bluuebunny/crossref_metadata_2025_split huggingface dataset:
In situ Bicarbonate Uptake by Bacteria‐Alvinella Associations
Authors: Alayse‐Danet A. M. , Gaill F. , Desbruyeres D. 
Published: May 2008

Abstract. Three species of Alvinellidae are found on walls of some hydrothermal chimneys at 13o N on the East Pacific Rise (EPR); numerous epibiotic bacteria were associated with two of these polychaetes, Alvinella pompejana and Alvinella caudata, but not with the third, Paralvinella grasslei. Many studies suggest that chemoautotrophic bacteria play a prominent role in deep‐sea hydrothermal vent ecosystems. Particularly important are the intracellular bacteria present in the giant pogonophores and bivalve molluscs.The abundant epibioses observed on these Alvinella species are unusual and the relationships between these bacteria and the worms are unknown. Previous results, including 13C values, morphological insertion of the bacteria on the epidermis, presence of ribulose biphosphate carboxylase, and fixation of 14C bicarbonate in some bacteria and in the dorsal epidermis, suggest that a trophic relationship could exist between Alvinella and its epibiotic bacteria. The present study compared the incorporation area of 14C bicarbonate in the 3 species. Paralvinella, which is devoid of epibiotic bacteria, served as a control.
A Qualitative and Quantitative Study of the Marine Algae in the Saronikos Gulf (Greece)
Authors: Diapoulis A. , Haritonidis S. 
Published: May 2008

Abstract. One hundred ninety‐seven macroalgal taxa, belonging to four classes, were identified at seven characteristic stations of the Saronikos Gulf.Species diversity was higher in cleaner waters. From the outer to the inner section, the number of species and the coverage increased in Bryopsidophyceae and decreased in Phaeophyceae and Rhodophyceae.
Role of Bacteria in the Carbon and Nitrogen Flow between Water‐Column and Sediment in a Shallow Marine Bay (Bay of Piran, Northern Adriatic Sea)
Authors: Herndl G. J. , Faganeli J. , Fanuko N. , Peduzzi P. , Turk V. 
Published: May 2008

Abstract. The interdependences between phytoplankton standing crop, bacterial biomass and the dissolved organic matter (DOM) pool in the water column were investigated and related to sediment parameters in a shallow marine bay (Bay of Piran, Northern Adriatic Sea) over an annual cycle. Bacterioplankton density varied between 1–10 × 105 cells ml‐1, with lowest density observed in March corresponding to the low Chi a concentrations during this period. Generation times as determined by dialysis incubations ranged between 4h (June) and 82 h (March). Mean bacterial secondary production rates during summer were about 40 mg C m‐1 d‐1 and 5mg C m‐3.d‐1 during winter. With a short time lag, DOM concentrations followed the fluctuation in Chi a.Sediment oxygen demand measurements revealed a mean mineralization rate of about 260 mg C m‐2 d‐1 during summer and 100–200 mg C m‐2 d‐1 in winter. Sediment bacterial density varied between 108 ‐ 109 cells g (sediment dry wt)‐1 in the top 5 cm sediment layer or, in terms of biomass, 4.3 g C m‐l during summer and 0.6 g C m‐2 during winter. Highest concentrations of DOM in pore waters were measured in September, coinciding with high rates of sediment oxygen demand.
Dietary Preferences and Carbon Absorption by two Grazing Gastropods, G/bbula umbilicaris (LINNÉ) and Jujubinus striatus (LINNÉ)
Authors: Peduzzi Peter 
Published: May 2008

Abstract. Ingestion rates and absorption efficiencies in Gibbula umbilicaris and Jujubinus striatus feeding on green algal films, diatoms, macro‐epiphytes, and dead Posidonia ocean/'ca‐Ieaves have been investigated in laboratory experiments.For both gastropod species, ingestion rates were highest in diatoms and thin green algal films as food source. G. umbilicaris exhibited significant lower consumption rates when feeding on seagrass debris or macro‐epiphytes, J. striatus consumed neither Posidonia‐debris nor macro‐epiphytes.Highest carbon absorption efficiencies were found in both gastropod species when feeding on diatoms and green algal films. Significantly lower efficiencies were found in G. umbilicaris when consuming seagrass debris or macro‐epiphytes.Analyses of fecal material confirmed these findings. Highest organic carbon contents were measured in fecal pellets produced after consumption of seagrass debris or macro‐epiphytes reflecting the presence of structural carbohydrates. SEM examinations of feces revealed mainly diatom frustules, refractory parts of macroalgal and other plant material. Analyses of gut contents gave similar results suggesting a basically microphagous herbivory for both gastropod species.Since seagrass debris and macro‐epiphytes are not used very effectively, the high absorption efficiencies when animals feed on the microfloral component of the periphyton are discussed as possible adaptation to limited food availability.
Seasonal Changes in Nitrogen, Free Amino Acids, and C/N Ratio in Mediterranean Seagrasses
Authors: Pirc Helmut , Wollenweber Bernd 
Published: May 2008

