Benthic Peracarids (Crustacea) from an unexplored area of Patagonian channels and Fjords.

BACKGROUND: The intricate geomorphology of the coastline in the Chilean Channels and Fjords region, together with the freshwater inputs from the ice fields provide the area with very unique ecological characteristics and a variety of habitats that favour great marine biodiversity. However, although Chilean Patagonia has been the focus of several expeditions and ecological surveys, the greatest emphasis has been either on the populated coasts of the Beagle Channel and the Straits of Magellan to the south or the area to the north of Golfo de Penas, leaving vast areas that remain largely unexplored. This leads to a latitudinal gap in the faunistic information and hinders zoogeographic studies to assess biogeographical connections along the eastern coasts of the Pacific. Peracarida is a taxonomic group that provides an excellent model for such studies because of their high abundance and biodiversity, benthic habits, small size and limited dispersal capacity. NEW INFORMATION: A dataset providing the first and only records of the benthic Peracarida between the latitudes 48-51.5°S of the Pacific coast of Chile is presented here, hence closing a geospatial gap for the study of the biogeographical connections of the Peracarida along the Eastern Pacific coast. The dataset comprises a total of 141 georeferenced records of 60 sublittoral species of Tanaidacea, Isopoda and Amphipoda. This and other studies reveal that the coastal fauna of the region follow a latitudinal distribution pattern at a larger scale and nested assemblages inside the channels and fjords that can be regarded as a consequence of the more restrictive conditions in the inner parts. In the present scenario of global warming that is expected to affect particularly polar and subpolar regions, the present dataset serves as a reference for the distribution patterns of benthic organisms with low dispersal capacity.

Additions to the Tanaidomorpha (Crustacea: Tanaidacea) from mud volcanoes and coral mounds of the Gulf of Cadiz and Horseshoe Continental Rise.

The Tanaidacea collection from various research cruises carried out in the Gulf of Cadiz and Horseshoe Continental Rise between 2004 and 2012 yielded four species new to science that are described herein. Two belong to genera recorded for the first time since the original descriptions of their type species: Cetiopyge, described from the Gulf of Mexico and Gamboa from shallow waters of Macaronesia. The other two belong to the genera Collettea and Paragathotanais, both with a worldwide distribution. Additionally, specimens of Tumidochelia uncinata are described and illustrated to complete previous descriptions. Identification keys to all known genera of Nototanaidae, and the Eastern Atlantic species of Paragathotanais and Collettea are provided. This works raises the number of tanaidacean species known from the deep-sea habitats in the study region to a total of 22.

New data on the Tanaidacea (Crustacea: Peracarida) from the Canary Islands, with a description of a new species of Apseudopsis.

Benthic samples from two harbours at El Hierro and Tenerife (Canary Islands) yielded three species of Tanaidacea. Tanais dulongii and Leptochelia savignyi are recorded for the first time in Tenerife and El Hierro, respectively. A new species of Apseudomorpha, Apseudopsis rogi, was collected in both harbours and can be differentiated from other species of the genus by the male having a cheliped merus with a distinctive, cylindrical dorso-proximal spur. This is the first species of Apseudopsis described for the Macaronesian region. A key to the Atlantic and Mediterranean species of Apseudopsis is provided.

A new species of heterochelous tanaidacean Tanaissus (Paratanaoidea: Tanaissuidae) from the north-west Iberian Peninsula.

A new species of tanaidomorph, Tanaissus bamberi, is described from the north-western region of the Iberian Peninsula. Its most remarkable character is the presence of morphologically different right and left chelae in the males. The species occurs sympatrically with T. lilljeborgi, mainly in intertidal and subtidal sediments of medium to muddy sands typical of fully marine and estuarine salinities.

Leucothoe kawesqari, a new amphipod from Bernardo O'Higgins National Park (Chile), with remarks on the genus in the Magellan Region (Crustacea, Peracarida).

Although the genus Leucothoe has been reported repeatedly in the Magellan Region, the citations in the Channels and Fjords Ecoregion were either unidentified or attributed to the previously considered cosmopolitan Leucothoe spinicarpa. In this work, Leucothoe kawesqari sp. n. is described, which can be distinguished from other species of the genus in the Southern Ocean by having eyes present, epimeral plates with no setae, anterior coxae not acutely produced or excavate, coxa 5 slightly bilobed, accessory flagellum present, mandibular palp article 3 shorter than ½ article 2, pereopods 5-7 basis expanded, ovoid, posterior margin weakly crenulate and telson apex irregularly truncated. The new species was found in hard substrates, both unvegetated and with macroalgae, mainly in kelp forest of Macrocystis pyrifera.

ResumenA pesar de que el género Leucothoe ha sido citado en la región Magallánica en repetidas ocasiones, las citas en la Ecorregión de Canales y Fiordos o bien no han sido identificados o atribuidos a la antes considerada especie cosmopolita Leucothoe spinicarpa. En este trabajo se describe Leucothoe kawesqarisp. n., que se distingue de otras especies del género que se encuentran en el Océano Antártico por presentar ojos, placas epimerales sin setas, coxas anteriores no puntiagudas ni excavadas, coxa 5 ligeramente bilobulada, flagelo accesorio, artículo 3 del palpo mandibular más corto que la mitad del artículo 2, bases de los pereiópodos 2­7 expandidas con el margen ligeramente crenulado y ápice del telson truncado e irregular. La nueva especie fue encontrada en sustratos duros, tanto sin vegetación como con macroalgas, dominadas por bosques de huiros de la especie Macrocystis pyrifera.

A new genus and species of Leptocheliidae (Crustacea: Peracarida: Tanaidacea) from Isla del Coco (Costa Rica).

Samples from the scarcely-studied sedimentary seabed from the Isla del Coco (Costa Rica) yielded a single species of Tanaidacea, belonging to a new genus of Leptocheliidae, Cocotanais. The new genus shows affinities with Pseudonototanais and Heterotanais in bearing a conspicuous forcipate cheliped in the males, which in Cocotanais has a modified merus and carpal flange. Other distinct characters of the males are a triangular cephalothorax, a three-articled antennular peduncle and swollen bases of pereopods 4-6. Females have a four-articled antennule, a maxilliped endite with three distal flat spines and two inner coupling hooks, and a maxilliped basis with two long setae. The species was found in sheltered bays, both free-living in the sediment and also as a commensal of anemones (Infraorder Boloceroidaria), thus representing the first reported case of such an association.