Quantitative habitat models for the conservation of the endangered European crayfish Austropotamobius pallipes complex (Astacoidea: Astacidae)

Crayfish are the largest mobile freshwater invertebrates and are keystone species in European aquatic ecosystems particularly in small streams and rivers. The white-clawed crayfish Austropotamobius pallipes (a species complex) is currently classified by the IUCN Red List as an endangered species (EN), because its populations have decreased significantly over the last decades in a number of European countries including Italy, due mainly to habitat modifications and the introduction and spread of alien species. Data on the ecological requirements of A. pallipes are needed to quantify the effects of habitat alteration, to simulate restoration scenarios, and to implement effective conservation measures for this species. We describe here a new methodology for modelling the habitat requirements for this endangered crayfish using the mesohabitat scale approach based on data from crayfish living in small streams draining the Italian foothills of the Alps (Lombardy region) and in streams in the mountainous areas of the Gran Sasso and Monti della Laga National Park (Abruzzo region). Data from seven morphologically different streams were used to train and validate the habitat models. The Random Forests algorithm was used to identify the best and most parsimonious habitat model, and to define the lowest number of variables to be surveyed in the future. The best habitat models were applied to each stream and used to classify each mesohabitat into suitability categories. Habitat flow-rating curves were developed to analyze spatio-temporal variation of habitat availability, and habitat time series analysis were used to define detailed management schemes for environmental river management. Flow releases and water temperature regimes were assessed for individual water diversions in order (1) to represent how physical habitat changes through time, and (2) to identify stress conditions for A. pallipes created by the persistent limitation of habitat availability. Results indicated that the kind of substrate in the stream bed (such as the proportion of fine-grained substrates), the water depth (whether shallow or deep), and the available cover (such as the presence of boulders, woody debris, and undercut banks) were all significant factors governing the occurrence of crayfish. The habitat models performed well in both calibration and validation phases (with accuracy ranging from 71% to 79% in training and from 69% to 73% in validation) and can be considered to be a valuable tool to predict the distribution of A. pallipes over a wide range of stream types. An example of how to establish environmental standards for small streams is presented. The proposed habitat model provides a useful tool that can be applied even when other commonly used methodologies are unsuitable. As such, this habitat model can be used to develop regional rules for the conservation of the endangered crayfish A. pallipes complex and for defining more site-specific management criteria

Colour variation in signal crayfish Pacifastacus leniusculus

External colouration in animals depends on the interaction of several different factors including the genetics and epigenetics processes that underlie the colour expression, the mechanisms of colour perception, and the general mechanisms controlling colour evolution and function. Among all, camouflage from predators and conspicuousness are of particular interest since pose animal to choose between opposite adjustment in colouration. The external colouration of crustaceans is mainly due to the accumulation of carotenoids in the exoskeleton and the epidermal layer, and the trade-off between camouflage and communication had lead to a variety of responses, involving signal partitioning, spectral sensibility, changing colouration or signalling behaviour. Here, we used digital images to explore intrapopulation variability of the external colouration of Pacifastacus leniusculus among body regions within an individual and between sexes. We found that i) ventral colouration of claws are more saturated and brilliant than upperparts, ii) males express a more saturated and brightness colouration than females, especially on the lower portion of claws, iii) colour intensity and brightness increases with size differently in different body regions, and iv) brightness is more variable in males than in females. All the above patterns support the hypothesis that colour in this species could be the result of a compromise between camouflage from predators and conspicuousness for communication. The results of this study suggest that carotenoid might have something to do with intraspecific communication and perform more complex functions than that of a simple pigment

[First reporting of the signal crayfish (Decapoda, Astacidae) in the Province of Savona, Italy]

In this short note we report the sudden and numerically significant expansion of signal crayfish (P. leniusculus) from Piedmont towards Liguria. P. leniusculus (Decapode Astacidae) is native to northwestern America, introduced in Italy in 1981 in the province of Bolzano, a few years later it was reported in Brugneto Lake (Genova district) and during the 2009 in the Valla stream (Alessandria district). The peculiarities of this species, originally from "cold water", making it potentially invasive in the Apennine watercourses and also the presence of this allochthonous decapod in the Savona district, would like to suggest the implementation of containment plans, acts at least to limit its spread

