Habitat use of an endangered cyprinodontid fish in a saline wetland of the Iberian Peninsula (SW Mediterranean Sea)

Aphanius iberus is an endemic fish restricted to a few populations along the Spanish Mediterranean coastline and included in international red lists. Information on its ecological requirements is needed to implement effective recovery and conservation measures. This two-year study aimed to analyse the effect of habitat changes, mainly in water salinity and refuge availability, on the life-history traits and microhabitat use of an A. iberus population inhabiting a littoral wetland managed for salt exploitation. The species was more abundant at the intake pond, which was characterised by lower water conductivity values and higher cover of the submerged macrophyte Ruppia cirrhosa. The pond with the highest values of water conductivity showed no presence of newborn individuals (< 10 mm), which probably indicates the reproduction failure of A. iberus or high mortality rates for younger individuals. Overall, the species’ selection of microhabitats was related to refuge presence (submerged vegetation and pond dykes). Juvenile individuals showed a strong dependence on sheltered microhabitats through the studied ponds, with R. cirrhosa meadows as important refuge areas for this age group. Results highlighted the importance of developing traditional maintenance and management measures for the conservation of such endangered fish species

The first occurrence of Cobitis paludica (de Buen, 1930) in the Segura River Basin (SE Iberian Peninsula)

The aim of the present report is to describe the establishment of viable populations of Cobitis paludica (de Buen, 1930) in the Segura River Basin. We found two isolated populations: one located in the upper part of the Segura River and the mouth of its tributary, the Zumeta River, and another in the Mundo River, between the Talave and Camarillas reservoirs. We hypothesised that the introduction of this species may be attributable to the deliberate or accidental introduction by anglers or fish translocation from the Tajo-Segura interbasin water transfer system. C. paludica is a threatened endemic fish species from the Iberian Peninsula, and it exhibits sharply declining populations. Therefore, further investigation is needed to assess the genetic origin of the populations reported in this report and to monitor the population trends to determine the population status and the appropriate management plan in the Segura River Basin.El presente trabajo constituye la primera referencia al establecimiento de poblaciones viables de Cobitis paludica (de Buen, 1930) en la cuenca del río Segura. Se han detectado dos poblaciones separadas geográficamente: una localizada en la zona alta del río Segura y la desembocadura del río Zumeta, y otra en el río Mundo, entre los embalses de Talave y Camarillas. Su presencia puede ser debida a la introducción deliberada o accidental por parte de los pescadores, o a la translocación de ejemplares a través del trasvase Tajo-Segura. C. paludica es una especie amenazada endémica de la Península Ibérica cuyas poblaciones se encuentran actualmente en declive. En este sentido, es necesario realizar estudios genéticos que confirmen el origen de estas poblaciones y desarrollar protocolos de seguimiento para establecer su estado poblacional y el plan de gestión de esta especie en la cuenca del río Segura

Environmental variables, habitat discontinuity and life history shaping the genetic structure of Pomatoschistus marmoratus

Coastal lagoons are semi-isolated ecosystems exposed to wide fluctuations of environmental conditions and showing habitat fragmentation. These features may play an important role in separating species into different populations, even at small spatial scales. In this study, we evaluate the concordance between mitochondrial (previous published data) and nuclear data analyzing the genetic variability of Pomatoschistus marmoratus in five localities, inside and outside the Mar Menor coastal lagoon (SE Spain) using eight microsatellites. High genetic diversity and similar levels of allele richness were observed across all loci and localities, although significant genic and genotypic differentiation was found between populations inside and outside the lagoon. In contrast to the FST values obtained from previous mitochondrial DNA analyses (control region), the microsatellite data exhibited significant differentiation among samples inside the Mar Menor and between lagoonal and marine samples. This pattern was corroborated using Cavalli-Sforza genetic distances. The habitat fragmentation inside the coastal lagoon and among lagoon and marine localities could be acting as a barrier to gene flow and contributing to the observed genetic structure. Our results from generalized additive models point a significant link between extreme lagoonal environmental conditions (mainly maximum salinity) and P. marmoratus genetic composition. Thereby, these environmental features could be also acting on genetic structure of coastal lagoon populations of P. marmoratus favoring their genetic divergence. The mating strategy of P. marmoratus could be also influencing our results obtained from mitochondrial and nuclear DNA. Therefore, a special consideration must be done in the selection of the DNA markers depending on the reproductive strategy of the species

Defining the importance of landscape metrics for large branchiopod biodiversity and conservation: the case of the Iberian Peninsula and Balearic Islands

