bluuebunny/crossref_metadata_2025 huggingface dataset:
A critical examination of substoichiometric isotope dilution analysis using thymidine and leucine
Authors: Bird David F.
Published: October 2008

Isotope dilution analysis is used to determine the specific activity of radiolabelled precursors such as 3H-thymidine and 3H-leucine incorporated into DNA or protein in environmental samples. However, it is shown theoretically, experimentally, and using the results of published studies that the method can be misleading when one of its many requirements is not met. First, on the basis of our current understanding of thymidine metabolism, it is not only possible, but probable, that endogenous thymidine synthesis will not remain constant at different concentrations of external thymidine addition. Changes in the rate of thymidine biosynthesis will significantly bias the results of the standard analysis. Yet it is very difficult or impossible to know whether changes have occurred in any particular case. Second, published results show evidence of stimulation of total thymidine incorporation rate at higher thymidine concentrations. These changes in incorporation rate will also bias the conclusions drawn from the assay. Third, impurities common to heavily labelled precursors can produce misleading results. Finally, the current statistical methodology of isotope dilution experiments can be greatly improved with little or no extra effort. It is suggested that, if possible, isotopes should be used empirically to derive conversion factors based on incubations; theoretical calculations based on isotope dilution experiments are not always trustworthy.
Growth of the dusky grouper Epinephelus marginatus (Linnnaeus, 1758) (Teleostei, Serranidae), in the Natural Marine Reserve of Lavezzi Islands, Corsica, France
Authors: Bouchereau J. L. , Body P. , Chauvet C.
Published: October 2008

The growth of Epinephelus marginatus living in the Natural Marine Reserve of the Lavezzi Islands was studied using the von Bertalanffy model. The growth parameters of this model were: L?=135.9 cm, K=0.08, t0=-0.80 years. The relationship between length and weight was W=12.5 10-2 TL2.60. Grouper lengths were similar in the Lavezzi Islands and in North Tunisia. The relative abundance of trophic resources in the Lavezzi Islands, due to a positive reserve effect and enhanced by a small population density of groupers, has great consequences on growth, compensating the effect of lower water temperature. A plausible explanation for the similarity between these two populations is that they belong to a single metapopulation.
Latitudinal changes of euphausiid assemblages related to the morphological variability of the sound scattering layer along Baja California, October 1994
Authors: Gómez-Gutiérrez J. , González-Chávez G. , Robinson C. J. , Arenas-Fuentes V.
Published: October 2008

Latitudinal changes in the euphausiid assemblages were compared to the morphological structure (size and compactness) of the sound scattering layer (SSL) during ten 24-h surveys made in October 1994 along the west coast of Baja California, México. During October, upwelling was found in the northern area from Punta Eugenia (28°N) to Ensenada (30°N) dominated by temperate species from the California Current System. In the southern sector of the peninsula, a northward movement of tropical waters transports a tropical zooplankton assemblage near Bahia Magdalena (24°N). The aggregation and the dispersion of the whole SSL (plankton and nekton) were investigated using a single beam vertical echosounder, Simrad EY-200, working at 200 kHz and the Hydro Acoustic Data Acquisition System (HADAS) that estimates patch variables of density and compactness. The size and shape of the SSL were obtained from the echogram visualization. The euphausiid species composition was obtained using an Isaacs-Kidd midwater trawl, bongo nets, and opening-closing nets. At Ensenada and Punta Eugenia, an area inhabited by a temperate euphausiid assemblage, large and dense SSLs were recorded over the continental shelf (mean sizes were 10-km and 7-km long with mean compactness of 15% and 19%). These regions were dominated by the neritic species Nyctiphanes simplex and the temperate species Nematoscelis difficilis, Euphausia pacifica, and Thysanoessa spinifera. In the southern area, a tropical euphausiid assemblage, dominated by Euphausia eximia, E tenera, and E. distinguenda, inhabits smaller and dispersed SSLs (mean size 5-km long and 11% compactness) located in the offshore area. The euphausiid biomass of the most abundant species indicated, N. simplex and N. difficilis, had their highest standing stock in the north (393 and 643 mg C 1000 m-3), with E. eximia in the southern area (186 mg C 1000 m-3). Euphausiid assemblage development in different biological environments, is evidenced by SSL morphology along the west coast of Baja California during autumn, is caused by strong latitudinal changes in physical oceanography that affect the biological interactions in each region.
On the distribution of silicic acid as a frontal zone tracer in the Indian sector of the Southern Ocean
Authors: Prego R. , Park Y. H. , Barciela M. C. , Morvan J. , Poncin J. , Tréguer P.
Published: October 2008

The subantarctic frontal zone surveyed during the April-May 1991 SUZIL cruise in the Crozet-Kerguelen-Amsterdam area shows a strong horizontal (north to south) gradient of dissolved silicate, increasing with depth, from 5 to 10 µmolSi kg-1 at 100 m, and 10 to 70 µmolSi kg-1 at 600 m. The northern limit of this frontal zone, which is formed by the confluence of the Subtropical and Subantarctic Fronts, is delimited at the surface by the 2 µmolSi kg-1 silicate isoline. Silicate-salinity diagrams also allow different water regimes to be positioned relative to the frontal zone. This sloping interface is between two water bodies, one to the north with more saline subtropical waters of less concentrated silicate than the southern one, corresponding to subantarctic waters which are less saline and richer in silicate. It is concluded that dissolved silicate can be used as a useful tracer of frontal zone water masses in the Indian sector of the Southern Ocean, providing a sound complement to other hydrographic data.
Age and growth of Aphia minuta (Pisces, Gobiidae) from the central Adriatic Sea
Authors: La Mesa M.
Published: October 2008

