Poptella fuscata,a new Stethaprionini from the upper Amazon basin,Peru (Characiformes: Characidae)

A new species of Poptella is described from the Río Putumayo, Upper Río Amazon basin, Peru. The new species is distinguished from congeners by having a dense field of dark chromatophores homogeneously spread over the posterior half of the body, posterior humeral blotch extending to three to four horizontal scale rows below the lateral line, and a higher number of branched dorsal-fin rays. The new species can be readily distinguished from P. paraguayensis by having a comparatively shorter predorsal spine.     

Pinus georginae (Pinaceae), a new species from western Jalisco, Mexico

Pinus georginae is described and illustrated as a new endemic species from the valleys in the southern basin of Río Ameca, Jalisco, western Mexico. It is closely related to Pinus praetermissa; however, after studying the cones and anatomy of the leaves in detail, characteristics were revealed that identify P. georginae as a distinct species.

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Resumen  Se describe e ilustra Pinus georginae como una especie nueva, endémica de algunos valles intermontanos al sur del Río Ameca, Jalisco, en el Occidente de México. Los árboles se parecen a Pinus praetermissa; sin embargo, al estudiar con detalle los conos y la anatomía de las acículas lo ubican a Pinus georginae como una entidad biológica con categoría específica independiente.

     

A new species of Profundulus (Cyprinodontiformes: Profundulidae) from the Honduran central highlands

A new species of Profundulus, Profundulus portillorum, from the Honduran central highlands is described. Profundulus portillorum belongs to the Profundulus labialis species group and is distinct from the Profundulus punctatus species group in that it lacks a humeral spot and less than half of the caudal fin is scaled. Within the P. labialis species group, P. portillorum has a more slender body, smaller eye, fewer anal rays, caudal rays and lateral‐line scales than other species. Forty‐one specimens were collected around emergent vegetation in the margins of two small (2–5 m in width, 20–40 cm in depth), high‐elevation (1300 m) tributaries of the Río Calam within the Río Ulúa drainage. These specimens represent the easternmost collection of any Profundulus and the first collection of any member of the P. labialis species group from Honduras.     

Specific jarosite biomineralization by Purpureocillium lilacinum,an acidophilic fungi isolated from Río Tinto

Río Tinto (Huelva, southwestern Spain) is an extreme environment with a remarkably constant acidic pH and a high concentration of heavy metals, conditions generated by the metabolic activity of chemolithotrophic microorganisms thriving in the rich complex sulfides of the Iberian Pyrite Belt (IPB). Fungal strains isolated from the Tinto basin were characterized morphologically and phylogenetically. The strain identified as Purpureocillium lilacinum specifically induced the formation of a yellow‐ocher precipitate, identified as hydronium‐jarosite, an iron sulfate mineral which appears in abundance on the banks of Río Tinto. The biomineral was characterized by X‐ray diffraction (XRD) and its formation was observed with high‐resolution transmission electron microscopy (TEM) and scanning electron microscopy (SEM) coupled to energy‐dispersive X‐ray spectroscopy (EDX) microanalysis. Jarosite began to nucleate on the fungal cell wall, associated to the EPS, due to a local increase in the Fe³⁺/Fe²⁺ ratio which generated supersaturation. Its formation has been also observed in non‐viable cells, although with much less efficiency. The occurrence of P. lilacinum in an ecosystem with high concentrations of ferric iron and sulfates such as Río Tinto suggests that it could participate in the process of jarosite precipitation, helping to shape and control the geochemical properties of this environment.     

Three new legumes endemic to the Marañón Valley,Perú

Two new species of legume, Caesalpinia celendiniana and Mimosa lamolina and one new variety, Caesalpinia pluviosa var. maraniona, from the inter-Andean Río Mara?ón Valley in northern Perú are described and illustrated. These add to the already impressive tally of endemics known from the seasonally dry tropical forests of the Río Mara?ón Valley, which apparently far exceeds the endemic plant diversity from other nearby inter-Andean dry valleys in Perú and southern Ecuador.     

