bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of photosynthesis and calcification rates of Corallina elongata Ellis and Solander, 1786, by measurements of dissolved oxygen, pH and total alkalinity
Authors: El Haïkali Bouazza , Bensoussan Nathaniel , Romano Jean Claude , Bousquet Vincent
Published: October 2008

Experiments were conducted on the calcareous red alga, Corallina elongata, a species representative of shallow water vegetal cover in Mediterranean areas with biomass ranging from 820 to 2544 gDW.m-2, in order to estimate its productivity and calcification rates. Carbonate and oxygen budgets were estimated on samples incubated in situ under natural light cycles, by measuring initial and final dissolved oxygen, pH and alkalinity levels. In light conditions, oxygen concentrations and pH values increased as a consequence of oxygen production and carbon dioxide consumption due to the productivity process, and were a direct function of sample biomass. Strictly-reverse dynamics were recorded in dark conditions. A comparison of photosynthetic performances was conducted on a non-calcareous green alga, Ulva rigida, which showed higher rates of oxygen production and pH modification than C. elongata, but no significant change in total alkalinity. For C. elongata, a significant decrease in total alkalinity with incubation time was observed under light conditions, which was directly related to the algal sample biomass (R2 = 0.95; n=16). Light to dark calcification ratio (L/D) was about 3.6. In these experiments, the photosynthetic quotient of C. elongata was 0.89, its net carbon productivity was 2.5 g C.m-2.d-1, gross production to daily respiration (Pg/R) was about 4.9 and its calcification rate was estimated at 13.8 g CaCO3.m-2.d-1.
Uroptychodes, new genus of Chirostylidae (Crustacea: Decapoda: Anomura), with description of three new species
Authors: Baba Keiji
Published: October 2008

Examination of materials collected from Indonesia, New Caledonia and vicinity, now deposited in the Muséum National d´Histoire Naturelle, disclosed three additional undescribed species of chirostylids belonging to the Uroptychus spinimarginatus group. The group is now shifted to a distinct genus Uroptychodes. Uroptychus grandirostris Yokoya, 1933, which can be transferred to Uroptychodes, has been a problematic species because of the brevity of the original description and the loss of the type material. However, a recent finding of a specimen, which is in poor condition, very much like the illustration of U. grandirostris by Yokoya (1933: Fig. 29), but different from the description of U. grandirostris given by van Dam (1939) for one of the type specimens, suggests that the type material of U. grandirostris includes at least two species. In this paper a neotype is selected for U. grandirostris. The genus Uroptychodes now contains 10 species. All these species are reviewed and a key to the species of the genus is provided.
A review of Strobopagurus Lemaitre, 1989 (Crustacea, Decapoda, Paguroidea, Parapaguridae), with description of a new species
Authors: Lemaitre Rafael
Published: October 2008

Species of the parapagurid genus Strobopagurus Lemaitre, 1989 are reviewed based primarily on abundant specimens obtained during French campaigns across the Indo-Pacific region. A new species, S.breviacus, is described. The genus contains two other species, S. gracilipes (A. Milne-Edwards, 1891), the type of the genus, and S.sibogae (de Saint Laurent, 1972). One taxon, Parapagurus kilburni Kensley, 1973, originally described from off eastern Africa, has been found to be a junior synonym of S.sibogae. An updated diagnosis of the genus, and diagnoses and comparative illustrations of all three species, are presented together with a key to aid in their identification. Information on live coloration is provided for S.gracilipes and S. sibogae; live coloration of S. breviacus is not known.
Preservation of juvenile hake (Merluccius merluccius L) in the western Mediterranean demersal trawl fishery by using sorting grids
Authors: Sardà Francesc , Molí Balbina , Palomera Isabel
Published: October 2008

The Mediterranean fishery has experienced a decline in catches over the past 20 years due to an excessive increase in effort caused by both increased trawler engine power and rapid technological advances in fishing technology and fish location. This has led to overexploitation, in which immature individuals support an increasing portion of the catches. The present study was undertaken to test a sorting grid and square-mesh-panel as juvenile exclusion systems. Our experience was a pilot study of such a system in the western Mediterranean. The purpose of these exclusion systems was to help juvenile hake escape from the net. The results demonstrate that the use of sorting grids for small fish in trawl gears in the Mediterranean is an efficient and practical means of avoiding the capture and discarding of unwanted individuals, with escape rates of over 50% (ranging between 50 and 90%). The grids were efficient and useful for excluding hake (Merluccius merluccius) on bottoms located at depths between 50 and 300 m, where hake are found all year round. A bar spacing of 20 mm yielded escape rates of L50 at 18.8 cm TL (L25 = 16.8 cm and L75 = 20.9 cm). Panels made of square meshes achieved poorer results than the grids. The grid system was effective for most of the species caught in the study area.
Selectivity of penaeid trap nets used in south eastern Australia
Authors: Broadhurst Matt K. , Wooden Michael E.L. , Young Damian J. , Macbeth William G.
Published: October 2008