Aphia minuta (Risso, 1810) is by far the most common pelagic gobiid of the Adriatic Sea and it is seasonally exploited by some local small-scale fishing fleets. Despite this, very few data on its biology in this area have been reported to date. Accordingly, age and growth of A. minuta were investigated by counting microincrements (daily rings) in the sagittal otoliths of 262 specimens caught in the central Adriatic between May 1996 and March 1997. Age of fish from 14 to 55 mm total length ranged between 42 and 275 days, confirming the short life span of this species. The von Bertalanffy growth parameters estimated by the age-length data pairs for the whole population were: L = 68.7 mm; K = 1.55 year-1; t0 = 0.077 year. The analysis of the monthly length-frequency distributions showed the simultaneous presence in late spring-early summer of two main cohorts which, together with the back-calculated hatch date distribution, indicated a more extended spawning period than previously reported in the literature. Because the fishery for A. minuta in the central Adriatic exploits the spawning stock it should be monitored and, if necessary, regulated.
Age and growth of leaping grey mullet (Liza saliens (Risso, 1810)) in Minorca (Balearic Islands)
Authors: Cardona Luis
Published: October 2008

A population of leaping grey mullet (Liza saliens (Risso, 1810) was studied in order to measure seasonal and annual growth rates. The annual growth rates were similar to those reported for other populations from the central Western Mediterranean and intermediate between those living in northern and southern areas. As usual, the growth rate of adult males was slower than that of females. Males reached adulthood in their third summer. Females of the same age showed a moderate gonadal development, but did not ripen until the next summer. Mullets of all ages gained weight only when the water temperature was higher than 20°C. However adults and immature fish showed reduced growth in mid-summer, when that of the juveniles peaked. This difference is not a consequence of the reproductive cost, because the growth rate of immatures was greatly reduced although they did not spawn.
Seasonal abundance of the dolphinfish, Coryphaena hippurus, in Hawaii and the tropical Pacific Ocean
Authors: Kraul Syd
Published: October 2008

This report looks at possible explanations for the seasonal abundance of the dolphinfish, Coryphaena hippurus, in Hawaii. In Hawaii and many parts of the Pacific Ocean, the abundance of C. hippurus (called mahimahi in Hawaii) varies seasonally in a pattern that is fairly consistent from year to year. Size frequency analysis shows that this pattern of seasonal landings matches the pattern of cohort abundance in certain years. The strongest cohorts are spawned in July, often stay in our fishing zone for at least 5 months, and may comprise the predominant portion of the catch through October. Even though mahimahi spawn copiously all year in captivity, the data here suggest that wild mahimahi either spawn less frequently, or their larvae survive better at certain times of the year. Thus, seasonal abundance of mahimahi in Hawaii might be a function of cohort survival. The abundance pattern also fits the pattern of change in seasonal surface temperatures, and it is quite possible that mahimahi migrate north and south to stay in the sea surface thermocline associated with the 23°C isotherm. Natural growth rates were derived from our size frequency analyses, and the rates matched growth rates reported in a previous study of otolith ring deposition. A significant increase in longline fishing in 1989 increased total landings but did not reduce the catch quantity or sales price for charter boat mahimahi.
Genetic homogeneity of dolphinfish (Coryphaena hippurus) in the western Mediterranean and the eastern Atlantic
Authors: Pla Carles , Pujolar Josep Martí
Published: October 2008

Dolphinfish (Coryphaena hippurus) is an epipelagic, highly migratory species distributed worldwide in tropical and temperate waters including the Mediterranean Sea. Protein electrophoresis analyses can provide knowledge of the genetic population structure of the species and therefore be used as a tool for fishery management. Areas sampled include the islands of Majorca and Sicily in the western Mediterranean and the Canary Islands in the eastern Atlantic. The results of the protein electrophoresis reveal a level of genetic variability similar to other highly migratory species. No differences were found among locations, and it was not possible to reject the null hypothesis of one panmictic population in the area studied.
Sexual development, maturity and reproduction of dolphinfish (Coryphaena hippurus) in the western and central Mediterranean
Authors: Potoschi A. , Reñones O. , Cannizzaro L.
Published: October 2008

Studies have been conducted on the sexual development, maturity and reproduction of the dolphinfish (Coryphaena hippurus L. 1758) in the Mediterranean area, with special reference to the Balearic islands and Sicily. Professional fishing, carried out from August to December 1996, uses FADs (Fish Attracting Devices) and surrounding nets. 2087 juvenile specimens of dolphinfish from the Ionian and southern Tyrrhenian seas, the Strait of Sicily and the Balearic islands were sampled. A small number of adult fish (39), which are not usually caught in surrounding nets, was sampled in the swordfish long-line by-catch. The gonads of the young fish were analysed monthly to establish the stage of development of the ovaries or testes, during the first few months of life. The gonads of the adult fish, sampled in the months of June-September only, were all mature. The specimens caught between October and December presented maturity stage V in the case of the females and I in the case of the males, indicating the end of the reproductive period. The gonado-somatic index (GSI) and condition factor (CF) were calculated for both genders. The trend of the GSI confirms the presence of immature specimens as regards the juvenile fish; the low value of GSI was obtained for the adults, probably associated with the post-reproduction conditions found in the October-December period. Most of the gonads sampled during the months between August and December belonged to young specimens born in early summer. This is confirmed by the juvenile stages (FL 2.5 to 4.3 cm) caught with plankton nets in the Strait of Messina area in July.
Fisheries and biology of Coryphaena hippurus (Pisces: Coryphaenidae) in the Pacific coast of Colombia and Panama
Authors: Lasso Jairo , Zapata Luis
Published: October 2008

