bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial distribution and biomass of aquatic rooted macrophytes and their relevance in the metabolism of a Mediterranean coastal lagoon
Authors: Obrador Biel , Pretus Joan Lluís , Menéndez Margarita
Published: October 2008

This work aims to characterise the current autotrophic compartment of the Albufera des Grau coastal lagoon (Menorca, Balearic Islands) and to assess the relationship between the submerged macrophytes and the limnological parameters of the lagoon. During the study period the submerged vegetation was dominated by the macrophyte Ruppia cirrhosa, which formed dense extensive meadows covering 79% of the surface. Another macrophyte species, Potamogeton pectinatus, was also observed but only forming small stands near the rushing streams. Macroalgae were only occasionally observed. Macrophyte biomass showed a clear seasonal trend, with maximum values in July. The biomass of R. cirrhosa achieved 1760 g DW m-2, the highest biomass ever reported for this species in the literature. The seasonal production-decomposition cycle of the macrophyte meadows appears to drive the nutrient dynamics and carbon fluxes in the lagoon. Despite the significant biomass accumulation and the absence of a washout of nutrients and organic matter to the sea, the lagoon did not experience a dystrophic collapse. These results indicate that internal metabolism is more important than exchange processes in the lagoon.
The occurrence of Natsushima bifurcata (Polychaeta: Nautiliniellidae) in Acharax hosts from mud volcanoes in the Gulf of Cadiz (south Iberian and north Moroccan Margins)
Authors: Ravara Ascensao , Cunha Marina R. , Rodrigues Clara F.
Published: October 2008

Fifteen specimens of nautiliniellid polychaetes were found in the mantle cavity of bivalves of the genus Acharax (Solemyidae) collected in several mud volcanoes from the Gulf of Cadiz. They were identified as Natsushima bifurcata Miura and Laubier (1990), a species previously known only from Sagami Bay (Japan). The morphological comparison of these specimens with the holotype suggests that they belong to the same morphological species, although further studies should consider whether they could be genetically different. The ecology of the species is discussed in relation to the available information on the family. The occurrence of Natsushima bifurcata in the Gulf of Cadiz is the first record of the species in the North Atlantic.
Comparative study on the reproductive biology of Torpedo torpedo (Linnaeus, 1758) and T. marmorata (Risso, 1810) in the central Mediterranean Sea
Authors: Consalvo Iván , Scacco Umberto , Romanelli Michele , Vacchi Marino
Published: October 2008

The reproductive biology of Torpedo torpedo (n = 535) and Torpedo marmorata (n = 385), collected in coastal waters of Latium (central Mediterranean Sea, Italy) between September 2000 and October 2001, was studied and compared. Males and females reached a maximum length of 445 and 477 mm TL in T. torpedo and 364 and 553 mm TL in T. marmorata. Males and females of T. torpedo reached length at sexual maturity (TL50%) at similar sizes (249 mm TL and 258 mm TL respectively) whereas TL50% in females of T. marmorata was greater than that of males (312 and 251 mm TL respectively). Analysis of the gonadosomatic index (GSI) and maximum oocyte diameter (MOD) in mature females suggested that gestation lasted about 6 months in T. torpedo and 9 to 10 months in T. marmorata. Fecundity was positively correlated with length in both species and, comparing ovarian and uterine fecundity, T. torpedo had a greater reproductive potential than T. marmorata. Size at birth of T. torpedo was smaller than that of T. marmorata and embryos of the latter showed a higher rate of mass increment with size than those of T. torpedo.
Baroclinic and wind-induced circulation in Tarragona harbour (northeastern Spain)
Authors: Mestres Marc , Pau Sierra Joan , Sánchez-Arcilla Agustín
Published: October 2008

The sustainability of harbour management from an environmental standpoint is a current concern for port authorities. It includes dealing with problems that may affect the quality of in-harbour waters. In semi-enclosed basins, the characteristics of the circulation pattern are one of the main factors influencing the water quality, since they determine the residence time of pollutants inside the basin and govern the interaction between inside waters and the cleaner outside waters. Although harbour hydrodynamics are affected by the constant traffic of vessels and the physical constraints imposed by harbour structures, the water dynamics in ports are generally governed by three mechanisms: tidal forcing, wind surface stress, and baroclinic effects. This study presents the characterisation of winter circulation features in Tarragona harbour (northeast Spain), based on both field data and numerical simulations. Due to the microtidal nature of the Mediterranean Sea, three-dimensional water density distribution and local wind are expected to be the most relevant driving mechanisms. The results obtained suggest that, although wind effects may be important in determining the water flow in and out of the harbour for small time-scales, in the long term the most important water exchange mechanism is related to the waterbody’s baroclinic structure, with wind forcing playing only a second-order role.
Lipid reserves of red mullet (Mullus barbatus) during pre-spawning in the northwestern Mediterranean
Authors: Lloret Josep , Demestre Montserrat , Sánchez-Pardo Josep
Published: October 2008

Lipid reserves are a particularly important attribute of fishes because they have a large influence on growth, reproduction and survival. This study analyses the lipid content of red mullet (Mullus barbatus) pre-spawners in three different areas of the northwestern Mediterranean in relation to trawling activities and river runoff. The muscle lipid was considered as an indicator of the somatic condition of individuals whilst the gonad lipid was used as a proxy of the energy invested in reproduction. The results show that fish with the highest muscle lipid levels inhabited the area where fishing impact was lowest. Since the abundance and biomass of polychaetes, which represent the main food source for red mullet, were found to be lower in trawled zones than in unfished ones, we suggest that differences in the muscle lipid levels between areas might be attributed to variation in prey abundance in relation to fishing impact. However, no impact of river runoff on lipid reserves of red mullet was observed. The results also show that muscle and gonad lipid reserves are not related to each other during pre-spawning.
Decapod crustaceans associated with the snakelock anemone Anemonia sulcata. Living there or just passing by?
Authors: Calado Ricardo , Dionísio Gisela , Dinis María Teresa
Published: October 2008