Abstract. Seasonal changes in nitrogen, free amino acids, and carbon were investigated in the three Mediterranean seagrasses Posidonia oceanica, Cymodocea nodosa, and Zostera noltii. Leaves, rhizomes, roots, as well as dead plant material were analysed separately. Highest N‐concentrations were obtained in the winter months, regardless of species or plant part. In contrast to the other two species, the N‐content in Posidonia was higher in the rhizomes than in the leaves.In the investigated species, marked differences in the free amino acid (FAA) composition were detected between species: Proline, lacking in Posidonia, was the main component in Cymodocea. In Posidonia, FAA decreased from 320umol g‐1 (dry wt) in leaf sheaths to 1.5 umol g‐1 (dry wt) in the leaf tips. The function of proline as a possible storage and/or stress metabolite is discussed.High C/N values in dead P. oceanica and C. nodosa rhizomes as well as in P. oceanica wrack seem to be related to considerable resistance to decomposition. Low C/N ratios did not increase in detached C. nodosa and Z. noltii leaves, which began to decompose shortly after detachment from the plants.
Foliose Dictyoceratida of the Australian Great Barrier Reef.
Authors: Bergquist Patricia R. , Ayling Avril M. , Wilkinson Clive R. 
Published: May 2008

Abstract. Seven species belonging to three genera of foliose Dictyoceratida are described placing emphasis on field recognition characteristics. These sponges are dominant elements of the Great Barrier Reef fauna.One new genus, Strepsichordaia, and two new species, Strepsichordaia lendenfeldi and Carterio‐spongia contorta, are described and full redescriptions of poorly known older species are given.Features of skeletal morphology and terpene chemistry which make this group of genera distinct within the Dictyoceratida are discussed and a new familial allocation is suggested.
Reproductive Biology of Liocarcinus puber and L holsatus (Decapoda, Brachyura, Portunidae) from the Gower Peninsula, South Wales
Authors: Choy Satish 
Published: May 2008

Abstract. Routine monthly samples of the commercially important portunid crab Liocarcimtx puber and the sympatric but ecologically separated L. holsatus were collected from the waters and shores around the Gowcr Peninsula, South Wales, between November 1983 and September 1985.The pubertal moult in L. puber occurred at 38 mm CW (carapace width) (females) and 42 mm CW (males). In L. holsatus this occurred at 17 mm (females) and 18.5 mm CW (males). The median size of ovigcrous females was 49.2 ± 6.7 mm CW in L. puber and 26.5 ± 2.0 mm CW in L. holsatus.Moulting and copulation occurred between spring and autumn, the moulting period of males being earlier than that of the females. Ovigcrous L. holsatus were recorded throughout the year, with highest proportions between February and April. L. puber were ovigcrous mainly between January and March; none was recorded between September and November. The number of eggs of the wild brood (range: 39,000–280,000 for L. holsatus and 40.000–262.000 for L. puber) was related to female body size as y = 3.099.51 c0.1126x, r = 0.90, n = 21 and y = 6,335.98 c0.051x, r = 0.88, n = 23, respectively, where y = number of eggs and x = carapace width (mm).Following successful copulation, females of both species were able to spawn more than once during an intcrmoult period.
Coral Reef Community Structure at Caño Island, Pacific Costa Rica
Authors: Guzmán Héctor M. , Cortés Jorge 
Published: May 2008

