RESUMO

A taxonomic study of deep-sea polychaetes collected at a depth of 2,805 m off the northern coast of California revealed a scaleworm of the family Sigalionidae with an attached parasitic copepod. The copepod represents an undescribed genus of the family Herpyllobiidae, comprising mesoparasitic copepods chiefly recorded from polychaetes of the family Polynoidae. Blakerius gen. nov. diverges from the other herpyllobiid genera by its possession of 1) a chalice-shaped ectosoma with several protuberances along the posterior margin and a long cylindrical shaft with a hyaline coating and integumental sculpturing, a short stalk with a small, anteriorly placed sclerotized ring, 2) a relatively large, discoid-shaped endosoma with digitiform process, and 3) attached male copepodids with 3-segmented antennules, containing limbless sac-like males. The new genus is compared with other herpyllobiids. This discovery increases the number of known herpyllobiid genera to six and is the first record of a herpyllobiid parasitizing a sigalionid polychaete.urn: lsid: zoobank.org:pub:5E31FEED-D3EB-460E-AEA4-02A9D3A778D6.

Assuntos

RESUMO

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. We also investigated patterns of richness, taxonomic distinctness, and distance decay of similarity between sampling stations as a ß-diversity measure. Finally, we examined the spatial relationships between polychaete assemblages and environmental variables to test the relative importance of spatial and environmental components in annelid polychaete community structure from the Southern Gulf of Mexico. We used a combination of eigenvector-based multivariate analyses (dbMEMs) and distance-based redundancy analysis (dbRDA) to quantify the relative importance of these explanatory variables on the spatial variations of taxonomic distinctness. The significance level of spatial and environmental components to the distribution of polychaete species showed that the combined effect of spatial processes and sediment characteristics explained a higher percentage of the variance than those parameters could alone.

Assuntos

RESUMO

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: Heterospio variabilis 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= 0.093, p = 0.0001). However, the variables selected to discriminate the specimens (partial Wilks' lambda > 0.57) were correlated to their size: number of branchiae, body width, prostomium width, rate length CH9/CH1-CH8, length CH1-CH8 and length CH9 (r > 0.5). So, we concluded that they belong to a single species with three morphotypes: morpho A with eight branchial pairs, morpho B with 5-6-7 pairs and morpho C with 4 pairs. No correlations between the distribution of the distinct morphotypes along the eastern gulf shelf and the environmental conditions where they settle were detected.

Assuntos

RESUMO

Nereidid polychaetes are well known from shallow marine habitats, but their diversity in the deep sea is poorly known. Here we describe an unusual new nereidid species found at methane seeps off the Pacific coast of Costa Rica. Specimens of Pectinereis strickrotti gen. nov., sp. nov. had been observed dating back to 2009 swimming just above the seafloor at ~1,000 m depth but were not successfully captured until 2018. Male epitokes were collected as well as a fragment of an infaunal female found in a pushcore sample. The specimens were all confirmed as the same species based on mitochondrial COI. Phylogenetic analyses, including one based on available whole mitochondrial genomes for nereidids, revealed no close relative, allowing for the placement of the new species in its own genus within the subfamily Nereidinae. This was supported by the unusual non-reproductive and epitokous morphology, including parapodial cirrostyles as pectinate gills, hooked aciculae, elfin-shoe-shaped ventral cirrophores, and elongate, fusiform dorsal ligules emerging sub-medially to enlarged cirrophores. Additionally, the gill-bearing subfamily Dendronereidinae, generally regarded as a junior synonym of Gymnonereidinae, is reviewed and it is here reinstated and as a monogeneric taxon.

