scholarly journals Occurrence, distribution and abundance of Halobates micans Eschscholtz, 1822 (Heteroptera, Gerridae) along the southeastern Brazilian coast

2009 ◽  
Vol 69 (1) ◽  
pp. 67-73 ◽  
Author(s):  
JF. Dias ◽  
CL. Lopes
Keyword(s):  
Austral Summer ◽  
Egg Laying ◽  
Brazilian Coast ◽  
Gas Vesicles ◽  
Low Salinity ◽  
South Atlantic Central Water ◽  
Tropical Water ◽  
Adult Females ◽  
Adult Sex Ratio ◽  
Marine Insect

Data collected during an oceanographic cruise along the southeastern Brazilian coast from Cape Frio (22° 58' S) and Paraná (27° 50' S) in March 1982 showed that the marine insect Halobates micans occurred along the Southeastern Brazilian Bight, but in lower abundance in low-temperature areas due to the intrusion and upwelling of South Atlantic Central Water, and in low-salinity areas in Coastal Water. Insect capture was higher at night and in the oligotrophic Tropical Water. The number of nymphs and adult females was higher, probably because of an active breeding season during the austral summer. Adult sex ratio was 1.3:1.0 (F:M). Floating gas vesicles of benthic Sargassum spp. and petroleum lumps were used by females for egg-laying.

Status of the Hawaiian monk seal (Monachus schauinslandi) population

1995 ◽  
Vol 73 (6) ◽  
pp. 1185-1190 ◽  
Author(s):  
W. G. Gilmartin ◽  
L. L. Eberhardt
Keyword(s):  
Complex System ◽  
Sex Ratios ◽  
Current Trend ◽  
Survival Rates ◽  
Hawaiian Monk Seal ◽  
Monachus Schauinslandi ◽  
Young Females ◽  
Adult Females ◽  
Unknown Factor ◽  
Adult Sex Ratio

Restoration of the Hawaiian monk seal (Monachus schauinslandi) population to its former abundance poses a number of problems in managing a complex system. Sharp differences in history and current trend exist among the six major pupping sites. A severely unbalanced adult sex ratio has resulted in deaths from "mobbing" of estrus females at two sites. Some unknown factor apparently severely reduced the numbers of females at three of the sites and thus produced the observed excess of males. Sex ratios subsequently decreased, but losses of adult females continue at two sites. A simple model indicates that sex ratios at the two sites where mobbing is a problem would require more than 10 years to approach an equilibrium value. Data on trends from counts are compared with estimates from reproduction and survival rates and agree closely except at one site (Kure Atoll), where introductions of young females have been made.

scholarly journals Salinity-induced mixed and barrier layers in the southwestern tropical Atlantic Ocean off the northeast of Brazil

Ocean Science ◽  
2011 ◽  
Vol 7 (1) ◽  
pp. 63-73 ◽  
Author(s):  
M. Araujo ◽  
C. Limongi ◽  
J. Servain ◽  
M. Silva ◽  
F. S. Leite ◽  
...  
Keyword(s):  
Barrier Layer ◽  
Austral Summer ◽  
Late Winter ◽  
Brazilian Coast ◽  
Tropical Atlantic ◽  
Austral Winter ◽  
Surface Salinity ◽  
Barrier Layer Thickness ◽  
Near Surface ◽  
Mixed Layers

Abstract. High-resolution hydrographic observations of temperature and salinity are used to analyze the formation and distribution of isothermal depth (ZT), mixed depth (ZM) and barrier layer thickness (BLT) in a section of the southwestern Atlantic (0°30´ N–14°00´ S; 31°24´–41°48´ W), adjacent to the northeastern Brazilian coast. Analyzed data consists of 279 CTD casts acquired during two cruises under the Brazilian REVIZEE Program. One occurred in late austral winter (August–October 1995) and another in austral summer (January–April 1997). Oceanic observations are compared to numerical modeling results obtained from the French Mercator-Coriolis Program. Results indicate that the intrusion of subtropical Salinity Maximum Waters (SMW) is the major process contributing to the seasonal barrier layer formation. These waters are brought by the South Equatorial Current (SEC), from the subtropical region, into the western tropical Atlantic boundary. During late austral winter southeastern trade winds are more intense and ITCZ precipitations induce lower surface salinity values near the equator. During this period a 5–90 m thick BLT (median = 15 m) is observed and BLT > 30 m is restricted to latitudes higher than 8° S, where the intrusion of salty waters between 8°–12.3° S creates shallow mixed layers over deep (ZT ≥ 90 m) isothermal layers. During austral summer, shallow isothermal and mixed layers prevail, when northeasterly winds are predominant and evaporation overcomes precipitation, causing saltier waters at the surface/subsurface layers. During that period observed BLT varies from 5 to 70 m and presents thicker median value of 35 m, when comparing to the winter. Furthermore, BLT ≥ 30 m is observed not only in the southernmost part of the study area, as verified during late winter, but in the latitude range 2°–14° S, where near-surface salty waters are transported westward by the SEC flow. These results indicate that the inclusion of salinity dynamics and its variability are necessary for studying mixed and barrier layer behaviors in the tropical Atlantic, where ocean-atmosphere coupling is known to be stronger.