Averrhoidium dalyi (Sapindaceae): a new species from western Amazonia

The present paper describes and illustrates the new speciesAverrhoidium dalyi and provides a key to the species ofAverrhoidium. The new species is known from lowland, terra firme forest in the Purus River basin, in Acre, Brazil, and from Manu National Park in Madre de Dios, Peru.

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Resumen  En el presente artículo se describe, discute e ilustra la nueva especieAverrhoidium dalyi coleccionada en la cuenca del Río Purus en el estado de Acre, Brasil y en el Parque Nacional del Manu en el departamento Madre de Dios, Peru. También en el presente se provee una clave para las especies deAverrhoidium.

     

A capture–recapture model of amphidromous fish dispersal

Adult movement scale was quantified for two tropical Caribbean diadromous fishes, bigmouth sleeper Gobiomorus dormitor and mountain mullet Agonostomus monticola, using passive integrated transponders (PITs) and radio‐telemetry. Large numbers of fishes were tagged in Río Mameyes, Puerto Rico, U.S.A., with PITs and monitored at three fixed locations over a 2·5 year period to estimate transition probabilities between upper and lower elevations and survival probabilities with a multistate Cormack–Jolly–Seber model. A sub‐set of fishes were tagged with radio‐transmitters and tracked at weekly intervals to estimate fine‐scale dispersal. Changes in spatial and temporal distributions of tagged fishes indicated that neither G. dormitor nor A. monticola moved into the lowest, estuarine reaches of Río Mameyes during two consecutive reproductive periods, thus demonstrating that both species follow an amphidromous, rather than catadromous, migratory strategy. Further, both species were relatively sedentary, with restricted linear ranges. While substantial dispersal of these species occurs at the larval stage during recruitment to fresh water, the results indicate minimal dispersal in spawning adults. Successful conservation of diadromous fauna on tropical islands requires management at both broad basin and localized spatial scales.     

The Electric Glass Knifefishes of the Eigenmannia trilineata species‐group (Gymnotiformes: Sternopygidae): monophyly and description of seven new species

Eigenmannia trilineata López and Castello, 1966 (Sternopygidae) was described from the Río de La Plata basin and subsequently cited from most South American river basins. Questions about the limits of this species raise the possibility of the occurrence of undescribed species misidentified as E. trilineata. Herein we propose the Eigenmannia trilineata species group for species that share the presence of the superior medial stripe on the flank. This group comprises: E igenmannia antonioi sp. nov. , from the Rio Anapu, Rio Amazonas basin; E igenmannia desantanai sp. nov. , from the Rio Cuiabá, Rio Paraguay basin; E igenmannia guairaca sp. nov. , from the Riacho Água do Ó, upper Rio Paraná basin; E igenmannia matintapereira sp. nov. , from the Rio Uneiuxi and Rio Urubaxi, Rio Negro basin; Eigenmannia microstoma (Reinhardt, 1852), from the Rio São Francisco basin; E igenmannia muirapinima sp. nov. , from small tributaries of the Rio Amazonas; E igenmannia pavulagem sp. nov. , from the tributaries of Rio Capim, Rio Guamá basin; E. trilineata, from the lower Rio Paraná basin and Río de La Plata basin; Eigenmannia vicentespelaea Triques, 1996, from São Vicente I and II caves, Rio Tocantins basin; and E igenmannia waiwai sp. nov. , from the Rio Trombetas basin. These species can be distinguished from each other by unique sets of meristics, morphometrics, osteological and colour pattern features. © 2015 The Linnean Society of London     

Geographic distribution and demography of Pithecia aequatorialis (pitheciidae) in Peruvian Amazonia