Assuntos

RESUMO

Oligobregma represents the most speciose genus of Scalibregmatidae with 17 valid species. Most of them occur at great depths and are found living on soft bottoms. Here, we present the descriptions of O. nonatoi sp. nov., O. cruzae sp. nov., and O. bakkeni sp. nov., sampled from the Brazilian continental shelf and slope, and a key to all species of Oligobregma. O. nonatoi sp. nov. differs from its congeners by the presence of a triangular prostomium with short rounded horns, acicular spines on notopodia of chaetigers 14 and on neuropodia of chaetigers 13. Oligobregma cruzae sp. nov. can be distinguished by the presence of a quadrangular prostomium with two short, rounded horns, acicular spines on chaetigers 14, and lyrate chaetae from chaetiger 5. Finally, O. bakkeni sp. nov. is unique among its congeners by the presence of acicular spines with rounded tips. This is the first record of this genus along the Brazilian coast and the specimens were collected on Esprito Santo, Campos and Santos sedimentary basins, both located in Brazilian southeast region. The sampling campaigns were carried out in scientific expeditions related to two research projects: Santos Project Santos Basin Environmental Characterization and Ambes Project Esprito Santo Basin Assessment Project, both coordinated by CENPES/PETROBRAS.

Assuntos

RESUMO

Background: In Mexico, there are six scientific collections of polychaetous annelids. The "Colección Poliquetológica" from the Universidad Autónoma de Nuevo León houses one of the three most important collections of annelids in the country, based on a number of lots and number of type materials deposited, as well as geographical coverage. New information: A catalogue of type materials of polychaete annelids housed at the "Colección Poliquetológica" from the Universidad Autónoma de Nuevo León (México) is presented for the first time. The Collection contains 37 holotypes, 174 paratypes and one syntype. These type materials are grouped in 15 families, 35 genera and 54 species of marine worms. Types were described mostly from the Mexican waters, with a low number of types from Ecuador, El Salvador, Argentina, USA, Philippines, New Caledonia and Japan.

RESUMO

Background: Parasphaerosyllis Monro, 1937 is a syllid genus, currently composed of four species: P.indica Monro, 1937 from the Arabian Sea, P.uschakovi (Chlebovitsch, 1959) from the Kurile Islands, P.ezoensis Imajima & Hartman, 1964 from Japan and P.malimalii Capa, San Martín & López, 2001 from the Pacific coast of Panama. The distribution of P.indica is circum-tropical to temperate waters, but the presence of species complexes has been suggested. In order to clarify the distribution of P.indica in many areas of the world, a re-description, based on examination of the type material, is required as a first step to a better understanding of its diagnostic features. New information: Parasphaerosyllisindica is re-described, based on holotype examination, a new species is established from the Gulf of California and Parasphaerosyllismalimalii is reported for the first time since its description in 2001. Parasphaerosyllisirregulata sp. nov. is distinguished from its congeners by the following features: 1) Palps are free at their base; 2) Two types of dorsal cirri are present: spherical to bulbous and moniliform cirri; 3) Both types of cirri are distributed irregularly. A spherical/bulbous and moniliform cirrus may appear together within the same segment (asymmetrical segment) or only a spherical/bulbous cirrus may appear in several consecutive segments (not alternating as occurs in congeners); 4) The spherical/bulbous cirri may have distal knobs with 1-3 terminal articles; and 5) Bidentate falcigers with short, sub-triangular blades with a proximal tooth slightly larger that the distal one. A taxonomic key to species of Parasphaerosyllis species is included.

RESUMO

Pseudoscalibregma Ashworth, 1901 is a small genus of the family Scalibregmatidae Malmgren, 1867. Currently, a total of eight valid species are accepted. Of these, the majority are found at great depths. This work contains the first report of Pseudoscalibregma to the Brazilian coast, with the description of three new species: Pseuscalibregma ermindae sp. nov., P. magalhaesi sp. nov. and P. parapari sp. nov. The material was sampled from the Brazilian southeast region, on Campos and Santos sedimentary basins, during scientific expeditions called Santos ProjectSantos Basin Environmental Characterization and Ambes ProjectEsprito Santo Basin Assessment Project, both coordinated by PETROBRAS/CENPES. We also include an identification key to Pseudoscalibregma species.

