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Concentrations of polybrominated diphenyl ethers (PBDEs) and methoxylated polybrominated diphenyl ethers (MeO-PBDEs); are reported in specimens of fish notothenioids Chaenocephalus aceratus (SSI), Trematomus bernacchii (ERN), and Nototheniops nudifrons (NOD) from the South Shetland Islands, Antarctica. Significant differences in the accumulation of 2'-MeO-BDE-68 and 6-MeO-BDE-47 were detected among the analysed species. MeO-BDEs were significantly higher in SSI (11.7, 8.6, and 14.1 ng g-1 lw) than in NOD (1.63, 1.63, and 3.0 ng g-1 lw) in muscle, liver, and gill, respectively. Feeding ecology traits explain the accumulation patterns of MeO-PBDEs. SSI has a higher feeding activity with a broader diet, followed by ERN, whereas NOD is a benthic/sedentary fish with a narrower diet. The accumulation of PBDEs was neither species-, nor tissue-specific. The current study expands the knowledge concerning the accumulation of PBDEs and MeO-PBDEs in Antarctic marine fish and supports the importance of species-specificity in the accumulation of MeO-PBDEs.

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The Central Andes region is considered an area of high environmental relevance in South America and it is rich in glaciers, which are the main fresh water sources and reservoirs of the region. The presence of organochlorine compounds (OCs) is an environmental threat due to their persistence and adverse effects on wildlife and humans. The levels of OCs, such as chlordane compounds (CHLs), dichlorodiphenyltrichloroethane and metabolites (DDTs), hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), and polychlorinated biphenyls (PCBs), were determined in muscle and liver tissues of fish and in sediments collected from different sites of the central Andes: the Mendoza River and the Yaucha River (rainbow trout: Oncorhynchus mykiss) and Carrizal Dam (silverside: Odontesthes bonariensis). Regardless of studied site and fish tissue, the general OC trend was: DDTs > PCBs > HCHs > CHLs > HCB. The results showed clear geographic distribution patterns for DDTs. Among the sampling sites, silverside fish showed the highest average load of DDTs (614 and 867 ng g-1 lw in muscle and liver tissues, respectively). Based on the biota-sediment bioaccumulation factor (BSAF), both rainbow trout and silverside fish showed comparable capability to accumulate p,p'-DDT in their tissues. Intraspecific correlational analysis showed that CB-138 in muscle and p,p'-DDT in liver were clearly correlated with the lipid content in silverside specimens, which highlights the relevance of taking into account the fat content and the type of target tissues.

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Durante más de 40 años se ha discutido el estatus taxonómico de diversas especies del enigmático género Heleobia de la Familia Cochliopidae (Caenogastropoda: Rissooidea). Como sucede con otras familias de rissooideos, la abundancia de caracteres convergentes y la escasez de sinapomorfías anatómicas han representado un problema para resolver las relaciones filogenéticas de Cochliopidae y definir la validez de varias de las especies nominales de esta Familia. Presentamos aquí una contribución molecular tendiente a resolver el estatus taxonómico de uno de los más abundantes géneros de la porción meridional de Sudamérica que incluye varias especies endémicas. Nuestra evidencia molecular reconfirma tres de los cuatro grupos de Heleobia en los que se han agrupado las especies del género en esta región: "australis", "parchappii" y "piscium". El cuarto, el grupo "hatcheri", no pertenece a Heleobia sino a un género diferente que no debería ser considerado como integrante de la Familia Cochliopidae, sino estrechamente relacionado al género Potamolithus Pilsbry y Rush, 1896

For over 40 years malacologists have been discussing the taxonomical status of Heleobia species, an enigmatic genus from Cochliopidae family (Caenogastropoda: Rissooidea). As with other rissooidean families, the considerable character convergence and the paucity of anatomical synapomorphies has proved to be a problem in resolving cochliopid phylogenetic relations and establishing the validity of several nominal cochliopid species. Here we present a molecular contribution to solve the taxonomical status of one of the most abundant Southern South America cochliopid genera which has many endemic species. We report molecular evidence that supports three of the four Heleobia groups described for this region, the "australis", "parchappii" and "piscium" groups. The fourth, the "hatcheri" group, belongs not to Heleobia but to a different genus which itself should not be considered as part of the family Cochliopidae but closely related to genus Potamolithus Pilsbry & Rush, 1896