To study the geographic distribution and demographic characteristics of Pithecia aequatorialis in Peruvian Amazonia, we undertook surveys and transect census in three river basins (Río Itaya, Río Tigre and Río Curaray) between 2004 and 2008. A total of 123 groups of P. aequatorialis was encountered during 1623 km of transect walks. Group size was uniform among the three areas (3.4–3.6 individuals), but surprisingly, population densities were higher in the area with strong hunting pressure (Río Itaya: 7.8 ind./km², vs. 5.6 and 5.9 km² in the Río Tigre and Río Curaray basins, respectively). The most common group composition included an adult pair with one offspring. Groups with more than one adult male and/or female accounted for 35% of sightings. Our observations extend P. aequatorialis range in Peru further south to the area between the Río Tigre and Río Corrientes, but exclude the area to the north between the Río Curaray and Río Napo. These findings are in contrast to previous distribution maps. P. aequatorialis was rarely seen in interspecific association during our censuses. Am. J. Primatol. 71:964–968, 2009. © 2009 Wiley‐Liss, Inc.     

Phylogeography, genetic structure, and gene flow in the endemic freshwater shrimp Palaemonetes suttkusi from Cuatro Ci��negas, Mexico

The valley of Cuatro Ciénegas in Mexico has the highest degree of local endemicity of any habitat in North America. A large number of endemic aquatic species occur both in the Cuatro Ciénegas basin and in the upper parts of the Río Salado de los Nadadores drainage, located immediately to the east of the valley. No natural surface flow occurs between these basins but artificial canals connect both areas. It is not clear whether the sharing of endemics between the Cuatro Ciénegas basin and the Río Salado is due to migration through canals. We conducted a phylogeographic study of mitochondrial haplotypes of the endemic shrimp Palaemonetes suttkusi to determine the evolutionary distinctiveness of the population found in Río Salado. We discovered that P. suttkusi likely has occurred naturally in both basins well into the distant past. Based on molecular clock analyses of the COI gene, the populations in the Río Salado and much of the Cuatro Ciénegas basin likely began diverging from each other between 1.9 and 11.2 Myr ago. The general levels of divergence are substantial but our results suggest there has also likely been recent gene flow between these basins. This is consistent with migration through human-made canals, but also consistent with the occurrence of natural gene flow during intermittent wet periods in the past million years. We also found significant differentiation of the Pozas Azules area from the rest of the Cuatro Ciénegas basin, a finding that is concordant with several phylogeographic studies on other aquatic endemics in Cuatro Ciénegas. We recommend that the upper parts of the Río Salado, the Pozas Azules area, and the rest of the Cuatro Ciénegas basin should each be considered independent evolutionarily significant units for conservation, and that migration of species through human-made canals should be monitored and controlled.     

Gametogenesis, histological gonadal cycle and in vitro fertilization in the whitemouth croaker (Micropogonias furnieri, Desmarest, 1823)

The whitemouth croaker (Micropogonias furnieri) is a demersal teleostean fish inhabiting the Atlantic Ocean from northern Venezuela to southern Argentina. In terms of biomass, the whitemouth croaker is the dominant sciaenid in the Río de la Plata and constitutes an important renewable resource for the Uruguayan and Argentinean fisheries. In the present study, analyzed were the gametogenesis and histological gonadal cycle in female and male whitemouth croakers collected at the Uruguayan coast of the Río de la Plata, between March 1997 and February 1998. In addition, the experimental conditions required to obtain mature viable gametes and achieve in vitro fertilization in this species were investigated. These studies indicate that the whitemouth croaker inhabiting the Río de la Plata is a multiple spawner, which reproduces on the Uruguayan coast between October and February. In vitro studies showed that following activation, sperm remain motile for up to 40 min, and under optimal dilution conditions that they retain a high fertilization capability for 15 min. Taken together these results could support future aquaculture research and exploitation of this species.     

A new species of Hyphessobrycon Durbin (Characiformes: Characidae) from the western Amazon basin in Colombia and Peru

Hyphessobrycon chiribiquete n. sp. is described from the Río Caquetá drainage in Colombia and the Río Ucayali drainage in Peru, western Amazon. The new species is diagnosed from its congeners by having the following combination of characters: a conspicuous narrow midlateral stripe, starting on the sides of the body behind the opercle near the lateral line; lateral stripe overlapped anteriorly with a vertically elongated humeral blotch; inner premaxillary teeth pentacuspid; margin of anal fin falcate in mature males.     