The present work identifies the decapod crustaceans that associate with Anemonia sulcata on the southwestern Atlantic coast of Portugal and characterises their host use pattern. It determines whether the anemone is monopolised by any species, resulting in the exclusion of conspecifics or other decapods and, under laboratory conditions, it evaluates the degree of association between each species and A. sulcata. From all sampled anemones, 79% harboured at least 1 decapod crustacean, with the majority displaying either one or two specimens (32 and 24%, respectively). The most abundant species were the shrimp Periclimenes sagittifer and the crab Inachus phalangium (representing 36 and 31% of collected specimens, respectively), which displayed lasting associations and were commonly recorded among the tentacles of the host. The species Eualus occultus, E. complex cranchii, Clibanarius erythropus, Maja brachydactyla, Pilumnus hirtellus and Polybius (Necora) puber displayed short-term associations, were mainly present on the substratum near the base, and avoided the tentacles of A. sulcata. Periclimenes sagittifer and I. phalangium were only recorded alone or in heterosexual pairs, appearing to efficiently defend their host against conspecifics. The majority of recorded species only seem to temporarily associate with A. sulcata, in order to seek protection from predators when other shelters are unavailable.
Origin and abundance of beach debris in the Balearic Islands
Authors: Martinez-Ribes Lorena , Basterretxea Gotzon , Palmer Miquel , Tintoré Joaquín
Published: October 2008

The abundance, nature and possible sources of litter on 32 beaches on the Balearic Islands (Mediterranean Sea) were investigated in 2005. Mean summer abundances in the Balearics reached approximately 36 items m-1, with a corresponding weight of 32±25 g m-1, which is comparable to the results of other studies in the Mediterranean. Multivariate analyses (principal component analysis and redundancy analysis) confirmed strong similarities between islands and a statistically significant seasonal evolution of litter composition and abundance. In summer (the high tourist season), debris contamination expressed as item abundance was double that in the low season and showed a heterogeneous nature associated with beach use. Cigarette butts were the most abundant item, accounting for up to 46% of the objects observed in the high tourist season. In contrast, plastics related to personal hygiene/medical items were predominant in wintertime (67%) and natural wood was the most important debris by weight (75%). In both seasons, litter characteristics suggested a strong relationship with local land-based origins. While beach users were the main source of summer debris, low tourist season litter was primarily attributed to drainage and outfall systems.
Revision of Chone Krøyer, 1856 (Polychaeta: Sabellidae) from the eastern central Atlantic and Mediterranean Sea with descriptions of two new species
Authors: Tovar-Hernández María Ana , Licciano Margherita , Giangrande Adriana
Published: October 2008

A neotype specimen is designated for Chone acustica (Claparède, 1870) with a full description. The original descriptions of Chone arenicola Langerhans, 1880 and Chone collaris Langerhans, 1880, both from Madeira, did not include some details and incomplete or misleading information was provided, so both species are redescribed. Amendments to the description of Chone longiseta Giangrande, 1992 are also given together with the methyl green staining pattern of Chone usticensis Giangrande et al. 2006. Two new species are described: Chone gambiae sp. nov., from the Gulf of Naples and Chone dunerificta sp. nov., from the Gulf of Salerno. This study shows the distribution of Chone duneri Krøyer, 1856, and Chone filicaudata Southern, 1914, to be restricted to the Arctic seas and North Atlantic Ocean, respectively. Records from the Mediterranean Sea are found to be erroneous.
Vertical diel dynamic of fish assemblage associated with an artificial reef (Northern Adriatic Sea)
Authors: Sala Antonello , Fabi Gianna , Manoukian Sarine
Published: October 2008

The vertical diel activity of a fish assemblage inhabiting the Senigallia artificial reef (northern Adriatic Sea, Italy) was evaluated from July to November 1996 using enhanced hydroacoustic techniques. Extensive seabed mapping of the area was done using a multibeam echosounder to obtain background imagery of the reef structures and identify the most suitable locations for placing stationary acoustic transducers. Three acoustic transducers were placed inside the reef area, while a fourth was located in the open sea outside the area. Data analysis was conducted on three different depth layers: surface, midwater and bottom. In each layer, diel fish biomass inside the reef showed two peaks, one in the early morning and the other in the late evening. Slightly different behaviour was observed outside the protected area. Comparison of the layers showed that fish biomass was not homogeneously distributed along the water column throughout the sampling period. There were high values in the middle and bottom layers until the end of August. However, no significant biomass variations in time were observed outside the reef where low values were always recorded in each layer.
Bioaccumulation and biochemical responses in mussels exposed to the water-accommodated fraction of the Prestige fuel oil
Authors: Solé Montserrat , Buet Astrid , Ortiz Laura , Maynou Francesc , Bayona Josep Maria , Albaigés Joan
Published: October 2008