scholarly journals The Biology of Crangon Vulgaris L. in the Bristol Channel and Severn Estuary

1947 ◽  
Vol 26 (4) ◽  
pp. 626-661 ◽  
Author(s):  
A. J. Lloyd ◽  
C. M. Yonge
Keyword(s):  
Low Temperatures ◽  
Egg Laying ◽  
Sexual Cycle ◽  
Minimum Length ◽  
Severn Estuary ◽  
Brackish Waters ◽  
Low Salinity ◽  
Egg Carrying ◽  
Wide Range ◽  
Shrimp Fisheries

Collections of some 22,000 female and 6000 male Crangon vulgaris were made throughout the year from the shrimp fisheries of the Severn Estuary and Bristol Channel. All animals were measured.The habits of the species are described; it can withstand a wide range of temperature but, though euryhaline, resembles other Decapoda in the inability to withstand low salinity combined with low temperature.Osmo-regulation is apparently largely inhibited at low temperatures and to a greater extent in the males than the females.Growth rate decreases with increasing age; in the female there is no increase in length when moulting from the ' neuter' to the egg-carrying intermoult. The duration of this intermoult, if spawning is successful, is about double that of the normal intermoult under the same temperature conditions. Growth almost ceases in the winter.Secondary sexual characters are described, especially the differences between the endopodites of the pleopods in the two sexes.Females become mature at a minimum length of 45 mm. in the Channel and seldom less than 50 mm. in the Estuary. The effect of the female sexual cycle on the size of the ovary and the form of the pleopods is described. The process of copulation is described; it can occur in the brackish waters of the estuary. Egg-laying always follows within two days of moulting into the egg-carrying condition but eggs are not retained if copulation has not occurred.The females lie on their sides during the act of spawning and the eggs are firmly attached within thirty minutes to the egg-carrying setae on the basipodites of the first to fourth pair of pleopods, then to those on the endopodite of the first pleopod, finally to those on the coxopodites of the last two pairs of pereiopods.

Varroa destructor (Acari: Varroidae) infestation in queen, worker, and drone brood of Apis mellifera (Hymenoptera: Apidae)

2002 ◽  
Vol 134 (3) ◽  
pp. 381-390 ◽  
Author(s):  
M.T. Santillán-Galicia ◽  
G. Otero-Colina ◽  
C. Romero-Vera ◽  
J. Cibrián-Tovar
Keyword(s):  
Apis Mellifera ◽  
Varroa Destructor ◽  
Egg Laying ◽  
Choice Test ◽  
Simultaneous Test ◽  
Adult Females ◽  
Drone Brood ◽  
Worker Brood

AbstractVarroa destructor Anderson and Trueman females were placed in contact with queen, worker, and drone brood cells of Apis mellifera L. that were soon to be sealed. In a non-choice test, V. destructor adult females were introduced into a comb containing either queen or worker brood cells; 0.62 and 18.28% of the mites entered the queen and worker brood cells, respectively. Only 1 of the 11 mites that entered queen brood cells oviposited, laying a single egg. In another test, brood cells were combined in the same comb in a 1:25:3 queen:worker:drone ratio. The percentages of egg-laying mites in queen, worker, and drone brood cells were 16.66, 61.86, and 79.06%, respectively. When queen, worker, and drone brood cells were combined in equal proportions (33.3:33.3:33.3), percent infestation was significantly different among queen (3.25%), worker (49.12%), and drone (90.07%) brood. Multiple infestation was found in drone brood cells but not in others. Also, mites were inoculated into sealed queen cells. These cells contained either one or two mites (either at the egg or protonymph stage). Conversely, in a simultaneous test with worker brood cells, the offspring per foundress mite included a mean of three individuals (either at the egg, protonymph, or deutonymph stage). It is concluded that V. destructor can infest queen, worker, and drone brood cells, but drone brood cells are preferred; in addition, queen brood cells do not provide an optimal environment for reproduction because it causes a delay in mite oviposition and (or) progeny development.