Modelling Environmental Niche for the Endangered Crayfish Austropotamobius pallipesComplex in Northern and Central Italy

The potential distribution of endangered species is a necessary step to assess species conservation status and manage reintroduction plans. In the context of a EU project on the endangered Austropotamobius pallipescomplex, we modelled the environmental niche of the species in two large areas of Northern (Lombardy, 43 records) and Central Italy (Abruzzo, Province of Isernia, Gran Sasso e Monti della Laga National Park; 69 records). Ecological niche models (ENMs) were built by using the maximum entropy approach as implemented in the MaxEnt software, which predicts the occurrence of a species using presence-only data. The environmental niche was modelled using six variables: altitude, slope, aspect, human disturbance, mean temperature of warmest quarter and distance from stream. Each study area was modelled independently. Both ENMs obtained high performance scores as measured by the AUC index (Northern Italy: 0.854; Central Italy: 0.817). Slope in Northern Italy and the mean temperature of warmest quarter in Central Italy achieved the greatest predictive power. Our results clearly show that the endangered white-clawed crayfish has a narrow range of habitat selection in the two study areas. Our findings may help researchers to select the best sites for future reintroductions in conservation projects

Prognostic and predictive role of neutrophil/lymphocytes ratio in metastatic colorectal cancer: a retrospective analysis of the TRIBE study by GONO.

Background Neutrophil/lymphocyte ratio (NLR), defined as absolute neutrophils count divided by absolute lymphocytes count, has been reported as poor prognostic factor in several neoplastic diseases but only a few data are available about unresectable metastatic colorectal cancer (mCRC) patients (pts). The aim of our study was to evaluate the prognostic and predictive role of NLR in the TRIBE trial. Patients and methods Pts enrolled in TRIBE trial were included. TRIBE is a multicentre phase III trial randomizing unresectable and previously untreated mCRC pts to receive FOLFOXIRI or FOLFIRI plus bevacizumab. A cut-off value of 3 was adopted to discriminate pts with low (NLR < 3) versus high (NLR ≥ 3) NLR, as primary analysis. As secondary analysis, NLR was treated as an ordinal variable with three levels based on terciles distribution. Results NLR at baseline was available for 413 patients. After multiple imputation at univariate analysis, patients with high NLR had significantly shorter progression-free survival (PFS) [hazard ratio (HR) 1.27 (95% CI 1.05-1.55), P = 0.017] and overall survival (OS) [HR 1.56 (95% CI 1.25-1.95), P < 0.001] than patients with low NLR. In the multivariable model, NLR retained a significant association with OS [HR 1.44 (95% CI 1.14-1.82), P = 0.014] but not with PFS [HR 1.18 (95% CI 0.95-1.46), P = 0.375]. No interaction effect between treatment arm and NLR was evident in terms of PFS (P for interaction = 0.536) or OS (P for interaction = 0.831). Patients with low [HR 0.84 (95% CI 0.64-1.08)] and high [HR 0.73 (95% CI 0.54-0.97)] NLR achieved similar PFS benefit from the triplet and consistent results were obtained in terms of OS [HR 0.83 (95% CI 0.62-1.12) for low NLR; HR 0.82 (95% CI 0.59-1.12) for high NLR]. Conclusion This study confirmed the prognostic role of NLR in mCRC pts treated with bevacizumab plus chemotherapy in the first line, showing the worse prognosis of pts with high NLR. The advantage of the triplet is independent of NLR at baseline