The activity of the antioxidant defences catalase (CAT, EC 1.11.1.6), glutathione peroxidase (t-GPX, EC 1.11.1.9), glutathione reductase (GR, EC 1.6.4.2), phase II glutathione S-transferase (GST, EC 2.5.1.18) along with the NADPH-dependent cytochrome c (CYP) reductase (EC 1.6.2.4), NADH-dependent cytochrome c reductase (EC 1.6.2.2), and NADH-dependent ferricyanide (b5) reductase (EC 1.18.1.1) was determined in the digestive gland of mussels Mytilus galloprovincialis fed with Tetraselmis sp. pre-exposed to the water accommodated fraction of the Prestige oil. Mussel gills were also used for measuring acetylcholinesterase activity (AChE, EC 3.1.1.7) and lipid peroxidation (LP) as an indication of neurotoxicity and oxidative stress damage respectively. Bioaccumulation of the selected polycyclic aromatic hydrocarbons (2 to 6 rings PAHs) in mussels after 2, 4, 7 and 10 days of exposure did not show any significant trend; the 2-3 ring PAHs were best represented (51%). A significant (p
Reproduction of the white grunt, Haemulon plumieri (Lacépede, 1802) (Pisces: Haemulidae) from Margarita Island, Venezuela
Authors: Palazón-Fernández José L.
Published: October 2008

P align=justify>The grunts (Haemulidae) are an important component of the artisan fisheries in eastern Venezuela, but their biology is poorly known. The object of the present work was to supply basic information about the reproductive biology of Haemulon plumieri in relation to sex ratio, size at maturity, spawning season and fecundity. Samples were collected from the northeast coast of Margarita Island between September 1994 and August 1995. A total of 469 specimens (232 females and 237 males) were examined. Sex ratio did not differ from 1:1 except in February 1995. Minimum size at maturity was 213 mm total length for females and 271 mm total length for males. Size at maturity (L50) was 309 mm total length for females and 357 mm for males. The spawning season extends throughout the year, with peaks in February-April and August-October. Fecundity ranged from 19873 to 535039 eggs, and was related to body length and weight. White grunt was characterised by asynchronous oocyte development and multiple spawning. The weight-length relationship for the sexes differed and showed negative allometry. Condition factor was over 95% during the sampling period, showing minimum values prior to the reproductive peak, which can be interpreted as the result of mobilisation of somatic energy reserves for reproductive development.
Role of the Jiaozhou Bay as a source/sink of CO2 over a seasonal cycle
Authors: Li Xuegang , Song Jinming , Niu Lifeng , Yuan Huamao , Li Ning , Gao Xuelu
Published: October 2008

The seasonal evolution of dissolved inorganic carbon (DIC) and CO2 air-sea fluxes in the Jiaozhou Bay was investigated by means of a data set from four cruises covering a seasonal cycle during 2003 and 2004. The results revealed that DIC had no obvious seasonal variation, with an average concentration of 2035 µmol kg-1 C in surface water. However, the sea surface partial pressure of CO2 changed with the season. pCO2 was 695 µatm in July and 317 µatm in February. Using the gas exchange coefficient calculated with Wanninkhof’s model, it was concluded that the Jiaozhou Bay was a source of atmospheric CO2 in spring, summer, and autumn, whereas it was a sink in winter. The Jiaozhou Bay released 2.60 x 1011 mmol C to the atmosphere in spring, 6.18 x 1011 mmol C in summer, and 3.01 x 1011 mmol C in autumn, whereas it absorbed 5.32 x 1010 mmol C from the atmosphere in winter. A total of 1.13 x 1012 mmol C was released to the atmosphere over one year. The behaviour as a carbon source/sink obviously varied in the different regions of the Jiaozhou Bay. In February, the inner bay was a carbon sink, while the bay mouth and the outer bay were carbon sources. In June and July, the inner and outer bay were carbon sources, but the strength was different, increasing from the inner to the outer bay. In November, the inner bay was a carbon source, but the bay mouth was a carbon sink. The outer bay was a weaker CO2 source. These changes are controlled by many factors, the most important being temperature and phytoplankton. Water temperature in particular was the main factor controlling the carbon dioxide system and the behaviour of the Jiaozhou Bay as a carbon source/sink. The Jiaozhou Bay is a carbon dioxide source when the water temperature is higher than 6.6°C. Otherwise, it is a carbon sink. Phytoplankton is another controlling factor that may play an important role in behaviour as a carbon source or sink in regions where the source or sink nature is weaker.
Cell cycle analysis of brain cells as a growth index in larval cod at different feeding conditions and temperatures
Authors: González-Quirós Rafael , Munuera Iyziar , Folkvord Arild
Published: October 2008

The percentage of cells dividing in a specific tissue of individual larvae can be estimated by analyzing DNA per cell by flow cytometry. An experimental test was carried out with cod (Gadus morhua) larvae, with brain as the target tissue, to validate this technique as an appropriate growth index for larval fish. Standard length (SL), myotome height, and %S-phase (% of cells in the S-phase of the cell-division cycle) variability were analyzed, with temperature (6 and 10°C), food level (high- and no-food) and larval developmental stage (first feeding, pre-metamorphosis and post-metamorphosis) as independent factors. Cod larvae grew faster (in SL) and presented a higher %S-phase under high-food conditions. Larval SL increased with temperature in rearing and experimental tanks. However, there was a significant interaction between temperature and food in the %S-phase. There were no significant differences in the %S-phase between 6 and 10°C at high-food levels. We suggest that this result is a consequence of temperature-dependency of the duration of the cell cycle. In the absence of food, larvae at 10ºC had a lower %S-phase than larvae at 6°C, which may be related to increased metabolic costs with increasing temperature. Considering the effect of temperature, the mean % S-phase explained 74% of the variability in the estimated standard growth rate.
The effect of protection on fish populations in the Ses Negres Marine Reserve (NW Mediterranean, Spain)
Authors: Rius Marc
Published: October 2008