Abstract. Around the Biological Reserve of Caño Island, Pacific Costa Rica, there are five large coral reef flats (with size ranges of 0.8–4.2 ha) built mainly of dead Pocillopora spp. At present, they are covered mainly by crustose coralline algae and microatolls of Porites lobata. From the upper reef slope to the reef base several corals grow in small patches (e. g., Pavona clavus, Pavona varians, Pavona gigantea, Gardineroseris planulata, Psammocora superficialis, Pocillopora elegans, Pocillopora damicornis); the massive coral Porites Iobata is predominant. Pocilloporid species are predominant on most other eastern Pacific reefs.The Caño Island reef is typical of a community whose structure has been controlled by both physical (in shallow water) and biological (in deeper water) factors. Shallow reef areas are influenced by strong wave action and extreme low tides. The distribution, abundance, and feeding preferences of corallivorous organisms (e. g., Acanthaster planci, Arothron meleagris, Pseudobalistes naufragium, Quoyula monodonta) on the deeper reef suggest that most pocilloporids are affected and limited by them. Although there is no evidence of any predator on Porites lobata at Caño Island, the triggerfish Pseudobalistes naufragium breaks off fragments of the coral while searching for food. These fragments often survive to form new colonies. Together, this dispersal mechanism, rapid injury recovery, and high resistance to environmental stress seem to enhance the distribution and dominance of the massive coral Porites lobata at Caño Island.
Spatio‐Temporal Distribution of Algal and Animal Communities in a Posidonia oceanica Meadow
Authors: MaZzella Lucia , Scipione Maria Beatrice , Buia Maria Cristina 
Published: May 2008

Abstract. Investigations were carried out in a Posidonia oceanica meadow at Ischia (Gulf of Naples) along a depth gradient from 1 to 32 m in November 1979 and May 1981.In these two months, different discontinuities were found at the sampling stations (1, 5, 10, 20, 30 m) at 10 m for leaf features, between 1 and 5 m for the algal community and the vagile fauna. The leaf features (length, surface, and biomass) along the transects show a delay in leaf production toward the deeper stations, below the thermocline.The algal community shows in both seasons and in all stations a persistence of an encrusting layer, mostly represented by Corallinaceae and the brown alga Myrionema orbiculare, while at the shallowest station (1 m) the community is characterized by a more developed upright layer.The vagile fauna of the leaf stratum, mostly represented by Polychaeta, Mollusca, and Crustacea (Peracarida and Decapoda), shows a consistent zonation in both seasons along the transect. A superficial community at I m, characterized by a low number of species and individuals and specialized for high environmental energy levels, and a deeper community, persistent in time and more strictly related to the Posidonia oceanica meadows, are identified.The influence of environmental factors and the importance of meadow structure for the zonation of the algal and animal communities are discussed.
Effect of Hydrocarbons and Decontaminating Substances on Bacterial Flora of Coastal Sediments
Authors: Crisafi Ermanno , Zaccone Renata , Genovese Lucrezia , Ferla Rosabruna La , Maugeri Teresa Luciana 
Published: May 2008

Abstract. Seventy six samples of coastal sediments collected in the Straits of Messina were studied in order to evaluate the effects of an oil spill and the consequent “clean‐up” operations on heterotrophic acrobic bacteria.In addition, in vitro tests were carried out to estimate the effects of five dispersants on the growth and oil degrading capacity of marine strains isolated from the same sediments.
The Effects of Industrial Pollution on the Development and Succession of Marine Fouling Communities II. Multivariate Analysis of Succession
Authors: Moran P. J. , Grant T. R. 
Published: May 2008

Abstract. The successional stages of fouling communities from 3 sites located along a pollution gradient within Port Kembla Harbour (Australia) were compared quantitatively with those from Wollongong Harbour, a relatively unpolluted area located close by.A multivariate classification of the data showed that the development of fouling communities in Port Kembla Harbour was very different from that in Wollongong Harbour, involving different types of species. In addition, the classification identified a secondary pattern in the data which showed that the species composition of the Port Kembla Harbour communities changed with time, independently of any seasonal effects.A principal coordinate analysis of the data was able to further expand on these findings. It demonstrated that the succession of fouling communities in Port Kembla Harbour involved a process whereby one group of species (ascidians) was gradually replaced through time by a second group of different species (bivalves). In contrast, the communities in Wollongong Harbour were dominated by inhibitory interactions. The succession in this area mainly involved species (particularly bryozoans) which colonised during the initial stages of development and remained in the communities as they continued to develop.Changes in the succession of fouling communities from Port Kembla Harbour were thought to be due to the loss of pollution sensitive species, such as bryozoans, from the environment. This was not attributed to the acute, toxic effects of the pollutants, but rather to more subtle and indirect effects.
Study of a Crustacea Decapoda Taxocoenosis of Posidonia oceanica Beds from the Southeast of Spain
Authors: García‐Raso J. E. 
Published: May 2008

