Biogeographical affinities of the aquatic community of Refugio Cave, a newly discovered Astyanax cave

Pachón cave in the Sierra de El Abra, in Northeast Mexico, stands out as hosting the world's most widely studied cavefish population – with over 500 scholarly articles published about the population. Refugio Cave was recently discovered in the El Abra region. This cave hosts the mysid cave shrimp Spelaeomysis quinterensis and the blind cave tetra fish, Astyanax mexicanus. This study aims to understand how the aquatic community of Refugio Cave es related to other cave populations in the area. For this purpose, the Histone H3 gene of mysid shrimps and the OCA2 gene that confers albinism in Astyanax fish was sequenced. Results support that the Refugio and Pachón aquatic communities, which are only 4.5 km away apart, are closely related. Thus, the Refugio Cave population may contribute to better understand the evolutionary history of such an important population and, perhaps, help with Pachon's cavefish conservation

DNA barcoding and integrative taxonomy of the heterolepisma sclerophylla species complex (Zygentoma: Lepismatidae: Heterolepismatinae) and the description of two new species

We present one of the first studies of DNA barcodes (COI sequences) in the basal insect order Zygentoma, and compare the data with nuclear (28S) and mitochondrial (16S) rDNA sequences and morphology for an integrative taxonomic study of the Heterolepisma sclerophylla Smith species group. DNA sequence analyses identified deep divisions between Queensland and New South Wales populations, and among populations in each state. Detailed morphological and morphometric evaluation of the specimens failed, in most cases, to identify unambiguous morphological characters of diagnostic value for each population, possibly due to the interaction of morphological conservatism with high levels of variability resulting from their continued moulting after reaching sexual maturity. Several strong consistent characters were identified to support the description of a southern Queensland population as a new species (Heterolepisma cooloola sp. nov.). The combined molecular and morphological data support the view that the presence of lanceolate scales and the absence of macrochaetae from the anterior margin of the frons are more significant to phylogeny than the arrangement of styli and the shape of the thoracic sternites in Heterolepisma. Specimens from Glen Davis, NSW, while indistinguishable from H. sclerophylla in all other characters examined, were found to possess one fewer pair of abdominal styli in both sexes and are also described as a new species (Heterolepisma coorongooba sp. nov.). Five lineages are recognized within the remaining NSW material but as reliable (non-overlapping) morphological and morphometric differences could not be identified, they are not described here as new species. Heterolepisma sclerophylla sensu stricto is considered to be a complex of morphologically ill-defined species or perhaps subspecies

Enhanced prey capture skills in Astyanax cavefish larvae are independent from eye loss

Enhanced food-finding efficiency is an obvious adaptive response to cave environments. Here, we have compared the food-finding abilities of Astyanax surface fish and blind cavefish young larvae in their first month of life, in the dark. Our results show that enhanced prey capture skills of cavefish are already in effect in fry soon after the yolk is depleted and the young larvae must find food for themselves. Moreover, using prey capture competition assays on surface fish fry with lensectomies, we showed that eye-dependent developmental processes are not the main determinant for enhanced prey capture skills. Finally, using F2 hybrid larvae resulting from crosses between surface fish and cavefish, we found that reduced eyes do not confer a selective advantage for prey capture by fry in the dark. We discuss these data with regards to our current developmental and genetic understanding of cavefish morphological and behavioral evolution

First record of a freshwater cave sponge (Porifera, unknown gen. and sp.) in a cave inhabited by Astyanax cavefish in the Sierra de El Abra, San Luis Potosí, Mexico

The karstic cave, la Cueva de Los Sabinos, located in the Sierra de El Abra in the state of San Luis Potosí, Mexico, is mostly known for hosting a population of blind, depigmented Astyanax mexicanus cavefish. Herein, we report the discovery of a non-pigmented sponge (Porifera) in the final sump of this cave. No genus or species name could be attributed because we did not collect any specimen. Up to now, the sponge distribution seems restricted to a single pool in la Cueva de Los Sabinos, but further careful exploration of other pools of the cave as well as closely related cavities is warranted. To our knowledge, this observation constitutes the fourth report of a freshwater, white, cave-adapted sponge in the world and the first for Mexico and North America. It is also the eleventh troglobite species encountered in Los Sabinos. Our discovery confirms the exceptionally rich biodiversity of this cave ecosystem

The First Phylogenetic Analysis of Palpigradi (Arachnida)—The Most Enigmatic Arthropod Order

Palpigradi are a poorly understood group of delicate arachnids, often found in caves or other subterranean habitats. Concomitantly, they have been neglected from a phylogenetic point of view. Here we present the first molecular phylogeny of palpigrades based on specimens collected in different subterranean habitats, both endogean (soil) and hypogean (caves), from Australia, Africa, Europe, South America and North America. Analyses of two nuclear ribosomal genes and COI under an array of methods and homology schemes found monophyly of Palpigradi, Eukoeneniidae, and a division of Eukoeneniidae into four main clades, three of which include samples from multiple continents. This supports either ancient vicariance or long-range dispersal, two alternatives we cannot distinguish with the data at hand. In addition, we show that our results are robust to homology scheme and analytical method, encouraging further use of the markers employed in this study to continue drawing a broader picture of palpigrade relationships.Organismic and Evolutionary Biolog

R.H. Moreno-Durán: fantasía y verdad. Valoración múltiple

Pocos escritores colombianos han explorado diversos géneros literarios con resultados satisfactorios; Moreno-Durán destaca en el panorama artístico de Colombia al cosechar logros en una amplia producción creativa que incluye novelas, cuentos, ensayos y en los últimos tiempos el teatro. / Contenido. Preliminares; Capítulo 1 - R.H. Moreno-Durán: a fondo; Capítulo 2 - R.H. Moreno-Durán: en breve; Anexos

Discovery of Two New Astyanax Cavefish Localities Leads to Further Understanding of the Species Biogeography

The Astyanax species complex has two morphs: a blind, depigmented morph which inhabits caves in México and an eyed, pigmented surface-dwelling morph. The eyed morph can also be found in a few caves, sometimes hybridizing with the cave morph. This species complex has arguably become the most prominent model system among cave organisms for the study of evolutionary development and genomics. Before this study, 32 caves were known to be inhabited by the cave morph, 30 of them within the El Abra region. The purpose of this study was to conduct new surveys of the area and to assess some unconfirmed reports of caves presumably inhabited by troglomorphic fish. We describe two new localities, Sótano del Toro #2 and Sótano de La Calera. These two caves comprise a single hydrologic system together with the previously described cave of Sótano del Toro. The system is inhabited by a mixed population of troglomorphic, epigeomorphic, and presumably hybrid fish. Furthermore, Astyanax cavefish and the mysid shrimp Spelaeomysis quinterensis show a phylogeographic convergence that supports the notion that the central Sierra de El Abra is a biogeographical region that has influenced the evolutionary history of its aquatic community across species. The presumptive location of the boundaries of this biogeographical region are identified

A New Species Of The Genus Cubacubana (Insecta: Zygentoma: Nicoletiidae) From A Mexican Cave

Volume: 113Start Page: 218End Page: 22

Two new species of the genus Anelpistina (Insecta: Zygentoma: Nicoletiidae) from Mexican caves, with redescription of the genus

Volume: 112Start Page: 59End Page: 6