Matelea sartago-diaboli, a new species of Apocynaceae: Asclepiadoideae from the inter-Andean dry valleys of Bolivia

Summary   Matelea sartago-diaboli is described from the Río Grande inter-Andean dry valley system of central Bolivia, and compared with the recently described Argentinian endemic M. calchaquina. The new species is illustrated, and its conservation status discussed.     

A new species of Caesalpinia from the Río Balsas Depression, Mexico, and an updated taxonomic circumscription of the Caesalpinia hintonii complex (Leguminosae: Caesalpinioideae: Caesalpinieae: Poincianella Group)

Caesalpinia oyamae, a new species from the Río Balsas Depression, Mexico, is described and illustrated based on morphological evidence. It is similar toCaesalpinia hintonii, and grows in seasonally dry forests, between 500–1490 m.     

Coltriciella sonorensis sp. nov. (Basidiomycota, Hymenochaetales) from Mexico: evidence from morphology and DNA sequence data.

Coltriciella sonorensis is described here as a new species from Mexico. It is characterized by pleuropodal, flabelliform basidiomes, rounded to elongated or daedaloid pores, a well-developed sub-hymenium, and oblong to cylindrical basidiospores, slightly attenuated towards the apex. The specimen was collected on soil in an open Quercus stand in mixed Quercus–tropical deciduous forest in the Sierra de álamos–Río Cuchujaqui Biosphere Reserve, Sonora, Mexico. From a phylogenetic perspective, the species appears to be related to C. oblectabilis, also occurring in Mexico.     

Electric fishes of the genus Sternarchorhynchus (Teleostei,Ostariophysi, Gymnotiformes); phylogenetic and revisionary studies

Analysis of 88 characters of external and internal body systems yielded a phylogenetic reconstruction of the Neotropical electric knifefish genus Sternarchorhynchus (Apteronotidae; Gymnotiformes). The results support a hypothesis of Sternarchorhynchus as the sister group to Platyurosternarchus. A series of synapomorphies, many involving major innovations of the neurocranium, jaws, suspensorium, and associated systems that permit an unusual mode of grasp‐suction feeding, support the monophyly of both genera. Synapomorphies largely resolve relationships within Sternarchorhynchus with basal nodes strongly supported by characters pertinent to prey capture and initial processing of food items. These possible key innovations may provide Sternarchorhynchus with a competitive advantage over other clades of the Apteronotidae and account for the species diversity of the genus in Neotropical rivers. Adaptive radiation in Sternarchorhynchus was analysed. Habitat preference transitions repeatedly occurred in the genus between deep‐river channel dwelling species and rheophilic species with preferences for higher energy setting including rapids and swift‐flowing fluviatile settings. Twenty‐two species of Sternarchorhynchus are described as new based on samples that originated in the smaller rivers draining into the Golfo de Paria, the Marowijne and Essequibo River basins, the Río Orinoco and in particular the Amazon River basin. The 32 species in Sternarchorhynchus make it the most speciose genus in the Apteronotidae. No claim to original US government works. Journal compilation © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 159 , 223–371.     

A new Hemigrammus from the upper Río Vaupés,Colombia (Characiformes: Characidae), with a discussion on the presence of an enlarged urogenital papilla in the family

Hemigrammus xaveriellus sp. nov. is described from the upper Río Vaupés basin (Amazon basin), Departamento Guaviare, Colombia. It is distinguished from all congeners by the combination of the following characters: presence of a conspicuous, dark, longitudinal midlateral stripe extending along the body; presence of a conspicuous rounded, horizontally elongated humeral blotch anterior to the beginning of the dark midlateral stripe; seven scale rows between the dorsal fin and lateral line (vs. five to six); and five scale rows between the lateral line and pelvic-fin insertion (vs. three to four). The single mature male of He. xaveriellus possessed a well-developed urogenital papilla, an unusual feature among characids. The presence of an enlarged urogenital papilla in the family is discussed, and comments regarding the putative relationships of the new species are presented.