scholarly journals Planktonic rotifers from a tropical estuary under high marine influence (Passos River, PE, Brazil).

2014 ◽  
Vol 42 (3) ◽  
Author(s):  
Simone JORGE FILHO ◽  
Sigrid NEUMANN-LEITÃO ◽  
Tâmara De Almeida e SILVA ◽  
Mauro De MELO JÚNIOR
Keyword(s):  
Rainy Season ◽  
Brachionus Plicatilis ◽  
Statistical Tests ◽  
River Estuary ◽  
Mesh Size ◽  
Northeastern Brazil ◽  
Light Extinction ◽  
Physical Parameters ◽  
Salinity Regime ◽  
Light Extinction Coefficient

Passos River estuary, which is very influenced by marine waters, were carried out monthly from August/2009 to September/2010. A 64µm mesh size plankton net was hauled during low tide at two fixed stations in spring tides. Physical parameters as temperature, salinity, transparency and light extinction coefficient were obtained simultaneously. Statistical tests (Man-Whitney) were performed to evaluate possible seasonal and spatial variations. The rotifers were represented by only four species. Although there was no significant seasonal variation, the highest abundances were registered in the rainy season, with an expressive predominance of Brachionus plicatilis Müller, 1786. However, a population pick was registered in the dry season (September/2009; 13182,03 org.m-3 ) and the lowest value was registered in the rainy season (2010 May; 7,56 org.m-3 ). Brachionus plicatilis Müller, 1786 was highlighted as salinity indicator as well as its extremely opportunistic condition in eutrophic ecossistems, while Rotaria rotatoria (Pallas, 1766) and Rotaria sp. indicated organic pollution. Due to the constant high salinity regime the estuary showed few species richness. Keywords: Indicator, Rotifers, Salinity, Northeastern Brazil.

scholarly journals Seasonal and spatial variability of appendicularian density and taxonomic composition in the Caravelas Estuary (Northeastern Brazil) and adjacent coastal area

2010 ◽  
Vol 53 (1) ◽  
pp. 161-169 ◽  
Author(s):  
Pedro Freitas de Carvalho ◽  
Sérgio Luiz Costa Bonecker
Keyword(s):  
Spatial Variability ◽  
Coastal Area ◽  
Rainy Season ◽  
River Estuary ◽  
Taxonomic Composition ◽  
Northeastern Brazil ◽  
Oikopleura Dioica ◽  
Seasonal And Spatial Variations ◽  
The Mean ◽  
Adjacent Coastal Area

This study aimed to identify and assess the seasonal and spatial variations of the appendicularians in the Caravelas River estuary and the adjacent coastal area. Samples were taken during 12 campaigns over five years (2001 and 2003-2006). Ten species were identified; the most abundant were Oikopleura dioica, Oikopleura rufescens, and Oikopleura longicauda. These species represented more than 95% of the total numbers of appendicularians. The remaining species were less frequent and occurred in low densities. The mean density of appendicularians found at the coastal stations (804 ind.m-3.) was higher than in the estuary (66 ind.m-3). However, the differences observed between the estuary and coastal stations were not significant (p=0.54). The samples taken during the dry season showed a higher mean density (587 ind.m-3) than in the rainy season (376 ind.m-3), and the differences between the seasons were statistically significant (p=0.004).

scholarly journals Cladocerans (Branchiopoda) of a tropical estuary in Brazil

2005 ◽  
Vol 65 (1) ◽  
pp. 107-115 ◽  
Author(s):  
M. N Paranaguá ◽  
S Neumann-Leitão ◽  
J. D Nogueira-Paranhos ◽  
T. A. Silva ◽  
T. Matsumura-Tundisi
Keyword(s):  
Rainy Season ◽  
High Tide ◽  
River Estuary ◽  
River Mouth ◽  
Mesh Size ◽  
Marine Species ◽  
Wide Distribution ◽  
Average Density ◽  
Chemical Pollution ◽  
Tropical Estuary

The study was conducted in the Capibaribe river estuary in Recife (Brazil) to assess the role played by cladocerans in a eutrophic environment. Samplings were carried out monthly at 4 fixed stations along the estuary from July 1987 to June 1988. Collections were made with a plankton net of 65 micrometers mesh size. Six cladocerans species were registered: Penilia avirostris, Diaphanosoma spinulosum, Chydorus barroisi, Ceriodaphnia rigaudi, Ilyocryptus spinifer, and Moina micrura. The most frequent species was Moina micrura with 49%. The only true marine species was Penilia avirostris, which was registered at station 1 (close to the river mouth), during high and low tide and in the dry season. The Cladocera average density decreased from 329 ind.m-3 (August 1987, high tide) to 2 ind.m-3 (March 1988, high tide) due to the high load of organic and chemical pollution received by the estuary. At all stations, D. spinulosum, M. micrura, and C. barroisi occurred with a wide distribution, mainly during the rainy season. C. rigaudi and I. spinifer were rare, occurring only during the rainy season. Cladocerans played an important role in the food webs of the plankton community of the Capibaribe tropical estuary and the dominance of a few small species indicated a hypereutrophic environment. A high level of disturbance was indicated by the decline in diversity of specialized species and the increase in abundance of opportunistic species like M. micrura.

