scholarly journals First record of an anomalously colored franciscana dolphin, Pontoporia blainvillei

2014 ◽  
Vol 86 (3) ◽  
pp. 1221-1226 ◽  
Author(s):  
MARTA J. CREMER ◽  
CAMILA M. SARTORI ◽  
BEATRIZ SCHULZE ◽  
RENAN L. PAITACH ◽  
ANNELISE C. HOLZ

On October 2011, a newborn franciscana dolphin with an anomalously coloration was sighted in Babitonga Bay, southern Brazil. The calf was totally white. Besides the potential mother and newborn, the group also had the presence of another adult, who always was swimming behind the pair. Both adults had the typical coloration of the species, with the back in grayish brown. The group, composed by the white franciscana calf, his pontential mother and one more adult, was reported in five occasions. The group was always in the same area where it was first recorded and showed the same position during swimming. Between first and last sighting of the white calf (113 days) the color has not changed. This is the first case of a white franciscana dolphin. This coloration has never been reported despite the high number of dead franciscanas recovered each year along the distribution of the species, resulting from accidental capture in fishing nets. This fact leads us to believe that this is a very rare characteristic for this species. We considered the possibility that this franciscana could be an albino dolphin.

2014 ◽  
Vol 60 ◽  
pp. S257-S260 ◽  
Author(s):  
Karine P. Vairo ◽  
Rodrigo C. Corrêa ◽  
Melise C. Lecheta ◽  
Maria F. Caneparo ◽  
Kleber M. Mise ◽  
...  

2008 ◽  
Vol 88 (6) ◽  
pp. 1099-1101 ◽  
Author(s):  
Glauco Caon ◽  
Eduardo Resende Secchi ◽  
Edison Capp ◽  
Luiz Carlos Kucharski

Milk is the only external energy source for mammals in their early stages of life. Its composition varies during lactation in baleen whales and pinnipeds, while only descriptive studies are available for odontocetes. The aim of this work was to identify the components of the milk of franciscana, Pontoporia blainvillei, from southern Brazil. Samples were manually collected from lactating females (N = 5) incidentally caught in the gill-net fishery. The amount of fat, protein, carbohydrate, mineral and trace metal content, and caloric value of the samples were estimated. Milk of the franciscana dolphin presented mean fat, protein and carbohydrate concentrations similar to those described for other coastal species. A significant increase in fat concentration was observed in winter months, with a higher energy density. Potassium was the mineral found in higher amounts. Zinc, mercury and copper were detected in low concentrations. Due to different habitat conditions along the species distribution, the presence of a highly seasonal reproductive period and inter-population genetic variability, studies on milk composition in other areas is recommended.


Author(s):  
Haydée A. Cunha ◽  
Teresa E. C. dos Santos ◽  
Luísa C. Alvarenga ◽  
Nathalia P. Cavaleiro ◽  
Marta J. Cremer ◽  
...  

Author(s):  
Silvina Botta ◽  
Eduardo R. Secchi ◽  
Mônica M.C. Muelbert ◽  
Daniel Danilewicz ◽  
Maria Fernanda Negri ◽  
...  

Age and length data of 291 franciscana dolphins (Pontoporia blainvillei) incidentally captured on the coast of Rio Grande do Sul State (RS), southern Brazil, were used to fit growth curves using Gompertz and Von Bertalanffy growth models. A small sample of franciscanas (N = 35) from Buenos Aires Province (BA), Argentina, were used to see if there are apparent growth differences between the populations. Male and female franciscana samples from both areas were primarily (78–85%) <4 years of age. The Von Bertalanffy growth model with a data set that excluded animals <1 year of age provided the best fit to data. Based on this model, dolphins from the RS population reached asymptotic length at 136.0 cm and 158.4 cm, for males and females, respectively. No remarkable differences were observed in the growth trajectories of males and females between the RS and BA populations.


2008 ◽  
Vol 100 (1) ◽  
pp. 119-122 ◽  
Author(s):  
L. Heinzelmann ◽  
P. C. Chagastelles ◽  
D. Danilewicz ◽  
J. A. B. Chies ◽  
J. Andrades-Miranda

Author(s):  
Daniel Danilewicz ◽  
Eduardo R. Secchi ◽  
Paulo H. Ott ◽  
Ignacio B. Moreno ◽  
Manuela Bassoi ◽  
...  

The patterns of habitat use by the franciscana dolphins (Pontoporia blainvillei) along its distribution are poorly known. This study investigates the patterns of habitat use with respect to depth for 181 individuals of different age, size, gender and reproductive condition off Rio Grande do Sul, southern Brazil. The results reveal that franciscanas are very homogeneously distributed according to depth. Individuals from all lengths utilize nearly the entire range of depths of the surveyed area. Larger or older animals do not use deeper waters than younger animals, indicating that body size and age are not limiting factors for franciscanas that occupy deeper or offshore waters. Gestation seems to not cause a change in the distribution of females. Although the sex-ratio of the overall data did not vary from 1:1 in different depth intervals, a small-scale comparison between the northern and southern coast demonstrated the existence of some kind of sexual segregation. Franciscana by-catch in Rio Grande do Sul is not sustainable and it is agreed that management procedures are needed. Nevertheless, the available data on species distribution do not allow the designing of a protected area in order to minimize the by-catches of a particular sex/reproductive class.


2012 ◽  
Vol 102 (2) ◽  
pp. 131-137 ◽  
Author(s):  
Marta J. Cremer ◽  
Pedro C. Pinheiro ◽  
Paulo C. Simões-Lopes

The present study provides information about the diet of sympatric populations of small cetaceans in the Babitonga Bay estuary. This is the first study on the diet of these species in direct sympatry. The stomach contents of seven Guiana dolphins Sotalia guianensis and eight franciscanas Pontoporia blainvillei were analyzed. The prey of both cetaceans was mostly teleost fishes, followed by cephalopods. We identified 13 teleost fishes as part of the diet of the franciscanas, and 20 as part of the diet of Guiana dolphins. Lolliguncula brevis was the only cephalopod recorded, and was the most important prey for both cetaceans. Stellifer rastrifer and Gobionellus oceanicus were also important for franciscana, so as Mugil curema and Micropogonias furnieri were important for Guiana dolphins. Stellifer rastrifer and Cetengraulis edentulus were the fishes with the highest frequency of occurrence for franciscana (50%), while Achirus lineatus, C. edentulus, S. brasiliensis, Cynoscion leiarchus, M. furnieri, M. curema, Diapterus rhombeus, Eugerres brasilianus and G. oceanicus showed 28.6% of frequency of occurrence for Guiana dolphins. Franciscanas captured greater cephalopods than the Guiana dolphins in both total length (z= -3.38; n= 40; p< 0.05) and biomass (z = -2.46; n = 40; p<0.05). All of the prey species identified occur inside the estuary, which represents a safe habitat against predators and food availability, reinforcing the importance of the Babitonga Bay for these cetacean populations.


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