Alexandra E. Rizzo

Composition and spatial distribution of the benthic macrofauna in the Cachoeira River estuary, Ilhéus, Bahia, Brazil

We analyzed the composition and spatial distribution of macrobenthos in the Cachoeira River estuary, Ilheus, Bahia, Brazil. Samples were taken bimonthly from...

Benthic macrofauna associated with decomposition of leaves in a mangrove forest in Ilhéus, State of Bahia, Brazil

We identified and quantified the benthic macrofauna associated with decomposing leaves of Rhizophora mangle and Laguncularia racemosa , to observe the differences in the abundance and composition of macrofauna between these mangrove species, and to examine whether the abundance and composition of organisms changed with different stations and collection times. Benthic macrofauna, mainly polychaetes and amphipods, were recorded from the fifth day after the installation of the experiment. Annelids including Oligochaeta and Polychaeta were the most numerous group. Crustacea were represented by peracarids (Amphipoda and Tanaidacea) and decapods. Of Hexapoda, only juvenile forms and pupae were present. The most abundant polychaete species was Perinereis brevicirrata , followed by Capitella cf. capitata, Heteromastus filiformis and Neanthes succinea . In one-way analysis of variance (ANOVA) there were no statistical differences between the macrofauna of mangrove species, seasons, or collection times, except among collection times for R. mangle litter bags. Two-way ANOVA showed homogeneity for macrofauna abundance between the groups of collection times for both mangrove species. The richness was similar for R. mangle litter bags, and showed a significant difference for L. racemosa . Abundance and richness were also similar between the mangrove species. The colonization of detritus by benthic invertebrates followed a successional sequence during the decomposition process. This suggests that the density of these organisms and their foraging behaviour affected the decomposition rates of leaves of R. mangle and L. racemosa .

Nephtyidae (Annelida: Polychaeta) from the Campos Basin, including two new species and a new record

Members of the marine polychaete family Nephtyidae are commonly found in soft substrates. Their most distinctive characteristic is the presence of interramal branchiae located between the notopodia and neuropodia. In the present study, five species of Nephtyidae: Aglaophamus fabrun sp. nov., Aglaophamus juvenalis (Kinberg, 1866), Inermonephtys inermis (Ehlers, 1887), Inermonephtys soldius sp. nov. and Nephtys squamosa Ehlers, 1887 were found in the Campos Basin, state of Rio de Janeiro, including two new species and a new record for the Brazilian coast. Aglaophamus fabrun sp. nov. has a proboscis with 10 pairs of distal papillae and approximately 20 subdistal papillae in rows, with 3-5 papillae in each row; and lacks an unpaired median papilla; the prostomium has a pair of eyes and a characteristic pigmentation pattern. Inermonephtys soldius sp. nov. has interramal branchiae starting from parapodium 5, and basal papillae starting on chaetiger 6. Inermonephtys inermis is a new record for the Brazilian coast. Descriptions, comments and a key to species of Nephtyidae recorded from Brazil are provided.

Glyceridae (Annelida: Polychaeta) from Guam, Mariana Islands with description of a new species of Glycera Savigny in Lamarck, 1818

Glycera juliae sp. nov., is described from shallow water sediments within Apra Harbor, Guam, Mariana Islands. This species is characterized by the presence of ailerons with rounded triangular base; proboscideal papillae of type 1 mainly digitiform with straight, median, longitudinal ridge and type 2 shorter and broader, oval to globular, without ridges; two slender triangular to digitiform prechaetal lobes, notopodial lobe slightly shorter than neuropodial lobe, two short postchaetal lobes, rounded anteriorly with posterior notopodial lobe becoming sub-triangular and longer than rounded neuropodial lobe; branchiae present, retractile, simple digitiform attached medially on anterior side of parapodia and a dark brown pigmentation forming transverse bands on prostomium and body segments. It is most similar to Glycera nicobarica and G. macintoshi by the shape of parapodial structures but also shares similarities with Glycera sphyrabrancha, G. branchiopoda, G. guatemalensis, G. semibranchiopoda and G. southeastatlantica by the shape and types of proboscidial papillae, differing on the shape of the ailerons, parapodial lobes and presence of branchiae. The occurrence of Glycera tesselata is confirmed for Guam and specimens are described and illustrated with SEM photographs.

