The Hydra regeneration assay reveals ecological risks in running waters: a new proposal to detect environmental teratogenic threats.

The regenerative ability of Hydra vulgaris was tested as potential biomarker for the development of a new eco-toxicological index. The test is based on the regeneration rate and the aberration frequency of the columna (body and adhesive foot) after separation from head and tentacles by a bistoury. Particularly, 45 columnae were submerged in the rearing solution (that is Hydra medium) to have control, and 285 in potential contaminated waters to have treatments, collected from 19 sites along 10 rivers in central Italy. ANCOVA and chi-square tests were used to compare values from each site to a laboratory control. Subsequently the values on regeneration rate and aberration frequency were inserted in a double entry matrix, where the match of the two entries in the matrix provides the score of the proposed Teratogenic Risk Index (TRI). Each score corresponded to one of the 5 teratogenic risk classes, to which a risk level was associated: from 1 (no risk) to 5 (very high risk). On the whole, 32% of the studied sites were classified as no teratogenic risk while the remaining showed a variable risk level from low to very high. This study proposed for the first time an early warning system to detect the presence of teratogens in running waters, providing a rapid and cost-effective evaluation method. Therefore, TRI may contribute to initiate adequate measures to manage riverine habitats, and to monitor the running water teratogenic status. Specifically, this index may provide the opportunity to identify the disturbance sources and then to drive the decisions, together with competent authorities, on the catchment and landscape management and on the possible use of waters for urban, agricultural, and industrial activities, since they may show significant effects on the human health.

Shell fluctuating asymmetry in the sea-dwelling benthic bivalve Mytilus galloprovincialis (Lamarck, 1819) as morphological markers to detect environmental chemical contamination.

Investigations on asymmetries showed that deviations from perfect bilateral symmetry are interpreted as environmental changes inducing developmental instability. Since morphological abnormalities increase with pollution, deformations may be considered indicators of the organism exposition to pollution. Therefore, the onset of asymmetry in otherwise normally symmetrical traits has been used as a measure of some stresses as well. In this context, we studied how marine pollution affects the valve morphological alterations in the mussel Mytilus galloprovincialis. We used 180 specimens (30 per site) from the aquaculture area of Goro (River Po delta, northern Adriatic Sea), translocated, and released within 50 × 50 × 50 cm cages in five sites: two disturbed and one undisturbed near Naples (eastern Tyrrhenian Sea), and one disturbed and one undisturbed near Siracusa (western Ionian Sea). Disturbed sites were stressed by heavy industrialization and heavy tankers traffic of crude and refined oil, and were defined basing on sediment contamination. In particular, by the cone-beam computed tomography we obtained 3D virtual valve surfaces to be analyzed by the geometric morphometric techniques. Specifically, we focused the levels of the shell shape fluctuating asymmetry in relation to the degrees of marine pollution in different sites of the Tyrrhenian Sea. The Mahalanobis distances (interpreted as proxy of the individual shape asymmetry deviation from the mean asymmetry) significantly regressed with the sediment contamination gradient. Indeed, although the left-right differences were normally distributed in each studied site, the individual asymmetry scores (IAS) significantly varied amongst the investigated sites. IAS showed higher values in disturbed areas than those of undisturbed ones in both Tyrrhenian and Ionian Sea. Our results are consistent with past studies on molluscans and other taxa, demonstrating some detrimental effects of chemicals on organisms, although the investigated morphological marker did not discriminate the real disturbance source. Our findings indicate that the mussels act as a prognostic tool for sea pollution levels driving detrimental effects on benthic community.

Concordance between macrophytes and macroinvertebrates in a Mediterranean river of central Apennine region.

The main aim of this study was to improve the knowledge about the concordance among macrophytes and macroinvertebrates to provide complementary information and facilitate the procedures for quality assessment of river ecosystems. Macrophytes and macroinvertebrates were collected in 11 sampling sites along a central Apennine calcareous river in October 2008 and June 2009. The concordance between the two biomonitoring groups was tested according to several environmental parameters. The comparison of data matrix similarities by Mantel test showed differences in the assemblage of macrophytes and macroinvertebrates along the river since correlation values were 0.04, p > 0.05 in October 2008 and 0.39, p > 0.05 in June 2009. The study revealed lack of concordance between the two groups, emphasizing that the information provided by macrophytes and macroinvertebrates does not overlap in terms of response to environmental parameters. Indeed, the two different biological groups resulted useful descriptors of different parameters. Together, they could represent a complementary tool to reflect the river environmental quality.

Integrating running water monitoring tools with the Micro Biological Survey (MBS) method to improve water quality assessment.

Running water habitats are among the most altered aquatic systems by human activities driving an increase in the organic components and the associated bacterial load as well. To contribute in improving the monitoring activities in running waters, here we tested the validity of the new Micro Biological Survey (MBS) method to specifically assess the bacterial load in running waters focusing on Total Viable Counts (at 22°C and 37°C) and Escherichia coli (at 44°C) in order to propose a new prognostic tool for watercourses. MBS method is an alternative colorimetric method for counting bacterial load in water and food samples that is easy to use and leads to a reliable and simple interpretation of results, being also faster and less expensive than traditional methods. Then, we compared MBS with the traditionally used reference method for the bacterial load, and with the most used biotic index for Italian watercourses based on the benthic invertebrates: the Extended Biotic Index (EBI). The last comparison was performed to validate the use of MBS in biomonitoring activities since the benthic invertebrate multi-species assemblage (and then EBI) alter own structure mainly depending on the organic component variation. During the first part of the study, the assessment of both linearity (regressions among bacterial concentrations) and accuracy (significant correlation between a measured value and a value used as reference) confirmed the validity of the MBS method. Second, the linear regressions between the three investigated microbial parameters vs. both physical-chemical descriptors and EBI, revealed the usefulness of MBS as a valid tool for routine microbiological analyses involved in rapid and easy field monitoring activities. This represents the first attempt to evaluate the river microbial status by exploiting the innovative MBS on running waters to propose it as new valuable monitoring tool in the biomonitoring field.

Transient Receptor Potential Melastatin-3 (TRPM3) Mediates Nociceptive-Like Responses in Hydra vulgaris.

The ability of mammals to feel noxious stimuli lies in a heterogeneous group of primary somatosensory neurons termed nociceptors, which express specific membrane receptors, such as the Transient Receptor Potential (TRP) family. Here, we show that one of the most important nociceptive-like pathways is conserved in the freshwater coelenterate Hydra vulgaris, the most primitive organism possessing a nervous system. In particular, we found that H. vulgaris expresses TRPM3, a nociceptor calcium channel involved in the detection of noxious heat in mammals. Furthermore, we detected that both heat shock and TRPM3 specific agonist (i.e., pregnenolone sulfate) induce the modulation of the heat shock protein 70 (HSP70) and the nitric oxide synthase (NOS), two genes activated by TRP-mediated heat painful stimuli in mammals. As expected, these effects are inhibited by a TRPM3 antagonist (i.e., mefenamic acid). Interestingly, the TRPM3 agonist and heat shock also induce the expression of nuclear transcription erythroid 2-related factor (Nrf2) and superoxide dismutase (SOD), known markers of oxidative stress; noteworthy gene expression was also inhibited by the TRPM3 antagonist. As a whole, our results demonstrate the presence of conserved molecular oxidative/nociceptive-like pathways at the primordial level of the animal kingdom.