Two experiments were done to estimate the selectivity of commercial and modified trap-net configurations in New South Wales (NSW), southeastern Australia. In the first experiment, a commercial trap net made entirely from 25 mm mesh and designed for use in shallow water was alternatively fished with a fine-meshed (9.5 mm netting) trap net (used as a control). In the second experiment, two trap-net configurations designed for use in deeper water and comprising the same anterior section (made from 25 mm mesh), but with different bunts made from (i) the conventional 25 mm mesh and (ii) 31 mm mesh were alternately fished against the control. Both of the conventional trap nets (comprising 25 mm mesh throughout) had low amounts of bycatch and similarly selected eastern king Penaeus plebejus, greasyback Metapenaeus bennettae and school prawns Metapenaeus macleayi across narrow selection ranges (< 3.4 mm) and at 50% retention lengths (between 18.53 and 21.50 mm) that were larger than the average commercially-accepted sizes (15-17 mm CL). Analyses of the selectivities and relative efficiencies of the trap-net configurations comprising the 25 and 31 mm bunts showed no benefit, in terms of maintaining prawn catches and reducing unwanted bycatch, associated with increasing mesh size in these gears. The utility of trap nets for selectively harvesting penaeids is discussed. We conclude that this type of fishing gear appears to have few deleterious impacts.
Activity patterns and foraging behaviour of Audouin' s gulls in the Ebro Delta, NW Mediterranean
Authors: Mañosa Santi , Oro Daniel , Ruiz Xavier
Published: October 2008

Twenty Audouin´s gulls, Larus audouinii, breeding in the Ebro Delta (NW Mediterranean) were radio-tracked in 1998 to study their foraging behaviour and activity patterns. Some detrimental effects of tagging on the breeding success of the birds were detected, especially when both members of the pair were tagged. The results were actually constrained by the low number of locations due to natural breeding failure and failure in tag emission, as well as the adverse effect of tagging. However, through a combination of aircraft surveys at sea and a fixed station for automatic tracking of the presence of the birds at the colony, novel individual-based information of home ranges and activity patterns was obtained. Trawler fishing activity seemed to influence both the foraging range and habitat use: while trawlers operated, gulls overlapped their fishing grounds with vessels, probably to scavenge on discards. Very few locations were obtained during a trawling moratorium period, although they were all recorded in coastal bays and terrestrial habitats. During the trawling activity period, gulls ranged over a minimum convex polygon area of 2900 km2. Gulls were tracked up to 40 km from the colony, but some individuals were observed beyond 150 km while still breeding. Arrivals and departures from the colony were in accordance with the trawling timetable. However, most birds also showed some nocturnal foraging activity, probably linked to active fishing of clupeoids (following diel migrations) or to the exploitation of purse-seine fishing activity. Foraging trips lasted on average 15 hours: males performed significantly shorter trips than females, which spent more time outside the colony. The proportion of nocturnal time involved in the foraging trips was the same for males and females, but whilst all males initiated their trips both during the day and at night, some females only initiated their trips during the day. Hatching success was found to be related to foraging effort by males. Gulls spent on average ca. 38% of their time budget outside the nesting territory, representing the time devoted mainly to flying, foraging and other activities.
Quantifying RNA and DNA in planktonic organisms with SYBR Green II and nucleases. Part A. Optimisation of the assay
Authors: Berdalet Elisa , Roldán Cristina , Olivar M. Pilar , Lysnes Kristine
Published: October 2008

Assay protocols for RNA and DNA in crude plankton extracts using the fluorochrome SYBR Green II are developed here. The method is based on the fluorescence in 3 aliquots: the first measures RNA after DNA digestion; the second measures DNA after RNA digestion; and the third measures residual fluorescence after digestion of both DNA and RNA. This residual fluorescence measurement is critical for accurate calculations of the nucleic acids. Optimisation of the assay conditions are described: fluorochrome concentration, buffer composition, fluorescence stability, temperature and duration of nuclease incubation. In the optimised procedure, the assays are performed in 5 mM Tris buffer (containing 0.9 mM CaCl2·2H2O and 0.9 mM MgCl2·6H2O, pH 8.0); DNase and RNase incubations are conducted at 37°C for 20 min; the fluorochrome is added to all assays at a final concentration of 3.5x10-4 and readings are done within the 10-60 min period following the SYBR Green II addition. The study evidenced the importance of the residual fluorescence after nuclease digestion, which is especially taken into account in the calculation of the nucleic acid concentrations. Finally, the variability of the fluorescent response to different RNA and DNA standards is examined; from the performed tests, calculations are based on rRNA from calf liver and DNA from calf thymus standards. The accompanying paper (Berdalet et al., 2005) describes the development of the extraction protocol, as well as the application of both protocols in measuring RNA/DNA ratios in natural plankton samples, and a comparison with ethidium bromide based methods.
Quantifying RNA and DNA in planktonic organisms with SYBR Green II and nucleases. Part B. Quantification in natural samples
Authors: Berdalet Elisa , Roldán Cristina , Olivar M. Pilar
Published: October 2008

Extraction procedures for RNA and DNA in crude extracts of natural microplankton samples are developed. The methodology is compatible with the fluorometric assay of RNA and DNA developed by Berdalet et al. (2005). Mechanical cell disruption using a manual tissue grinder is combined with chemical extraction using 0.5% sarcosine and 0.5 mM EDTA in 5 mM Tris, pH 8.0, to release the nucleic acid. The new extraction and assay procedure is used to estimate the RNA/DNA ratios of fish larvae and natural microplankton communities maintained in the laboratory under different nutritional conditions. In the two experiments, the RNA/DNA ratios were related to the nutrient availability of the organisms. The level of sensitivity of the method is experimentally set at ca. 40 ng of RNA and 10 ng DNA in the 1 ml assay, which corresponds to a minimum biomass requirement of ca. 400 ng ml-1 protein or 3 µg ml-1 dry weight. The precision, estimated at different steps of the procedure, had an overall coefficient of variation of ?10%. The new approach provides RNA/DNA ratios comparable with those obtained with ethidium bromide.
Infestation of Polydora rickettsi (Polychaeta: Spionidae) in shells of Crepidula fecunda (Mollusca: Calyptraeidae) in relation to intertidal exposure at Yaldad Bay, Chiloe, Chile
Authors: Beltrán Carlos , Vargas Luis , Quijón Pedro
Published: October 2008