The fisheries and biology of the dolphinfish Coryphaena hippurus were studied between August 1994 and December 1996, using data obtained from the fishery fleet that operates in the area known as Panama Bight. The data showed a seasonal pattern of total catches with peaks from December through April and a total catch during three years of 1322.30 t., demonstrating the migratory pattern of the species. Based on the sex ratio (1 male: 0.96 female) and the reproductive index, the migration was spawning related. The diet is based on fishes (Exocoetidae, Scombridae, and Signathidae), mollusks (Loliginidae) and crustaceans (Portunidae). The relationship of fork length (fl) and total weight for the species was modeled based on the equation Wt = 0.0224 x (fl) 2.78 reflecting allometric growth. The frequency histograms showed lengths between 29 and 197 cm of fork length (35 and 238 cm of total length) with a mode around 105 cm and average length of 98.21 cm. The growth parameters were L? = 194 cm, K = 0.91 cm/year and t0 = - 0.1049. Data on C. equiselis, the other species of the same family, are reported.
Sicilian dolphinfish (Coryphaena hippurus) fishery
Authors: Potoschi A. , Cannizzaro L. , Milazzo A. , Scalisi M. , Bono G.
Published: October 2008

In 1996, a census was taken of the Sicilian fisheries that engage in dolphinfish (Coryphaena hippurus L. 1758) fishing. Two different surveys were conducted; data on fishing boats were obtained from the Naval Registers and frominterviewing boat owners on the wharf. The area sampled was divided into 3 zones and 6 strata. 205 boats were recorded in the eastern zone (Tyrrhenian and Ionian seas), 57 boats located in 4 different strata were recorded in the western zone. Fishing activities in the Ionian area begin in early August and end in December. In all other areas of Sicily, dolphinfish fishing begins in early September and continues until December. A census was also taken of the equipment used by the various boats for this activity in the different areas. The surveys showed that FADs are the most commonly employed method for dolphinfish fishing. The geographical distribution, number and characteristics were recorded for each area surveyed. The catches for the 1996 fishing season distributed for strata and zone are reported.
Capture of Grammicolepis brachiusculus Poey, 1873 (Grammicolepididae) off the Canary Islands
Authors: González J. A. , Rico V. , Santana J. I.
Published: October 2008

Morphometric and meristic characteristics, as well as estimations of fecundity, of two ripe females of Grammicolepis brachiusculus (Grammicolepididae) caught off the Canary Islands are reported. This is the first record of this species for the Canary Islands and its third finding in the North-Eastern Atlantic.
Eurytemora americana Williams, 1906, not Eurytemora affinis (Poppe, 1880), inhabits the Bahía Blanca estuary, Argentina
Authors: Hoffmeyer Monica S. , Frost Bruce W. , Castro María B.
Published: October 2008

The aim of this report is to clarify the taxonomical identity of the species of Eurytemora (Copepoda, Calanoida) present in the Bahía Blanca estuary, Argentina. Observations of taxonomical details were performed and the results led us to conclude that this species is Eurytemora Americana Williams, 1906 and not Eurytemora affinis (Poppe, 1880), as previously identified. E. Americana is a recent invader in this estuary and could have been accidentally introduced with ballast water of ships.
Larval development of Cyrtograpsus affinis (Dana) (Decapoda, Brachyura, Varunidae) from Río de la Plata estuary, reared in the laboratory
Authors: Spivak Eduardo D. , Cuesta José A.
Published: October 2008

The complete larval development of the crab Cyrtograpsus affinis (Brachyura, Varunidae) was obtained by culture in the laboratory. Five zoeal stages, the megalopa and the first crab are described and illustrated. Larval development from hatching to first crab took 29 days at 20° C and 35 PSU. The genus Cyrtograpsus only consists of three species. Larval development of C. altimanus and C. angulatus had been described previously. In the present study, morphological larval characters of the three species are compared. Generic larval features are also compared with those of other Varunidae genera.
Distribution of Euphausia mucronata at the upwelling area of Peninsula Mejillones, northern Chile: The influence of the oxygen minimum layer
Authors: Escribano R. , Marin V. , Irribarren C.
Published: October 2008