Assuntos

RESUMO

Spatio-temporal responses of the intertidal macrobenthic community to the effects of a submarine outfall (SO) and a new sewage treatment plant (EDAR) were evaluated, analyzing changes in macrofaunal assemblages and community structure. Study was conducted in a SW Atlantic coastal area in 4 stages: BSO (Before the SO), Du (During the construction of the SO), ASO (After the SO start-up) and AEDAR (After the treatment plant start-up). Boccardia proboscidea and Brachidontes rodriguezii contributed most to the differences between all stages at the site nearest to the discharge point. Number of individuals was highest at BSO and Du. Richness and diversity were lowest at the BSO and highest at the Du. Furthermore, the richness decreased slightly, and the diversity increased at AEDAR. Evenness was highest at the BSO and AEDAR. The nestedness was the dominant process driving the differences between the BSO stage community and the rest of the stages. SO affects the composition and structure of the intertidal macrobenthic community near the outfall area, as organic matter discharge further offshore favour the development of a more diverse intertidal community, including species sensitive to organic enrichment.

Assuntos

RESUMO

The polychaete Family Cirratulidae is one of the most abundant and diverse groups of Annelida, although it remains poorly known worldwide. Dodecaceria Ørsted, 1843 is one of the least described genera of Cirratulidae. The present report is the first taxonomic study of the genus Dodecaceria for the Brazilian coast. Cirratulidae were collected at Rocas Atoll, the first Brazilian marine protected area and the only atoll in the South Atlantic Ocean. We described one new species, Dodecaceria zelinhae n. sp., and a new record of D. dibranchiata Blake & Dean, 2019, previously only known from Panama. The new species is distinguished from other Dodecaceria species by having lateral tentacles, a smooth peristomium, 3-5 pairs of branchiae, hooks from chaetiger 11 in notopodia and 9 in neuropodia. Dodecaceria dibranchiata, a Caribbean species, is here recorded for the first time in the South Atlantic Ocean.

Assuntos

RESUMO

Two species of genera Apoprionospio and Prionospio are described from the Colombian Caribbean. Apoprionospio sanguarensis sp. nov. and Prionospio gabriellae sp. nov. are new to science. Apoprionospio sanguarensis sp. nov. is distinguished from the three previously described Apoprionospio species by having the smallest body size, triangular prostomium, three pairs of eyes, the branchial pairs 1-3 are cirriform, wrinkled, the anterior notochaetae arranged from chaetiger 2 onwards arranged in three rows, and all hooded hooks lack secondary hoods. Prionospio gabriellae sp. nov. is distinguished from all Prionospio species with five branchial pairs by having dorsal crests across the dorsum on chaetigers 16-25. Closely related species are P. heterobranchia Moore, 1907 and P. caribensis Delgado-Blas, 2014 and Prionospio gabriellae sp. nov. differs from both species in that it has a small medial peak in the dorsal region of prostomium, the first neuropodial lamellae is very small, the shaped of branchial pairs 2 and 3 are cirriform, neuropodial postchaetal lamellae on chaetiger 2 is square, all chaetae of chaetiger 1 are arranged in a row. We propose raising the status of Apoprionospio dayi japonica Imajima, 1989 to the species level as A. japonica Imajima, 1989. A key and a table detailing the most relevant characters of Apoprionospio species and a key to all species of Prionospio with five pairs of branchiae are provided.

Assuntos

RESUMO

The family Sigalionidae is characterized, among other features, by including scale worms with large bodies. However, among sigalionids, the subfamilies Sthenelanellinae, Pholoinae, and Pisioninae stand out by their small representatives with few segments and fragile bodies. In the Tropical Northwestern Atlantic, which includes part of the Gulf of Mexico and the Caribbean Sea, these subfamilies have been rarely studied, with few species recorded, and questionable records. This contribution aims to improve the knowledge of sthenelanellins, pholoins, and pisionins in the region through a faunistic study based on material from two Mexican scientific collections: the Reference Collection of Laboratorio de Biodiversidad y Cambio Climático (BIOMARCCA) and the Reference Collection of Benthos (ECOSUR) of El Colegio de la Frontera Sur. Pisione wolfi is confirmed from the Tropical Northwestern Atlantic, and three new species are described: Sthenelanella pechi sp. nov., S. sarae sp. nov. and Taylorpholoe anabelae sp. nov. A key to all Sthenelanella and Taylorpholoe species is also included.