Structure and dynamics of Gobiidae larvae (Teleostei, Perciformes) in a tropical estuary: seasonal relationships with tidal cycles

2014 ◽  
Vol 94 (7) ◽  
pp. 1557-1568 ◽  
Author(s):  
Eduardo A.P. Gomes ◽  
Ana C.T. Bonecker
Keyword(s):  
Rainy Season ◽  
Fish Larvae ◽  
Abiotic Factors ◽  
River Estuary ◽  
River Mouth ◽  
Temporal Distribution ◽  
Mesh Size ◽  
Distribution Patterns ◽  
Flood Tide ◽  
Estuarine System

This study aims to describe the spatial and temporal distribution patterns of Gobiidae larvae at a tropical estuarine system in south-east Brazil (Macaé). The samples were collected in six stations, through oblique hauls using a bongo net (330 µm mesh size), coupled to a flowmeter, during the night in the ebb and flood tides in March, July and October 2006 and in February 2007. In the Macaé River estuary was collected a total of 1,234 Gobiidae larvae, representing nine taxa. The highest densities occurred in the river mouth during the flood tide in the rainy season. The most abundant groups were: Gobiosoma parri, Gobionellus oceanicus and Ctenogobius boleosoma. Gobiosoma parri was also dominant at the Macaé estuary, which also presented higher densities in the coastal stations during the rainy season (March), both the flood as the ebb tide. Gobionellus oceanicus and Ctenogobius boleosoma were characteristic of the dry season in the mouth and river stations during the flood tide. The abiotic factors chlorophyll-a and temperature were considered biologically significant for Gobiidae larvae distribution. The spatial and seasonal variations together with the tide influence the distribution of the fish larvae Gobiidae family in the Macaé River estuary and its coastal zone.

scholarly journals Perkinsus sp. infecting three important mollusks from Jaguaribe River estuary, Ceará, Brazil

2020 ◽  
Vol 57 (1) ◽  
pp. e158316
Author(s):  
Maximiano Pinheiro Dantas Neto ◽  
Rodrigo Maggioni ◽  
Luiz Fagner Ferreira Nogueira ◽  
Jamille Martins Forte ◽  
Rubens Galdino Feijó ◽  
...  
Keyword(s):  
Rainy Season ◽  
River Estuary ◽  
Major Axis ◽  
Northeastern Brazil ◽  
Bivalve Mollusks ◽  
High Similarity ◽  
Dry Period ◽  
Intensity Of Infection ◽  
Chain Reaction ◽  
Polymerase Chain

This work investigated the occurrence of Perkinsus sp. in clam Anomalocardia brasiliana, oyster Crassostrea sp. and mussel Mytella falcata from the Jaguaribe River estuary, northeastern Brazil. The collection of clam (N = 300), oysters (N = 300) and mussels (N = 300) were carried out in the estuary of the Jaguaribe River, Ceará, in March and April (rainy season) and October (dry season) in 2017. The mollusks were measured in their major axis, open, and had their tissues submitted to tissue incubation techniques in Ray’s fluid thioglycollate medium (RFTM), histology, real-time polymerase chain reaction (qPCR), PCR and sequencing. The RFTM assays showed Perkinsus sp. infecting the three mollusks investigated. The prevalence of infected clams was 1.33% in both sampling periods, oysters ranged from 2.66 (rainy season) to 8% (dry period), and mussels from 0% (dry period) to 51.33% (rainy season). The intensity of infection was very light to light in clams, very soft to severe in oysters and very soft to moderate in mussels. Histological analyses showed cells of Perkinsus sp. infecting the gills and connective tissue around the digestive gland of some individuals. The qPCR generated amplicons in all positive samples in RFTM, confirming the presence of Perkinsus sp., while the sequencing evidenced high similarity (99%) with the species P. beihaiensis. In conclusion, the results obtained contribute to increasing knowledge about the occurrence of Perkinsus sp. in bivalve mollusks from northeastern Brazil.

scholarly journals Phytoplankton nyctemeral variation at a tropical river estuary (Itamaracá - Pernambuco - Brazil)