Analysis of zooplankton samples from 53 stations obtained around Peninsula Mejillones (Northern Chile), from two strata: 0-50 m and 150-200 m, during active upwelling in December 1996, allowed the study of horizontal and vertical distribution of Euphausia mucronata, endemic Krill of the Humboldt Current. Information from CTDO and a fluorometer was used to analyze the influence of oceanographic variables on distribution of E. mucronata. E. mucronata was found distributed all around the Peninsula, although with greater aggregations in the southern area, especially in the deeper layer. Stepwise multiple regression showed that none of the variables (temperature, salinity and chlorophyll) was significantly correlated to numerical abundance of the species. However there was a significant effect of depth of the oxygen minimum layer (OML), defined as 0.5 ml O2 l-1, on integrated abundance of the species, such that individuals are more likely to be found in areas where the OML is deeper. A vertical distribution parameter suggested a diurnal migrational pattern. This parameter was also correlated with distance to shoreline. The OML rises abrutply in nearshore areas because of active upwelling, but there are still nearshore zones where the OML remains deep. Therefore E. mucronata appears to aggregate around the upwelling lenses and filaments, where phytoplankton is more concentrated, but at the same time avoiding places where the OML is too shallow.
Reproduction of the cutlassfish Trichiurus lepturus in the southern Brazil subtropical convergence ecosystem
Authors: Silva Martins Agnaldo , Haimovici Manuel
Published: October 2008

The reproduction of the cutlassfish Trichiurus lepturus was studied from samples collected in bottom trawl surveys on the continental shelf and shelf break off southern Brazil. The mean total length (LT) at first gonadal maturity was 63.9 cm for males and 69.3 cm for females. Batch fecundity ranged from 3,917 in a specimen of 70 cm LT to 154,216 in a specimen of 141 cm but the number of spawning batches in each season was not established. Spawning occurs in late spring and summer in the continental shelf and probably year round over the shelf break. High surface temperatures and moderate stratification of the water column were associated with the final stages of gonadal maturation. Seasonal and spatial differences in sex ratios, sizes, maturity stages and feeding intensities suggest that adult female T. lepturus remain during the cold season in the continental shelf of southern Brazil to feed, while adult males move to warmer waters northward or offshore.
Immuno flow cytometry in marine phytoplankton research
Authors: Peperzak L. , Vrieling E. G. , Sandee B. , Rutten T.
Published: October 2008

The developments in the combination of flow cytometry and immunology as a tool to identify, count and examine marine phytoplankton cells are reviewed. The concepts of immunology and flow cytometry are described. A distinction is made between quantitative and qualitative immunofluorescence. Quantitative immunofluorescence, the identification and enumeration of phytoplankton cells, is the research area that has advanced rapidly in the past decade, and is reviewed extensively. Key steps of quantitative immunofluorescence, fixation and immunolabel intensity, are discussed in more detail. Qualitative immunofluorescence is a new, hardly explored but highly interesting development in which qualitative -physiological- variables related to e.g. nutrient limitation or primary production are measured in individual cells instead of phytoplankton populations as a whole. Several combinations of immunological probes, both for species identification and for physiological measurements, are proposed. A special case of qualitative immunofluorescence is the measurement of phytoplankton toxins in single cells from natural populations. It is anticipated that the future use of semiconductor nanocrystals or quantum dots as fluorophores will greatly enhance signal detection in flow cytometry, and hence in both quantitative and qualitative immunofluorescence applications.
CytoBuoy: a step forward towards using flow cytometry in operational oceanography
Authors: Dubelaar G. B.J. , Gerritzen P. L.
Published: October 2008

While the performance of biological sensors in real time monitoring networks is limited to bulk values like chlorophyll fluorescence, in practice the implementation of automated phytoplankton taxonomy remains a remote option. Aiming to reduce this gap we developed a flow cytometer called CytoBuoy for autonomous in situ operation, for instance in a moored buoy with wireless data transfer. Although not comparable to microscopy, flow cytometers detect and count particles allowing a limited level of particle characterization based on the light scatter and fluorescence properties of the individual particles. CytoBuoy analyses a large size range of particles, typical for marine coastal zones and fresh waters. The `field´ design implies a tradeoff between the accuracy and versatility of laboratory flow cytometers and the qualities needed for trouble free autonomous operation in situ. The optics and electronics however were designed for maximal reflection of the particle morphology in the measured signals. Whereas standard cytometers reduce these to single peak or area `listmode´ numbers, the signal courses are preserved fully by CytoBuoy and transferred to the computer as raw data, which allows more extended morphological analysis. Extended field tests will have to show how the system holds in various environments and weather conditions.
Variations of the macrobenthic community in a seagrass transplanted area of the Lagoon of Venice
Authors: Pranovi F. , Curiel D. , Rismondo A. , Marzocchi M. , Scattolin Mario
Published: October 2008

Modifications in a benthic community, induced by an experimental transplant of seagrass (Cymodocea nodosa Ucria), were studied in an area located in the southern basin of the Lagoon of Venice. Two surveys, carried out in March and September 1996, indicated that species composition and numerical dominants changed with season, with increasing dissimilarity between the transplanted meadow and the surrounding area. The latter was used as a control area and was characterised by the presence of pleustophytic algae (Ulva rigida, Gracilaria verrucosa, Chaetomorpha linum). Comparison with a natural C. nodosa bed showed that, only two vegetative seasons after transplant, seagrass performance and the structure of the macrobenthic community were quite similar to those recorded in a natural meadow. The experiment demonstrated the importance of C. nodosa transplant in the Lagoon of Venice and the changes induced in the whole benthic community by the introduction of seagrass in an area previously lacking it.
Egg and early larval development of laboratory reared goldblotch grouper, Epinephelus costae (Steindachner, 1878) (Pisces, Serranidae)
Authors: Glamuzina Branko , Glavic Niksa , Tutman Pero , Kozul Valter , Skaramuca Bosko
Published: October 2008