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Durante más de 40 años se ha discutido el estatus taxonómico de diversas especies del enigmático género Heleobia de la Familia Cochliopidae (Caenogastropoda: Rissooidea). Como sucede con otras familias de rissooideos, la abundancia de caracteres convergentes y la escasez de sinapomorfías anatómicas han representado un problema para resolver las relaciones filogenéticas de Cochliopidae y definir la validez de varias de las especies nominales de esta Familia. Presentamos aquí una contribución molecular tendiente a resolver el estatus taxonómico de uno de los más abundantes géneros de la porción meridional de Sudamérica que incluye varias especies endémicas. Nuestra evidencia molecular reconfirma tres de los cuatro grupos de Heleobia en los que se han agrupado las especies del género en esta región: "australis", "parchappii" y "piscium". El cuarto, el grupo "hatcheri", no pertenece a Heleobia sino a un género diferente que no debería ser considerado como integrante de la Familia Cochliopidae, sino estrechamente relacionado al género Potamolithus Pilsbry y Rush, 1896(AU)

For over 40 years malacologists have been discussing the taxonomical status of Heleobia species, an enigmatic genus from Cochliopidae family (Caenogastropoda: Rissooidea). As with other rissooidean families, the considerable character convergence and the paucity of anatomical synapomorphies has proved to be a problem in resolving cochliopid phylogenetic relations and establishing the validity of several nominal cochliopid species. Here we present a molecular contribution to solve the taxonomical status of one of the most abundant Southern South America cochliopid genera which has many endemic species. We report molecular evidence that supports three of the four Heleobia groups described for this region, the "australis", "parchappii" and "piscium" groups. The fourth, the "hatcheri" group, belongs not to Heleobia but to a different genus which itself should not be considered as part of the family Cochliopidae but closely related to genus Potamolithus Pilsbry & Rush, 1896(AU)

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In the present work, persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and metabolites, polybrominated diphenyl ethers (PBDEs), and hexachlorocyclohexane (HCH) were analyzed in three Antarctic notothenioids fish species: Trematomus newnesi (TRN), Notothenia coriiceps (NOC) and Notothenia rossii (NOR). The contribution of each POP-family to the total load was as follows: ΣPCB (40%)>ΣDDT (27%)>ΣPBDEs (23%)>ΣHCH (10%). Among the 23 PCB congeners analyzed, penta-CBs homologues were the prevalent group, followed by hexa-CBs and hepta-CBs. DDT and its metabolites presented the following trend: p,p'-DDT>p,p'-DDE~p,p'-DDD. PBDE profile was dominated by BDE-47 and BDE-99 congeners, followed by BDE-100>BDE-28>BDE-154, BDE-153. Among HCHs, the γ-HCH isomer was detected in all samples, constituting 69% total HCH load, while α-HCH and ß-HCH contributions were 15% and 16%, respectively. The levels of POPs reported here suggest that NOR and NOC are more susceptible to accumulate the analyzed contaminants than TRN, a species not previously analyzed for POPs. Distribution of POPs among different tissues of the three species (muscle, liver, gonads, and gills) was also investigated. Considering lipid weight, the general pattern of POPs distribution in tissues indicated that while gonads showed higher levels of PCBs, DDTs and HCH, the most significant PBDE concentrations were recorded in gills. Also, a comparative analysis of POPs concentration in fish samples from Antarctic area was included.

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Ultrasound leaching-dispersive liquid-liquid microextraction using solidification of floating organic droplet (USL-DLLME-SFO) technique is proposed for extraction and isolation of polybrominated diphenyl ethers (PBDEs) from sediment and further determination by gas chromatography-tandem mass spectrometry (GC-MS/MS). Parameters that affect the efficiency of the procedure were investigated by a full factorial (2(k)) screening design. Variables showing significant effects on the analytical responses were considered within a further central composite design (CCD). The optimization assays have led to following protocol: ultrasound assisted lixiviation of 1g sediment was carried out by using 1.2 mL MeOH. Further, the analytes were isolated from 0.4 mL of the extract using the DLLME-SFO technique. The microextraction was performed using 0.1 mL MeOH, 22 mg 1-dodecanol, 1 mL NaCl solution 6.15M and 4.4 mL ultrapure water as dispersive and extracting solvents, medium ionic strength and dispersant bulk, respectively. Under optimum conditions, the method exhibits good performance in terms of linearity and precision (RSD<9.2%), with recoveries above 71% and limits of detection (LODs) within the range 0.5-1.8 pgg(-1) dry weight (d.w.). Method validation was demonstrated through the analysis of environmental sediment samples in which PBDEs were detected and quantified. The presence of BDE-47, -100, -99 and -153 was reported within the concentration range of

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