Abstract. During 1986 and 1987 a decapod crustacean taxocoenosis of Posidonia oceanica beds from the southeast of Spain has been studied.Data on abundance‐dominance of the 50 species found and other information such as reproduction and the selective use of gastropod shells by the dominant hermit crabs arc given.Differences in richness and cquitability between shallow (3–4 m) and deeper (5–7 m) samples arc also shown.The taxocoenosis presents a geometrical distribution in which only 9 species have a relative abundance higher than 1 % and in which the structure is basically controlled by the two dominant hermit crabs, Cestopagitius limidus and Calcium tubularis, and hydrodynamic conditions.
Analysis of Benthic Communities in the Cyclades Plateau (Aegean Sea) Using Ecological and Paleoecological Data Sets
Authors: Zenetos Argyro , Papathanassiou Evangelos , Aartsen Jacobus J. Van 
Published: May 2008

Abstract. In the Cyclades plateau (Aegean Sea), a qualitative and quantitative analysis of macro‐benthic fauna was carried out in 1986. Standard multivariate analysis techniques were applied to both ecological (living benthic fauna) and paleoecological data sets in order to distinguish distribution patterns.Results showed that caution must prevail in drawing conclusions from a limited data set. The clearest classification was obtained using total living fauna, while the dead molluscan fauna gave a similar pattern; this indicates similar response to the environmental conditions of the area. In the analysis of the living molluscan fauna, the groups failed to show any clusters, probably as an effect of some impoverished sites.In the two groups delineated, depth seems to be the major factor in the distribution of species.The fact that two distinct data sets (subfossil assemblages and living communities), when treated separately, produce similar grouping indicates that the subfossil assemblages could be reliably used as a first approach for determination of the living communities' distribution patterns.
Deposit Feeding and Sediment:
Authors: Amon Rainer M. W. , Herndl Gerhard J. 
Published: May 2008

Abstract. The effect of defecation and decomposition of fecal pellets egested by the deposit feeding Holothuria tubulosa Gmelin on the microbial productivity of sediments was investigated in microcosm experiments. H. tubulosa specimens were collected from a 5m deep seagrass meadow in the nearshorc waters of the Mediterranean Sea off Lacco Ameno (Island of Ischia, Gulf of Naples, Italy). Experiments were performed under different temperature regimes. Bacterial production in the incubation media and within fecal pellets increased with increasing temperature, ranging from 0.8 to 1.65 μg C 1‐1 h‐1 at 14 oC and up to 16.5 μg C ‐1‐1 h‐1 (27 oC) in the incubation media. The corresponding values within fecal pellets ranged between 3.6 and 8.5 μg C g‐l (fecal matter dry wt) h‐1 (14oC) and 30.3μg C g‐1 (fecal matter dry wt) h‐1 (27oC). Incubation experiments on the effect of feces on natural sediments indicated that fecal pellet production by H. tubulosa enhanced sediment bacterial production by about 30 %.Two independent methods were used to estimate leaching of dissolved carbohydrates from fecal pellets. One method was based on the increase in total dissolved carbohydrates (TDCHO) in the incubation medium of the HgCl2‐treated jars, the other on the decrease in total particulate carbohydrates (TPCHO) of the fecal matter. For the experiment performed at 14 oC, we calculated a TDCHO‐leaching rate of 26.4 % d‐1 based on the increase in the HgCl2‐treated jar, while 20 % d‐1 were obtained from the decline in the TPCHO fraction of the fecal matter.
Life Cycle of Liocarcinus arcuatus (Brachyura: Portunidae) in the Ría de Arousa (Galicia, NW Spain): Role of Beach and Mussel Raft Culture Areas
Authors: Freire J. , Muiño R. , Fernández L. , González‐Gurriarán E. 
Published: May 2008

Abstract. The population biology of the portunid crab Liocarcinus arcuatus is analyzed over a yearly cycle in beach zones and mussel raft culture areas in the Ria de Arousa.The breeding cycle of this species has two annual peaks, which result in two annual cohorts that are recruited in different areas. The growth rate is higher in the group settled in spring than in autumn, and, especially, in the culture areas compared with the beach zones. There are movements from the beach zones to the raft polygons related to reproductive and feeding behavior as well as growth. The role of mussel culture in the dynamics of this species is discussed.
The Meiobenthos Along a Mediterranean Deep‐Sea Transect off Calvi (Corsica) and in an Adjacent Canyon
Authors: Soetaert Karline , Heip Carlo , Vincx Magda 
Published: May 2008

