[MARMAM] new paper on franciscana male dolphin reproductive aspects
María Victoria Panebianco
panebianco at macn.gov.ar
Thu Mar 29 13:49:48 PDT 2012
We are pleased to announce the publication (online at this stage) of the
following article in Animal Reproduction Science:
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
Available from: http://dx.doi.org/10.1016/j.anireprosci.2012.02.005.
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
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