The embryonic and early larval development of the laboratory-reared goldblotch grouper, Epinephelus costae (Steindachner, 1878), are described and illustrated. The eggs, with a mean diameter of 926±19 µm and a range from 890-950 µm, were spherical and transparent with transparent chorion. Embryonic development lasted 24 hours at 25.5°C. Newly-hatched larvae were 1.762±0.047 mm in length. Absorption of the yolk sac was complete after the third day, when larvae reached 2.95±0.231 mm in total length. The mouth opened 60 hours after hatching, and was in function after 80 hours, with an opening diameter ranging from 280-320 µm. Larvae had two fields of intensive pigmentation, one above the intestine, and the other between the anus and the end of the notochord.
Effects of different levels of UV-B radiation on marine epilithic communities: a short-term microcosm study
Authors: Danilov R. A. , Ekelund N. G.A.
Published: October 2008

Epilithic communities from brackish coastal water of the east coast of Sweden were studied in order to reveal their responses to different levels of UV-B radiation. The experiment was conducted for seven days in an indoor microcosm system. The epilithic communities were exposed daily to different doses of UV-B radiation: 1, 3, 5 and 7 hours, respectively. The intensity of the UV-B radiation used was similar to that in natural environments. After seven days clear shifts both in species composition and community structure were observed. All species of diatoms showed negative correlation with enhanced levels of UV-B. On the other hand, abundance of cyanobacteria was positively correlated with enhanced levels of UV-B (Calothrix aeruginea, R=0.49;Oscillatoria amphibia, R=0.93; Pseudanabaena mucicola, R=0.26). Communities dominated by diatoms and green algae at the initial stage of the experiment did show a drastic decrease in diatom abundance under UV-B stress and finally became dominated by cyanobacteria. Among green algae the abundance of Cladophora sericea correlated positively (R=0.33) with enhanced exposure to UV-B, while Monoraphidium-species exhibited negative correlation to UV-B. Otherwise, no significant correlation between other green algae species identified and UV-B stress could be detected. We conclude that UV-B radiation, even at lower levels, is capable to induce severe changes to marine epilithic communities. The trends revealed in the present study predict a shift from communities dominated by diatoms and green algae to those dominated by cyanobacteria.
The use of cardiac monitoring in the assessment of mercury toxicity in the subtropical pebble crab Gaetice depressus (Brachyura: Grapsidae: Varuninae)
Authors: Aagaard A. , Styrishave B. , Warman C. G , Depledge M. H.
Published: October 2008

Heart rates were monitored in the pebble crab, Gaetice depressus using a non-invasive, computer aided cardiac monitoring system. A high degree of intra- and interindividual variability was observed, as was the presence of endogenous circatidal and circadian rhythms. Both acute and sublethal toxicities of mercury were determined. LC50´s (96) for mercury were between 0.16-0.20 mg l-1. Exposure to HgCl2 above LC50 (96) (0.3 mg Hg l-1) resulted in rapid and statictically significant increases in heart rate whereas exposure to a concentration lower than LC50 (96) (0.1 mg Hg l-1) resulted in progressive reduction in heart rate similar to that of control crabs
Side scan sonar image and geologic interpretation of the Ría de Pontevedra seafloor (Galicia, NW Spain)
Authors: García-Gil Soledad , Durán Ruth , Vilas Federico
Published: October 2008

High-resolution side scan sonar has been used for mapping the seafloor of the Ría de Pontevedra. Four backscatter patterns have been mapped within the Ría: (1) Pattern with isolated reflections, correlated with granite and metamorphic outcrops and located close to the coastal prominence and Ons and Onza Islands. (2) Pattern of strong reflectivity usually located around the basement outcrops and near the coastline and produced by coarse-grained sediment. (3) Pattern of weak backscatter is correlated with fine sand to mud and comprising large areas in the central and deep part of the Ría, where the bottom currents are weak. It is generally featureless, except where pockmarks and anthropogenic features are present. (4) Patches of strong and weak backscatter are located in the boundary between coarse and fine-grained sediments and they are due to the effect of strong bottom currents. The presence of megaripples associated to both patterns of strong reflectivity and sedimentary patches indicate bedload transport of sediment during high energy conditions (storms). Side scan sonar records and supplementary bathymetry, bottom samples and hydrodynamic data reveal that the distribution of seafloor sediment is strongly related to oceanographic processes and the particular morphology and topography of the Ría.
Fatty acid and sterol composition of gametophytes and sporophytes of Chondrus crispus (Gigartinaceae, Rhodophyta)
Authors: Tasende M. G.
Published: October 2008