Abstract. Meiobenthos densities (excluding hard‐shcllcd foraminifcrans) were compared along a Mediterranean deep‐sea transect off Calvi (Corsica) and in an adjacent canyon. Chloroplastic Pigment Equivalent values (CPE) provided an estimate of the amount of primary production reaching the bottom.The stations along the transect were characterized by a low CPE content of the sediment, decreasing with increasing station depth. CPE values in the canyon were much higher, which probably resulted from import of material from the adjacent bay of Calvi. Similarly, meiobenthos densities along the transect were much lower than at comparable depths along the canyon.Meiobenthos density was significantly and positively correlated with CPE values.Nematodes were the most abundant taxon at all stations, followed by copepods + nauplii and the soft‐shelled foraminiferans. The meiobenthos was most abundant in the upper half centimeter. Nematode and foraminiferan densities tended to decline less rapidly with increasing depth into the sediment. Specimens belonging to the recently described phylum Loricifera, larvae of the parasitic crustacean class Tantulocarida, and fragments of an infaunal Xenophyophoria (large protozoans) are reported for the first time from the Mediterranean.
The Sponge Population of the Cabrera Archipelago (Balearic Islands): Characteristics, Distribution, and Abundance of the Most Representative Species
Authors: Uriz María Jesús , Rosell Dolors , Martín Daniel 
Published: May 2008

Abstract. The abundance, distribution, and species richness of the littoral sponges (0–55 m) from the Cabrera Archipelago (Balearic Islands) were studied along light gradients from the surface to the sea bottom and from cave mouths to their inner parts. A total of 98 species (11 Calcarea and 87 Demospongiae) were recorded, 8 of which are new records for the Spanish coast.Cluster and correspondence analyses enabled the identification of a sciophilous sponge group including three subgroups: sponges found only in semi‐dark cave habitats, a subgroup common to the coralligenous, precoralligenous, and semi‐dark cave biocoenoses, and a third subgroup exclusive to the coralligenous biocoenosis. A small number of photophilic species and other species having a wide bathymetric distribution made up another separate group. No species clusters for the different semi‐sciophilous (either fleshy or carbonate) or photophilic seaweed communities were discernible. The number of sponge species was negatively correlated with the irradiance level.
Diurnal Variation in Pigment Content in Porphyra laciniata and Chondrus crispus and its Relation to the Diurnal Changes of Underwater Light Quality and Quantity
Authors: López‐Figueroa Félix 
Published: May 2008

Abstract. Short‐term diurnal changes in the pigment content of two red algae, Porphyra laciniata and Chondrus crispus, in their natural environment (Helgoland, North Sea) were detected. Simultaneously, diurnal variations in underwater light quality and quantity were analyzed. A relation between rapid changes in pigment content at twilight and drastic changes in certain wavelength bands: red: far‐red, green: red, and blue: red was observed. Through these ratios, which were detected by various photoreceptor systems, the algae were able to modulate the pigment content during the course of the day.SummaryDiurnal changes in the total photosynthetic pigment (chlorophyll a and biliprotein) contents and pigment ratios of the red algae Porphyra laciniata growing at 0.5 m and 3.5 m and Chondrus crispus at 2‐2.5 m under natural conditions in Helgoland (North Sea) in July 1990 have been observed.The underwater light quality and quantity, the attenuation coefficient (K) in some wavebands, and the ratios: red: far‐red (R: FR), green: red (G: R), and blue: red (B: R) throughout the day and at different depths (0.5, 1, 1.5, 2.5, and 3.5 m) were measured at the same time as the pigment contents. At twilight, rapid quality changes were observed. Directly after this period, major pigment changes in Porphyra and Chondrus were detected.Drastic changes in the pigment content in Porphyra laciniata at twilight, immediately after this period, and after noon were observed. The pigment content of plants growing at 0.5 m and plants transplanted to 3.5m were significantly different (P <0.05). Porphyra at 3.5m had higher PE/PC and PE/Chl a ratios than at 0.5 m. The maximum biliprotein level was observed immediately after noon. The algae growing at deeper levels produced more biliprotein in response to a simultaneous decrease in light intensity and an increase in the G: R ratio. In addition, at dawn, an “inverse chromatic adaptation” was observed, since PE/PC and PE/Chl a ratios during this period decreased when G/R increased.In Chondrus crispus, diurnal Chl a variations showed a reverse pattern in relation to biliprotein variations: the biliprotein content increased during daylight, while Chl a decreased. Maximum PE and PC was produced after noon. The biliprotein: Chl a ratio showed a clear circadian rhythm.The changes in R: FR, G: R, and B: R ratios are proposed as being “photomorphogenic signals” which control the pigment content in algae. Because R: FR and G: R ratios increase linearly with depth, the detection of light quantity changes through these ratios is proposed.