107 research outputs found
Hallazgo de anémonas anillo (Anthozoa, Actiniaria) en la región de Azores
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Comparison of fluorescent bands during staining of statoliths of the squid Loligo forbesi (Cephalopoda : Loliginidae)
info:eu-repo/semantics/publishedVersio
Meso- and Bathypelagic Fish Interactions with Seamounts and Mid-Ocean Ridges
The World Ocean\u27s midwaters contain the vast majority of Earth\u27s vertebrates in the form of mesoand bathypelagic (\u27deep-pelagic,\u27 in the combined sense) fishes. Understanding the ecology and variability of deep-pelagic ecosystems has increased substantially in the past few decades due to advances in sampling/observation technology. Researchers have discovered that the deep sea hosts a complex assemblage of organisms adapted to a “harsh” environment by terrestrial standards (i.e., dark, cold, high pressure). We have learned that despite the lack of physical barriers, the deep-sea realm is not a homogeneous ecosystem, but is spatially and temporally variable on multiple scales. While there is a well-documented reduction of biomass as a function of depth (and thus distance from the sun, ergo primary production) in the open ocean, recent surveys have shown that pelagic fish abundance and biomass can \u27peak\u27 deep in the water column in association with abrupt topographic features such as seamounts and mid-ocean ridges. We review the current knowledge on deep-pelagic fish interactions with these features, as well as effects of these interactions on ecosystem functioning. We highlight the recent discoveries from the Mid-Atlantic Ridge (via the Census of Marine Life field project MAR-ECO) that were presented at the international symposium “Into the Unknown, Researching Mysterious Deep-Sea Animals,” hosted by the Okinawa Churaumi Aquarium, Okinawa, Japan, Feb 2007
Deep-Pelagic Fishes and the Mid-Atlantic Ridge: Interactions and Vectoring of Gelatinous Carbon to Higher Trophic Levels?
The assemblage structure and vertical distribution of deep-pelagic fishes relative to a mid-ocean ridge system is described from an acoustic and discrete-depth trawling survey conducted as part of the international Census of Marine Life field project MAR-ECO. A survey along the Mid-Atlantic Ridge (MAR), covering the full depth range (0 to \u3e3000 m) with a combination of gear types, was conducted to understand the role of the pelagic fauna in ecosystem dynamics. A total of 205 fish species were collected by midwater sampling. Depth was by far the primary assemblage composition determinant, with ridge section secondary. The dominant ichthyofaunal component was a widespread assemblage of fishes between 750-3000 m, from Iceland to the Azores. Some zonation was apparent in the northern and southern ends of this large depth stratum, with six smaller assemblages of fishes exhibiting limited distributions. Biomass per volume reached a water column maximum in the bathypelagic zone between 1500-2300 m. This stands in stark contrast to the general “open ocean” paradigm that biomass decreases exponentially from the surface downwards. As much of the summit of the MAR extends into this depth layer, a likely explanation for this midwater maximum is ridge association. Fish density within the benthic boundary layer (within 200 m of the ridge) was nearly double that of the water column and biomass was approximately 50% higher. Of the ‘ridge-associating’ species, two species known to consume gelata, Bathylagus euryops and Scopelogadus beanii, contributed over half of the fish biomass of this layer. These data suggest that a pelagic fish-gelata trophic linkage may be a key element of benthic-pelagic coupling over mid-ocean ridges, thus supporting enhanced nekton biomass over ridges in the absence of terrigenous nutrient input. Ongoing research to better understand this trophic linkage will be presented
Occurrence of Grammicolepis brachiusculus Poey, 1873 (Pisces: Grammicolepididae) in the Azores Archipelago
Three specimens of Grammicolepis brachiusculus were caught by the commercial bottom hand and longline fisheries off Terceira and Faial Islands, Azores Archipelago. This is the first record of the species for the region, and one of few ever caught in the NE Atlantic
Space Shuttle ice suppression system validation, volume 3
The influence of nozzle size without wind, on wind penetration, the influence of nozzle pressure on wind penetration, wind velocity effects, nozzle pressure effects, nominal velocity, wind velocity effects on wind penetration, and nozzle azimuth angle effects are plotted
Case Report: Pure Red Cell Aplasia due to Angioimmunoblastic T-Cell Lymphoma.
Pure red cell aplasia (PRCA) is a rare bone marrow failure characterized by a progressive normocytic anemia and reticulocytopenia without leukopenia and thrombocytopenia. It can be associated with various hematological disorders but exceedingly rarely with angioimmunoblastic T-cell lymphoma (AITL). We report the case of a 72-year-old woman with PRCA associated with AITL. The patient presented with severe anemia (hemoglobin 2.6 g/dL) and a low reticulocyte count 0.7%. Direct and indirect Coombs tests were positive. A CT scan of the chest, abdomen, and pelvis revealed multiple lymphadenopathies. A cervical lymph node biopsy was compatible with AITL. A bone marrow biopsy showed medullary involvement by AITL and a severe erythroid hypoplasia with a myeloid:erythroid ratio of 19.70. The patient was started on CHOP and after 6 cycles the PET scan confirmed complete remissioninfo:eu-repo/semantics/publishedVersio
Space Shuttle ice suppression system validation, volume 1
Preliminary analytical considerations and the experimental investigation of the flow field for the desired configurations in the absence of wind effects are discussed. A wind tunnel test program to determine the effect of different wind conditions on ice suppression system (ISS) performance is also discussed
Some observations on the biology of sardine (Sardina pilchardus Walb.) off Galicia NW Spain
6392 specimen of sardines were sampled during the period 1980-1984. The spawning
season was ca1culated from the monthly percentages of mature individuals, gonadosomatic index, condition factor and viscera1 fat. The size and age at first maturation and the size/weight ratio were calculated.Pendant la periode 1980-1984 des echantillonages biologiques regulieres sur
la sardine ont ete realises et 6932 exemplaires ont été examinées. On determine
la saison de ponte a partir de l'evolution mensuelle du pourcentage des individus
mûrs et de la variation du l'indice gonadosomatique, le facteur de condition
et la graisse viscerale. On calcule aussi la taille et l'age de premiere maturation
et les equations taille/poid vive et poid eviscere
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