María Fernanda Negri

Age and growth of franciscana dolphins, Pontoporia blainvillei (Cetacea: Pontoporiidae) incidentally caught off southern Brazil and northern Argentina

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 ¼ 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.

Diet composition of franciscana dolphin Pontoporia blainvillei from southern Buenos Aires, Argentina and its interaction with fisheries

Fil: Paso Viola, Maria Natalia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Austral de Investigaciones Cientificas; Argentina

Population Genetics of Franciscana Dolphins (Pontoporia blainvillei): Introducing a New Population from the Southern Edge of Their Distribution

Due to anthropogenic factors, the franciscana dolphin, Pontoporia blainvillei, is the most threatened small cetacean on the Atlantic coast of South America. Four Franciscana Management Areas have been proposed: Espiritu Santo to Rio de Janeiro (FMA I), São Paulo to Santa Catarina (FMA II), Rio Grande do Sul to Uruguay (FMA III), and Argentina (FMA IV). Further genetic studies distinguished additional populations within these FMAs. We analyzed the population structure, phylogeography, and demographic history in the southernmost portion of the species range. From the analysis of mitochondrial DNA control region sequences, 5 novel haplotypes were found, totalizing 60 haplotypes for the entire distribution range. The haplotype network did not show an apparent phylogeographical signal for the southern FMAs. Two populations were identified: Monte Hermoso (MH) and Necochea (NC)+Claromecó (CL)+Río Negro (RN). The low levels of genetic variability, the relative constant size over time, and the low levels of gene flow may indicate that MH has been colonized by a few maternal lineages and became isolated from geographically close populations. The apparent increase in NC+CL+RN size would be consistent with the higher genetic variability found, since genetic diversity is generally higher in older and expanding populations. Additionally, RN may have experienced a recent split from CL and NC; current high levels of gene flow may be occurring between the latter ones. FMA IV would comprise four franciscana dolphin populations: Samborombón West+Samborombón South, Cabo San Antonio+Buenos Aires East, NC+CL+Buenos Aires Southwest+RN and MH. Results achieved in this study need to be taken into account in order to ensure the long-term survival of the species.

Biological parameters of franciscana dolphins, Pontoporia blainvillei , by-caught in artisanal fisheries off southern Buenos Aires, Argentina

Fil: Negri, Maria Fernanda. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Austral de Investigaciones Cientificas; Argentina

Essential and non-essential heavy metals in skin and muscle tissues of franciscana dolphins (Pontoporia blainvillei) from the southern Argentina coast

Franciscana dolphin, Pontoporia blainvillei, is a small and ‘vulnerable’ cetacean, which exhibits coastal marine habits according to the IUCN (2008). The aim of this work was to determine the presence of essential (Zn and Cu) and non-essential (Cd, Pb, Cr and Ni) heavy metals in skin (n=33) and muscle (n=36) tissues of franciscana dolphins from southern Buenos Aires, establishing the influence of biological parameters on the accumulation of these pollutants. Histological standardised methods were used to determine both age and sexual maturity of the dolphins. Heavy metal concentrations were determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Zn was 8-fold higher than Ni in the skin. Zn was significantly affected by the age of the specimens and might be influenced by the state of body condition. Ni showed a behaviour pattern similar to that of non-essential heavy metals. The relationship between Ni and Zn concentration determined in skin and muscle might provide a tool for studying the general condition of endangered marine mammal species such as franciscana dolphins.

Metales pesados en el riñón del delfín franciscana, Pontoporia blainvillei (Cetácea: Pontoporiidae) y su relación con parámetros biológicos

RESUMEN. En este estudio se determino los niveles de metales pesados (Cd, Pb, Zn, Cu, Cr y Ni) en el tejido renal del delfin franciscana, Pontoporia blainvillei, y se establecio la influencia de los parametros ecologicos y biologicos sobre la bioacumulacion de estos elementos. Se analizaron muestras de 38 ejemplares colectados entre 2004 y 2010 en el sur de Buenos Aires, Argentina. La edad de los animales y el estado de madurez sexual se determinaron por metodos histologicos, y los niveles de metales pesados por Espectrofotometria de Absorcion Atomica. No se determinaron diferencias significativas para las concentraciones de Zn, Cu y Cd entre ambos sexos. Los niveles de Cd presentaron diferencias segun el estado de madurez sexual y se relacionaron positivamente con la longitud, peso corporal y edad. Los niveles de Cd, Cu y Zn resultaron menores a los informados en estudios previos realizados en el norte de Buenos Aires y Uruguay. Palabras clave: elementos traza, Pontoporia blainvillei, madurez sexual, edad, condicion corporal, sur de Argentina. Heavy metals in kidney tissues of Franciscana dolphin, Pontoporia blainvillei (Cetacea: Pontoporiidae), and their relationship with biological parameters

Genetic diversity and population structure of the franciscana dolphin, Pontoporia blainvillei, in Southern Buenos Aires, Argentina

ABSTRACT The franciscana dolphin, Pontoporia blainvillei, is endemic to the coastal waters of the southwestern Atlantic Ocean and the most endangered dolphin in the area. Four Franciscana Management Areas (FMAs) are currently recognised; however, results of genetic studies suggest the requirement for additional FMAs and highlight the need for more detailed studies in the southern extreme of the species distribution. With this aim, we studied the genetic diversity and population structure of the species analysing an mtDNA control region fragment (434 bp) in 44 individuals collected in four sampling sites located in Southern Buenos Aires. Haplotype diversity (H = 0.75 ± 0.05) was mostly higher than the observed in endangered or near threatened odontocetes. Population structure analyses suggest that three different genetic populations should be recognised within FMA IV: Northern, Eastern and Southern Buenos Aires. Altogether, these results should be taken into account in future conservation plans for the species.

Morphological Analysis of the Flippers in the Franciscana Dolphin, Pontoporia blainvillei, Applying X-Ray Technique

Pectoral flippers of cetaceans function to provide stability and maneuverability during locomotion. Directional asymmetry (DA) is a common feature among odontocete cetaceans, as well as sexual dimorphism (SD). For the first time DA, allometry, physical maturity, and SD of the flipper skeleton—by X‐ray technique—of Pontoporia blainvillei were analyzed. The number of carpals, metacarpals, phalanges, and morphometric characters from the humerus, radius, ulna, and digit two were studied in franciscana dolphins from Buenos Aires, Argentina. The number of visible epiphyses and their degree of fusion at the proximal and distal ends of the humerus, radius, and ulna were also analyzed. The flipper skeleton was symmetrical, showing a negative allometric trend, with similar growth patterns in both sexes with the exception of the width of the radius (P ≤ 0.01). SD was found on the number of phalanges of digit two (P ≤ 0.01), ulna and digit two lengths. Females showed a higher relative ulna length and shorter relative digit two length, and the opposite occurred in males (P ≤ 0.01). Epiphyseal fusion pattern proved to be a tool to determine dolphins age; franciscana dolphins with a mature flipper were, at least, four years old. This study indicates that the flippers of franciscana dolphins are symmetrical; both sexes show a negative allometric trend; SD is observed in radius, ulna, and digit two; and flipper skeleton allows determine the age class of the dolphins. Anat Rec, 297:1181–1188, 2014.