This work is the result of a 3-year monitoring programme for assessing the effect that the Ses Negres marine reserve has had on fish populations. Species richness (based on fish species that are considered to be reserve effect indicators), and the size structure of 4 species vulnerable to angling and spear fishing were studied by visual censuses conducted both inside and outside the marine reserve. Analysis of fish populations inside the reserve showed a reserve effect (larger sizes, higher abundance and richer fish assemblages) when compared to the non-reserve sites, especially by the end of the study period. The results highlight the importance of marine reserves for the recovery of fish populations. Future management plans are discussed for this marine reserve.
Trophic relationships of the spinner dolphin at Fernando de Noronha Archipelago, SW Atlantic
Authors: Martins Silva-Jr José , De Lima Silva Flávio José , Sazima Cristina , Sazima Iván
Published: October 2008

We present an overview of predator-prey and other trophic relationships of spinner dolphins (Stenella longirostris) around Fernando de Noronha Archipelago, off northeastern Brazil, with use of original data and a brief review of data published elsewhere. Records were made while snorkelling among the dolphins in daytime. Individual fish pursuit and coordinated school herding were the two hunting tactics recorded. Three small prey types (oceanic squids, fishes, and prawns) were recovered from vomits collected in situ and from stomachs of two stranded dolphins. In their turn, spinners were preyed on by the cookiecutter sharks (Dalatiidae) as evidenced by round and crater-like wounds and circular scars. Additionally, the dolphins were preyed on by large sharks (Lamnidae, Carcharhinidae), as evidenced by crescent-shaped wounds and scars. Unidentified fishes bit fin pieces, as evidenced by variably-shaped marks. On the other hand, dolphins’ particulate faeces, vomits and live roundworms were eaten by plankton-feeding fishes. Thus, the trophic role of the spinner dolphins of Fernando de Noronha may be summarised as that of : 1) a predator of small oceanic squids, fishes, and prawns; 2) a prey for the small, piece-eating cookiecutter sharks and other unidentified fishes; 3) a prey for large sharks able to kill a dolphin; and 4) a particulate food supplier for plankton-eating fishes.
Observations on the population characteristics of Apionsoma (Apionsoma) misakianum (Sipuncula: Phascolosomatidae), a new species for the Mediterranean fauna
Authors: Açik Sermin
Published: October 2008

The present paper deals with the ecology and population characteristics of the sipunculid Apionsoma (A.) misakianum from the Aegean Sea, which is a new record for the Mediterranean Sea. A total of 571 specimens of this species were collected at 25 stations between 41 and 195 m depth. The majority of specimens were found between the depth intervals 101-150 m (46%) and 151-200 m (45.2%). The biometrical parameters such as the trunk length and individual wet weight of the specimens were evaluated using regression and correlation analyses. In addition, the morphological, ecological and distributional features of the species are given and discussed.
Interactions between shorebirds and benthic invertebrates at Culbin Sands lagoon, NE Scotland: Effects of avian predation on their prey community density and structure
Authors: Mendonça Vanda M. , Raffaelli David George , Boyle Peter R.
Published: October 2008

In the North Sea, during autumn-winter, intertidal flats often receive a massive influx of migratory shorebirds (wildfowl, waders and seabirds), which utilise the high prey densities that are available. The present study was conducted at Culbin Sands lagoon, NE Scotland, in 1994-1996, to investigate benthic invertebrate standing stock, and the energy flow from benthic invertebrates to shorebirds. Benthic invertebrate standing stock was estimated to be 500 kJ m-2 yr-1, and shorebird consumption efficiency to be 18% of the available standing stock. A series of manipulative field experiments were then conducted to test the effects of shorebirds on benthic invertebrate densities and community structure. Birds were excluded from caged areas (exclosures), and benthic invertebrate densities (total and by class size) in caged and uncaged areas were compared for each season separately. During autumn-winter, especially the gastropod Hydrobia ulvae and larger-sized (>15 mm) clams Macoma balthica were observed to be the most impacted species, being significantly more abundant in bird-exclosures than in bird-accessed areas.
In vivo measurements of the seasonal photosynthetic fluorescence of the Mediterranean coral Cladocora caespitosa (L.)
Authors: Peirano Andrea
Published: October 2008

In situ photosynthetic fluorescence of the zooxanthellate Mediterranean coral Cladocora caespitosa (L.) was measured seasonally on colonies from 5 to 27 m depth using an INF-300 Integrating Natural Fluorometer (Biospherical Instrument Inc.). This oceanographic instrument, used to measure the in vivo phytoplankton chlorophyll a (Chl a) fluorescence, was adapted to record the natural fluorescence of C. caespitosa by SCUBA divers. The resulting curves of natural fluorescence of Chl a vs photosynthetically active radiation (PAR 400-700 nm) showed that: (1) natural fluorescence was limited by light availability in both deep and shallow colonies in all seasons; (2) photosynthesis occurred in C. caespitosa also in winter, when temperature is low and seawater turbidity contributes significantly to PAR attenuation; and (3) the efficiency of the Chl a fluorescence increased from summer to winter. This last finding outlines the winter coupling between zooxanthellae activity and calcification processes and is consistent with the formation of the high density band in the coral skeleton.
Marine and brackish-water molluscan biodiversity in the Gulf of California, Mexico
Authors: Hendrickx Michel E. , Brusca Richard C. , Cordero Mercedes , Ramírez R. Germán
Published: October 2008

