‘Tropicalization’, the phenomenon of species shifting their ranges, has become increasingly prevalent as a response to environmental modifications induced by global change. This study points to an accelerated tropicalization process of marine fish species in the Gulf of Cadiz, a bioinvasion hotspot adjacent to the Strait of Gibraltar. We report accelerated, unusual, and rare occurrences of 15 fish species expanding and potentially establishing their ranges in the Gulf of Cadiz, driven by ocean warming over the past decade. These new insights are the combined consequence of a range expansion of some species, likely facilitated by temperature increases, an intensification of maritime traffic (with a consequent rise in propagule pressure), and a possible increase in sampling efforts and citizen science.

We propose a novel measure of the market return tail risk premium based on minimum-distance state price densities recovered from high-frequency data. The tail risk premium extracted from intra-day S&P 500 returns predicts the market equity and variance risk premiums and expected excess returns on a cross section of characteristics-sorted portfolios. Additionally, we describe the differential role of the quantity of tail risk, and of the tail premium, in shaping the future distribution of index returns. Our results are robust to controlling for established measures of variance and tail risk, and of risk premiums, in the predictive models.

The temporal and spatial variation of Paralonchurus brasiliensis density (fish per m2) in relation to environmental factors was studied on the coasts of Ubatuba and Caraguatatuba, south-eastern Brazil. The fish were collected by shrimp fishery trawl on a monthly basis from January to December, 2002. Seven depths were previously established and for each one the temperature, salinity, organic matter content and grain size of the sediment (φ) was measured. The seasonal analysis of temperature and salinity indicated the presence of the water masses South Atlantic Central Water (SACW) and Coastal Waters (CW) acting in the study area. A total of 29,808 fish were collected during the study period. The highest densities were registered during the summer and autumn indicating an association with CW. The fish population moved to shallow depths during the intrusion of the cold water mass, SACW. The highest densities were registered in depths where the sediment composition ranged from fine sand to silt–clay. Thus, the temperature and type of the sediment are the main environmental factors which affect the spatial–temporal variation of P. brasiliensis density in south-eastern Brazil.

The parasite–host interactions among two isopod species Cymothoa spinipalpa and Rocinela signata and five marine fish species, Chloroscombrus chrysurus, Caranx crysos, Oligoplites saliens, Lutjanus synagris and Trichiurus lepturus, are described here and registered for the first time on the coast of Bahia, north-eastern Brazil. Based on samples using different fishing techniques in different seasons from 2006 to 2009, discussions of the ecological and clinical association of these interactions are presented in this paper. Most fish species showed high prevalence indices associated with a high abundance of host fish.

The spatio-temporal distribution of the soft bottom dwelling shrimp Nematopalaemon schmitti and the effect of environmental conditions (sediment characteristics, temperature, salinity and dissolved oxygen) on its abundance were studied at Ubatuba Bay, south-eastern coast of Brazil. Surveys were conducted monthly from September 1995 to August 1996. Each sampling set comprised eight different transects distributed within the bay. Comparisons of CPUE of shrimp among sampling stations demonstrated that the abundance of N. schmitti was the greatest during winter, when average water temperature within the bay was considerably lower than during the rest of the year. Most shrimps (more than 95%) were collected at a single transect located at the northernmost side of the bay, demonstrating the extremely patchy distribution of this species. A multiple regression analysis using data only from this northernmost transect indicated that temperature was the most relevant factor affecting the abundance of N. schmitti during the year.