We studied the infestation of the burrowing polychaete Polydora ricketsi on the shells of Crepidula fecunda in relation to the degree of intertidal exposure in Yaldad Bay (Chile). 175 specimens of C. fecunda were collected from five stations located at tidal levels experiencing air exposures of 0, 2, 4, and 6 hours, respectively. The spionid Polydora rickettsi inhabited C. fecunda shells and occurred at all the sampling stations. However, only those gastropods exposed for two hours showed significantly higher degrees of infestation. Gastropods collected under and over that tidal level exhibited lower degrees of infestation and were not significantly different among them. There was not a clear relationship between shell surface and polychaete infestation. Large P. rickettsi were found only at the station with the highest gastropod aggregation at the lower intertidal, suggesting that exposure exerts some limitation to old but not necessarily young infesting polychaetes.
Fecundity and spawning of Abralia verany (Rüppell, 1844) (Cephalopoda: Enoploteuthidae) in the Aegean Sea
Authors: Salman Alp , Laptikhovsky Vladimir
Published: October 2008

A total of 24 female Abralia verany specimens, with a mantle length between 26-47 mm, were investigated. The mean potential fecundity (PF) and mean relative fecundity (RF) of ovaries were calculated as 26584 eggs and 4379 eggs g-1, respectively. The mean egg number determined in the oviduct was 251. Diameters of ripe eggs in the oviduct were approximately 1.01 mm. According to the findings given above the PF values of A. verany in the eastern Mediterranean are higher than the ones off northwest Africa.
Long-term changes in the mean trophic level of Central Chile fishery landings
Authors: Arancibia Hugo , Neira Sergio
Published: October 2008

We explore long-term changes in the mean trophic level (TLm) of Central Chile fishery landings, using a 21 years data series (1979-1999) of official landings (Chilean Fisheries Service) of 16 species that comprise about 95% of total landing, and their corresponding trophic level estimated using gut content analysis and a trophic model of the Central Chile marine ecosystem. Because total landings off Central Chile have been strongly influenced by landings of horse mackerel (Trachurus symmetricus), which is a trans-zonal fishery resource (sensu FAO), and the periodic occurrence of El Niño Southern Oscillation (ENSO) events in the study area, we explore changes in TLm both excluding landings of horse mackerel and excluding landings in ENSO years. When landings of horse mackerel are excluded, a significant decline in TLm is found, at a rate of 0.175 per decade, which is higher than the global rate of 0.10 estimated by Pauly et al. (1998). Fisheries in Central Chile seem to have been fishing down the food web as the result of fishery-induced changes, since ENSO events do not seem to have induced a significant effect in this trend. Therefore, we suggest that landings of horse mackerel have masked the fishing down the food web process in local fisheries.
Contribution of fish farming to the nutrient loading of the Mediterranean
Authors: Karakassis Ioannis , Pitta Paraskevi , Krom Michael D.
Published: October 2008

Mediterranean fish farming has grown exponentially during the last 20 years. Although there is little evidence of the impact on the trophy status around fish farms, there are concerns that the release of solute wastes from aquaculture might affect larger scales in the ecosystem by changing the nutrient load. After combining information from various sources on waste production and on nutrient loads, it was concluded that the overall N and P waste from fish farms in the Mediterranean represents less than 5% of the total annual anthropogenic discharge, and the overall annual increase in P and N pools in the Mediterranean, under a production rate of 150000 tons, is less than 0.01%. The proportion of fish farming discharged nutrients was slightly higher in the eastern Mediterranean. A simple model was used to assess the long-term effects of nutrients released from various sources taking into account the water renewal rate in the Mediterranean. We conclude that, in the long term, fish farm waste could cause a 1% increase in nutrient concentrations in contrast to other anthropogenic activities which might double the Mediterranean nutrient pool.
Effects of changing seawater temperature on photosynthesis and calcification in the scleractinian coral Galaxea fascicularis, measured with O2, Ca2+ and pH microsensors
Authors: Al-Horani Fuad A.
Published: October 2008

Single polyps of Galaxea fascicularis were fixed to glass vials with underwater epoxy resin. After regeneration into microcolonies they were used for microsensor measurements of photosynthesis and calcification under different incubating temperatures. Gross photosynthesis was found highest at temperatures of 23 and 26°C (ca. 0.022 mole O2 m-3 s–1), close to the ambient temperature (i.e. 26°C). At 35°C, gross photosynthesis was irreversibly inhibited as the microcolonies bleached. The net photosynthesis rapidly decreased with temperature and became negative at temperatures higher than 29°C. Profiles of O2 and Ca2+ showed a strong effect of temperature on them. The concentrations of Ca2+ measured on the polyp surface also showed temperature dependence of Ca2+ uptake. In the dark and below 29°C, the surface Ca2+ concentration was temperature independent. During illumination, the surface Ca2+ concentration showed a dip at 26°C (ca. 8.7 mM), indicating maximum uptake rates at ambient temperature. However, at 32°C and higher, Ca2+ was slightly higher at the tissue surface than in the seawater, in both light and dark, resulting from calcium dissolution. The surface pH in light increased gradually from 8.3 to 8.6 with increasing temperature to 23°C, and thereafter remained constant to 29°C. At 32°C, the pH became slightly acidic compared with the water phase, probably due to a decrease in the uptake of CO2 by photosynthesis. The largest difference in pH between light and dark incubations was at temperatures between 23 and 29°C (7.5-7.7 in dark versus 8.6-8.7 in light), which indicate high rates of photosynthesis and respiration in this temperature range. It is concluded that photosynthetic activity in the coral is maintained up to rather high temperatures (32°C), but corals at super-optimum temperatures (above 26°C) consume more O2 than they produce, decalcify and produce CO2
Stock assessment of sardine (Sardina pilchardus, Walb.) in the Adriatic Sea with an estimate of discards
Authors: Santojanni Alberto , Cingolani Nando , Arneri Enrico , Kirkwood Geoff , Belardinelli Andrea , Giannetti Gianfranco , Colella Sabrina , Donato Fortunata , Barry Catherine
Published: October 2008