A database containing taxonomic, distributional and ecological data of 2194 species of marine molluscs (1528 Gastropoda, 565 Bivalvia, 59 Polyplacophora, 21 Scaphopoda, 20 Cephalopoda, and one Monoplacophora) known to the Gulf of California, Mexico, was used to analyse their latitudinal and bathymetric distribution, to define their substrate preferences, and to elaborate a biodiversity model for the study area. The model was based on a comparison between the set of data associated with each species (i.e., depth range, associated substrates and geographic distribution within the Gulf) and the environmental conditions prevailing in the Gulf (i.e., depth and substrate), using a georeferenced grid of 2 x 2 nautical miles. Results are presented as predictive biodiversity distribution maps for the major molluscan groups. Putative biodiversity ranges were defined using a percentage accumulative system with 20% classes. As expected, the highest biodiversity occurs along the coastline and around the islands. A south-north biodiversity gradient is observed, although it is less evident between the southern and central Gulf.
Age estimation of the Atlantic bonito in the eastern Mediterranean Sea using dorsal spines and validation of the method
Authors: Zaboukas Nikolaos , Megalofonou Persefoni
Published: October 2008

Growth parameters were studied in 397 specimens of the Atlantic bonito caught in the eastern Mediterranean Sea (Aegean and Ionian Seas) ranging from 7.2 to 72.5 cm in fork length and from 2 to 5400 g in total weight. The study of the growth bands in spine sections showed that one translucent ring is formed annually during the cold season. The growth parameters estimated (L∞ = 82.99 cm, K = 0.24, t0 = -0.77) express the growth of the species more realistically than previous studies in the Mediterranean Sea and the Atlantic Ocean.
Reproductive biology of the squirrelfish, Holocentrus adscensionis (Osbeck, 1765), caught off the coast of Pernambuco, Brazil
Authors: Shinozaki-Mendes Renata A. , Vieira Hazin Fabio Hissa , De Oliveira Paulo Guilherme , Correia de Carvalho Felipe
Published: October 2008

In the present work, specimens of Holocentrus adscensionis, caught off Pernambuco State, northeast Brazil, by small scale artisanal fishing boats, were analyzed with regard to gonad maturation, gonad index, size at first sexual maturity, fecundity, type and time of spawning. Two hundred and three specimens were randomly collected, 102 males and 101 females, resulting in a sex ratio very close to 1:1. Size at first sexual maturity was estimated at 14.6 cm fork length, which is smaller than the most caught size class. Females in final maturation were only recorded from October to March, while the proportion of resting females was the highest in June and July. The seasonal variation of sexual stages, together with the variation of the monthly mean gonad index, with the lowest values for females being recorded from May to July, suggests lower sexual activity for this species during this period of the year, which coincides with winter time. The pattern of ovarian development indicates that spawning is synchronous, with oocytes ripening in more than two groups. It is therefore characterized as a batch spawning. Absolute fecundity ranged from 56274 to 249863 oocytes.
Trawl catch composition during different fishing intensity periods in two Mediterranean demersal fishing grounds
Authors: Sánchez Pilar , Sartor Paolo , Recasens Laura , Ligas Alessandro , Martin Javier , De Ranieri Stefano , Demestre Montserrat
Published: October 2008

The study was carried out in two fishing grounds on the Mediterranean continental shelf: one in the Adriatic Sea and one in the Catalan Sea. Samplings on board otter trawlers were performed from November 2002 to December 2003 in the Catalan Sea and from February 2003 to January 2004 in the Adriatic Sea. The Adriatic fishing ground was affected by high fishing intensity from January to June, while the Catalan area was highly exploited from September to February. Fishing activity in the Adriatic area was closed for 45 days, and 62 days in the Catalan area; both periods were in summer. Totals of 92 and 88 species were collected in the Adriatic and Catalan fishing grounds respectively. The species composition of the retained and discarded fractions showed close agreement between the two areas. Mullus barbatus showed very low discard rates in both areas, as well as Loligo vulgaris in the Catalan Sea and Merluccius merluccius in the Adriatic Sea. In both fishing grounds Squilla mantis showed high catch rates with low discards, except in March in the Catalan area. In the Adriatic Sea Liocarcinus depurator was characterized by large discard fractions. In both fishing grounds the retained fraction was slightly higher in the high fishing intensity periods than in the low intensity ones (Adriatic Sea: 0.613 vs 0.524; Catalan Sea: 0.597 vs 0.539), even though the Kruskall Wallis test revealed significant differences (p
Age, growth and mortality of white grunt (Haemulon plumierii) from the central coast of Brazil
Authors: Neves Araújo Júlio , Silva Martins Agnaldo
Published: October 2008

