[MARMAM] new paper on franciscana male dolphin reproductive aspects

[María Victoria Panebianco]

We are pleased to announce the publication (online at this stage) of the 
following article in Animal Reproduction Science:

Abstract

As the first study to investigate reproductive aspects of male franciscana 
dolphins –Pontoporia blainvillei– in Argentine waters, the aim of this paper 
was to assess sexual maturity by using histological and morphometric 
methods. P. blainvillei was labeled as “Vulnerable” by the IUCN in 2008. The 
specimens analyzed were either incidentally caught in artisanal fishing nets 
(n = 47) or found stranded on the beach (n = 3). Testis weight and 
testicular index of maturity were reliable indicators of sexual maturity, 
being their values: MTW: 1.14 ± 0.60 – 4.49 ± 1.94; IM: 0.03 ± 0.01 – 0.09 ± 
0.03, for immature and mature specimens’ respectively. It was found that the 
Hierarchical Cluster Analysis might be appropriate for establishing sexual 
maturity stage, based on both the body morphometric measurements and age. 
The values for age, standard length and total weight at attainment sexual 
maturity were 2.92 – 3.54 years, 126.19 – 126.27 cm and 23.47 – 23.75 kg. 
Considering the extremely low relative testis weight, the reversed sexual 
length dimorphism, the absence of secondary sexual characteristics, and the 
lack of scars from intrasexual combats in males, the hypothesis that sperm 
competition does not occur in the species, and male combats for accessing 
female reproductive may be rare for Pontoporia blainvillei is reinforced. 
All these features fit the species within a serial monogamous mating system.
Keywords: Pontoporia; reproductive biology; sexual maturity; testis; South 
America, Argentina.

Available from: http://dx.doi.org/10.1016/j.anireprosci.2012.02.005.

Best wishes.

___________
Dra. María Victoria Panebianco
Postdoctoral Research felow
Lab. de Ecología, Comportamiento y Mamíferos Marinos (LECyMM)
Museo Argentino de Ciencias Naturales "Bernardino Rivadavia" (MACN-CONICET)
Av. Ángel Gallardo 470, C1405DJR, Buenos Aires, Argentina
Tel.: 54-11-4982-9410/6595 int.:211
Fax: 54-11-4982-5243/4494