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En las últimas décadas, se viene registrando en el Atlántico noreste un cada vez mayor número de citas de especies ictiológicas de aguas cálidas más meridionales. Diversos trabajos relacionan este fenómeno con el aumento de la temperatura de las costas europeas como consecuencia del calentamiento global. En este contexto, se documenta para el mar Cantábrico la primera cita de un ejemplar de góbido del género Zebrus de distribución principalmente mediterránea y con tan solo unas pocas citas en el océano Atlántico. ABSTRACT: In recent decades, an increasing number of records of ichthyological species from more southern warm waters have been recorded in the northeast Atlantic. Several studies relate this phenomenon to the increase in the temperature of European coasts as a consequence of global warming. In this context, here we document the first record for the Cantabrian sea of a specimen of a gobid fish belonging to Zebrus genus, which typically exhibit a Mediterranean distribution with only a few records in the Atlantic Ocean.

The economic feasibility for captive breeding of marine ornamental fish in small spaces is poorly known, especially when considering threatened species. The present study analyzed the economic feasibility for producing Yellow Neon Goby (Elacatinus figaro) (vulnerable) in urban aquaculture systems through different production scenarios: pessimistic, normal, and optimistic, at sales prices of US$ 5.71, US$ 7.62, and US$ 9.52/unit. The financial analysis pointed the total cost of production per animal available to marine ornamental fish trade was between US$ 3.99 and R$ 8.03, with labor and rent as the main expenses. Six of the nine observed schemes showed profitability, including under loss conditions of an entire cycle. The net present value (NPV 8%) reached US$ 83,256 (negative value, unfeasible) until US$ 230,122 (positive value, viable), with profitable conditions presenting an internal rate of return (IRR) ranging from 10.87 to 97.84% and return on capital observed from the first to the sixth year of activity. In addition to the sustainable potential for biodiversity conservation, these results expressed reinforce urban ornamental aquaculture as a profitable instrument for public policy in socioeconomic development at large urban centers and their peripheral regions. [ABSTRACT FROM AUTHOR]

Round goby (Neogobius melanostomus (Pallas, 1814)) is an invasive species in the Oder River. In this study, age of 147 fish was determined using scales and otoliths, and the Fraser-Lee back-calculation method was used for population structure and theoretical length growth rates with 3 mathematical models of growth: von Bertalanffy, Ford–Walford and 2nd degree polynomial. Fish condition was determined using Fulton, Le Cren and Clark equations. Average total length and weight of fish was 162.00 mm and 83.00 g, respectively. Males were more abundant than females, representing 70% of the fish caught, and achieved greater total lengths and weights. Age 2+ dominated females and 3+ males age groups. Of the three mathematical models used to estimate fish growth, the 2nd degree polynomial model had the best fit to back-calculated lengths. Males had slightly higher growth rates than females in the first two years of life but comparable in subsequent years. The diet consisted of various benthic organisms that varied with fish age. The most frequently occurring food component was Dreissena polymorpha, which accounted for approximately 70% in the diet of fish with a body length greater than 191 mm. [ABSTRACT FROM AUTHOR]

Slender Mudskipper (Scartelaos tenuis) is one of the dominant fishes in inter-tidal mud flats area. Reproduction and population parameters of 2047 Slender mudskipper were studied monthly from october 2008 to september 2009. The asymptotic length (Lâ) and growth coefficient (K) were estimated as 19.43(cm) and 0.64(yr-1), respectively. The minimum and maximum T.L. was 1.1 and 19.5cm, respectively. The value of to was -8.28, and Tmax was 4.6 year. The growth equation of Von Bertalanffy was obtained at L(t) = 19.43(1- exp (-0.64(t- (-0.28))) for this species. The rates of natural mortality (M) on Pauly's empirical equation, was estimated 1.51 (yr-1). Five cohorts were distinguished annualy on Bhattacharya's method with mean length of 7.89, 11.42, 13.86, 15.6 and 16.81cm. Maximum recruitment was in Seprember at 18.8 percent. Reproductive studies showed that peak of maturity season occurred in April. The female to male ratio was calculated as 1:1.47 and chi-square analysis showed that it was statistically significant deviated from 1:1. LM50 is attained at a total length of 13.3cm. The mean of absolute and relative fecundity were 6742 (±1939) and 707 (±210), respectively. The length-weight relationship was as W= 0.02735 L 2.1655, that was isometric growth. Result showed that slender mudskipper population was in congenial condition, nevertheless less not evaluated.