scholarly journals COMPOSIÇÃO E DISTRIBUIÇÃO DO FITOPLÂNCTON EM ÁREAS COSTEIRAS E OCEÂNICAS DA REOIAO SUESTE DO BRASIL

1986 ◽  
Vol 1 (3) ◽  
Author(s):  
Frederico Pereira Brandini ◽  
Cristine Louise Braum Moraes
Keyword(s):  
Great Influence ◽  
Nutrient Concentrations ◽  
Brazilian Coast ◽  
Trichodesmium Erythraeum ◽  
Tropical Water ◽  
Brazil Current ◽  
Total Phytoplankton ◽  
Phosphate Nitrate ◽  
Anabaena Sp ◽  
Oligotrophic Condition

Total phytoplankton samples and hydrographical parameters were collected from the surface of 16 stations located in the southeastern sector of the brazilian coast during the autumn cruise of the R/V “ Almirante Saldanha” . The limits of temperature (22 — 25°C) and salinity (35,0 — 37,1 x 10‘s) observed indicated the great influence of the Tropical Water over the sampling area where the oligotrophic condition is certainly due to the low nutrient concentrations of this watermass. Phosphate, nitrate and silicate ranged from 0.0 to 0.63, 1.41 to 5.69 and from 4.10 to 25,25 ftg-at.r1, respectively.The most frequent diatoms were Coscinodiscus spp, Coscinosira sp, Pleurosigma sp, Pseudoeunotia doliolus, Thalassionema nitzschioides, Thalassiothrix frauenfeldii and T. mediterrânea, among 49 species observed. Prorocentrum and Protoperidinium spp dominated the dinoflagellate population although the genus Ceratium was represented by a greater number of species. Cyanophycean cells were abundant in coastal (Anabaena sp) and oceanic (Trichodesmium erythraeum) samples.The phytoplankton community was numerically dominated by nanoplanktonic organisms like phytoflagellates (including monads) and the coccolithophorid Coccolithus huxleyi. The phytoplankton association observed in the present study is typical of oligotrophic warm waters of the Brazil Current. Amostras de fitoplâncton total e parâmetros hidrográficos foram obtidos na superfície de 16 estações localizadas no setor sudeste da costa brasileira durante o outono de 1983. Os limites de temperatura (22 — 25°C) e salinidade (35,0 — 37,1 x10 “) observados indicaram a influência da Água Tropical na área estudada onde as condições oligotróficas são devidas à baixa concentração de nutrientes nessa massa d’água. Fosfato, nitrato e silicato variaram entre 0,0 e 0,63, 1,41 e 5,69, e 4,10 e 25,25 /ig-at.r1, respectivamente.As diatomáceas mais freqüentes foram Coscinodiscus spp, Coscinosira sp, Fleurosigma sp, Pseudoeunotia doliolus, Thalassionema nitszchioides, Thalassiothrix frauenfeldii e T. mediterrânea, dentre as 49 espécies observadas. Prorocentrum e Protoperidinrum spp dominaram a população de dinoflagelados apesar do gênero Ceratium ter apresentado o maior número deespécies. As cianofíceas Anabaena sp e Oscillatoria (=Trichodesmium) erythraeum foram abundantes nas amostras costeiras e oceânicas.A comuindade fitoplanctônica foi numericamente dominada por organismos do nanoplâncton, tais como fitoflagelados (incluindo-se mônadas) e o cocolitoforídeo Coccolithus huxleyi. A associação fitoplanctônica observada no presente trabalho é típica das águas quentes e oligotróficas da Corrente do Brasil.