Fatty acids and sterols of gametophytes and sporophytes of Chondrus crispus were isolated and identified. Although chemical variation in the proportions of other natural compounds (eg. different carrageenan type) between gametophytes and sporophytes has already been observed, this is the first comparative study of the lipid composition in both generations. The content of fatty acids and sterols in gametophytes (0.710 and 0.190 mg g-1 dry weight respectively) was higher than in sporophytes (0.622 and 0.113 mg g-1 dry weight). The main fatty acids were palmitic, palmitoleic, oleic, arachidonic and eicosapentaenoic acids. These five fatty acids represented more than 78% of the all fatty acid composition in both generations. In addition unsaturated fatty acids were present in a much greater quantity (>80%) than saturated fatty acids. However, differences in the distribution of fatty acids between the two generations were observed. Gametophytes demonstrated higher amounts of monounsaturated fatty acids while sporophytes had a relatively higher content of saturated and polyunsaturated fatty acids. The major sterol in both generations was cholesterol (> 94%). Differences were also observed in the sterol distribution between gametophytes and sporophytes, the former containing smaller amounts of 7-dehydrocholesterol and stigmasterol, while the latter had smaller amounts of 22-dehydrocholesterol, campesterol and sitosterol. Gametophytes were lacking 24-methylenecholesterol. Fatty acids and sterol of algal class, families and sometimes even species are characteristic to those particular taxa, and could be useful as chemotaxonomic markers. The results of this study showed that intra-specific variation in algae can be occured.
Seasonal pattern of zooplankton biomass in the Argentinian shelf off Southern Patagonia (45º - 55º S)
Authors: Sabatini María E. , Alvarez Colombo Gustavo L.
Published: October 2008

Zooplankton biomass in the Argentine Sea off Southern Patagonia was measured during thirteen research cruises carried out between 1992 and 1997 and interpreted in the context of the feeding habits of regional fish resources. Samples were collected with a Nackthai sampler (400-500 µm mesh size) towed obliquely through the water column. Wet weights of the size fraction smaller than 5 mm (mostly made up of copepods), amphipods, euphausiids, mysids and chaetognaths were determined separately. Total zooplankton biomass increased from spring to summer or early autumn. The highest values were consistently located in coastal waters between 51° and 52°S and near the shelf-break from 46° to 48°S. In spring most of the biomass of the entire region was built up of copepods. During late summer-early autumn the contribution of the larger groups increased, with amphipods dominating in the coastal area and euphausiids being more abundant in deeper waters. Mysid biomass was significant only in the innermost coastal area in spring and autumn. The occurrence and densities of chaetognaths increased offshore.
Descriptions of two new species of Eunice Cuvier, 1817 (Polychaeta: Eunicidae) from coastal islands of the State of Sao Paulo, Brazil
Authors: Nogueira J. M.M. , Steiner T. M. , Amaral A. C.Z.
Published: October 2008

Two new species of Eunice from coastal islands of the state of São Paulo are described, both of them living in colonies of the coral Mussismilia hispida. One species was also collected from a sandy beach. Eunice insularis has short palps and antennae in a horseshoe, without articulations; most of the specimens studied are abranchiate, but some have one branchial filament in a few parapodia. Eunice marconii also has palps and antennae without articulations, in a horseshoe, and 1-3 long slender branchial filaments from the anterior to posteriormost chaetigers. These new species are compared with the morphologically closest congeners.
New records of Pennatulacea (Anthozoa: Octocorallia) from the African Atlantic coast, with description of a new species and a zoogeographic analysis
Authors: López-González Pablo J. , Gili Josep María , Williams Gary C.
Published: October 2008

A collection of pennatulaceans from ten cruises, acquired between 1982 and 1989 from off the western African coast comprises ca. 350 specimens of 13 species. One of the cruise is from the Gulf of Guinea and eight from the Southeast Atlantic. Fifty-four stations were sampled from depths of 91-1112 m. One previously undescribed species in the genus Stylatula is reported and described as new from samples collected from the Namibian continental shelf. Considering these collections, and previous records, the pennatulaceans in the western African region show biogeographic affinities with three geographic areas: West Africa (55.5% of the species), which comprises the Canary, Gulf of Guinea, and Benguela regions; the North Atlantic (3.7% of the species), which represents the more widespread Atlantic taxa; and Cape Endemic (7.4% of the species), which comprises the southern African region.
First data on ovary maturation and fecundity in the squid family Histioteuthidae
Authors: Laptikhovsky Vladimir
Published: October 2008

The potential fecundity of histioteuthid squid ranges from 3,000 to 275,000 oocytes. During maturation a significant oocyte resorption occurs in many species; therefore only advanced maturing females can be taken into account for fecundity estimation.
Aspects of the reproductive biology of the toadfish, Halobatrachus didactylus (Schneider, 1801) (Pisces: Batrachoididae)
Authors: Palazón-Fernández José L. , Arias Alberto M. , Sarasquete Carmen
Published: October 2008

The biology of Halobatrachus didactylus has received special attention during recent years because of its use as an experimental species in toxicology and cardiology experiments. The object of the present work is to supply basic information about the reproductive biology of this species. Samples were collected in Cádiz Bay between February 1999 and March 2000. A total of 901 specimens (440 females and 461 males) were examined. Sex ratio did not differ from the theoretical 1:1, except in May 1999, and February 2000. Minimum size at maturity was 191 mm total length for females and 160 mm total length for males. Approximately 50 % of the population matured at 262 mm for females and 302 mm for males. The spawning season extends from March to August, with a peak in May-June. Fecundity ranged from 227 to 1233 eggs/female, and was related to body length and weight. Length-weight relationship for the sexes differed, and showed positive allometry. The condition factor showed a minimum in the spawning season, which is interpreted as the result of mobilization of somatic energy reserves needed for reproductive development, and/or the use of reserves stored in the body as a source of energy in spawned fish, influenced by reduced feeding during this period.
Metazoan parasites of grey mullets (Teleostea: Mugilidae) from the Mistras Lagoon (Sardinia - western Mediterranean)
Authors: Merella Paolo , Garippa Giovanni
Published: October 2008

