Taxonomic distinctness and diversity patterns of a polychaete (Annelida) community on the continental shelf of the Southern Gulf of Mexico.

The spatial patterns of taxonomic diversity of annelid polychaete species from the continental shelf in the Southern Gulf of Mexico were examined in this study. We used taxonomic distinctness and its spatial variations to explore the diversity patterns and how they change between Southern Gulf of Mexico regions. In addition, using taxonomic distinctness as a dissimilarity measure and Ward's Clustering, we characterized three distinct faunal assemblages.

Morphometric and taxonomic approach to describe (Annelida, Longosomatidae), a new species with three size-dependent morphotypes, from the Gulf of California, Eastern Pacific.

The Longosomatidae, a poorly known polychaete family, includes only 23 recognized species; in this study, based on morphometric and taxonomic analyses, we describe a new species with three morphotypes: from the Gulf of California, Mexico. The specimens examined exhibit large morphological variations but were clearly separated from close species due to a unique combination of morphological characters: chaetiger 9 as the first elongated chaetiger, four to eight branchial pairs; chaetae from chaetiger 10 forming rings in two rows, posterior row with thin and robust capillaries, anterior row with subuluncini, aristate spines, acicular spines and thick acicular spines. With the discriminant analysis, carried out on 11 morphometric characters, the presence of three morphological groups were recognized (Wilks' lambda= 0.

, a new species of Capitellidae (Annelida, Polychaeta) from the Gulf of California, with morphological remarks on species with hooks in thoracic chaetigers.

from the Gulf of California shelf is described, illustrated, and compared with its congeners bearing hooded hooks in thoracic chaetigers. This new species is characterized by the presence of a prostomial palpode, only notopodia in the first chaetiger, hooded hooks in neuropodia of chaetiger 11, and its distinct methyl green staining pattern consisting of: chaetigers 1-4 slightly stained, chaetigers 5-10 with green bands encircling the segments, and a darker, solid, green band encircling the body in chaetigers 11-12. It is mainly distributed in the central Gulf of California in fine sand bottoms (62-96%) at 32-106.

Motile macrofauna associated with pelagic Sargassum in a Mexican reef lagoon.

Buildup of decaying pelagic Sargassum on the beaches and coasts of the Mexican Caribbean during the massive arrivals of 2015 and 2018 had detrimental impacts on the environment and tourist industry. To avoid ecological and economic impacts from massive beaching of Sargassum, it would be better to remove the pelagic algal masses while still at sea. However, out at sea, pelagic Sargassum rafts constitute an ecosystem with a diversified associated fauna and their removal could impact this fauna.

Experimental evidence of pollination in marine flowers by invertebrate fauna.

Pollen transport by water-flow (hydrophily) is a typical, and almost exclusive, adaptation of plants to life in the marine environment. It is thought that, unlike terrestrial environments, animals are not involved in pollination in the sea. The male flowers of the tropical marine angiosperm Thalassia testudinum open-up and release pollen in mucilage at night when invertebrate fauna is active.

Eusyllinae, Exogoninae and Autolytinae (Syllidae: Polychaeta) from the Southern Mexican Pacific, with the description of three new species.

Previous studies have dealt recently with syllid polychaetes in soft sediments from Acapulco Bay (Southern Mexican Pacific) with new species and new records of the subfamily Syllinae published, but the remaining subfamilies found in the area had not been included. This study deals with syllids belonging to those subfamilies: Eusyllinae, Exogoninae and Autolytinae, since the Anoplosyllinae were not found. Three species are described as new: Odontosyllis septemdentata n.

Labrorostratus caribensis, a new oenonid polychaete from the Grand Caribbean living in the body cavity of a nereidid, with emendation of the genus.

Endoparasitic relationships among polychaetes are uncommon and mostly restricted to about 20 species of the family Oenonidae. We herein describe Labrorostratus caribensis, a new oenonid species living in the body cavity of a nereidid polychaete in Chinchorro Bank (Mexican Caribbean). This is the first report of a parasitic relationship between oenonids and nereidids in the Grand Caribbean region.

Description of two new species of Pisione (Polychaeta: Sigalionidae) and first record of Pisione galapagoensis Westheide in the Southern Mexican Pacific.

The genus Pisione Grube 1857 was composed up to now of 40 species and 4 subspecies. Although distributed worldwide, in the Mexican Pacific little is known about its taxonomy and distribution, and only two species of this genus have been recorded: Pisione longispinulata Aguado & San Martín, 2004 and Pisione remota (Southern, 1914), but the records of the latter remain questionable. For this study, 406 pisionids from soft sediments of Acapulco Bay, Southern Mexican Pacific, were examined.

Nereis alacranensis, a new species of polychaete (Annelida, Nereididae) from Alacranes Reef, southern Gulf of Mexico, with a key to Nereis from the Grand Caribbean.

A new species of polychaete, Nereis alacranensis n. sp., was found in dead coral rocks in the intertidal zone of Alacranes reef, southern Gulf of Mexico.

Hyalella cenotensis, a new species of Hyalellidae (Crustacea: Amphipoda) from the Yucatán Peninsula, Mexico.

In this study the first blind species of Hyalella for Mexico is described; it is the second in the genus to be recorded there. The new species is closer to the eyeless species: H. anophthalma Ruffo, 1957, H.

Description and distribution of two new species of Paraonidae (Annelida: Polychaeta) from a lagoon-estuarine ecosystem in the Southern Gulf of Mexico.

The aim of this study was to analyze the taxonomy and distribution of the polychaetes of the family Paraonidae from a lagoon-estuarine ecosystem in the Gulf of Mexico. The samples come from 20 soft bottom stations in the Términos Lagoon during the dry and rainy seasons, of which eight included paraonids. In all, 1183 specimens belonging to two new species were identified: Aricidea (Acmira) hirsuta (1125 specimens) and Paradoneis carmelitensis (58 specimens).