Assessment of oxidative stress and bioaccumulation of the metals Cu, Fe, Zn, Pb, Cd in the polychaete Perinereis gualpensis from estuaries of central Chile.

The estuaries of the Aconcagua and Maipo Rivers of central Chile are receptors of residues that contain metals from anthropic activities including agriculture, mining and smelters, which have different levels in the two basins. This study postulates that the exposition to metals is different in the two estuaries and that their sediments contain bioavailable chemical agents that produce oxidative stress. The aim of the study was to evaluate the effect of estuarine sediments on the polychaete Perinereis gualpensis using oxidative stress biomarkers and to determine the metal concentrations in sediments and their accumulation in P. gualpensis. Sediments and organisms were collected in December 2015 and January 2016 in the estuaries. The Catapilco estuary was used as control, since its basin has little anthropic activity. The metal concentrations of Fe Cu, Pb, Zn and Cd were determined in tissues of the organisms and in sediments. The granulometry, conductivity, redox potential, pH and organic matter in sediments were determined, as well as catalase activity and lipid peroxidation. The results show that the concentrations of metals in sediments were higher in the estuary of the Aconcagua River: Cu: 48 ± 2µgg-1; Fe: 154 ± 19mgg-1, Pb: 20 ± 3µgg-1 and Zn: 143 ± 20µgg-1. In tissues, Pb and Fe were higher in the estuary of the Maipo River, while Cd was detected only in the Catapilco River mouth. Catalase activity was greater in the estuary of the Aconcagua River and lipid peroxidation in the estuary of the Catapilco River. Significant regressions were found between biomarkers of oxidative stress and metal concentrations in tissues of P. gualpensis. In conclusion, the sediments of the studied estuaries contain bioavailable chemical agents that provoke oxidative stress in P. gualpensis, which may be a risk for the benthic communities of these ecosystems. This species is proposed to monitor metals bioavailability and oxidative stress in estuarine sediments.

The importance of a functional approach on benthic communities for aquaculture environmental assessment: Trophic groups - A polychaete view.

Polychaetes were studied to assess the effect of aquaculture activity on the seafloor. Very high biodiversity of species was recorded associated with aquaculture centres with Cirratulidae, Spionidae and Paraonidae families being the most diverse and abundant families. The spatial distribution of polychaete trophic groups was the best descriptor for detecting changes on the benthos. Surface and subsurface deposit-feeding species dominated the sites closest to the rafts cages, highlighting Capitella capitata and Cirratulus cirratus as opportunistic species. While replacement and species succession were observed with increasing presence of carnivores and omnivores in sites further away from the salmon cages and experiencing less impact. Analyses based on the distance of feeding modes and ecological groups from the disturbance source were better indicators of the impact that the traditional community approach or sediment biogeochemistry. Therefore, functional traits studies should always be considered on environmental assessments of benthic systems impacted by aquaculture.

Three new species of Syllis Savigny in Lamarck, 1818 (Annelida, Syllidae) from Chilean Patagonia.

Three new species of the genus Syllis Savigny in Lamarck, 1818, from the Chilean Patagonia are described, figured and discussed. The specimens were collected in boulders, sediment bottoms, Macrocystis pyrifera holdfasts, and inside tubes of Chaetopterus cf. variopedatus. Syllis patagonica n. sp., is characterized by its color pattern, short, fusiform dorsal cirri, plenty of hyaline inclusions, acuminate posterior acicula, and compound chaetae with slightly bidentate falcigers. Syllis terraeignium n. sp., has similar compound chaetae, but dorsal cirri are longer than those of the above mentioned species, a long proventricle, and the posterior acicula are straight, pointed. Finally, Syllis patersoni n. sp., has a slender, elongated body, with moderately long dorsal cirri, plenty of hyaline inclusions, acuminate posterior acicula, and compound chaetae composed by falcigers and short spiniger-like.

Exogoninae (Annelida: Syllidae) from Chilean Patagonia.

The subfamily Exogoninae was studied from samples collected in shallow waters of the fjords and channels of the Patagonian region of Chile. Two new species are described: Exogone yagan n. sp. and Erinaceusyllis carrascoi n. sp. The species Exogone heterosetoides, Erinaceusyllis bidentata and Erinaceusyllis perspicax are newly reported to Chile, as well as the genus Erinaceusyllis San Martín, 2005. Parapionosyllis brevicirra, Sphaerosyllis hirsuta and Salvatoria rhopalophora, n. comb., are also reported, with the latter redescribed. Finally, we redescribe Exogone anomalochaeta from Antarctica. Most of the species were found inside tubes of Chaetopterus cf. variopedatus; this habitat is new for Exogoninae. This research is a new taxonomic account of Syllidae in Chile and improves the knowledge of Exogoninae of the Patagonian region.

New Prionospio and Aurospio Species from the Deep Sea (Annelida: Polychaeta).

The number of records of the genus Prionospio Malmgren, 1867, from the deep sea (>2000 m) are relatively few and do not reflect the actual occurrence of species nor their potential ecological importance. In this paper we describe five new species of this genus (Prionospio amarsupiata sp. nov., P. vallensis sp. nov., P. branchilucida sp. nov., P. hermesia sp. nov. and P. kaplani sp. nov.) all of which are abundant members of the deep-sea community. We also describe two new species of the genus Aurospio Maciolek, 1981 (Aurospio abranchiata sp. nov. and A. tribranchiata sp. nov.) again common elements of the abyssal fauna. Two of the new species have characters which question the generic distinctiveness of Prionospio and Aurospio. The problems in differentiating these two genera are discussed.