First molecular approach to the octopus fauna from the southern Caribbean.

The octopus fauna from the southern Caribbean is an understudied field. However, recent taxonomic work in the Colombian Caribbean has led to the discovery of several new species in the family Octopodidae. To provide molecular evidence for recent descriptions in the area (i.e., Octopus taganga, O. tayrona and Macrotritopus beatrixi) and contribute to the systematics of the family, we reconstructed the first molecular phylogenies of the family including Colombian Caribbean octopus species. Using cytochrome c oxidase subunit I and rhodopsin sequences from specimens collected in three sites (Santa Marta, Old Providence and San Andrés Islands) we inferred maximum-likelihood trees and delimited species with PTP. Our mitochondrial analysis supported the monophyly of species found in the area (i.e., O. taganga, O. hummelincki and O. briareus). The genetic distinction of the species O. tayrona and O. insularis was not resolved, as these were found in one clade together with Caribbean O. vulgaris and O. aff. tayrona species (O. spB) and delimited as a single species. Additionally, our results suggest a distant relationship of the Type I O. vulgaris group (Caribbean region) from the other forms of the species complex (Old World and Brazil). Lastly, the third newly described species M. beatrixi emerged as an independent lineage and was delimited as a single species. However, its relationship to other species of its genus remains unknown due to the lack of sequences in databases. Altogether, our molecular approach to the octopus fauna from the southern Caribbean adds on information to the relationship of Octopodidae species world-wide by providing sequences from recently described species from an understudied region. Further studies employing higher taxon sampling and more molecular information are needed to fill taxonomic gaps in the area and account for single-locus resolution on the systematics of this group.

First observations of the bigfin squid Magnapinna sp. in the Colombian Southern Caribbean.

Herein, first observations are reported of Magnapinna squids in the Colombian Southern Caribbean. Two specimens were observed by Remote Operated Vehicles (ROV) during exploratory drilling surveys for hydrocarbons at 1,883 and 2,294 m depth. These are the first observations of specimens of Magnapinna in the Southern Caribbean. Resumen La primera observación del calamar Magnapinna sp. en el caribe sur colombiano. Dos especímenes de calamares de aleta grande fueron observados con submarino de operación remota (ROV) durante un proyecto de perforación exploratoria de hidrocaburos a profundidades de 1,883 y de 2,294 m, respectivamente. Estas son las primeras observaciones de especímenes de Magnapinna en el Caribe Sur.

A new catfish species of the genus Trichomycterus (Siluriformes: Trichomycteridae) from the río Orinoco versant of Páramo de Cruz Verde, Eastern Cordillera of Colombia

A new Trichomycterus is described from a highland tributary of the río Meta (Orinoco basin), along the east flank of Páramo de Cruz Verde, Eastern Cordillera of Colombia. The new species is distinguished from most of its congeners by having a reduced posterior cranial fontanel, restricted to the parieto-supraoccipital, cleithrum pierced by several foramina, and an unique combination of four irregular rows of conic teeth in premaxilla and dentary, 13-14 opercular odontodes, 41-43 interopercular odontodes, 6-7 branchiostegal rays, 40 or 41 free vertebrae, 14-18 ribs, first ray of pectoral fin slightly projected as a short filament, 7-8 branched pectoral-fin rays, dorsal-fin origin at same level of pelvic-fin insertion, anal-fin origin posterior to dorsal-fin base, caudal-fin margin slightly rounded, a single upper hypural plate (3+4+5), and coloration pattern consisting in ground color dark brown with a thin mid-lateral dark stripe. Phylogenetic relationships of the new species based on the shared presence of derived features related to posterior cranial fontanel and cleithrum are discussed. The new species is also compared to the only two described species from Andean tributaries of río Orinoco basin.

É descrita uma espécie nova de Trichomycterus de um pequeno tributário dos Andes da bacia do río Meta (bacia do río Orinoco), no flanco oriental do Páramo de Cruz Verde na Cordilhera Oriental da Colômbia. A espécie nova distingue-se da maioria de seus congêneres por apresentar uma fontanela craniana posterior reduzida, restrita ao parieto-supraoccipital, cleitro perfurado por vários forames e uma combinação única de quatro fileiras irregulares de dentes cónicos no pré-maxilar e no dentário, 13-14 odontódeos operculares, 41-43 odontódeos interoperculares, 6-7 raios branquiostégios, 40 ou 41 vértebras livres, 14-18 costelas, o primeiro raio da nadadeira peitoral ligeiramente projetado em um curto filamento, 7-8 raios ramificados na nadadeira peitoral, origem da nadadeira dorsal no mesmo nível de inserção das nadadeiras pélvicas, origem da nadadeira anal posterior à base da nadadeira dorsal, margem da nadadeira caudal ligeiramente arredondada, uma única placa hipural superior (3+4+5) e padrão de coloração em um fundo de cor marrom escuro com uma fina listra escura média lateral. As relações filogenéticas da espécie nova com base na presença compartilhada de caracteres derivados relacionados com a fontanela craniana posterior e o cleitro são discutidas. A espécie nova também é comparada com as duas únicas espécies descritas de afluentes dos Andes da bacia do río Orinoco.

Trichomycterus venulosus (Steindachner, 1915), a junior synonym of Eremophilus mutisii Humboldt, 1805 (Siluriformes: Trichomycteridae) and not an extinct species

Reexamination of the syntypes of the enigmatic Trichomycterus venulosus, described from Páramo de Cruz Verde, Eastern Cordillera of Colombia, allowed us to assess its actual taxonomic status. This nominal species is demonstrated to constitute a junior synonym of Eremophilus mutisii, and then not represents a case of extinction of a fish endemic to Colombia, as currently accepted. .

O reexame dos síntipos do enigmático Trichomycterus venulosus, descrito do Páramo de Cruz Verde, Cordilheira Oriental da Colômbia, nos permitiram avaliar o seu status taxonômico atual. Demonstra-se que esta espécie nominal constitui um sinônimo júnior de Eremophilus mutisii, e, portanto, não representa um caso de extinção de um peixe endêmico da Colômbia, como atualmente é aceito.