The deficiency in the distributional data of invertebrate taxa is one of the major impediments acting on the bias towards the low awareness of its conservation status. The present study sets a basic framework to understand the large branchiopods distribution in the Iberian Peninsula and Balearic Islands. Since the extensive surveys performed in the late 1980s, no more studies existed updating the information for the whole studied area. The present study fills the gap, gathering together all available information on large branchiopods distribution since 1995, and analysing the effect of human population density and several landscape characteristics on their distribution, taking into consideration different spatial scales (100 m, 1 km and 10 km). In overall, 28 large branchiopod taxa (17 anostracans, 7 notostracans and 4 spinicaudatans) are known to occur in the area. Approximately 30% of the sites hosted multiple species, with a maximum of 6 species. Significant positive co-occurring species pairs were found clustered together, forming 4 different associations of large branchiopod species. In general, species clustered in the same group showed similar responses to analysed landscape characteristics, usually showing a better fit at higher spatial scales.Brazilian Conselho Nacional de Desenvolvimento Cientifico e Tecnologico-CNPq [401045/2014-5]Spanish Ministry of Education, Culture and Sport [FPU014/06783]info:eu-repo/semantics/publishedVersio

Habitat quality affects the condition of Luciobarbus sclateri in the Guadiamar River (SW Iberian Peninsula): Effects of disturbances by the toxic spill of the Aznalcóllar mine

This study analyzes the somatic condition of southern Iberian barbel Luciobarbus sclateri (Günther, 1868) in the Guadiamar River (SW Iberian Peninsula). This river was seriously affected by a toxic spill of about 4 million cubic meters of acidic water and 2 million cubic meters of mud rich in heavy metals. Once the spill removal works concluded, sites affected and unaffected by the accident were sampled to study its effects on the fish fauna. The ecological variables registered were related to water quality, physical state of reaches, ecological quality, resources exploited by fish, and potential intra-specific interactions. From an initial 15 ecological variables, seasonal water flow and pH explained most of the variation in barbel condition. This study shows that the Guadiamar River, 56 months after the accident, is still undergoing a recovery process where, beyond ecological variables, proximity to the affected area is the most influential factor for fish condition. © 2012 Springer Science+Business Media B.V

Evaluation of the invasive blue crab Callinectes sapidus as a Pb and Cd bioindicator in the Segura River Basin (Southeast Spain)

The main objective of this study was to evaluate the levels of two heavy metals, Cd and Pb, in the invasive blue crab Callinectes sapidus and so explore the possibilities of using this species as a bioindicator organism. Blue crabs were captured at the mouth of the river Segura (Guardamar del Segura, Spain), an area that has suffered heavy anthropogenic impact. The crabs were euthanized, sexed and biometric parameters were taken. The hepatopancreas, gills, muscle and carapace were separated; sediments from the study area were also sampled. Element concentrations were analysed by inductively coupled plasma optical emission spectrometry (ICP-OES), and the Biological Sediments Accumulation Factor (BSAF) and Individual Mean Bioaccumulation Index (IMBI) were calculated. Pb concentrations were higher than Cd in the hepatopancreas, gills and muscle; no statistical differences were found between the sexes. Cd and Pb concentrations in sediments were lower than the reference values reported in several works. BSAF was higher for Cd than Pb in the hepatopancreas, gills and carapace. For Cd, the hepatopancreas was the tissue with the highest BSAF, followed by gills. As well, the hepatopancreas had the highest IMBI, followed by the gills, muscle and carapace. For practical field monitoring for metal contamination in this ecosystem the blue crab could be useful but larger specimens would be needed for biomonitoring

Evaluation of the invasive blue crab Callinectes sapidus as a Pb and Cd bioindicator in the Segura River Basin (Southeast Spain)

The main objective of this study was to evaluate the levels of two heavy metals, Cd and Pb, in the invasive blue crab Callinectes sapidus and so explore the possibilities of using this species as a bioindicator organism. Blue crabs were captured at the mouth of the river Segura (Guardamar del Segura, Spain), an area that has suffered heavy anthropogenic impact. The crabs were euthanized, sexed and biometric parameters were taken. The hepatopancreas, gills, muscle and carapace were separated; sediments from the study area were also sampled. Element concentrations were analysed by inductively coupled plasma optical emission spectrometry (ICP-OES), and the Biological Sediments Accumulation Factor (BSAF) and Individual Mean Bioaccumulation Index (IMBI) were calculated. Pb concentrations were higher than Cd in the hepatopancreas, gills and muscle; no statistical differences were found between the sexes. Cd and Pb concentrations in sediments were lower than the reference values reported in several works. BSAF was higher for Cd than Pb in the hepatopancreas, gills and carapace. For Cd, the hepatopancreas was the tissue with the highest BSAF, followed by gills. As well, the hepatopancreas had the highest IMBI, followed by the gills, muscle and carapace. For practical field monitoring for metal contamination in this ecosystem the blue crab could be useful but larger specimens would be needed for biomonitoring