STRIOCADULUS MAGDALENENSIS, A NEW DEEP-SEA SCAPHOPOD (MOLLUSCA: SCAPHOPODA: GADILIDAE) FROM THE COLOMBIAN CARIBBEAN*

ABSTRACT We describe a new bathyal species of scaphopod belonging to the genus Striocadulus Emerson based on conchological and radular characters . The specimens were collected at a depth of 404-412 m off Bocas de Ceniza (Colombian Caribbean) . Striocadulus magdalenensis new species can be distinguished from its other congeners by differences in its apical section, and both number and extent of longitudinal striae. This is the first record of this genus in the Atlantic Ocean

Poliquetos (Annelida: Polychaeta) del mar Caribe colombiano

El presente listado se ha realizado con información recopilada a partir de varias fuentes bibliográficas (Laverde-Castillo & Rodríguez 1987; Rodríguez 1979; Rodríguez 1988;Dueñas 1999, Londoño et al. 2002) y complementada con material depositado y revisado en el National Museum of Natural History (USNM) en Washington D.C., en el Museode Historia Natural Marina de Colombia en Santa Marta (MHNMC), en la Universidad de CÛrdoba en Montería (UCLZAN) y en colecciones personales

Babosas y liebres de mar (Mollusca: Gastropoda: Opisthobranchia) de Colombia

The sea slugs comprise the subclass Opisthobranchia, placed within gastropods (phylum Mollusca), a group that exhibits a wide range of body forms, from shelled organisms externally similar to caenogastropods, to highly derived shell-less forms. With shell loss, many additional external structures are acquired, such as cerata, sensory tentacles, and rhinophores. These structures serve a variety of sensory, defensive, and respiratory functions (Gosliner 1994). They are mostly bilaterally symmetrical and often with parapodial lobes (Thompson 1976).Las babosas de mar comprenden la subclase Opisthobranchia, situada dentro de los gasterópodos (phylum Mollusca), un grupo que exhibe un amplio arreglo en sus formas corporales y comprende desde organismos con concha, externamente similares a los caenogastropodos hasta una gran variedad de organismos que carecen de conchas. Estos han sufrido una detorsión que los ha llevado a la reducción o pérdida de la concha. Con la pérdida de la concha, varias estructuras adicionales externas están presentes como las ceratas, tentáculos sensoriales y rinóforos. Estas estructuras cumplen con una variedad de funciones sensoriales, defensivas y respiratorias (Gosliner 1994). La mayoría de estos organismos poseen una simetría bilateral y lóbulos parapodiales (Thompson 1976)

Quitones (Mollusca: Polyplacophora) del mar Caribe colombiano

El presente documento actualiza el inventario incrementándolo en seis especies, la mayoría de ellas producto de colectas recientes en diferentes localidades, incluyendo los fondos de la plataforma y del talud continental del Caribe colombiano, estas últimas durante las campañas efectuadas por el INVEMAR entre 1998 y 2001 en el marco de los proyectos “Macrofauna I y II”, cuyo material de referencia fue depositado en el Museo de Historia Natural Marina de Colombia (MHNMC)

Poliquetos (Annelida: Polychaeta) del mar Caribe colombiano

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A time-calibrated molecular phylogeny of the precious corals: Reconciling discrepancies in the taxonomic classification and insights into their evolutionary history

Background: Seamount-associated faunas are often considered highly endemic but isolation and diversification processes leading to such endemism have been poorly documented at those depths. Likewise, species delimitation and phylogenetic studies in deep-sea organisms remain scarce, due to the difficulty in obtaining samples, and sometimes controversial. The phylogenetic relationships within the precious coral family Coralliidae remain largely unexplored and the monophyly of its two constituent genera, Corallium Cuvier and Paracorallium Bayer & Cairns, has not been resolved. As traditionally recognized, the diversity of colonial forms among the various species correlates with the diversity in shape of their supporting axis, but the phylogenetic significance of these characters remains to be tested. We thus used mitochondrial sequence data to evaluate the monophyly of Corallium and Paracorallium and the species boundaries for nearly all named taxa in the family. Species from across the coralliid range, including material from Antarctica, Hawaii, Japan, New Zealand, Taiwan, Tasmania, the eastern Pacific and the western Atlantic were examined. Results: The concatenated analysis of five mitochondrial regions (COI, 16S rRNA, ND2, and ND3-ND6) recovered two major coralliid clades. One clade is composed of two subgroups, the first including Corallium rubrum, the type species of the genus, together with a small group of Paracorallium species (P. japonicum and P. tortuosum) and C. medea (clade I-A); the other subgroup includes a poorly-resolved assemblage of six Corallium species (C. abyssale, C. ducale, C. imperiale, C. laauense, C. niobe, and C. sulcatum; clade I-B). The second major clade is well resolved and includes species of Corallium and Paracorallium (C. elatius, C. kishinouyei, C. konojoi, C. niveum, C. secundum, Corallium sp., Paracorallium nix, Paracorallium thrinax and Paracorallium spp.). A traditional taxonomic study of this clade delineated 11 morphospecies that were congruent with the general mixed Yule-coalescent (GMYC) model. A multilocus species-tree approach also identified the same two well-supported clades, being Clade I-B more recent in the species tree (18.0-15.9 mya) than in the gene tree (35.2-15.9 mya). In contrast, the diversification times for Clade II were more ancient in the species tree (136.4-41.7 mya) than in the gene tree (66.3-16.9 mya). Conclusions: Our results provide no support for the taxonomic status of the two currently recognized genera in the family Coralliidae. Given that Paracorallium species were all nested within Corallium, we recognize the coralliid genus Corallium, which includes the type species of the family, and thus consider Paracorallium a junior synonym of Corallium. We propose the use of the genus Hemicorallium Gray for clade I-B (species with long rod sclerites, cylindrical autozooids and smooth axis). Species delimitation in clade I-B remains unclear and the molecular resolution for Coralliidae species is inconsistent in the two main clades. Some species have wide distributions, recent diversification times and low mtDNA divergence whereas other species exhibit narrower allopatric distributions, older diversification times and greater levels of mtDNA resolution

