Hormonal signaling in cnidarians : do we understand the pathways well enough to know whether they are being disrupted?

Author Posting. © The Author, 2006. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Ecotoxicology 16 (2007): 5-13, doi:10.1007/s10646-006-0121-1.Cnidarians occupy a key evolutionary position as basal metazoans and are ecologically important as predators, prey and structure-builders. Bioregulatory molecules (e.g., amines, peptides and steroids) have been identified in cnidarians, but cnidarian signaling pathways remain poorly characterized. Cnidarians, especially hydras, are regularly used in toxicity testing, but few studies have used cnidarians in explicit testing for signal disruption. Sublethal endpoints developed in cnidarians include budding, regeneration, gametogenesis, mucus production and larval metamorphosis. Cnidarian genomic databases, microarrays and other molecular tools are increasingly facilitating mechanistic investigation of signaling pathways and signal disruption. Elucidation of cnidarian signaling processes in a comparative context can provide insight into the evolution and diversification of metazoan bioregulation. Characterizing signaling and signal disruption in cnidarians may also provide unique opportunities for evaluating risk to valuable marine resources, such as coral reefs

The impacts of seawater physicochemical parameters and sediment metal contents on trace metal concentrations in musselsa chemometric approach

The concentrations of Al, Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Ni, Pb, Sr, Zn, and Hg were studied in Mytilus galloprovincialis collected from the coastal area of Montenegro. The impact of seawater temperature, salinity, dissolved oxygen, total organic carbon (TOC), and metal content in sediment samples on the metal contents in mussels collected from three locations in four different seasons was analyzed by a Pearson correlation coefficient (r), principal component analysis (PCA), and cluster analysis (CA). These analyses were used to discriminate groups of samples, elements, and seawater parameters, according to similarity of samples chemical composition in different seasons, as well as the impact of seawater parameters and surface sediment composition on the mussels' element concentrations. Synergistic interactions occurred between seawater TOC, Fe, and Al concentrations in mussels. Compared with other studies, which are usually performed under constant laboratory conditions where mussels undergo only one stress at a time, this study was performed in nature. The analyses showed the importance of considering simultaneously acting environmental parameters that make determining of separate impacts of each factor selected very difficult and complex

Elemental concentrations in skin and internal tissues of Commerson’s dolphins (Cephalorhynchus commersonii) from subantarctic waters

The skin of cetaceans is the most accessibletissue, and its sampling has been proposed as a noninvasivemethod to evaluate trace element concentrations in free-rangingpopulations. In the present work, concentrations ofessential (Cl, Na, K, Mg, Fe, Zn, Mn and Co), nonessential(As and Ag), and of unknown essentiality (Br, Rb and Cs)elements were determined in the skin from nine by-caughtCommerson´s dolphins (Cephalorhynchus commersonii)from Tierra del Fuego, Argentina. Skin correlations withinternal tissues (lung, liver, kidney and muscle) wereassessed to evaluate how the skin represents internal elementconcentration for monitoring purposes. Elementalcontents were analyzed by instrumental neutron activationanalysis (INAA). Regarding tissue distribution, skin hadthe highest concentration of Zn being two orders of magnitudehigher than internal tissues, while other elementssuch as Co and Rb had similar concentrations among tissues.High mean concentrations of Cl, Na, Mg, Br and Mnwere observed in the lung and liver. Our results support theuse of skin to evaluate Fe, Br and Rb concentrations ininternal tissues for biomonitoring purposes; however, otherelements did not show significant skin-to-tissue correlations.Overall, toxic element levels were far below concentrationsfound to cause harm in marine vertebrates. Thisstudy provided baseline data on elemental concentrationsin tissues of Commerson´s dolphins in subantarctic watersfrom the South Atlantic Ocean.Fil: Cáceres Saez, Iris. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Museo Acatushún de Aves y Mamíferos Marinos Australes; ArgentinaFil: Ribeiro Guevara, Sergio. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Unidad de Actividad de Ingeniería Nuclear. Laboratorio de Análisis por Activación Neutróica; ArgentinaFil: Prosser Goodall, Rae Natalie. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Museo Acatushún de Aves y Mamíferos Marinos Australes; ArgentinaFil: Dellabianca, Natalia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Museo Acatushún de Aves y Mamíferos Marinos Australes; ArgentinaFil: Cappozzo, Humberto Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Fundación de Historia Natural Félix de Azara; Argentina. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; Argentin