Analytical stock assessment of sardine (Sardina pilchardus, Walb.) in the Adriatic Sea from 1975 to 1999 was performed taking into account the occurrence of discarding at sea of sardine caught by the Italian fleet. We have attempted to model the fishermen’s behaviour using data collected by an observer on board fishing vessels. This enabled us to estimate the amounts of discards, which were added to the catches landed, collected by ISMAR-CNR Ancona. Discards were calculated for the period 1987-1999, as their values were negligible before 1987. Stock assessment on the entire data series from 1975-1999 was carried out by means of Virtual Population Analysis (VPA). Discarding behaviour differs among ports due to different local customs and market conditions. The quantity added to the annual total catch ranged from 900 tonnes to 4000 tonnes, corresponding to between 2% and 15% of the total corrected catch. VPAs indicated that mid-year sardine stock biomass rose steadily from 400,000 tonnes in 1975 to a peak of 950,000 tonnes in 1984. Subsequently, biomass declined steadily to the more recent values, around 300,000 tonnes. Although discarded quantities were relatively high, their influence on stock assessment was not strong because of the high level of both catch and, in particular, estimated biomass at sea.
Growth of common octopus (Octopus vulgaris) in cages suspended from rafts
Authors: Chapela Albert , González Ángel F. , Dawe Earl G. , Rocha Francisco J. , Guerra Ángel
Published: October 2008

Two ongrowing experiments were conducted using a raft deployed for rearing mussels during summer and winter in the Ria of Vigo, Galicia, NW Spain. Two 3 m x 1.5 m x 6 m galvanized iron ongrowing cages were suspended from this platform, each equipped with dens constructed from PVC pipe. Small common octopus (Octopus vulgaris) were captured by the small-scale creel fishery in the ria and placed in one of two sex-specific experimental cages. Specimens were fed a standard diet (fish, decapod crustacean and mussels) at a daily feeding rate of 5% of the total weight of the animals in each cage. Due to the very high mortality as a result of decreased salinity in the winter experiment and spawning during the summer experiment, only data from the first 75 days of each experiment were compared. Growth rates were significantly higher in summer than in winter for both sexes, which was probably due to higher ambient culture temperatures during summer. Mortality was also higher during summer than winter. It was concluded that culture of common octopus on mussel rafts may be viable, especially if problems related to salinity, the acquisition of specimens from the wild and losses due to spawning can be reduced.
Effects of the toxic dinoflagellate Karlodinium sp. (cultured at different N/P ratios) on micro and mesozooplankton
Authors: Vaqué Dolors , Felipe Jordi , Sala M. Montserrat , Calbet Albert , Estrada Marta , Alcaraz Miquel
Published: October 2008

An experimental study was carried out to investigate whether two potential predators such as Oxyrrhis marina (phagotrophic dinoflagellate) and Acartia margalefi (Copepoda: Calanoida) had different responses when feeding on toxic (Karlodinium sp.-strain CSIC1-) or non-toxic (Gymnodinium sp1) dinoflagellates with a similar shape and size. Both prey were cultured at different N/P ratios (balanced N/P = 15, and P-limited N/P > 15) to test whether P-limitation conditions could lead to depressed grazing rates or have other effects on the predators. Both predators ingested the non-toxic Gymnodinium sp1, and low or non-ingestion rates were observed when incubated with Karlodinium sp. The dinoflagellate O. marina did not graze at all on Karlodinium sp. at N/P > 15 and very little at NP = 15, as its net growth rates were always negative when feeding on Karlodinium sp. cultured under P-limitation conditions. A. margalefi had lower ingestion rates when feeding on Karlodinium sp. grown at N/P = 15 than when feeding on Gymnodinium sp1, and did not graze on P-limited Karlodinium sp. Nevertheless, feeding on Karlodinium sp. grown under N/P =15 or N/P > 15 did not have any paralyzing or lethal effect on A. margalefi after 24 h. Finally, a direct effect on the viability of A. margalefi eggs was detected when healthy eggs were incubated for 5 days in the presence of Karlodinium sp. grown under N/P =15 or N/P > 15, producing a decrease in viability of 20% and 60% respectively.
Horizontal distribution of tintinnids in the open waters of the South Adriatic (Eastern Mediterranean)
Authors: Krsinic Frano , Grbec Branka
Published: October 2008