A time-calibrated molecular phylogeny of the precious corals: reconciling discrepancies in the taxonomic classification and insights into their evolutionary history

<p>Abstract</p> <p>Background</p> <p>Seamount-associated faunas are often considered highly endemic but isolation and diversification processes leading to such endemism have been poorly documented at those depths. Likewise, species delimitation and phylogenetic studies in deep-sea organisms remain scarce, due to the difficulty in obtaining samples, and sometimes controversial. The phylogenetic relationships within the precious coral family Coralliidae remain largely unexplored and the monophyly of its two constituent genera, <it>Corallium</it> Cuvier and <it>Paracorallium</it> Bayer & Cairns, has not been resolved. As traditionally recognized, the diversity of colonial forms among the various species correlates with the diversity in shape of their supporting axis, but the phylogenetic significance of these characters remains to be tested. We thus used mitochondrial sequence data to evaluate the monophyly of <it>Corallium</it> and <it>Paracorallium</it> and the species boundaries for nearly all named taxa in the family. Species from across the coralliid range, including material from Antarctica, Hawaii, Japan, New Zealand, Taiwan, Tasmania, the eastern Pacific and the western Atlantic were examined.</p> <p>Results</p> <p>The concatenated analysis of five mitochondrial regions (COI, 16S rRNA, ND2, and ND3-ND6) recovered two major coralliid clades. One clade is composed of two subgroups, the first including <it>Corallium rubrum</it>, the type species of the genus, together with a small group of <it>Paracorallium</it> species (<it>P. japonicum</it> and <it>P. tortuosum</it>) and <it>C. medea</it> (clade I-A); the other subgroup includes a poorly-resolved assemblage of six <it>Corallium</it> species (<it>C. abyssale, C. ducale, C. imperiale, C. laauense, C. niobe,</it> and <it>C. sulcatum</it>; clade I-B). The second major clade is well resolved and includes species of <it>Corallium</it> and <it>Paracorallium</it> (<it>C. elatius, C. kishinouyei, C. konojoi, C. niveum, C. secundum, Corallium</it> sp., <it>Paracorallium nix, Paracorallium thrinax</it> and <it>Paracorallium</it> spp.). A traditional taxonomic study of this clade delineated 11 morphospecies that were congruent with the general mixed Yule-coalescent (GMYC) model. A multilocus species-tree approach also identified the same two well-supported clades, being Clade I-B more recent in the species tree (18.0-15.9 mya) than in the gene tree (35.2-15.9 mya). In contrast, the diversification times for Clade II were more ancient in the species tree (136.4-41.7 mya) than in the gene tree (66.3-16.9 mya).</p> <p>Conclusions</p> <p>Our results provide no support for the taxonomic status of the two currently recognized genera in the family Coralliidae. Given that <it>Paracorallium</it> species were all nested within <it>Corallium</it>, we recognize the coralliid genus <it>Corallium</it>, which includes the type species of the family, and thus consider <it>Paracorallium</it> a junior synonym of <it>Corallium</it>. We propose the use of the genus <it>Hemicorallium</it> Gray for clade I-B (species with long rod sclerites, cylindrical autozooids and smooth axis). Species delimitation in clade I-B remains unclear and the molecular resolution for Coralliidae species is inconsistent in the two main clades. Some species have wide distributions, recent diversification times and low mtDNA divergence whereas other species exhibit narrower allopatric distributions, older diversification times and greater levels of mtDNA resolution.</p

Babosas y liebres de mar (Mollusca: Gastropoda: Opisthobranchia) de Colombia

-Artículo revisado por pare

Quitones (Mollusca: Polyplacophora) del mar Caribe colombiano

-Artículo revisado por pare