Assuntos

RESUMO

Scalibregmatidae Malmgren, 1867 is a relatively small family of annelids, with only two taxa reported to Brazil. In this work, we expand the scientific knowledge of this group by presenting two new Scalibregma Rathke, 1843 species. The new species S. lanai sp. nov. and S. cinthyae sp. nov. were collected during an expedition to the Campos and Santos oceanographic basins. Scalibregma cinthyae sp. nov. is unique among its congeners by the presence of two rows of paired lobes on the mouths upper and lower lips, whereas S. lanai sp. nov. is unique among its congeners by the presence of two rows of paired lobes on the mouths lower lip, branchiae from chaetigers 35, and lyrate chaetae with equal tynes. We provide an identification key to all Scalibregma species.

Assuntos

RESUMO

The aim of the present study was to investigate the effect of dredging activities on the structure of the macrobenthic community of a port complex in São Luís do Maranhão (2°S, Brazil). Sampling was performed on four occasions: pre-dredging, dredging 1 (25% of the material dredged), dredging 2 (75% of the material dredged) and post-dredging. Total mean density was 430.8 ± 55.0 ind/m², with 147.76 ± 280.82 ind/m² at pre-dredging, 161.90 ± 285.67 ind/m² at dredging 1, 53.83 ± 72.15 ind/m² at dredging 2 and 67.29 ± 72.58 ind/m² after dredging, revealing a reduction during dredging 2. The most representative groups were Polychaeta, Oligochaeta, Crustacea and Mollusca. Lumbrineris sp. (Polychaeta) was present in all sampling periods and was the dominant species. Richness and Shannon diversity of the species were higher in the pre-dredging and post-dredging periods, with reductions during the dredging activities (dredging 1 and 2). Principal component analysis revealed a correlation with granulometry and heavy metals in the sediment. The dredging activities led to a reduction in the macrobenthic community. Moreover, post-dredging recovery was insufficient for the recovery of the community.(AU)

Assuntos

RESUMO

Maldanids are tube-building polychaetes, known as bamboo-worms; inhabit diverse marine regions throughout the world. The subfamily Euclymeninae was proposed to include forms with anal and cephalic plates, a funnel-shaped pygidium, and a terminal anus. Euclymene, the type genus of Euclymeninae, has about 18 valid species. Euclymene vidali sp. nov. is defined and members of the species described from Northeastern Brazil. Members of this species have 23 chaetigers, and one pre-pygidial achaetous segment; nuchal grooves extend through three quarters of the cephalic plate, and there is one acicular spine with a denticulate tip. Euclymene africana, and E. watsoni, are here recognized, respectively, as Isocirrus africana comb. nov., and I. watsoni comb. nov. Three monotypic genera are invalid: Macroclymenella, Eupraxillella, and Pseudoclyemene; their species should be recognized as Clymenella stewartensis com. nov., Praxillella antarctica com. nov., and Praxillela quadrilobata com. nov., respectively. An identification key and a comparative table for all species of Euclymene are provided. A comparative table for all genera of Euclymeninae is also furnished. The paraphyletic status of Euclymene and Euclymeninae is discussed. The taxon Maldanoplaca is not code compliant and should only be regarded as an informal name.

Assuntos

RESUMO

Estuarine environments are suggested to be the final receivers of human pollution and are impacted by surrounding urbanization and compounds carried by the river waters that flow from the continent. Polycyclic aromatic hydrocarbons (PAHs) are among the contaminants that can reach estuaries and can directly affect marine conservation, being considered highly deleterious to organisms living in these environments. This research investigated the meiofauna of three estuaries exposed to different levels of urbanization and consequently different levels of PAH concentrations, in order to assess how these compounds and environmental factors affect the distribution, structure and diversity of these interstitial invertebrates. A total of 15 major meiofauna groups were identified, with Nematoda being the dominant taxon (74.64%), followed by Copepoda (9.55%) and Polychaeta (8.56%). It was possible to observe significant differences in all diversity indices studied in the estuaries. With the exception of average density, the diversity indices (richness, Shannon index and evenness) were higher in the reference estuary, Goiana estuarine system (GES). On the other hand, the Timbó estuarine system (TES) had the lowest Shannon index value and richness, while the Capibaribe estuarine system (CES) had the lowest evenness value. The latter two estuaries (TES and CES) presented intermediate and high levels of urbanization, respectively. The ecological quality assessment (EcoQ) in the studied estuaries was classified from Poor to Moderate and the estuary with the lowest demographic density in its surroundings, GES, showed a better ecological quality (Moderate EcoQ). A significant distance-based multivariate linear modelling regression (DistLM) was observed between the environmental variables and the density of the meiobenthic community, where PAHs and pH were the main contributors to organism variation. The sediments were characterized by predominance of very fine sand and silt-clay in the most polluted environments, while the control site environment (GES) was dominated by medium grains. The highest concentrations of PAHs were found in the most urbanized estuaries, and directly affected the structure of the interstitial benthic community. The metrics used in the present study proved to be adequate for assessing the environmental quality of the investigated estuaries.