The horizontal distribution of oceanic tintinnids was studied in the South Adriatic Sea during 11 cruises undertaken between 1980 and 1990. Of the 70 species identified, there were 47 surface, 16 subsurface, 4 mid-water, and 3 deep-sea species. The dominant surface and subsurface species were Dictyocysta mitra and Codonella aspera. Undella claparedei. Parundella lohmanni predominated in the mid-water layers and Xystonellopsis scyphium in the deep-sea layers. Ingression of water masses from the Ionian Sea and the formation of a cyclonic gyre are important in determining the horizontal distribution of tintinnids in the South Adriatic. Periods of strong advection of waters from the Ionian Sea impose a longitudinal type of distribution on tintinnids, characterized by high species diversity, low abundance, and the transport of southern species to the Middle and North Adriatic. This differs from “eddy type” distribution, in which species diversity is lower, population density is greater in all layers, and the transport of species northward ceases. It may be assumed that mesopelagic and deep-sea tintinnids depend on food resources transported by sinking Middle Adriatic dense waters (MadDW).
Zooplankton and ichthyoplankton distribution on the southern Brazilian shelf: an overview
Authors: Lopes Rubens M. , Katsuragawa Mario , Dias June F. , Montú Mónica A. , Muelbert José H. , Gorri Charles , Brandini Frederico P.
Published: October 2008

The southern Brazilian coast is the major fishery ground for the Brazilian sardine (Sardinella brasiliensis), a species responsible for up to 40% of marine fish catches in the region. Fish spawning and recruitment are locally influenced by seasonal advection of nutrient-rich waters from both inshore and offshore sources. Plankton communities are otherwise controlled by regenerative processes related to the oligotrophic nature of the Tropical Water from the Brazil Current. As recorded in other continental margins, zooplankton species diversity increases towards outer shelf and open ocean waters. Peaks of zooplankton biomass and ichthyoplankton abundance are frequent on the inner shelf, either at upwelling sites or off large estuarine systems. However, meandering features of the Brazil Current provide an additional mechanism of upward motion of the cold and nutrient-rich South Atlantic Central Water, increasing phyto- and zooplankton biomass and production on mid- and outer shelves. Cold neritic waters originating off Argentina, and subtropical waters from the Subtropical Convergence exert a strong seasonal influence on zooplankton and ichthyoplankton distribution towards more southern areas. This brief review highlights the need for further experimental studies on zooplankton life cycle strategies in order to understand the major processes controlling food web dynamics in this shelf ecosystem.
New genus, three new species and new records of Herpyllobiidae Hansen, 1892 (Crustacea, Copepoda) parasites of polychaetes from Antarctica
Authors: López-González Pablo J. , Bresciani José , Conradi Mercedes
Published: October 2008

During the Antarctic Polarstern cruises ANT XIX/3 (ANDEEP-I), XIX/5 (LAMPOS), and XXI/2 (BENDEX) new material of symbiotic copepods associated with polynoid polychaetes was collected. Here the authors present results for the highly modified family Herpyllobiidae Hansen, 1892. New records of Herpyllobius antarcticus Vanhöffen, 1913 and Herpyllobius polarsterni López-González, Bresciani and Conradi, 2000 are provided from the eastern Weddell Sea and Bouvet Island respectively. A new species of the genus Eurysilenium Sars, 1870, E. australis, is described from specimens collected at the eastern Weddell Sea. A new genus, Gottoniella gen. nov., is proposed to include two species, G. antarctica sp. nov. and G. andeepi sp. nov., described from material collected from the Weddell Sea and Scotia Arc.
Otolith chemical composition as a useful tool for sciaenid stock discrimination in the south-western Atlantic
Authors: Volpedo Alejandra V. , Fernández Cirelli Alicia
Published: October 2008

Striped weakfish (Cynoscion guatucupa) and whitemouth croaker (Micropogonias furnieri) are important commercial and recreational species found in abundance along the South American Atlantic coast. In recent years otolith chemical composition has been used as a tool for identifying fish stocks for several species. The chemical composition of C. guatucupa and M. furnieri otoliths was determined by inductively coupled plasma-optical emission spectrometry (ICP-OES) in samples from coastal sites (Partido de La Costa, Mar del Plata and San Blás Bay). Significant differences in the ratios of Mg/Ca, Mn/Ca and Sr/Ca for C. guatucupa otoliths and Cd/Ca, Cu/Ca, Mg/Ca, Sr/Ca and Zn/Ca for M. furnieri otoliths suggest the existence of two different fish stocks, one originating in the north (including Samborombón Bay and Partido de La Costa fisheries) and another originating in the south (including “El Rincón” and San Blás fisheries). These results agree with previous studies on the same species using different methodologies. These stocks may be separated by an oceanographic barrier, the “Frente El Rincón”. Otolith chemical composition has not been previously used in South America for identifying fish stocks and may be a simple, quick and useful tool for the sustainable exploitation and management of commercial species.
The use of a square mesh codend and sorting grids to reduce catches of young fish and improve sustainability in a multispecies bottom trawl fishery in the MediterraneanEl uso de copo de malla cuadrada y rejillas separadas para reducir las capturas de pece
Authors: Sardà Francisco , Bahamon Nixon , Molí Balbina , Sardà-Palomera Francesc
Published: October 2008