White grunt (Haemulon plumierii) otoliths were collected from 1997 to 1999 off the central coast of Brazil. Analysis of the edges of otolith sections suggests that one translucent and one opaque zone are formed once a year. Observed size and age class ranges for H. plumierii were 218–378 mm total length (TL) and 2–28 years, respectively. The von Bertalanffy growth models estimated were significantly different between sexes. The growth models for females, males and all fish were Lt = 298.0[1 – e– 0.59(t–0.08)], Lt = 331.8[1 – e– 0.35(t+1.08)] and Lt = 312.2[1 – e– 0.48(t+0.32)], respectively. Growth is fast during the first 4 years of life, when the average fish size is already in excess of 80% of the asymptotic size. The maximum age observed in this study is greater than those previously reported for H. plumierii. The natural mortality rate (M) estimate based on the oldest observed fish was 0.15 year-1, while total mortality (Z) from the age-based catch curve was 0.21 year-1 (95% confidence interval: 0.18–0.24 year-1). These estimates show that the stock was under low to moderate levels of exploitation in the late 1990s.
High genetic differentiation with no evidence of hybridisation between four limpet species (Patella spp.) revealed by allozyme loci
Authors: Sá-Pinto Alexandra , Alexandrino Paulo , Branco Madalena
Published: October 2008

The occurrence of hybridisation between limpet species of the genus Patella has always been a contentious issue. Although a previous allozyme study reported high differentiation and no hybridisation between Patella vulgata Linnaeus, 1758, Patella depressa Pennant, 1777 and Patella ulyssiponensis Gmelin, 1791 along English shores, the recent finding of an mtDNA haplotype of P. depressa in a P. vulgata individual raised new doubts on this issue. To further study the possibility of hybridisation between limpet species and their level of genetic differentiation, ten allozyme loci were screened using starch gel electrophoresis for P. ulyssiponensis, P. depressa, P. vulgata and Patella rustica Linnaeus, 1758, from the Atlantic coast of the Iberian Peninsula. Our results show high differentiation between species, which could be clearly separated into different clusters with a Bayesian clustering algorithm. No significant signs of hybridisation were detected between any of the four species. Thus, the hypothesis of hybridisation between P. vulgata and P. depressa across their sympatric distribution is not supported. Two sympatric clusters were recovered within P. vulgata that could be related to Hardy-Weinberg disequilibrium found in locus MPI. Finally, due to the high level of intraspecific variability, the studied loci are interesting tools for the analysis of population structure and stock identification.
Metal speciation in surface sediments of the Vigo Ria (NW Iberian Peninsula)
Authors: Belzunce Segarra María Jesús , Prego Ricardo , Wilson M. Jeff , Bacon Jeff , Santos-Echeandía Juan
Published: October 2008

Total concentrations and chemical forms of metals in surface sediments of the Vigo Ria (NW Iberian Peninsula) were determined following the sequential extraction method proposed by Tessier et al. (1979). Total values ranged from 7 to 14 µgCo g-1, 52 to 76 µgCr g-1, 18 to 82 µgCu g g-1, 136 to 209 µgMn g g-1, 18 to 30 µgNi g g-1, 24 to 112 µgPb g g-1, 62 to 185 µgZn g g-1 and 18 to 34 mg g g-1 for Fe. The distribution of metals is strongly influenced by the presence of urban and industrial centres. A decreasing concentration trend was observed towards (i) the outer-oceanic part of the ria and (ii) the northern shore in the middle part. Cobalt, Cr, Fe, Mn, and Ni were found to be strongly associated with the residual fraction of the sediment (65-78%), whereas Cu is significantly present in the oxidisable phase (34-72%) and Pb and Zn are found in both the reducible (14-49%) and the oxidisable (14-39%) phases. The speciation patterns reflect natural uncontaminated conditions in the outer part of the ria. However, a significant fraction of the Cu, Pb, and Zn in the sediments of the southern margin of the middle part of the ria, which supports most of the population and industrial activities, is present in labile forms, so a potential pollution risk may exist.
Postlarval development of Halicarcinus planatus females (Crustacea, Decapoda, Hymenosomatidae) in the estuary of the Deseado River, Argentina
Authors: Vinuesa Julio H. , Ferrari Lucrecia
Published: October 2008

This study analyses morphology and morphometric growth changes of Halicarcinus planatus females until their terminal moult, and characterises new juvenile stages. Monthly samples were collected in the estuary of the Deseado River, Santa Cruz Province, Argentina. Crabs were sampled between the mid-intertidal and upper subtidal levels. Intermoult stages were analysed in sub-samples of adolescents and adults, and the presence of epizoic organisms was registered. Juveniles and adults were reared at the laboratory and examined for moult changes. All 3376 crabs caught were females, indicating a clear spatial segregation between sexes. Five juvenile stages (immature 1, 2, 3, 4 and adolescent) and a mature one were recognised on the basis of morphology and morphometry. All immature stages differed in cephalothorax width (CW) and abdomen width (AW). Positive allometry was observed in some juvenile stages and isometry in an immature stage and in mature females. Adolescents and adults encompassed a wide range of sizes, and the considerable size overlap between them suggests an anomalous growth process. Moult staging analysis indicated that adolescents have a high incidence of pre-moult stages in winter, when the terminal moult occurs. The measurements performed in laboratory-reared females indicated no abnormal increases during the moult. The terminal moult occurs within a wide size range, perhaps in association with mating.
Ichthyofauna assemblages from two unexplored Atlantic seamounts: Northwest Bank and João Valente Bank (Cape Verde archipelago)
Authors: Monteiro Pedro , Ribeiro Daniel , Silva José A. , Bispo João , Gonçalves Jorge M.S.
Published: October 2008