FUNDAMENTAL AND APPLIED RESEARCH ON FRESHWATER DECAPODS IN ITALY

The study group of freshwater decapods established within the Italian Association of Freshwater Ichthyologists aims at improving knowledge on the biology of both native and alien freshwater crayfish, shrimps, and crabs which currently inhabit Italian lentic and lotic waters, promoting at the same time the establishment of a network of experts that guarantees an adequate spread of correct useful and usable information, not only for management activities by the local and national competent authorities, but even by non-experts. The group deals with taxonomy, systematic, zoogeography, ecology, ethology, physiology, anatomy, genetics, conservation (of natives) and management (of aliens) of freshwater decapods in Italy. Our main aim is to update the status of freshwater decapods within the national territory, useful for monitoring programs on these species and the habitats where they inhabit. It is necessary to study all the aspects of this order because many species represent an ecological (as a keystone species), fauna (some taxa are interesting peninsular endemisms), biogeographical (the Whole order includes peculiar models of dispersion, migration and vicariance) and evolutionary (there are stimulating case studies of adaptive radiation phenomena linked to a specific ecological value) heritage. Also from an applied perspective, freshwater decapods have a peculiar double aspect linked to the conservation of aquatic environments: on the one side some species can be considered as valuable biological indicators, but on the other side many alien species are reported to be invasive and their management is mandatory, according to the new European and Italian legislations, and should be ecologically, economically and culturally examined to evaluate their effects on environment, human activities and health

Color variation in signal crayfish Pacifastacus leniusculus

Abstract External coloration in animals depends on the interaction of several different factors including the genetics and epigenetics processes that underlie the color expression, the mechanisms of color perception, and the general mechanisms controlling color evolution and function. Among all, camouflages from predators and conspicuousness are of particular interest because pose animal to choose between opposite adjustment in coloration. The external coloration of crustaceans is mainly due to the accumulation of carotenoids in the exoskeleton and the epidermal layer, and the trade-off between camouflage and communication had led to a variety of responses, involving signal partitioning, spectral sensibility, changing coloration, or signaling behavior. Here, we used digital images to explore intrapopulation variability of the external coloration of Pacifastacus leniusculus among body regions within an individual and between sexes. We found that 1) ventral coloration of claws are more saturated and brilliant than upper parts, 2) males express a more saturated and brightness coloration than females, especially on the lower portion of claws, 3) color intensity and brightness increases with size differently in different body regions, and 4) brightness is more variable in males than in females. All the above patterns support the hypothesis that color in this species could be the result of a compromise between camouflage from predators and conspicuousness for communication. The results of this study suggest that carotenoid might have something to do with intraspecific communication and perform more complex functions than that of a simple pigment

Impatto dell’ittiofauna alloctona sulla comunità autoctona nel reticolo idrografico minore del fiume Ticino

L’introduzione di specie alloctone rappresenta la seconda minaccia alla conservazione della biodiversità a livello globale; ancora più gravi sono gli impatti negli ecosistemi d’acqua dolce. Le specie ittiche alloctone in Italia sono sensibilmente più numerose a quelle presenti in altri stati europei e la maggior parte delle immissioni è da ascriversi all’intervento umano. Lo scopo del seguente lavoro è quello di indagare gli effetti della competizione delle specie ittiche alloctone sulla componente autoctona. Sono state indagate 23 stazioni nella rete idrica minore del fiume Ticino nelle province di Varese, Milano e Novara, in cui sono state campionate 10 specie alloctone (n= 886) e 14 specie autoctone (n= 4179). Per valutare l’effetto della competizione sono state condotte analisi sia a livello di comunità sia a livello di singole specie. Le analisi hanno evidenziato una correlazione positiva significativa tra l’indice di diversità di Shannon delle comunità di specie autoctone e quello delle specie alloctone; ciò fa pensare che non vi siano effetti evidenti di competizione a livello di comunità. Questa correlazione è emersa anche tra l’abbondanza di Barbus barbus e la comunità di specie autoctone sia in termini di biomassa totale sia in numero di individui; mentre il numero di individui di Misgurnus anguillicaudatus correlava negativamente sia con la biomassa della comunità autoctona sia con la biomassa di Telestes muticellus. Questo risultato potrebbe essere spiegato da una maggiore resistenza di Misgurnus anguillicaudatus a fenomeni di carenza idrica, che possono verificarsi anche nell’area di studio