis, Hemiancistrus fugleri, Hemiancistrus holostictus, Hemiancistrus maracaiboensis, Hemiancistrus panamensis, Hemiancistrus wilsoni) are recognized in Hypostomus. Multivariate analysis reveals that the newly described species differ from one another in shape space, but overlap broadly with other Peckoltia (Peckoltia lujani), narrowly with other Peckoltia (Peckoltia greedoi), or broadly with Etsaputu (Peckoltia ephippiata).

Peckoltia cavatica is described as a new species and P. braueri is redescribed. Peckoltia cavatica and P. braueri differ from all other Peckoltia by having distal orange bands on the dorsal and caudal fins when alive and by having the plates and bones of the head and nape outlined in black. Peckoltia cavatica is found in the Essequibo River basin, and P. braueri is found in the Takutu River basin. The species differ in that P. cavatica has weaker dorsal saddles, the plates and bones of the head and nape are completely outlined in black (vs. partially outlined in P. braueri), lacks vermiculate lines on the pterotic-supracleithrum, lacks at least one, broken band in the caudal fin, and has wider orange bands.

Baryancistrus demantoides and Hemiancistrus subviridis are two new species of loricariids from southern Venezuela with an olive ground coloration and white to cream-colored or golden-yellow spots. Baryancistrus demantoides is known only from the upper río Orinoco drainage while H. subviridis is also known from the río Casiquiare drainage. In addition to its coloration, B. demantoides can be distinguished from all other ancistrins by having the dorsal and adipose fins connected by an expanded posterior section of the dorsal-fin membrane, golden-yellow spots confined to the anterior portion of the body, and greater than 30 teeth per jaw ramus. Hemiancistrus subviridis can be separated from all other ancistrins by coloration, lacking a connection between the dorsal and adipose fins and having less than 30 teeth per jaw ramus.
Baryancistrus demantoides e Hemiancistrus subviridis são duas espécies novas de loricariídeos do sul da Venezuela, de cor de fundo verde-oliva e manchas brancas a creme ou amarelo-douradas. Baryancistrus demantoides é conhecida somente da bacia do rio Orinoco superior, enquanto H. subviridis é também conhecida da bacia do rio Casiquiare. Além da coloração, B. demantoides pode ser distinguido de todos os outros ancistríneos por ter as nadadeiras dorsal e adiposa conectadas por uma secção posterior expandida da membrana da nadadeira dorsal, manchas amarelo-douradas restritas à porção anterior do corpo, e mais de 30 dentes por ramo mandibular. Hemiancistrus subviridis pode ser separado de todos os outros ancistríneos pela falta de uma conecção entre as nadadeiras dorsal e adiposa e por possuir menos de 30 dentes por ramo mandibular

Numerous rivers, interrupted by large waterfalls and extensive rapids, drain the geologically ancient Guiana Shield Highlands. We describe a new armoured catfish genus and two new species endemic to the upper Ireng and Kuribrong rivers, respective tributaries of the Amazon and Essequibo basins in western Guiana. Corymbophanes ameliae sp. nov. is distinguished by having vermiculations on the abdomen, bands on the caudal fin, the anal fin i,5 and narrow caudal peduncle. Yaluwak primus gen. & sp. nov. is distinguished by having evertible cheek odontodes, a plated snout, a tall caudal peduncle and absence of adipose fin and iris operculum. We present a new molecular phylogenetic analysis inclusive of these and several related genera that suggests that the Corymbophanes clade (Araichthys, Corymbophanes, Cryptancistrus, Guianancistrus, Hopliancistrus and Yaluwak) originated in the Guiana Shield with secondary dispersal to the Brazilian Shield. Within the Guiana Shield, relationships among Corymbophanes and Yaluwak are consistent with geodispersal between drainages via headwater capture, although an uplift-mediated relictual distribution cannot be ruled out. ND2 haplotype structure among C. ameliae populations suggests that ichthyofaunal diversity on the Guiana Shield escarpment is shaped not only by inter-, but also intrafluvial barriers to gene flow.

The broadstripe shiner, Pteronotropis euryzonus is a freshwater minnow endemic to a small area that includes the tributaries of the middle and lower Chattahoochee River in Alabama and Georgia. Populations of P. euryzonus appear fragmented because individuals have not been detected in the main channel. This suggests limited dispersal potential and low gene flow between populations, and previous studies have suggested multiple forms of P. euryzonus in the Chattahoochee. In total, 125 samples of P. euryzonus were collected for genetic analysis from 23 sites in 11 tributaries of the Chattahoochee River, and museum specimens were used for morphometric analyses. The mitochondrial genes cytochrome c oxidase I (COI) and cytochrome b (cytb) were used to assess the genetic structure of P. euryzonus throughout its range. Geometric morphometrics were used to quantify shape variation among populations. Results suggest the presence of three genetically distinct populations: Northern, Pataula, and Southern, which also exhibit distinct morphologies. These populations support previous hypotheses of multiple forms of P. euryzonus in the Chattahoochee River. The presence of three genetically and morphologically distinct populations has significant conservation implications for P. euryzonus, which is currently listed as imperilled in both Alabama and Georgia. Three distinct populations, a restricted range, and recent disturbance to gene flow from local infrastructure may necessitate further protections to prevent extirpation. Copyright © 2015 John Wiley & Sons, Ltd.

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