Behavioural seasonality of the estuarine dolphin, Sotalia guianensis, on the north-eastern Brazilian coast

2008 ◽  
Vol 1 ◽  
Author(s):  
Fernando Roberto Guilherme-Silveira ◽  
Flávio José de Lima Silva
Author(s):  
Humberto F. M. Fortunato ◽  
Thierry Pérez ◽  
Gisele Lôbo-Hajdu

AbstractThe Order Suberitida is defined as a group of marine sponges without an obvious cortex, a skeleton devoid of microscleres, and with a deletion of a small loop of 15 base pairs in the secondary structure of the 28S rDNA as a molecular synapomorphy. Suberitida comprises three families and 26 genera distributed worldwide, but mostly in temperate and polar waters. Twenty species were reported along the entire Brazilian coast, and although the north-eastern coast of Brazil seems to harbour a rich sponge fauna, our current knowledge is concentrated along the south-eastern Atlantic coast. A survey was implemented along the northern coast of Brazil, and the collection allowed the identification of six species belonging to the Order Suberitida. Two of them are considered new to science: Suberites purpura sp. nov., Hymeniacidon upaonassu sp. nov., and four, Halichondria (Halichondria) marianae Santos, Nascimento & Pinheiro, 2018, Halichondria (H.) melanadocia de Laubenfels, 1936, Suberites aurantiacus (Duchassaing & Michelotti, 1864), and Terpios fugax Duchassaing & Michelotti, 1864, are re-described. Taxonomic comparisons are made for Tropical Western Atlantic species and type species of the four genera. Finally, an identification key for the Western Atlantic Suberites species is provided.


Soil Research ◽  
2014 ◽  
Vol 52 (2) ◽  
pp. 140 ◽  
Author(s):  
A. G. B. M. Albuquerque ◽  
T. O. Ferreira ◽  
G. N. Nóbrega ◽  
R. E. Romero ◽  
V. S. Souza Júnior ◽  
...  

Wetland soils, especially those under a semi-arid climate, are among the least studied soils in the tropics. The hypersaline tidal flats on the north-eastern Brazilian coast, locally named apicum, are coastal wetland ecosystems in the peripheral portions of semi-arid estuaries. Despite their great ecological importance, they have been highly impacted by anthropogenic activities. Morphological and analytical data of six soil profiles, representative of the different coastal compartments (mangroves, apicum and coastal tablelands) of the north-eastern Brazilian coast, were examined to better understand the pedogenesis of apicum soils. The hypersaline tidal flat soils were classified as Typic Fluvaquents and Typic Sulfaquents with the following main characteristics: predominance of sand fraction (62–77%); presence of high-activity clays (>24 cmolc kg–1 clay); clay fraction comprising kaolinite, illite, smectite and an interstratified smectite/illite; exchangeable complex dominated by Na+ (ESP ≥15%); elevated levels of salinity (electrical conductivity, EC 25–44 dS m–1); alkaline pH values (7.5–9.5). The sandy texture and quartz-dominated composition of the hypersaline, tidal flat soils indicate a pedogenesis associated with the superficial addition of mineral material. This upbuilding process would have lowered the watertable (relatively to the ground level) and decreased the flooding frequency by the tides, favouring salinisation and solonisation processes at the hypersaline tidal flats. Furthermore, the still-existing hydromorphism would have promoted the maintenance of gleisation and sulfidisation. The presence of pyrite on the hyper-saline tidal flat soils further corroborates the formation of apicum soils from/over buried mangroves.


2007 ◽  
Vol 24 (2) ◽  
pp. 265-270 ◽  
Author(s):  
Fábio G. Daura-Jorge ◽  
Marcos R. Rossi-Santos ◽  
Leonardo L. Wedekin ◽  
Paulo C. Simões-Lopes

The behavioral patterns of the estuarine dolphin, Sotalia guianensis (P. J. van Bénéden, 1864), were compared between two populations along the Brazilian coast: Caravelas (Bahia), along the eastern coast, and Norte Bay (Santa Catarina), along the southern coast. Applying the focal-group sampling in both areas, information such as the geographic position (UTM) of groups and predominant behavioral patterns were obtained. Geographic positions were used to calculate the total distance traveled by estuarine dolphin groups on each observation day. Since the distance traveled varies with time, the daily mean speed of the dolphin’s group was used as an index of movement intensity. Two comparable and easily recognizable behavioral patterns were considered: travelling and foraging. Overall movement intensity and behavioral pattern frequency were similar between both areas. However, a seasonal variation was observed in both parameters in Norte Bay, while in Caravelas these parameters were homogeneous throughout the year. Variation in the behavior of the estuarine dolphin was consistent with variations in environmental factors, such as water temperature.