The marine and estuarine fishes of the British Isles currently include 17 species of gobioid percomorphs. The criteria for recognising these, apart from external features, involve the skeleton and the male genitalia, and all are goby-grade, the most speciose and varied of three main structural grades in the Gobioidei. The typical goby pelvic disc, formed by fusion of the paired pelvic fins and completed with a tranverse anterior membrane, is illustrated and distinction made between the generalised condition of separate pelvics and those gobiid pelvic fins that are secondarily separated. British gobies are divisible into four categories, two 'gobiine' and two 'gobionelline', using patterns of head lateral-line canals and free neuromast organs, as well as first dorsal fin pterygiophore sequence and number of vertebrae. These are the gobiines with the Gobius group comprising six Gobius species and one Thorogobius, and the single 'longitudinal' gobiine Lesueurigobius, the subject of another presentation. The British gobionellines comprise the sand-gobies, with five confirmed Pomatoschistus species, one each of Gobiusculus and Buenia, and two of Lebetus. The other gobinellines are two aphiine progenetic species placed in Aphia and Crystallogobius respectively. In conclusion, the British gobiines are illustrated with brief notes on size, habitat, and distribution.

In fish, fecundity correlates with female body size and egg-tending males often eat small broods. Therefore, small females may prefer to spawn in nests that already contain many eggs, to ensure the brood is as large as possible. In contrast, large females may prefer nests with few eggs, if high egg number or density has a negative effect on egg survival, or if there are drawbacks of spawning last in a nest. To test the hypothesis that female body size affects nest (and male mate) choice, using the sand goby ( Pomatoschistus minutus), we allowed small and large females to choose between two males that were matched in size - one guarding a small clutch and the other a large clutch, respectively. We recorded where females spawned (measure of female preference), the combined brood size, male courtship, egg care and nest building. We also quantified the effect of brood size and egg density on egg survival in a separate data set. Although the combined broods did not exceed the small brood sizes that are at risk of being eaten, both small and large females preferred to spawn in nests with smaller clutch sizes. This preference could not be explained by more courtship or male parental effort, nor by reduced survival of larger or denser broods. Instead, our result might be explained by females avoiding the danger of cannibalism of young eggs by males or the risk of reduced egg health associated with being near the nest periphery. [ABSTRACT FROM AUTHOR]

Most introduced non-native species fail to establish as a result of mortality or reproductive failure. An established population can increase the probability of survival and reproductive success of newly introduced individuals by reducing both Allee effects and demographic stochasticity. Previously, attention has been paid to the establishment phase of the invasion process and its probability modelled as a stochastic process, while the spread phase has received less attention. By analyzing data collected during the spread phase of an invasion of the round goby, Neogobius melanostomus, in Hamilton Harbour, Lake Ontario, we develop an analytical approach to backcalculate the time to establishment and to determine the time to habitat saturation. Our modelling shows that: (1) during the transition between arrival and establishment, propagule pressure in the form of new adults entering the area can be very low and still represent a significant probability of establishment; (2) much higher concentrations of juveniles would be needed to pose a significant risk of invasion; (3) the demographic contribution of propagule pressure during the spread phase is low and its total elimination will not halt population growth and spread; (4) a short elapsed time between arrival and establishment indicated that the transition between these two phases can be characterized as a deterministic process with high propagule pressure and low adult mortality rates; and, (5) very aggressive management actions would be needed to halt population growth after population establishment, suggesting that preventative measures are the most effective management options available to reduce risk of future invasions. [ABSTRACT FROM AUTHOR]

A significant expansion of offshore windpower is expected in northwestern Europe in the near future. Little is known about the impacts it may have on the marine environment. Here, we investigate the potential for wind turbines to function as artificial reefs and fish aggregation devices (FADs), i.e. whether they would locally increase fish densities or alter fish assemblages. Fish communities and habitat composition were investigated using visual transects at two windpower farms off the southeastern coast of Sweden, central Baltic Sea. Fish abundance was greater in the vicinity of the turbines than in surrounding areas, while species richness and Shannon–Wiener diversity (H′) were similar. On the monopiles of the turbines, fish community structure was different, and total fish abundance was greater, while species richness and diversity (H′) were lower than on the surrounding seabed. Blue mussels and barnacles covered most of the submerged parts of the turbines. On the seabed, more blue mussels and a lesser cover of red algae were recorded around the power plants than elsewhere. Results from this study suggest that offshore windfarms may function as combined artificial reefs and fish aggregation devices for small demersal fish. [Copyright &y& Elsevier]