2004 ◽  
Vol 64 (1) ◽  
pp. 81-94 ◽  
Author(s):  
S. R. Lacerda ◽  
M. L. Koening ◽  
S. Neumann-Leitão ◽  
M. J. Flores-Montes
Keyword(s):  
Rainy Season ◽  
River Estuary ◽  
Mesh Size ◽  
Dry Season ◽  
Tropical River ◽  
Cylindrotheca Closterium ◽  
The North ◽  
Marine Influence ◽  
Dry Seasons ◽  
Made In

The Botafogo estuary is of socio-economical importance for Pernambuco State. It is located at the north of Santa Cruz Channel, Itamaracá, Pernambuco, Brazil (07º42'50"S and 34º52'10"W). There is a critical need to understand its functioning because of the rate at which this area is being converted to land uses. The phytoplankton dynamics was studied to enhance the knowledge of and verify the possible changes which have occurred in this ecosystem. Sampling was carried out with a plankton net 65 micrometers mesh size for qualitative data, and a Van Dorn bottle for quantitative data. Concurrent hydrological and chlorophyll-a data were collected. Samplings were made in one fixed station in July 1996 (rainy season) and December 1996 (dry season), at 3-hour intervals during 24 hours. Eighty-seven specific and infra-specific taxa were identified from net plankton samples. Diatoms were most frequent, mainly Coscinodiscus centralis and Odontella regia in the rainy and dry seasons, respectively. Phytoplankton density varied from 205,000 to 1,210,000 cell.L-1 in the dry season, and from 230,000 to 2,510,000 cell.L-1 in the rainy season, indicating eutrophic conditions. Most numerically abundant were the diatoms Cyclotella meneghiniana and Cylindrotheca closterium and the phytoflagellates. The ecosystem is polluted, and deleterious effects are minimized by the marine influence which allows periodic water renewal.

Epidemiology of pediatric hydrocephalus in Haiti: analysis of a surgical case series

2019 ◽  
Vol 23 (5) ◽  
pp. 568-576
Author(s):  
Michael Ragheb ◽  
Ashish H. Shah ◽  
Sarah Jernigan ◽  
Tulay Koru-Sengul ◽  
John Ragheb
Keyword(s):  
Public Health ◽  
Logistic Regression ◽  
Head Circumference ◽  
Rainy Season ◽  
Statistical Tests ◽  
Multivariate Logistic Regression Analysis ◽  
Case Series ◽  
Multivariate Logistic Regression ◽  
Surgical Case ◽  
Operative Notes

OBJECTIVEHydrocephalus is recognized as a common disabling pediatric disease afflicting infants and children disproportionately in the developing world, where access to neurosurgical care is limited and risk of perinatal infection is high. This surgical case series describes the Project Medishare Hydrocephalus Specialty Surgery (PMHSS) program experience treating hydrocephalus in Haiti between 2008 and 2015.METHODSThe authors conducted a retrospective review of all cases involving children treated for hydrocephalus within the PMHSS program in Port-au-Prince, Haiti, from 2008 through 2015. All relevant epidemiological information of children treated were prospectively collected including relevant demographics, birth history, hydrocephalus etiology, head circumference, and operative notes. All appropriate associations and statistical tests were performed using univariate and multivariate logistic regression analyses.RESULTSAmong the 401 children treated within PMHSS, postinfectious hydrocephalus (PIH) accounted for 39.4% (n = 158) of cases based on clinical, radiographic, and endoscopic findings. The majority of children with hydrocephalus in Haiti were male (54.8%, n = 197), born in the rainy season (59.7%, n = 233), and born in a coastal/inland location (43.3%, n = 61). The most common surgical intervention was endoscopic third ventriculostomy with choroid plexus cauterization (ETV/CPC) (45.7%, n = 175). Multivariate logistic regression analysis yielded coastal birth location (OR 3.76, 95% CI 1.16–12.18) as a statistically significant predictor of PIH. Increasing head circumference (adjusted OR 1.06, 95% CI 0.99–1.13) demonstrated a slight trend toward significance with the incidence of PIH.CONCLUSIONSThis information will provide the foundation for future clinical and public health studies to better understand hydrocephalus in Haiti. The 39.4% prevalence of PIH falls within observed rates in Africa as does the apparently higher prevalence for those born during the rainy season. Although PIH was the most frequent etiology seen in almost all birth locations, the potential relationship with geography noted in this series will be the focus of further research in an effort to understand the link between climate and PIH in Haiti. The ultimate goal will be to develop an appropriate public health strategy to reduce the burden of PIH on the children of Haiti.