Assuntos

RESUMO

Introduction: The bivalve Semimytilus patagonicus is a potentially useful bioindicator because of its feeding mechanism, and the worm Pseudonereis gallapagensis is also interesting as a bioindicator because it is benthonic, abundant, and a food source for the squid Doryteuthis gahi. However, their sensitivity to contaminants has not been sufficiently studied. Objective: To test the usefulness of the mussel Semimytilus patagonicus and the polychaete Pseudonereis gallapagensis as ecotoxicological tools for detergents in the marine environment. Methods: We used 120 individuals of S. patagonicus from Miraflores and 120 of P. gallapagensis from Barranco (both near the city of Lima, Peru). For the bioassays, we used two anionic detergents (active ingredient, ai, Sodium Dodecylbenzene Sulfonate). For S. patagonicus, with an average valve length of 32.3 ± 6.4 mm, we tested "Double power Ariel®" (90 %) at concentrations of 17.5, 35, 70 and 140 mg ai l-1, evaluated after 48 and 72 h of exposure; and for P. gallapagensis, with a total body length of 20.4 ± 8.8 mm, we tested "Caricia®" at 62.5, 125, 250, 500 and 1 000 mg of ai l-1 at 24, 48 and 72 h of exposure. Results: The LC50 values (Mean Lethal Concentration) were 34.95 mg ia l-1 for S. patagonicus and 102.48 mg ia l-1 for P. gallapagensis at 72 h of exposure. The detergents were toxic for S. patagonicus and slightly toxic for P. gallapagensis. The risk classification for S. patagonicus is "harmful" and for P. gallapagensis "not classifiable". Conclusions: These two bioindicators allow evaluating the acute toxicity of SDBS-based commercial detergents in the marine aquatic environment.

Introducción: El bivalvo Semimytilus patagonicus es un bioindicador potencialmente útil por su mecanismo de alimentación, y el gusano Pseudonereis gallapagensis también es interesante como bioindicador por ser bentónico, abundante y fuente de alimento para el calamar Doryteuthis gahi. Sin embargo, su sensibilidad a los contaminantes no ha sido suficientemente estudiada. Objetivo: Probar la utilidad del mejillón S. patagonicus y el poliqueto P. gallapagensis como herramientas ecotoxicológicas para detergentes en el medio marino. Métodos: Se utilizaron 120 individuos de S. patagonicus de Miraflores y 120 de P. gallapagensis de Barranco (ambos cerca de la ciudad de Lima, Perú). Para los bioensayos se utilizaron dos detergentes aniónicos (ingrediente activo, ia, dodecilbenceno sulfonato de sodio). Para S. patagonicus, con una longitud valver promedio de 32.3 ± 6.4 mm, probamos Ariel Doble Poder® (90 %) a concentraciones de 17.5, 35, 70 y 140 mg·ia·l-1, evaluadas a las 48 y 72 h de exposición; y para P. gallapagensis, con una longitud corporal total de 20.4 ± 8.8 mm, probamos Caricia® a 62.5, 125, 250, 500 y 1 000 mg·ia·l-1 a las 24, 48 y 72 h de exposición. Resultados: Los valores de CL50 (Concentración Letal Media) fueron de 34.95 mg·ia·l-1 para S. patagonicus y 102.48 mg·ia·l-1 para P. gallapagensis a las 72 h de exposición. Los detergentes fueron tóxicos para S. patagonicus y levemente tóxicos para P. gallapagensis. La clasificación de riesgo para S. patagonicus es "nocivo" y para P. gallapagensis "no clasificable". Conclusiones: Estos dos bioindicadores permiten evaluar la toxicidad aguda del detergente comercial a base de SDBS en el ambiente acuático marino.