INFLUENCE OF TEMPERATURE AND HUMIDITY ON LONGEVITY, FECUNDITY, AND RATE OF INCREASE OF THE MITE TYROPHAGUS PUTRESCENTIAE (SCHRANK) (ACARINA: ACARIDAE) REARED ON MOLD CULTURES

1961 ◽  
Vol 39 (6) ◽  
pp. 869-876 ◽  
Author(s):  
I. Rivard
Keyword(s):  
Egg Production ◽  
Food Products ◽  
Egg Laying ◽  
Oviposition Period ◽  
Tyrophagus Putrescentiae ◽  
Influence Of Temperature ◽  
Adult Females ◽  
Rate Of Increase ◽  
Temperature And Humidity

Adult females of Tyrophagus putrescentiae (Schrank), a mite that infests stored food products, were reared individually on mold cultures at all combinations of five temperatures and four humidities. A definite diminution in life usually occurred with increase in either temperature or humidity, and the oviposition period was the most affected. Total egg-production and rate of laying were highest at 72.5° F and 90% R.H., and both generally decreased with an increase in temperature or decrease in humidity from these values. Peak of egg-laying, however, was reached sooner at higher temperatures but egg-production was maintained at relatively high levels for shorter periods. Rate of increase was greatest and approximately the same at 90% R.H. within the range 72.5° to 81.5° F.

scholarly journals HYDRODYNAMICS AND BIO-OPTICAL ASSESSMENT OF TWO PRISTINE SUBTROPICAL ESTUARIES IN SOUTHERN BRAZIL

2014 ◽  
Vol 62 (4) ◽  
pp. 265-278 ◽  
Author(s):  
Mauricio Almeida Noernberg ◽  
Byanka Damian Mizerkowski ◽  
Nicole Gabriele Paloschi ◽  
Joaquim Pereira Bento
Keyword(s):  
Water Column ◽  
Light Absorption ◽  
Austral Summer ◽  
Biosphere Reserve ◽  
Salt Transport ◽  
Vertical Shear ◽  
Small Scale ◽  
Brazilian Coast ◽  
Estuarine System ◽  
Physical Processes

Measuring small-scale physical processes and how they affect the spatial patterns of sea water's optical constituents plays a key role in understanding the functioning of complex coastal ecosystems such as estuaries. The spatial variations of physical and bio-optical water properties were investigated during one spring tidal cycle in austral summer, on two transects across the channel of the Medeiros and Itaqui sub-estuaries. These sub-estuaries are a biosphere reserve, and part of the Paranaguá Estuarine System, located on the Southern Brazilian coast. Both sub-estuaries were classified as Type 1a, wellmixed with low stratification. The salinity variations are in phase with the water level, and the tidal propagation is well represented by a standing wave. The vertical velocity profiles showed little vertical shear, and the intensity of the u-component of the velocity varied semi-diurnally. The upper estuary salt transport was dominated by tidal diffusion in an unstable water column. The optical environment presented a mixed dominance of optically active substances, as indicated by the absorption coefficients of dissolved and particulate matter. The colored dissolved organic matter (CDOM) showed overall conservative behavior and was dominant in light absorption below 550 nm in the Medeiros, while nonalgal particles play the most important role in light absorption in the Itaqui in the blue absorption band. The phytoplanktonic contribution is prominent in the red domain and increases as a function of saline intrusion. However, due to the influence of freshwater discharge and the re-suspension of bottom sediments induced by physical processes, the concentrations of the optical components in the water column do not generally have any simple relationships between them.

scholarly journals The shelf and coastal waters off southern Brazil

1961 ◽  
Vol 11 (2) ◽  
pp. 101-112 ◽  
Author(s):  
Ingvar Emílsson
Keyword(s):  
Surface Waters ◽  
Maximum Velocity ◽  
Water Layer ◽  
Subtropical Zone ◽  
Low Salinity ◽  
The North ◽  
Tropical Water ◽  
Brazil Current ◽  
Salinity Water ◽  
Current Flows