In order to improve the capacity of bottom trawl fishing gears to reduce catches of young fish and discards in a highly exploited demersal trawl fisheries in the Mediterranean, the size-selection performance of a 36-mm square-mesh codend and two sorting grids with 20 and 15 mm bar spacing was assessed. Alternate hauls were used to assess the selectivity of 36-mm square-mesh codend. Selectivity of sorting grids was assessed using a double codend in which fish that escaped through the grid were captured in the lower codend while other fish were guided into the upper codend. The mean selection length (L50) for European hake was 18.5 cm and that for the Atlantic horse mackerel was 14.0 cm with the 36-mm square-mesh codend . These values are close to their current minimum landing sizes (20 cm for hake and 12 cm for horse mackerel). The sorting grid with 20-mm bar spacing showed L50 value of 13.3 cm for hake, suggesting that a larger grid-spacing would be needed to obtain sufficient sorting performance. Similarly, for Atlantic mackerel the estimated L50 of 14.3 cm indicates that larger grid spacing is required to attain an L50 that would be close to the current MLS (18 cm). For Atlantic horse mackerel and red mullet, the L50 obtained with the sorting grid with 20-mm bar spacing was close to the MLS of these species (the MLS of red mullet is 11 cm). The selectivity of the sorting grid with 15-mm bar spacing was generally very poor. Size-selection performance of sorting grids was assessed for the first time in the local fisheries. In order to effectively improve size-selection, seasonal and depth-dependent differences between target and by-catch species must be taken into account, which is a good indicator of the difficulty of implementing a single mesh size or grid spacing in the Mediterranean demersal trawl fishery.
Diet of Risso's dolphin (Grampus griseus) in the western Mediterranean Sea
Authors: Blanco Carmen , Raduán Mª Ángeles , Raga Juan Antonio
Published: October 2008

The diet of Risso’s dolphin in the Mediterranean is described based on 15 animals stranded between 40°25’N 00°32’W and 37°35’N 00°45’E from April 1987 to January 2003. The prey were mainly oceanic cephalopods. Pelagic octopods, especially A. argo, were the most abundant (mean = 41.28%; SD±34.32). Species belonging to the families Ommastrephidae, Histioteuthidae and Onychoteuthidae were also frequent components of its diet. The bathymetric distribution of cephalopods shows that Risso’s dolphin preferentially feeds on the middle slope (600 to 800 m depth) in the Mediterranean.
Sperm ultra-structure and spermiogenesis in Syllis krohni (Polychaeta: Syllidae), with some observations on its reproductive biology
Authors: Lepore Elena , Sciscioli Margherita , Mastrodonato Maria , Gherardi Miriam , Giangrande Adriana , Musco Luigi
Published: October 2008

yllidae show a wide spectrum of both reproductive strategies and sperm types. Analysis of their reproductive patterns could drastically change the presently accepted taxonomic hierarchy of the group. To further contribute to the knowledge of Syllidae we have described the sperm ultra-structure and the spermiogenesis of Syllis krohni (Ehlers, 1864). Mature sperm has a cone-shaped acrosome whose distal end is notched by a trough that transversely encircles its anterior portion. During spermiogenesis, the acrosomal vesicle undergoes modifications leading to its final shape with a posterior opening. The nucleus appears flattened anteriorly and forms a cleft that surrounds the proximal centriole in its distal region. A 9+2 flagellar axoneme is observed. Up to five mitochondria surround the distal centriole. The spermatozoon of S. krohni can be ascribed to the ect-aquasperm type that is typical in species having external fertilisation and appears to be very similar in appearance to that of the congeneric species thus far investigated. The main difference is in the shape of the acrosome, which is more elongated and as long as the nucleus. Reproduction of syllids seems to be conservative within sub-families, and the sperm morphology can probably help in phylogenetic reconstruction. External fertilisation is a widespread strategy within the genus Syllis, probably leading to a substantial similarity in sperm morphology being maintained. It is hypothesised, however, that within the same sperm type linked to a particularly reproductive strategy, the acrosome ultra-structure can be indicative of phylogeny.
Modelling small-scale coastal fisheries of Galicia (NW Spain) based on data obtained from fisheries: the case of Sepia officinalis
Authors: Rocha Francisco , Otero Jaime , Outeiral Raquel , González Ángel F. , Gracia Joaquín , Guerra Ángel
Published: October 2008

The small-scale cuttlefish (Sepia officinalis) fishery in Galician waters (NW Spain) was studied using a model based on data obtained from fishers. This model was applied using information obtained from the small-scale Galician fleet in 1998. A total of 139 personal interviews were carried out at 62 Galician ports. This information was used to estimate catches per unit effort (CPUE) and total catch for the cuttlefish gillnet fishery. The fleet, which fishes in Galician waters within ICES divisions VIIIc and IXa, was composed of two groups: 600 vessels fishing for cuttlefish in only five months of the year (short season: November to March), and 141 vessels fishing for cuttlefish all year (extended season). Estimated total catch during the fishing season for the whole Galician fleet was 1301 t (869 t short season and 432 t extended season) and average CPUE values were 14.5 kg haul-1 trip-1 vessel-1 (short season) and 12.8 kg haul-1 trip-1 vessel-1 (extended season). To test the reliability of the model, the outputs obtained from the model for a subset of 37 ports (59.7% of all ports) were compared with the official catch statistics for these ports. Differences between total catches estimated by the model and those determined directly at these ports were not significant.
Ontogenetic development of Parablennius pilicornis (Pisces: Blenniidae) in controlled conditions
Authors: Faria Cláudia , Gil Fátima , Almada Vítor C.
Published: October 2008