Assuntos

RESUMO

Natural and experimental wood falls harbor a rich and abundant macrofaunal community in the deep-sea. Two undescribed capitellids have been collected from wood species bundles deployed at 3,100 m at the Deadwood 2 site in Monterey Bay and several other locations in the northeastern Pacific. Capitella blakei sp. nov. is a widely distributed deep-sea capitellid in the northeastern Pacific occurring from the Monterey canyon north to the Endeavour segment of the San Juan de Fuca Ridge, a range of almost 1,400 km. It belongs to a group of Capitella species having only individuals with male external characteristics, chaetigers 17 with notopodial and neuropodial capillaries and is readily distinguished from its congeners by the presence of a peristomium clearly separated from prostomium, deep lateral and ventral grooves, and methyl green staining pattern. Capitella multibranchiata sp. nov. is unique in the genus by the presence of branchiae on abdominal notopodial and neuropodial segments. The adult morphology of both species is described and compared to their most apparently related congeners. Our results have shown a greater diversity of deep-sea Capitella than previously known. The wide geographical distribution of C. blakei sp. nov. on wood habitats indicates that these wood falls may be functioning as ecological and evolutionary stepping-stones between the enriched sediments of vents and seeps.

Assuntos

RESUMO

In the present study, the Hg levels in freshly collected polychaete species and their associated sediments were evaluated from Todos os Santos Bay, Northeastern Brazil. Additionally, it was also measured the Hg distribution along the annelids' body parts (anterior region, abdomen, and posterior region). Total Hg concentration was as follows: 13.6-144 µg kg-1 (Scolelepis chilensis, deposit feeder), 8.2-122 µg kg-1 (Laeonereis acuta, deposit feeder), 95-612 µg kg-1 (Armandia agilis, deposit feeder); 96.6-206 µg kg-1 (Lumbrineris sp., carnivorous), 75.3-112 µg kg-1 (Goniada echinulate, carnivorous), and 115-198 µg kg-1 (Branchiomma sp., suspension feeder). In turn, Hg levels in sediments ranged from 2.77 ± 0.24 to 6.38 ± 0.15 µg kg-1. Hg concentrations found in polychaete soft tissues were higher than those found in the sediments. Specific habits, feeding behavior, trophic level, and stressful environmental conditions are the main factors affecting the Hg levels in the species studied. The bioaccumulation factor (BAF), contamination factor (CF), and ecological risk assessment (Er) were calculated. The BAF values were higher than 1 for all studied species, indicating Hg bioaccumulation in the annelids, but the low levels of CF e Er showed those Hg levels present low to no significant ecological risk for the biota and benthonic organisms living in the sediments. Finally, no statistically significant difference was observed for Hg concentration levels along the polychaete body parts.

Assuntos

RESUMO

The dipteran fauna from the Brazilian Amazon remains poorly known, including that of forensic interest, such as the Sepsidae. The sepsid fauna of two secondary forests in the eastern Amazon was surveyed utilizing rotting bovine lung and feces (humans, bovines, and monkeys). We obtained 17 sespid species in six genera, most of them on bovine dung and rotting bovine lung. Two new species are described herein: Archisepsis bosque sp. nov. and Archisepsis verae sp. nov. The genus Palaeosepsis Duda, 1926 and the species Archisepsis polychaeta (Ozerov, 1993), Archisepsis diversiformis (Ozerov, 1993), Microsepsis mitis (Curran, 1927), Meropliosepsis sexsetosa Duda, 1926, and Palaeosepsis cf. golovastikOzerov, 2004 are newly recorded from the Brazilian Amazon.

Assuntos