Underwater censuses by divers were used to study the fish assemblages from two unexplored Atlantic seamounts in the Cape Verde archipelago. Fifty three species of 27 families were recorded: 27 in Northwest Bank and 46 in João Valente Bank. Northwest Bank had dense schools, while João Valente Bank had higher species richness and smaller schools. Both seamounts were dominated mainly by coastal species directly depending on seabed habitat (Demersal or benthopelagic). Of the 53 fish species recorded, 22.6% were of continental African origin, while 9.4% and 5.7% were endemic of the Cape Verde Islands and of the Macaronesia province, respectively. Most species (64.2%) had a very wide biogeographic distribution: cosmopolitan (22.6%), amphi-Atlantic (28.3%) and Atlantic-Mediterranean (13.2%). Northwest Bank and João Valente Bank may have a permanent fish community supported by various oceanographic-topographic interactions. João Valente Bank seems more diverse, which is probably associated with algae cover and with a larger area providing additional suitable and more varied habitats. The geographic proximity to the coast and the presence of oceanic and/or oceanodromous species suggests that the upper part of these seamounts may act both as attraction points and as “stepping-stones” for the dispersal of coastal species.
Partial characterization and response under hyperregulating conditions of Na+-K+ ATPase and levamisole-sensitive alkaline phosphatase activities in chela muscle of the euryhaline crab Cyrtograpsus angulatus
Authors: Andrea Pinoni Silvina , López Mañanes Alejandra Antonia
Published: October 2008

The occurrence, characteristics and response to changes in environmental salinity of Na+-K+ ATPase and levamisole-sensitive alkaline phosphatase (AP) activities were studied in chela muscle of the euryhaline crab Cyrtograpsus angulatus. Chela muscle exhibited an Na+-K+ ATPase activity which was strongly dependent on ATP concentration, pH and temperature of the reaction mixture. Maximal activity was found at 1 mM ATP, 30-37°C and pH 7.4. Levamisole-sensitive AP activity was characterised at physiological pH 7.4 and at pH 8.0. I50 for levamisole-sensitive AP activity was 8.8 mM and 8.0 mM at pH 7.4 and 8.0, respectively. At both pH levels, levamisole-sensitive AP activity exhibited Michaelis-Menten kinetics (Km=3.451 mM and 6.906 mM at pH 7.4 and 8.0, respectively). Levamisole-sensitive AP activities were strongly affected by temperature, exhibiting a peak at 37ºC. In crabs acclimated to low salinity (10; hyperegulating conditions), Na+-K+ ATPase activity and levamisole-sensitive AP activity at the physiological pH were higher than in 35 psu (osmoconforming conditions). The response to low salinity suggests that both activities could be components of muscle regulatory mechanisms at the biochemical level secondary to hyperegulation of C. angulatus. The study of these activities under hyperegulating conditions contributes to a better understanding of the complexity of biochemical mechanisms underlying the adaptive process of euryhaline crabs.
A physiological approach to oceanic processes and glacial-interglacial changes in atmospheric CO2
Authors: Pelegrí Josep L.
Published: October 2008

One possible path for exploring the Earth’s far-from-equilibrium homeostasis is to assume that it results from the organisation of optimal pulsating systems, analogous to that in complex living beings. Under this premise it becomes natural to examine the Earth’s organisation using physiological-like variables. Here we identify some of these main variables for the ocean’s circulatory system: pump rate, stroke volume, carbon and nutrient arterial-venous differences, inorganic nutrients and carbon supply, and metabolic rate. The stroke volume is proportional to the water transported into the thermocline and deep oceans, and the arterial-venous differences occur between recently-upwelled deep waters and very productive high-latitudes waters, with atmospheric CO2 being an indicator of the arterial-venous inorganic carbon difference. The metabolic rate is the internal-energy flux (here expressed as flux of inorganic carbon in the upper ocean) required by the system’s machinery, i.e. community respiration. We propose that the pump rate is set externally by the annual cycle, at one beat per year per hemisphere, and that the autotrophic ocean adjusts its stroke volume and arterial-venous differences to modify the internal-energy demand, triggered by long-period astronomical insolation cycles (external-energy supply). With this perspective we may conceive that the Earth’s interglacial-glacial cycle responds to an internal organisation analogous to that occurring in living beings during an exercise-recovery cycle. We use an idealised double-state metabolic model of the upper ocean (with the inorganic carbon/nutrients supply specified through the overturning rate and the steady-state inorganic carbon/nutrients concentrations) to obtain the temporal evolution of its inorganic carbon concentration, which mimics the glacial-interglacial atmospheric CO2 pattern.
Species of Galacantha and Munidopsis (Crustacea: Decapoda: Anomura: Galatheidae) from the deep-waters off Taiwan, with the description of two new species
Authors: Osawa Masayuki , Lin Chia-Wei , Chan Tim-Yam
Published: October 2008

One species of the genus Galacantha A. Milne-Edwards, 1880, and 20 species of Munidopsis Whiteaves, 1874, including two new species, are reported from the deep-waters off Taiwan. Munidopsis echinata n. sp. closely resembles M. colombiana Pequegnat and Pequegnat, 1971 from the Caribbean Sea, but differs in lacking an antennal spine on the carapace and having a much longer antennal peduncle. Munidopsis tuberosa n. sp. appears close to M. granosicorium Williams and Baba, 1990 from the northeast Pacific, but the configuration of the carapace and rostrum separates these two species. Altogether 31 species of Munidopsis are now recorded from Taiwan, indicating a particularly rich deep-sea fauna of the island.
Feeding ecology of the transparent goby Aphia minuta (Pisces, Gobiidae) in the northwestern Adriatic Sea
Authors: La Mesa Mario , Borme Diego , Tirelli Valentina , Di Poi Elena , Legovini Sara , Fonda Umani Serena
Published: October 2008