A new record of Mytilopsis leucophaeata (Bivalvia: Dreissenidae) in Rio de Janeiro (Brazil)

Mytilopsis leucophaeata naturally occurs in oligo- to mesohaline estuaries along the Atlantic coast of the USA and Mexico. In Brazil, M. leucophaeata was first recorded in 2004 in estuaries adjacent to the Port of Recife (Pernambuco State, north-eastern Brazil). Here, we present the second record of the species in Brazil, and the first for the south-eastern region, in the Rodrigo de Freitas lagoon (Rio de Janeiro State). This lagoon, located within a major urbanized area of Rio de Janeiro City, is highly affected by coastal development, but used for various nautical sports. The imminence of the Olympic Games, to be held in Rio de Janeiro in 2016, requires specific attention to the importance of monitoring and controlling this new invasive species. Action has to be taken to prevent its dispersal to other estuarine and lagoon ecosystems of Rio de Janeiro State due to movement of boats and sport equipment.

First record of Trochochaeta japonica (Annelida: Spionidae) in Brazil with identification key to species of the genus

Polychaetes of the spionid genus Trochochaeta occur mainly in the northern hemisphere, including North and Central America. In South America, they have been reported only from the northeast region of Brazil - Sergipe and Paraíba - despite numerous biological investigations around the continent. In 2006, a dense population (up to 7000 individuals per square meter) of Trochochaeta was discovered in the estuary of Santos, São Paulo, Brazil, hosting the busiest container sea port in Latin America, and in 2008, one Trochochaeta specimen was found in Camamu Bay, Bahia. We identify these worms as Trochochaeta japonica Imajima, 1989 and describe and illustrate their morphology. This is the first record of the species from outside of its type locality in Honshu, Japan. It might have been introduced to the estuary of Santos as larvae in ballast water of ocean-going vessels. We review the systematics of Trochochaeta and provide an identification key to 12 currently recognized species.

Three new species of Diplocirrus Haase, 1915 (Polychaeta: Flabelligeridae) from Campos Basin in SE Brazil.

Currently, 16 species of Flabelligeridae have been recorded in Brazil, four in the genus Diplocirrus: D. glaucus Malmgren, 1867 from Ubatuba, D. capensis Day, 1961 from Santos (São Paulo State) and Diplocirrus sp. from off north of Rio de Janeiro. Diplocirrus glaucus australis Nonato, 1981 is considered a nomen nudum. In the present study, three new species are described: Diplocirrus rugosus sp. nov., Diplocirrus salazarvallejoi sp. nov. and Diplocirrus acafi sp. nov., all collected from soft bottoms off southeast Brazil. A key to all Diplocirrus species is provided.

Laubieriopsis petersenae n. sp. and L. cf. cabiochi (Amoureux, 1982) (Polychaeta: Fauveliopsidae) from dredge disposal sites off Honolulu, Hawaii

Fauveliopsid polychaetes have been collected at dredge disposal sites off Honolulu from 397-507 m depth. We report and describe the first Pacific record of Laubieriopsis cf. cabiochi (Amoureux, 1982), originally described from the North Atlantic. A new species, Laubieriopsis petersenae, n. sp. is described as being the species in the genus with the lowest number of body segments (15). Other distinctive features are the presence of bidentate aciculars on thoracic chaetigers, and unpaired genital papilla present on the right side of chaetiger 6/7. The new species is most similar to the L. brevis complex from the Atlantic and L. hartmanae and L. brevis japonica from the Pacific Ocean, but differs on the combination of the characters cited above. We provide an emended diagnosis for this genus to include the ultrastructure of the acicular with rows of spines, and a key to all described species.