The full developmental sequence from egg to juvenile of Parablennius pilicornis in controlled conditions is described. Embryonic development lasted 9 days at 18.0 to 21.0°C, 14 days at 17.0 to 20.0°C, 16 days at 16.0 to 19.0°C and 17 days at 14.0 to 18.5°C. Newly hatched larvae measured 3.1 mm total length (TL), had the mouth and anus open, pigmented eyes, almost no yolk, and the pectoral fins were small and unpigmented. Most larvae settled between day 66 and 69 after hatching (27.0 mm TL) and showed full juvenile pigmentation patterns between day 91 and 93 (30.0 mm TL). However, on day 61/62 after hatching (when they were more than 25.0 mm) they began to show a complex agonistic repertoire.
New contribution to the reproductive features of bluemouth Helicolenus dactylopterus dactylopterus from northeast Atlantic (Azores Archipelago)
Authors: Mendonça Ana , Isidro Eduardo , Menezes Gui , Rui Pinho Mário , Melo Octávio , Estácio Susana
Published: October 2008

This work describes and identifies the macroscopic and corresponding microscopic changes of the gonads of an important commercial fish species, Helicolenus dactylopterus dactylopterus, from Azores Archipelago. The new contribution relates the macroscopic scale with the histological stages. The annual changes in the gonad, together with the analysis of the monthly gonadosomatic indices, and complementary observations with scanning electron microscopy, allow us to conclude that the females are internally inseminated between July and November and spawn between January and March. There is a separation between female and male reproductive cycles. The overall sex-ratio observed was 1:1, but seasonal and length related differences were observed. This suggests differences and changes in availability, probably related to the annual reproductive cycle and changes in feeding behaviour
Interpopulational differences in the female reproductive cycle of the southwestern Atlantic estuarine crab Chasmagnathus granulatus Dana, 1851 (Brachyura: Grapsoidea: Varunidae)
Authors: Ituarte Romina B. , Bas Claudia , Luppi Tomás A. , Spivak Eduardo D.
Published: October 2008

The female reproductive biology of Chasmagnathus granulatus Dana, a semiterrestrial burrowing crab endemic to the southwestern Atlantic, was compared in two contrasting coastal habitats: San Antonio (SA, marine) and Mar Chiquita (MC, estuarial). Mature females were collected monthly for 1.5 years and the ovarian cycle was described using a qualitative scale. Gonadosomatic (GSI) and hepatosomatic (HSI) indexes were calculated. The highest GSI and HSI occurred early in the reproductive season in SA and during the non-reproductive season in MC. The beginning and duration of the reproductive season also differed between populations: it started later and was shorter in SA. In MC, secondary vitellogenesis continued when the reproductive season had finished, and the ovaries remained fully developed throughout the non-reproductive season (winter). Therefore, females of MC were ready to lay eggs as soon as spring environmental conditions appeared. However, SA females did not attain a fully developed ovary during winter. A limited food supply would restrict the available energy to complete secondary vitellogenesis at the end of the reproductive season in SA, after the last spawning. Thus, the vitellogenic cycle should be completed in the following spring, causing a delay in the beginning of the reproductive period. In addition, the higher temperature amplitude may cause the reproductive period in SA to end early.
Antimicrobial activity of Iberian macroalgae
Authors: Salvador Noemí , Gómez Garreta Amelia , Lavelli Luca , Ribera María Antonia
Published: October 2008

The antibacterial and antifungal activity of 82 marine macroalgae (18 Chlorophyceae, 25 Phaeophyceae and 39 Rhodophyceae) was studied to evaluate their potential for being used as natural preservatives in the cosmetic industry. The bioactivity was analysed from crude extracts of fresh and lyophilised samples against three Gram-positive bacteria, two Gram-negative bacteria and one yeast using the agar diffusion technique. The samples were collected seasonally from Mediterranean and Atlantic coasts of the Iberian Peninsula. Of the macroalgae analysed, 67% were active against at least one of the six test microorganisms. The highest percentage of active taxa was found in Phaeophyceae (84%), followed by Rhodophyceae (67%) and Chlorophyceae (44%). Nevertheless, red algae had both the highest values and the broadest spectrum of bioactivity. In particular, Bonnemaisonia asparagoides, Bonnemaisonia hamifera, Asparagopsis armata and Falkenbergia rufolanosa (Bonnemaisoniales) were the most active taxa. Bacillus cereus was the most sensitive test microorganism and Pseudomonas aeruginosa was the most resistant. The highest percentages of active taxa from Phaeophyceae and Rhodophyceae were found in autumn, whereas they were found in summer for Chlorophyceae.
Sediment as a constituent of Mediterranean benthic communities dominated by Caulerpa racemosa var. cylindracea
Authors: Piazzi Luigi , Balata David , Foresi Luca , Cristaudo Cristina , Cinelli Francesco
Published: October 2008

Mediterranean macroalgal assemblages in areas invaded and non-invaded by Caulerpa racemosa var. cylindracea were compared and trapped sediments were characterised. Results showed that assemblages invaded by C. racemosa var. cylindracea differed greatly from non-invaded ones: encrusting and erect algae, both articulated and foliose, decreased in invaded areas, while opportunistic filamentous species increased their abundance The percentage of sediment was 7 times higher in areas invaded by C. racemosa var. cylindracea than in non-invaded areas. Characteristics of trapped sediments were similar in all the studied assemblages, while redox values were lower in the invaded ones. Results suggested that sediment constitutes an important component in C. racemosa var. cylindracea populations, probably enhancing the competitive ability of this species.
Reproductive biology of the striped goby, Gobius vittatus (Gobiidae) in the northern Adriatic Sea
Authors: Kovacic Marcelo
Published: October 2008