A total of 127 specimens of grey mullets (Teleostea: Mugilidae) from the Mistras Lagoon (Sardinia - western Mediterranean) were examined for metazoan parasites. Five species of grey mullets were found: Chelon labrosus, Liza aurata, L. ramada, L. saliens and Mugil cephalus. Forty-one species of parasites were identified: 14 monogeneans, 5 crustaceans, 18 digeneans, 3 nematodes and 1 acanthocephalan; 26 of them being reported from Sardinia for the first time. Findings of faunal interest are: Ergenstrema sp. (Monogenea) in L. saliens; Caligus pageti (Crustacea) in L. aurata and L. saliens; Saturnius sp. (Digenea) in C. labrosus, L. aurata and L. saliens; Capillaria sp. (Nematoda) in C. labrosus, L. aurata and M. cephalus. The dynamics and distribution of ectoparasites were partially influenced by salinity, while the interpretation of the results for endoparasites was more complex. The data obtained show the richness of the parasite fauna of grey mullets from the Mistras Lagoon, providing additional environmental information on this body of water.
The application of species specific DNA-targeted probes and fluorescently tagged lectin to differentiate several species of Pseudo-nitzschia (Bacillophyceae) in Chinhae Bay, Korea
Authors: Seob Cho Eun , Gyu Park Jong , Cheol Oh Bong , Chul Cho Yong
Published: October 2008

We applied molecular methods using a DNA probe and fluorescently tagged lectins to discriminate toxic Pseudo-nitzschia multiseries from the Chinhae Bay for a Korean harmfulalgae monitoring program. From the binding activity of lectins, P. multistriata, P. subfraudulenta, P. pungens, P. multiseries and P. cuspidata bound ConA, whereas P. subpacifica and P. delicatissima did not. Ribosomal RNA-targeted oligonucleotide probes (muD1, puD1 and deD1) specifically reacted to P. multiseries, P. pungens and P. delicatissima, respectively, whereas auD1, frD1 and amD1 probes did not bind to P. multiseries, P. pungens, P. cuspidata, P. multistriata, P. subpacifica, P. subfraudulenta and P. delicatissima. In particular, fluorescent FITC-conjugated WGA specifically bound to P. multiseries but not to P. pungens, indicating that this is a desirable method for their rapid and easy discrimination. In addition, we tested a species-specific oligonucleotide DNA probe (muD1) using the whole cell hybridization filter tube system, and the WGA lectin probe to discriminate P. multiseries in the field. The oligonucleotide probe and fluorescent WGA bound specifically to P. multiseries and these labelled cells were correlated to label cell abundance. These results imply that DNA and lectin probes are apporopriate tools for counting P. multiseries and distinguishing morphologically similar Pseudo-nitzschia species in natural samples, therefore, these methods are especially pertinent since rapid separation and quantitative estimation of cell abundance of P. multiseries are now important for a routine harmful algae monitoring program in Korean waters.
Isopod fauna, excluding Epicaridea, from the Strait of Gibraltar and nearby areas (Southern Iberian Peninsula)
Authors: Castelló José , Carballo José Luis
Published: October 2008

A total of 42 isopod species from the Strait of Gibraltar and nearby areas were found, including the first record of Munna fabricii, Monodanthura maroccana, Campecopea hirsute, and Natatolana gallica from the Mediterranean; Synisoma nadejda and Uromunna petiti from the Atlantic; and Munna fabricii, Uromunna petiti, Monodanthura maroccana, Stellanthura cryptobia and Natatolana gallica from the Iberian waters. This article includes the previous records from the Iberian waters for all the species. The greatest number of species were found in Tarifa (16 species), located in the transition zone between the Atlantic Ocean and the Mediterranean Sea. According to depth, the distribution of species was as follows: 18 species were collected in the intertidal zone, mostly Dynamene edwardsi and Ischyromene lacazei; 33 species were found between 1 and 10 m, 13 species were found between 11 and 20 m, and 6 species were found between 21 and 28 m, mostly Janira maculosa. According to habitat, 16 species were collected on soft bottoms, 2 species on Zostera, and 22 species on algae substrata, mostly Halopteris, Asparagopsis and Cystoseira. The most diverse genus was Cymodoce (5 species). This paper contributes to the taxonomic, faunistic and biogeographical knowledge of the benthic communities from the Strait of Gibraltar and nearby areas.
Age and growth of Pontinus kuhlii (Bowdich, 1825) in the Canary Islands
Authors: López Abellán L. J. , Santamaría M. T. G. , Conesa P.
Published: October 2008

Pontinus kuhlii is a Scorpaenidae which forms part of the bottom longline by-catch in the Canary Islands fisheries within setting operations from 200 to 400 metres depth. Information on their biology and on the age determination and growth of the species is very scarce. The main objective of the study was to look at this biological aspect based on 421 specimens caught in the Canarian Archipelago during the period July 1996 and August 1997, 286 of which were male, 130 female and 5 indeterminate. Age was determined through the interpretation of annual growth rings of otoliths and scales, and the results fitted the von Bertalanffy growth function. Otolith sectionings were discarded due to annuli losses caused by the edge structure. The structures used in age interpretation showed numerous false rings that made the process difficult, causing 17% of the cases to be rejected. However, the age interpretations from scales showed less variability in relation to the whole otolith. The ages of the specimens ranged from 6 to 18 years for males and from 6 to 14 years for females. The growth parameters for males were: K= 0.132, L? = 46.7 and to= 1.74; for females: K= 0.094, L?= 46.3 and to= 0.05; and for the total: K= 0.095, L?= 52.2 and to= 1.01.
A simple model for submaximal exchange through the Strait of Gibraltar
Authors: Delgado Javier , García Lafuente Jesús , Vargas Juan Miguel
Published: October 2008

