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 Reproduction of a whiptail lizard (Ameivula ocellifera, Teiidae) from a coastal area in northeastern Brazil

2014 ◽  
Vol 86 (3) ◽  
pp. 1263-1272 ◽  
Author(s):  
DJAN ZANCHI-SILVA ◽  
DIVA M. BORGES-NOJOSA ◽  
CONRADO A.B. GALDINO
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Coastal Area ◽  
Rainy Season ◽  
Female Body ◽  
The State ◽  
Northeastern Brazil ◽  
Egg Volume ◽  
Female Reproduction ◽  
Female Body Size

The reproductive ecology of Ameivula ocellifera was studied from September 2009 to August 2010 in a coastal area of the state of Ceará, Brazil. Females reproduced continuously throughout the year, with a peak at the end of the rainy season. Even though there was a predominance of pre-reproductive individuals in the sample, gonadal activity of males peaked synchronously to female reproduction. Mean clutch size was 1.98 ± 0.56 and positively associated with female body size, while mean egg volume was 510.54 ± 84.29 mm3 and unrelated to female body size. We did not find any association between clutch size and average egg volume.

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 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.

Sign in / Sign up

Export Citation Format

Share Document