The striped goby, Gobius vittatus Vinciguerra, 1883 is a Mediterranean gobiid species considered to be rare and lacking in data on its reproduction. Sex ratio, length and age at first maturity, annual cycle of gonad development, spawning period and fecundity of G. vittatus were studied on 704 specimens collected by SCUBA diving in the northern Adriatic Sea (Kvarner area) from April 2001 to March 2002. The monthly sex ratio did not differ significantly, except during the spawning season, when it was strongly biased in favour of females. The estimated length at first maturity was 32.8 and 35.4 mm for females and males, respectively. In both sexes gonad development started in the first year of life. All specimens were mature by the third year. The spawning season was from April to July. Total fecundity ranged from 560 to 3045, with an average of 1426 ± 89 ripe eggs/fish. The simultaneous presence of three clearly distinct sizes of oocytes in ripe ovaries indicate that this species is a multiple spawner.
On the record of Red seabream Pagrus major (Temminck and Schlegel,1843) (Osteichthyes: Sparidae) in the Adriatic Sea
Authors: Dulcic Jakov , Kraljevic Miro
Published: October 2008

One specimen of red seabream Pagrus major, 44.9 cm total length, was caught in the eastern middle Adriatic (Island Molat, Cape Bonaster) by long-line hook at a depth of about 20 m on a hard rocky bottom on 25 September 2004. It is the first record of this species in the Adriatic Sea and Mediterranean area.
Experimental studies on the feeding ecology of Munida subrugosa (White, 1847) (Decapoda: Anomura: Galatheidae) from the Magellan region, southern Chile
Authors: Karas Patricia , Gorny Matthias , Alarcón-Muñoz Rubén
Published: October 2008

Feeding behaviour and food uptake rates of the anomuran crab Munida subrugosa from the southern Magellan region (Chile) were studied under laboratory conditions. Crabs exhibited a marked preference for meat versus macroalgae, with uptake rates being 14 times higher. Different algal species were ranked according to structure and detrital cover. Observations suggest that scavenging and cannibalism, restricted to injured or moulting individuals, are regularly applied in the natural habitat, whereas active hunting is only performed on suitable prey. The main food resource is suggested to be of microscopic origin, given the time spent on typical food uptake movements for detritus and suspended food. The findings of this study, backed up by results of simultaneously carried out stomach analysis, proved M. subrugosa to be an opportunistic feeder that can make use of different forms of food uptake.
Decapod crustacean assemblages off the West coast of central Italy (western Mediterranean)
Authors: Fanelli Emanuela , Colloca Francesco , Ardizzone Giandomenico
Published: October 2008

Community structure and faunal composition of decapod crustaceans off the west coast of central Italy (western Mediterranean) were investigated. Samples were collected during five trawl surveys carried out from June 1996 to June 2000 from 16 to 750 m depth. Multivariate analysis revealed the occurrence of five faunistic assemblages: 1) a strictly coastal community over sandy bottoms at depths
Comparison of the catches of European hake (Merluccius merluccius, L. 1758) taken with experimental gillnets of different mesh sizes in the northern Tyrrhenian Sea (western Mediterranean)
Authors: Sbrana Mario , Belcari Paola , De Ranieri Stefano , Sartor Paolo , Viva Claudio
Published: October 2008

The impact of the gillnet fishery on Merluccius merluccius (European hake) was investigated in the northern Tyrrhenian Sea, western Mediterranean. Four mesh sizes were tested: 53, 62.5, 70 and 82 mm. Horse mackerel (Trachurus trachurus), hake and tub gurnard (Chelidonichthys lucerna) dominated the catches, from a minimum of 89% (82 mm mesh) to a maximum of 97.8% (70 mm) of the biomass caught. Efficiency of the four meshes was not significantly different with respect to the total hake catches. Selectivity on M. merluccius was assessed by Sechin and SELECT methods. Tangling was an important catch modality for hake, as evidenced by the results of the Sechin model which described only the first mode of the size distributions corresponding to the entangled specimens. SELECT showed that the bi-modal function gave the best adjustment to the length-frequency distributions; the modal catch sizes were 33, 39.2, 43.6 and 51 cm total length respectively for the 53, 62.5, 70 and 82 mm mesh sizes. Taking into account the size of first maturity for females (35.1 cm TL), 62.5 mm is the most adequate mesh for exploiting hake as it gives some protection to both immature specimens and large females.
Vitellogenesis, oocyte maturation pattern, spawning rhythm and spawning frequency in Otolithes ruber (Schneider, 1801) (Sciaenidae) in the Kuwaiti waters of the Arabian Gulf
Authors: Dadzie Stephen
Published: October 2008

Vitellogenesis, oocyte maturation pattern, spawning rhythm, spawning frequency, batch fecundity and oocyte diameter-frequency distribution of the tigertooth croaker, Otolithes ruber (Schneider, 1801) in Kuwaiti waters were investigated from March 1999 to February 2000 and from January to May 2005, using histological and morphological methods. Oogenesis is described in four phases: vitellogenic, mature, spent and regressed. Vitellogenesis, in turn, is described in three classes: early vitellogenic, mid-vitellogenic and late vitellogenic. Development of the yolky oocyte is an asynchronous process resulting, by the time of oocyte maturation, in a clear differentiation between a ready batch of oocytes (ready for spawning) and a reserve pool. Consequently, O. ruber is capable of spawning multiple times during the reproductive season. Spawning frequency estimates, based on the final oocyte maturation (FOM) method indicated that the species spawns once every 2.8 days, while the estimates based on the post-ovulatory follicle (POF) method indicated a spawning every 2.2 days, during a 5-month spawning season lasting from January to May. Batch fecundity (BF) was significantly positively correlated with both ovary-free body weight (OFBW) (p