Cossura yacy sp. nov. (Cossuridae, Annelida) from a tropical Brazilian estuary

The family Cossuridae is monogeneric for Cossura Webster & Benedict, 1887 which currently has 28 known species, three of which already recorded for Brazilian coast. In the present study we describe Cossura yacy sp. nov. increasing to 29 the number of known Cossuridae species. We have found and analyzed 60 individuals of C. yacy sp. nov. from São Marcos estuarine complex (ca. 02°S; 44°W) around São Luís Harbor (Maranhão, Brazil). It differs from other species of genus also by the presence of the two pairs of nuchal organs at lateral margins of the peristomium, branchial filament in the median region of the third chaetiger and by short and long capillary smooth chaetae with spinulosa on the distal half. These two chaetal types are present through the body both in the neuropodia and in the notopodia. Adults specimens of the Cossura yacy sp. nov. have seven notopodial and five neuropodial chaetae in the 5th parapodium; nine notopodial and seven neuropodial chaetae in the 20th parapodium; five notopodial and six neuropodial chaetae in the 43th parapodium. Pygidium has three long anal cirri, reaching the fourth posterior segment.

Cossura yacy sp. nov. (Cossuridae, Annelida) from a tropical Brazilian estuary

The family Cossuridae is monogeneric for Cossura Webster & Benedict, 1887 which currently has 28 known species, three of which already recorded for Brazilian coast. In the present study we describe Cossura yacy sp. nov. increasing to 29 the number of known Cossuridae species. We have found and analyzed 60 individuals of C. yacy sp. nov. from São Marcos estuarine complex (ca. 02°S; 44°W) around São Luís Harbor (Maranhão, Brazil). It differs from other species of genus also by the presence of the two pairs of nuchal organs at lateral margins of the peristomium, branchial filament in the median region of the third chaetiger and by short and long capillary smooth chaetae with spinulosa on the distal half. These two chaetal types are present through the body both in the neuropodia and in the notopodia. Adults specimens of the Cossura yacy sp. nov. have seven notopodial and five neuropodial chaetae in the 5th parapodium; nine notopodial and seven neuropodial chaetae in the 20th parapodium; five notopodial and six neuropodial chaetae in the 43th parapodium. Pygidium has three long anal cirri, reaching the fourth posterior segment.(AU)

Description of three new species of Eumida Malmgren, 1865 (Phyllodocidae, Annelida) from Southern and Southeastern Brazil.

We describe three new species of Eumida from shallow estuarine and shelf bottoms from south and southeastern Brazil as part of a regional survey of the family Phyllodocidae. Previous regional records of Eumida sanguinea (Örsted, 1843) are herein referred to Eumida dracodermica sp. nov. The two species differ in the size of the prostomium, the distribution of micropapillae on the proboscis, and the shape of the dorsal cirri. Eumida macrophthalma sp. nov. has much larger eyes than the other two species described herein. The dorsal cirri on anterior median segments are rounded and on median and posterior segments they are asymmetrical and cordiform, longer than the dorsal cirri in Eumida dracodermica sp. nov. The lanceolate median dorsal cirri in Eumida delicata sp. nov. are only shared with E. ockelmanni Eibye-Jacobsen, 1987. It is also possible to diagnose the three species by their dorsal whitish pigmentation patterns on the first segments of living or well conserved animals.

Recovery of macrobenthos in defaunated tropical estuarine sediments.

In the estuarine environment, hypoxia and/or anoxia have become a major cause of benthic defaunation and are strongly associated with increased eutrophication. Mesoscale field experiments were carried out to examine the recolonization and recovery time of macrobenthos after defaunation. Azoic sediments were achieved by covering four areas with polyethylene sheeting. Temporal changes and depth distribution of macrobenthos within the defaunated sediments were compared with those in undisturbed natural sediments at the same site. Within 3 days, annelids appeared as the first immigrants. After 153 days, the process of recovery had not yet been completed in terms of species richness. Whereas diversity and evenness showed no significant differences between treatments during the entire experiment, multivariate analyses proved that differences between treatments were still significant 93 days after the start of the experiment.

First occurrence of the family Paralacydoniidae (Annelida: Polychaeta) in the South Atlantic Ocean / Primeira ocorrência da família Paralacydoniidae (Annelida: Polychaeta) no Oceano Atlântico Sul

Paralacydoniid polychaetes belonging to the genus Paralacydonia Fauvel 1913 were collected during the REVIZEE Program/South Score/Benthos ("Avaliação do Potencial Sustentável dos Recursos Vivos na Zona Econômica Exclusiva") on the outer shelf and continental slope off the south-southeastern coast of Brazil between 156 and 400 m depth. This new report extends the known geographic distribution of the family, which had previously been recorded in the North Atlantic as far as the Gulf of Mexico. Paralacydonia is here treated as monotypic; P. mortenseni Augener 1924 and P. weberi Horst 1923 are considered synonyms of Paralacydonia paradoxa Fauvel 1913.

Poliquetas paralacidoniídeos pertencentes ao gênero monotípico Paralacydonia Fauvel 1913 foram coletados durante o Programa REVIZEE/Score Sul/Bentos ("Avaliação do Potencial Sustentável dos Recursos Vivos na Zona Econômica Exclusiva") na plataforma externa e talude continental na costa sul-sudeste do Brasil entre 156 e 400 m de profundidade. Esta nova ocorrência amplia grandemente a distribuição geográfica dos representantes da família, a qual tinha sido previamente registrada no Atlântico Norte até o Golfo do México. Paralacydonia é tratado aqui como monotípico; P. mortenseni Augener 1924 e P. weberi Horst 1923 são considerados sinônimos de Paralacydonia paradoxa Fauvel 1913.