This work presents a simple two-layer model for the water exchange through the Strait of Gibraltar. The model is inspired by the work of Bormans and Garrett (1989) and focus on the case of submaximal exchange with an unique hydraulic control at the section of minimum cross-area. The first part describes the model and justifies the assumed simplifications. Some aspects regarding its performance are also analysed. The second part applies the model to interpret the seasonal signals in the exchanged flows that were observed during the Canary Islands Azores Gibraltar Observations (CANIGO) project. These signals are compatible with submaximal exchange, which suggests that the oceanographic conditions in the nearby Alboran Sea are able to influence the exchange via interface depth variations.
Parvipalpus onubensis, a new species (Crustacea: Amphipoda: Caprellidea) from the Atlantic coast of Southern Spain
Authors: Guerra-García J. M. , García-Asencio I. , Sánchez-Moyano J. E.
Published: October 2008

Parvipalpus onubensis n. sp. is described based on the specimens collected from sediments on the coast of Huelva (Southwest Spain). The new species is compared with the other species in the genus: Parvipalpus capillaceus (Chevreux, 1887), P. linea Mayer, 1890 and P. major Carausu, 1941. Parvipalpus onubensis differs from the remaining species of Parvipalpus by the simultaneous combination of the following characters: small size (body length up to 2.8 mm), rostrum present, body completely smooth, flagellum of antenna 1 with 5 articles in males and 3 in females, mandibular palp 2-articulate, incisor and lacinia mobilis 4-toothed and penes well developed.
Settlement and juvenile habitat of the European spiny lobster Palinurus elephas (Crustacea: Decapoda: Palinuridae) in the western Mediterranean Sea
Authors: Díaz David , Marí Marc , Abelló Pere , Demestre Montserrat
Published: October 2008

Settlement characteristics, like timing, depth, microhabitat and density of European spiny lobster Palinurus elephas are described for the very first time. Regular SCUBA-diving surveys were conducted from July 1998 to January 2000 on rocky bottoms of three different geologic origins to assess substratum-dependent differences in recruitment density. Settlement of pueruli took place in June-July, a few weeks after sea surface temperature started to rise. The highest density of juveniles was found at 10-15 m depth. Most spiny lobsters settled in limestone rocks, into empty holes of the date mussel Lithophaga lithophaga, which provided daytime refuge. As they grew, individuals were increasingly found in larger holes and crevices of the rock surface. Sizes were estimated from photographs taken at night when the animals were actively foraging. The smallest observed individuals measured 7.5-8 mm carapace length (CL), but they reached 15-18 mm CL at the end of October. The consequences of our results for the management of the spiny lobster populations in the northwestern Mediterranean are summarily discussed.
Seasonal grazing and food preference of herbivores in a Posidonia oceanica meadow
Authors: Peirano Andrea , Niccolai Ilaria , Mauro Roberto , Nike Bianchi C.
Published: October 2008

Seasonal grazing of the fish Sarpa salpa (L.), the urchin Paracentrotus lividus Lamarck and the isopods Idotea spp. was compared with the C/N ratio of adult and intermediate leaves and epiphytes of Posidonia oceanica (L.) Delile, collected at three different depths. Despite seasonal differences in grazing, herbivores showed preferences throughout the year for adult leaves with more epiphyte and higher N contents. The maximum grazing on adult and intermediate leaves was observed in September and in June for fish and in March for urchins, whereas it was irregular for isopods. Grazing by the three herbivores was not related to their preference for leaves or epiphytes, notwithstanding the seasonal differences in their C and N contents. We concluded that herbivores show no preference for food type throughout the year and that seasonal consumption of P. oceanica is related mainly to herbivore behaviour.
Age and growth of Crystallogobius linearis (von Düben, 1845) (Teleostei: Gobiidae) from the Adriatic Sea
Authors: La Mesa M.
Published: October 2008

Age and growth of the crystal goby Crystallogobius linearis (von Düben, 1845) were investigated by means of daily growth increment counts on the sagittal otoliths. Samples of C. linearis, obtained as by-catch of the Aphia minuta fishery, were collected in a coastal area of the central Adriatic Sea between March and September 1996. Otolith age-readings were carried out on 167 specimens, ranged from 14 to 41 mm of total length, and indicated that the population was composed of individuals from two to seven months old. Growth of both males and females appeared practically linear over the whole size range studied, although in females a slight decrease in growth rate of older specimens was observed. Furthermore, the hatch date distribution of C. linearis, obtained by the backcalculation of the ageing data, indicated a long breeding season of at least eight months. The results of this study indicated that, as reported from literature for most nektonic gobies, the crystal goby is also characterised by a short life span, during which a high reproductive effort is displayed throughout a long breeding season.
Obituary: Buenaventura Andreu Morera (1920 -2001)
Authors: Bas Peired Carles
Published: October 2008

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