The feeding ecology of the transparent goby Aphia minuta was examined in spring (May 2003) in the coastal waters off Comacchio, in the northwestern Adriatic Sea. Stomach content analysis indicated A. minuta to be a planktivorous species, feeding exclusively on pelagic invertebrates. The diet composition was dominated by the calanoid copepods Acartia clausi and Temora longicornis, followed in decreasing order of importance by other copepods (especially calanoids and Oncaea spp.) and larvae of decapods, polychaetes and bivalves. A. minuta exhibited a generalistic feeding strategy with a relatively broad niche width. Abundant taxa in the environment, such as A. clausi and T. longicornis, were seldom selected, whereas rare taxa, such as larvae of polychaetes and decapods, were highly selected. According to the observed ontogenetic shift in diet, small-size individuals relied preferentially on juvenile T. longicornis and Oncaea spp., whereas large-sized specimens consumed preferably A. clausi and calanoids. The positive relationship found between prey and fish size may help to mitigate the intraspecific competition for food resources.
Recent brachiopods from the Persian Gulf and their biogeographical significance
Authors: Bitner Maria Aleksandra , Logan Alan , Gischler Eberhard
Published: October 2008

Two brachiopod species Discradisca indica (Dall, 1920) and Argyrotheca jacksoni Cooper, 1973, together with Lingula sp., have been identified from the Persian Gulf. These species, added to the two species Terebratulina retusa (Linnaeus, 1758) and Megerlia truncata (Linnaeus, 1767) previously identified by Jackson (1921), and Lingula anatina Lamarck, 1819 by Emig (1988) bring the total to 5 species for the region. The genera Discradisca and Argyrotheca are recorded for the first time from the Persian Gulf. This fauna shows biogeographical affinities to the Indian Ocean and the Mediterranean faunas. The disjunct geographical distribution of Discradisca suggests this genus is a relict of an ancient Tethyan fauna.
Distribution and abundance of early life stages of Sardina pilchardus in the Gulf of Tunis (Central Mediterranean Sea) in relation to environmental and biological factors
Authors: Zarrad Rafik , Missaoui Hechmi , Alemany Francisco , Hamza Asma , Salah Romdhane Mohamed , García Alberto , Jarboui Othman , M’rabet Ridha
Published: October 2008

Four seasonal surveys were carried out in the Gulf of Tunis between summer 2002 and spring 2003 to study the abundance and distribution of Sardina pilchardus eggs and larvae in relation to environmental parameters. In the Gulf of Tunis, Sardina pilchardus begins spawning in autumn (23 eggs/10 m²) and attains its peak in winter (257 eggs/10 m²) when the mean SST is lowest (13.4°C). Sardine reproduction seems to be triggered by the decrease in the SST. In winter, the main spawning areas were located to the south of Zembra Island and the north of Cape Bon. Larvae were more abundant in winter (38 larvae/10 m²), while lower densities were collected in autumn and spring (1 larva/10 m²). The highest abundance of larvae (288 larvae/10 m²) was recorded southwest of Zembra Island. Eggs and larvae were mainly concentrated in the relatively warmer and saltier waters with high zooplankton abundance and, inversely, with a low concentration of nitrate and chlorophyll a and a low diatom abundance.
Ontogenetic dietary shift and feeding strategy of Raja undulata Lacepède, 1802 (Chondrichthyes: Rajidae) on the Portuguese continental shelf
Authors: Moura Teresa , Figueiredo Ivone , Farias Inês , Serra-Pereira Bárbara , Neves Ana , Borges Maria de Fátima , Serrano Gordo Leonel
Published: October 2008

Under the scope of an ecosystem approach to fisheries, the understanding of trophic interactions is important for the assessment and consequently the proposal of suitable management measures. Raja undulata, like other rajids, is an important demersal predator in the Portuguese coastal community for which the biological and ecological information is still scarce. The ontogenetic dietary shift was investigated. Major length groups were defined through cluster analysis of the mean abundance of prey items. Prey diversity and feeding strategy were evaluated by length group. Multivariate analysis of variance was performed to test the influence of the factors sex, season and maturity on the diet of this species. It was concluded that R. undulata has a dietary ontogenetic shift within the definition of three major length groups (MLGs): 200-550 mm; 550-750 mm and 750-1000 mm. Diet varied from small and semi-pelagic to large and benthic prey. The feeding strategy of the species also changed from a generalised to a specialised diet. The decapod Polybius henslowi was the main prey item, especially for larger predators. Differences were found between sexes, maturity stages and seasons in each MLG.
Population biology and habitat associations of benthic fish species in the shallow areas of a Mediterranean coastal lagoon (SE Iberian Peninsula)
Authors: Verdiell Cubedo David , Oliva Paterna Francisco J. , Egea Serrano Andrés , Torralva Forero Mar
Published: October 2008

The present study investigates the seasonal variation in fish abundance, fish biomass, reproductive status and population structure of four dominant benthic fish species, Salaria pavo, Pomatoschistus marmoratus, Gobius cobitis and Gobius niger, in the shallow and littoral areas of the Mar Menor coastal lagoon. In addition, the seasonal habitat associations of each species were studied by assessing environmental variables related to the habitat structure: submerged vegetation cover, submerged vegetation density, water depth and substrate composition. The temporal variations in fish density, standing stock and size frequency distributions of these species can largely be attributed to the seasonality of their breeding and juvenile recruitment periods. Moreover, habitat associations for these species were similar to those obtained in other Mediterranean and Atlantic coastal lagoons.