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Length-weight relationships (LWRs) for six fish species caught from tidepools in an intertidal rocky shore in the Gulf of Cadiz are presented. This study presents the first data on LWR for Clinitrachus argentatus (WT = 0.0069 * TL3.077), Coryphoblennius galerita (WT = 0.0051 * TL3.409), and Parablennius incognitus (WT = 0.0090 * TL3.113) outside the Mediterranean Sea and adjacent eastern waters. The data of LWRs for juveniles of Symphodus roissali (WT = 0.0117 * TL3.091), Serranus scriba (WT = 0.0165 * TL2.881), and Diplodus cervinus (WT = 0.0152 * TL3.060) are also presented for first-time. Due to fish body shape may vary during growth in relation to size, studies covering a specific size range relating to life stage can be useful to estimate the LWRs for different development phases. The findings of this study fill the gap in LWRs data for immature fish in S. roissali, S. scriba and D. cervinus. Moreover, because intertidal zones and their adjacent subtidal areas represent nursery grounds for species that eventually recruit to coastal fisheries, the LWRs estimates for other species can also help to understand the population dynamics and conservation for native fish species.

The short-term site fidelity of intertidal fish species was studied in a rocky intertidal zone in southern Portugal using visible implant elastomer tagging. Eleven fish species were caught, tagged and released, seven of which were recaptured. The larger tide pool with the highest complexity level and located at a lower position in the shore level did not have recaptures, while in others the individual fish species recaptured rate ranged from 11.1 to 38.9%, suggesting that the shore height is a dominant factor influencing site fidelity. Although the breeding season seems not to be the only explanation for the recapture rate, the higher mean recapture rates of Parablennius sanguinolentus, Lipophrys pholis and Gobius cobitis may be related to the parental behaviour of these species during that period. Site fidelity of juveniles of Scorpaena porcus in tidepools is reported for the first time, showing the importance of this habitat as a nursery ground. info:eu-repo/semantics/publishedVersion

Biological connectivity studies are crucial for explaining the structure of marine populations of species with a pelagic larval stage. Numerical modelling is a powerful tool for evaluating marine d...

The reproductive cycle of seven common species (Gobius paganellus, Gobius bucchichi, Gobius cobitis, Parablennius sanguinolentus, Salaria pavo, Tripterygion tartessicum and Symphodus roissali) on rocky shores in the Gulf of Cadiz and their relationship with the sea surface temperature (SST) is analysed. Partial data on Scorpaena porcus are also given. Fecundity of these short lifespan species shows a positive linear correlation between the number of oocytes and an increase in female size. Spawnings are concentrated in the first 7 months of the year. An analysis of reproductive growth with respect to SST shows that water temperature in the winter months affects the timing of the onset of reproduction in most species. Recruitment is takes place throughout the year, but a temporal segregation within different families occurs in their spawning as well as recruitment.

The structural patterns of the mesozooplankton community of San José Gulf (SJG), a one of a kind semi-enclosed basin located in the northern margin of the Valdés Peninsula (Argentine Patagonia), were studied by means of semi-automatic image analysis. Samples were obtained bimonthly during the warm season (October 2012?April 2013) at stations distributed on a regular grid. Cluster analyses outlined two spatially consistent groups of stations showing similar patterns when based on physical (SST, Chl-a, and bottom depth) and community structure (abundance, biomass, and slope of the size spectra) descriptors, each broadly distributed on one of two previously described hydrographic domains formed by the interaction of tidal circulation, coastal morphology, bottom topography, and seasonal vertical stratification. Examination of the slope of the mesozooplankton size spectra revealed that the stratified waters of the East Domain sustain higher proportions of small organisms and higher biomass, suggesting potentially low trophic transfer efficiency compared to its vertically-mixed West counterpart. Three-clustering analyses resulted in still spatially consistent groups of stations when based on the community descriptors, revealing the existence of a transition zone, presumably resulting from intermediate hydrodynamic conditions. Principal component analysis revealed that biomass of cladocerans modulates the size spectra and is related with distances from sampling stations to SJG´s mouth. Overall, a consistent spatial correlate was found between physical conditions of water masses and the structure of the mesozooplancton community contained within. Fil: Hernández Moresino, Rodrigo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina Fil: Di Mauro, Rosana Patricia. State University of Louisiana; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Crespi Abril, Augusto Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina. Universidad Nacional del Comahue; Argentina. Universidad Nacional de la Patagonia; Argentina Fil: Villanueva Gomila, Gabriela Lujan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina Fil: Cano Compaire, Jesus. Universidad de Cádiz; España Fil: Baron, Pedro Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina

