Phylogeography of the Endangered Franciscana Dolphin: Timing and Geological Setting of the Evolution of Populations

Latin American aquatic mammals: an overview of 12 years focusing on molecular techniques applied to conservation

“…The authors proposed that the two lineages should be regarded as Evolutionarily Significant Units (ESU) sensu Moritz (1994), to reflect their distinctiveness and emphasize the need to preserve each ESU. This finding was reexamined by Nara et al (2022) in a phylogeographic study with a large number of sequences from the entire distribution, including for the first time a large sample from Espírito Santo. Besides confirming the strong differentiation between the two ESUs, Nara et al (2022) dated the evolutionary splitting of the main lineages, which roughly correspond to the four main FMA, and discussed how they could have been caused by Pleistocene events.…”

“…This finding was reexamined by Nara et al (2022) in a phylogeographic study with a large number of sequences from the entire distribution, including for the first time a large sample from Espírito Santo. Besides confirming the strong differentiation between the two ESUs, Nara et al (2022) dated the evolutionary splitting of the main lineages, which roughly correspond to the four main FMA, and discussed how they could have been caused by Pleistocene events. Finally, their population structure analyses detected nine populations, and although limited by lack or small sampling in some areas and by being based in a single mtDNA locus, it is the most geographically comprehensive analysis conducted to date.…”

Ecological traits of the franciscana dolphin (Pontoporia blainvillei) from the Late Pleistocene to the present days based on stable isotope analysis

“…FMA III includes the shallow waters of Rio Grande do Sul State in southern Brazil to Uruguay, and FMA IV is comprised of the coastal regions of Argentina (Secchi et al, 2003a). Further subdivision of these areas has been proposed recently by Nara et al (2022). Differences in its distribution are mainly related to ecological divergence for niche occupation (Barbato et al, 2019) that lead to different degrees of reproductive isolation (e.g., Cunha et al, 2014; Nara et al, 2022).…”

“…Further subdivision of these areas has been proposed recently by Nara et al (2022). Differences in its distribution are mainly related to ecological divergence for niche occupation (Barbato et al, 2019) that lead to different degrees of reproductive isolation (e.g., Cunha et al, 2014; Nara et al, 2022). Temperature, salinity, bathymetry, and the availability of prey species are considered important environmental variables for their ecological niche (Amaral et al, 2018; Gomez & Cassini, 2015).…”

“…We investigated the ecological traits of the franciscana dolphin, P. blainvillei , through geological time—from the Late Pleistocene to the Holocene (i.e., present day)—by analyzing the bone carbonate isotopic composition (δ 13 C and δ 18 O) of fossil and contemporary specimens from southern Brazil (FMA III). Because the genetic split that originated in the FMA III occurred during the Early Pleistocene, as evidenced by mitochondrial DNA data (Nara et al, 2022), we considered fossil and contemporary franciscanas to belong to the same population.…”