2011 ◽  
Vol 91 (7) ◽  
pp. 1561-1566 ◽  
Author(s):  
Bruno Garcia Andrade ◽  
Paulo Márcio Santos Costa ◽  
Alexandre Dias Pimenta

The genus Opaliopsis from Brazil is revised based on three deep-water species. Opaliopsis atlantis (Clench & Turner, 1952) is confirmed as occurring in north-eastern and south-eastern localities. Opaliopsis opalina (Dall, 1927) is reported for the first time in the south-western Atlantic. A new species, Opaliopsis cearense, is described from the north-eastern Brazilian coast, and is distinguished by its large number of fine spiral cords per teleoconch whorl.


2012 ◽  
Vol 10 (4) ◽  
pp. 351
Author(s):  
Anne Karoline Japp ◽  
Gislaine De Fatima Filla

The present work aimed to estimate the population density of Sotalia guianensis in the Bay of Antonina, southern Brazilian coast, by linear transects, distance method. The average group size in the total area was 2.57 individuals/group. The study area is 28.1 km2 and it was divided in two sub-areas, an outer area closer to the sea and another more enclosed with a higher fresh water input. In the Sector I, the one with greater marine influence, the density estimation found was D = 3.01 animals/ km2 (Variation Coefficient, VC 24.67%), whereas in Sector II there was no estuarine dolphin record. Also, during the rainy season a higher density value was found in the bay (D = 4.99 individuals/ km2, VC 15.93%). When the area division was ignored an overestimation of density was found (D = 3.80 animals/km2; VC 15.71%) due to the data extrapolation beyond the sampled area, including areas not much used by the dolphins. This superestimation due to the few estuarine dolphins records in the Bay of Antonina and also to the method used, which was biased by existing of sand banks at low tide which made it impossible to access all transects.


2016 ◽  
Vol 97 (8) ◽  
pp. 1581-1584 ◽  
Author(s):  
João Carlos Gomes Borges ◽  
Larissa Molinari Jung ◽  
Vitor Luz Carvalho ◽  
André Lucas De Oliveira Moreira ◽  
Fernanda Löffler Niemeyer Attademo ◽  
...  

Currently, little is known about the helminth fauna in sirenian species. Therefore, the objective of this study was to assess the frequency of infection by Pulmonicola cochleotrema in Antillean manatees (Trichechus manatus manatus), in the North-eastern region of Brazil. Between the years of 1989 and 2014, 88 manatees found on the North-eastern Brazilian coast were clinically examined. They included animals that were found dead, animals maintained in captivity and specimens reintroduced into conservation areas. During their physical examination, helminths present in necropsied carcasses and in reintroduced animals were collected, as well as faecal samples. Parasites were detected in 7.95% (7/88) of the animals; all specimens collected being identified as P. cochleotrema. Only adult manatees were infected, and in two cases clinical signs were observed. This is the first report on the occurrence of P. cochleotrema in Antillean manatees in the states of Paraíba and Sergipe, in the North-eastern coast of Brazil.


Author(s):  
Marina Cyrino Leal Coutinho ◽  
Paulo Cesar Paiva ◽  
Cinthya Simone Gomes Santos

Species definition is not an easy task, when considering the more than 27 known species concepts. Among them, the morphospecies concept has been one of the most applied since it is based on the use of observable morphological features. Morphometry has been used to delimitate morphospecies or similar taxa complementing the morphological observations and contributing to clarify taxonomic problems. Specimens from the sympatric speciesPerinereis anderssoniandPerinereis ponteni,collected from the north-eastern to southern coast of Brazil and considered synonymous by some authors, were compared through morphometric analyses for the evaluation of their taxonomic status. Morphometric analysis indicates that notopodial cirri lengths in the median and posterior regions on the body clearly allowed differentiation between the two species. Our results indicate that the number and arrangement of paragnaths demonstrate a pattern of variation that effectively differs and could be used to discriminate these twoPerinereisspecies. This distinction was confirmed by the restricted among-population variability within each species, even when populations that are geographically very distant from each other were considered.


Author(s):  
Fernando José König Clark ◽  
André Luiz Machado Pessanha

The feeding biology of bahia sprat (Rhinosardinia bahiensis) was studied in two habitats of a tropical semi-arid estuary, on the north-eastern Brazilian coast. Samplings were collected on a monthly basis (January 2010–February 2011), and fish were caught during the day using an 8 m beach seine. Habitat use was size-dependent, with tidal mudflat occupied by higher size-classes than tidal creeks, which were occupied by smaller conspecifics. The diet analysis of different size-classes revealed that all sizes of fish consumed similar taxa (Calanoida, Cyclopoida and Decapoda larvae), and that the relative proportion of taxa consumed reflected fish size. Dietary differences between the two nursery areas mainly reflected prey availability. Although high diet overlap was only found between some size-classes in tidal mudflat, these results seem to demonstrate a strategy for efficient use of space potential; intraspecific competition was probably minimized by a differential habitat use patterns.


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