The present work on the feeding ecology of Scorpaena porcus according to season, sex and size, is the first study carried out in the rocky intertidal in the NE Atlantic. Previous studies were carried out with fish collected in fishing grounds from Mediterranean areas. A total of 106 fish were caught in monthly samplings from April 2008 to July 2010 in three areas of the rocky intertidal zone in the Gulf of Cadiz. The diet composition varied with season, size and sex. Shrimps were the main diet resource during all year, but other prey were also important depending on the season. As the size of fish increased, predation on smaller crustaceans decreased and consumption of larger crustaceans and fish augmented. Females and males based their diet on shrimps, while indeterminate fish fed largely on amphipods. No significant differences were found between feeding intensity and season, size and sex. Nevertheless, the PERMANOVA results showed that the number of prey is affected by the interaction between sex and size class. Our results highlight that S. porcus is a stenophagic species that shows a gradual segregation in the use of resources as it grows, which indicates there is no intraspecific competition in the rocky intertidal.

This paper describes the use of resources and diet of nine resident fish species in the rocky intertidal zone of the Gulf of Cadiz and examines whether their populations are affected by trophic competition. A stomach content analysis of the nine species revealed that only one was herbivorous ( Parablennius sanguinolentus ), while the rest were mainly carnivorous ( Gobius bucchichi , Gobius cobitis , Gobius paganellus , Zebrus zebrus , Salaria pavo , Lepadogaster lepadogaster , Scorpaena porcus and Tripterygion tripteronotum ). The most frequently consumed prey were amphipods, isopods, polychaetes, decapods, chironomids, tanaidaceans, gastropods, copepods, cumaceans and ostracods. In most species, the occurrence of polychaetes and molluscs was higher in the cold season, whereas that of isopods, decapods, chironomids and fish increased in the warm season. In general, larger specimens consumed larger prey, with an increase in the occurrence of isopods, decapods and fish. An analysis of trophic niche breadth defined G. cobitis as generalist, G. bucchichi as opportunist and S. porcus as specialist, whereas the values obtained for the other species did not indicate a clearly defined strategy. Low diet overlap values and the segregation observed in several analyses indicated an adequate distribution of resources.

Intertidal fish are adapted to live in a fluctuating environment and are considered suitable bioindicators of environmental change. Understanding the relationship between fish species distribution and environmental variables is fundamental for comparative analysis among geographical locations and identification of long-term trends predicted by global warming. Here we analysed a combination of the main micro- and macroscale factors that affect the distribution and abundance of rocky intertidal fish communities. Monthly sampling of fish assemblages at 3 sites in the rocky intertidal zone of the Gulf of Cadiz was conducted from 2008 to 2014. Fish assemblage descriptions were based on relative abundance, biomass, diversity and evenness. A canonical correspondence analysis was performed to evaluate the relationship between pool characteristics (substratum type, depth and surface area) and the abundance of fish assemblages in tidepools. The results showed differences between protected and unprotected sites, which may indicate that human pressure induces changes at all assemblage levels. At all sites, the lowest abundance was observed in the year with the greatest wave energy. The diversity at the 3 sites showed interannual variation correlated with pool complexity, wave energy and air temperature. These findings increase our understanding of the mechanisms that regulate the distribution of fish assemblages in shallow coastal waters and provide a useful baseline for future management and conservation of these areas.

In the Gulf of Mexico, the distribution of larval fish assemblages have been linked to continental shelf vs oceanic habitats and mesoscale structures such as cyclonic and anticyclonic eddies. Myctophids have a worldwide distribution and are one of the mesopelagic fish families with higher biomass, thus playing a key role in the trophic structure of oceanic communities. However, studies focused on their larval ecology and distribution within the gulf are limited. This study evaluated whether the formation of myctophid larval assemblages can be linked to local adult population spawning patterns and/or oceanographic conditions and surface transport. Ichthyoplankton samples were collected in August–September 2015 using standard bongo net tows. Stations extended throughout Mexico's Exclusive Economic Zone (19°N–25°N) deep water region, including the Yucatan Channel. Myctophid comprised 24.6% of the standardized total larval abundance and were present at all stations. Two dominant assemblages (out of six identified with a Bray–Curtis dissimilarity analysis) were found in stations of the central gulf and the Bay of Campeche. The high proportion of preflexion larvae coupled with differences in hydrographic parameters and surface circulation between the central gulf and the Bay of Campeche, indicated that local adult fish populations and their spawning patterns likely contribute more to the formation of these assemblages than oceanographic conditions and surface transport. Stations from the northern Yucatan Peninsula located within the region of influence of the Loop Current shared a common assemblage, which may reflect biogeographic differences in the myctophid species composition between the northern Caribbean and western gulf. These results highlight the importance of adult distribution and local spawning, providing insight into biogeographic patterns during the early life stages of mesopelagic fishes in the Gulf of Mexico.