The data collected on three oceanographic cruises undertaken in 1956 indicate that the main branch of the Brazil Current flows southwards along the continental slope, where it reaches maximum velocity, and further, that a well defined limit is found between the warm and saline tropical water from the north and that situated over the central part of the shelf. This is especially the case during the summer months (October-March). Below the Brazil Current a water layer of lower salinity and temperature is found. This water mass is formed near the western extremity of the Subtropical Convergence where it sinks and flows northwards to reappear near or at the surface in an area situated between the lighter, south-flowing, tropical water, and the coastal water. Such a distribution of density across the Current is to be expected in view of the dynamics of ocean currents. There are, however, evidences which indicate the occurrence of upwelling from moderate depths, in particular near Cabo Frio where the prevailing winds from NE drive the surface waters offshore. It is further suggested that the upwelling is maintained by a thermohaline mechanism as the density of the cold and low salinity water is decreased by heating from solar radiation. In order to maintain dynamic stability, the heated water must consequently flow out of the area and be replaced by water from below which in turn suffers the same decrease of density, and so on. Such mechanism might, together with prevailing winds, be responsible for permanent or periodic upwelling near other regions in the tropical and subtropical zone of the oceans where salinity decreases with depth.

scholarly journals Spatial and temporal variation of the zooplankton community in the area of influence of the Itajaí-açu River, SC (BRAZIL)

2008 ◽  
Vol 56 (3) ◽  
pp. 211-224 ◽  
Author(s):  
Charrid Resgalla Junior ◽  
Vitor Gonçalves Coutinho de Souza ◽  
Leonardo Rubi Rörig ◽  
Carlos Augusto França Schettini
Keyword(s):  
Saline Water ◽  
River Mouth ◽  
Zooplankton Community ◽  
Temporal Variations ◽  
Spatial And Temporal Variation ◽  
North Coast ◽  
Brazilian Coast ◽  
The North ◽  
Tropical Water ◽  
Area Of Influence

On the north coast of the State of Santa Catarina (Brazil), the Itajaí-Açu River mouth shows a low-saline water plume on the internal shelf with strong density gradients. This oceanographic condition has a possible influence over the pelagic community, and it has been little investigated on the Brazilian coast. The present work seeks to evaluate the spatial and temporal variations of the zooplankton community in the area of influence of the Itajaí-açu River, and its relations with the abiotic forces of temperature (seasonal variation) and salinity of the river plume. For this purpose, 14 monthly oceanographic cruises were carried out during the years 2002 and 2003, to obtain physical and chemical parameters, and zooplankton hauls in 9 sampling points. The zooplankton analyses were carried out at the lowest taxon possible to characterize the resident community of the river mouth. It was observed that the zooplankton presented the highest densities in winter and spring. The species with higher densities and frequencies of occurrence were Paracalanus quasimodo, Parvocalanus crassirostris, Acartia lilijeborgi, Temora stylifera, T. turbinata, and Penilia avirostris, indicating a prevalence in this region, of Tropical Water from the Brazil Current and greater similarity with the coastal community of the Southeast region of Brazil. However, even for the species typical of Tropical Water, there were alterations in dominance of the species, due to the seasonality and level of flow rate of the river on the salinity of the internal shelf of the study area.

scholarly journals Population biology of Eudendrium caraiuru (Cnidaria, Anthoathecata, Eudendriidae) from São Sebastião Channel, Southeastern Brazil

2005 ◽  
Vol 95 (3) ◽  
pp. 241-246 ◽  
Author(s):  
Otto M. P. Oliveira ◽  
Antonio C. Marques
Keyword(s):  
Mediterranean Sea ◽  
Population Biology ◽  
Southeastern Brazil ◽  
Brazilian Coast ◽  
Similar Species ◽  
Low Salinity ◽  
Low Salinity Water ◽  
Salinity Water ◽  
Morphological Differences ◽  
Ecological Differences

The ecology of Eudendrium spp. from the Brazilian coast is poorly known, although it already proved to be useful and important as a tool to solve some taxonomical problems of the genus. The seasonality and reproduction patterns of a population of Eudendrium caraiuru Marques & Oliveira, 2003 were studied. Data were sampled from test panels immersed in the water off Cabelo Gordo de Dentro beach, in São Sebastião Channel, Southeastern Brazil, from July 1999 to July 2000, every three months. Eudendrium caraiuru was active throughout the study period. Reproductive peaks of the species were regulated by cold and low-salinity water, although part of the population always bore mature gonophores. In addition to morphological differences, ecological differences between E. caraiuru and its similar species, E. glomeratum Picard, 1951, especially from well known populations of the Mediterranean Sea, corroborated that these species are diverse lineages of a unique ancestor.

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