Dietary overlap and food resource partitioning among fish species of a tropical estuary in Northeastern Brazil

Gaia Scientia ◽  
2016 ◽  
Vol 10 (4) ◽  
pp. 86-95 ◽  
Author(s):  
Adna Ferreira da Silva Garcia ◽  
Ana Lúcia Vendel
Keyword(s):  
Resource Partitioning ◽  
Species Coexistence ◽  
Food Resource ◽  
River Estuary ◽  
Niche Overlap ◽  
Northeastern Brazil ◽  
Dietary Overlap ◽  
Feeding Niche ◽  
Tropical Environments ◽  
Food Resource Partitioning

The current work investigates dietary overlap and food partitioning among nine abundant carnivorous fishes caught in the shallow waters of the Paraíba do Norte river estuary, Paraíba State, Brazil. Fishes were sampled with a beach seine net between January and December 2008 and a total of 958 specimens had their stomach content analyzed. Crustacea was the dominant food resource for Lutjanus alexandrei, L. jocu and Bathygobius soporator, whereas Telostei were consumed mainly by Centropomus undecimalis and C. parallelus. In contrast, Polychaeta were preyed upon mainly by Diapterus rhombeus, Eucinostomus argenteus, Sciades herzbergii and S. parkeri. Although most species consumed similar food items, they did that in varying proportions and amounts. Overall, the niche overlap among species was low (< 0.60), but there were several cases where pair of species had their feeding niche highly overlapped (between 0.72 and 0.97). These findings corroborate the hypothesis that food resource partitioning determines species coexistence in estuarine tropical environments.

scholarly journals Salinity and freshwater discharge determine rotifer distribution at the Mossoró River Estuary (Semiarid Region of Brazil)

2010 ◽  
Vol 70 (3) ◽  
pp. 551-557 ◽  
Author(s):  
AMA. Medeiros ◽  
JEL. Barbosa ◽  
PR. Medeiros ◽  
RM. Rocha ◽  
LF. Silva
Keyword(s):  
Species Richness ◽  
Rainy Season ◽  
Salinity Gradient ◽  
River Estuary ◽  
Positive Influence ◽  
Freshwater Discharge ◽  
The Other ◽  
Semiarid Region ◽  
Inverse Estuary ◽  
Species Richness And Abundance

The present study aimed at evaluating differences in rotifer distribution in three estuarine zones in an inverse estuary located in the Semiarid Region of Brazil. Zones were chosen based on their proximity to the ocean and river border as a means of reflecting a horizontal salinity gradient. High freshwater discharge during the rainy season was the major determinant of rotifer composition. On the other hand, due to higher salinity values during the dry season, very low values of species richness and abundance were observed in all zones. Therefore, the study highlights the constraints of salinity and the positive influence of seasonality and river proximity on rotifer species in a semiarid estuarine environment.

Temporal variation in the weight-size relationship of the mangrove crab Ucides cordatus L. (Decapoda: Ucididae) in relation to its life cycle phases

2014 ◽  
Vol 64 (4) ◽  
pp. 333-342 ◽  
Author(s):  
Marcos de Miranda Leão Leite ◽  
Cynthia Yuri Ogawa ◽  
Carla Ferreira Rezende ◽  
José Roberto Feitosa Silva
Keyword(s):  
Life Cycle ◽  
Condition Factor ◽  
River Estuary ◽  
Total Weight ◽  
Northeastern Brazil ◽  
Annual Life Cycle ◽  
Ucides Cordatus ◽  
Mangrove Crab ◽  
Significant Difference ◽  
The Relationship

The relationship between weight and size of individuals can be used to evaluate the status of a population, which is particularly useful for natural populations that are being exploited. Ucides cordatus occurs on the Atlantic coast of the American continent, from Florida (USA) to Santa Catarina (Brazil). This species is economically very important, most of all in the Northeastern area of Brazil, as well as in the Dominican Republic and Suriname. The objective of this study was to analyze life phases (‘fattening’, ‘matumba’, ‘milk-crab’, ‘maturation’ and ‘walking’) by use of the weight-length relationships, as well as temporal variations in this condition factor for each sex of U. cordatus. For this purpose, individuals were sampled monthly for twenty-four months at the Jaguaribe River estuary, Ceará State, Northeastern Brazil. The relationship between total weight and cephalothorax width was established using regression analysis, adjusted by a power equation. The dynamics of the condition factor were analyzed for each sex using the variation of its averages related to annual life cycle; this was done for each of the previously-mentioned phases. The relationship between total weight and cephalothorax width showed an isometric growth in males and negative allometric growth in females suggesting that, for the same reference size, males are heavier than females. When considering the average of the female condition factors, these were greater than those for males during the annual life cycle, except during the ‘maturation’ phase, which is the phase with a higher demand of energetic reserves for males. Annual variation of the condition factor in females presented no significant difference.

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