|
|
Lima, Camilla S.; Magalhães, Rafael F.; Marmontel, Miriam; Meirelles, Ana Carolina; Carvalho, Vitor Luz; Lavergne, Anne; Thoisy, Benoit de; Santos, Fabrício R.
(detail)
|
| |
|
2019 |
A hybrid swarm of manatees along the Guianas coastline, a peculiar environment under the influence of the Amazon River plume.
An. Acad. Bras. Ciênc. 91, supl. 3: e20190325. 3 figs. https://doi.org/10.1590/0001-3765201920190325 Aug. 26, 2019.
–ABSTRACT: The West Indian (Trichechus manatus) and Amazonian (T. inunguis) manatees have a sympatric occurrence at the mouth of the Amazon River. A result of this interspecific encounter is the occurrence of hybrids, which are frequently found along the coasts of Amapá state in Brazil, French Guiana and Guyana. Here we present new genetic evidence indicating the occurrence of a hybrid swarm along the Guianas Shield coastline, which is an interspecific hybrid zone that also separates T. manatus populations located east (Brazil) and west (Caribbean, Gulf of Mexico, Florida and Antilles). In addition, we suggest that this hybrid population occupies a peculiar mangrove-rich environment under strong influence of the Amazon River plume, which requires an independent management and should be considered a special conservation area.
|
|
|
Vilaça, Sibelle T.; Lima, Camilla S.; Mazzoni, Camila J.; Santos, Fabrício R.; Thoisy, Benoit de
(detail)
|
| |
|
2019 |
Manatee genomics supports a special conservation area along the Guianas coastline under the influence of the Amazon River plume.
Estuarine, Coastal & Shelf Science 226(1): 106286. 2 tabs. 2 figs. https://doi.org/10.1016/j.ecss.2019.106286 Oct. 15, 2019.
–ABSTRACT: The West Indian manatee (Trichechus manatus) occurs along the Atlantic coastline and the adjacent freshwater systems of South, Central and North America, from Alagoas (Brazil) to Florida (USA) and the Greater Antilles. The Amazonian manatee (Trichechus inunguis) is the only sirenian adapted exclusively to freshwater and is endemic to the Amazon River basin. Previous studies have reported hybrids between T. inunguis and T. manatus close to the Amazon River mouth, likely composing an extensive hybrid zone under the influence of the Amazon River plume along the Guianas coast in South America. We have generated ddRAD SNP data, and sequences of nuclear and mtDNA loci to characterize the manatees' genomic composition along the French Guiana coastline. Using analyses and simulations to examine the process of hybridization, we found this population to be formed by introgressed or later generation interspecific hybrids. We also describe the first pure T. inunguis found outside the Amazon River basin. Our results indicate that T. inunguis can survive in the Amazon River plume and have colonized independent water streams of the Guianas coastline where they likely hybridize with T. manatus. This hypothesis offers a plausible explanation for the known extension of the hybrid zone between the two species along the Guianas coastline. It also reinforces the importance of the Amazon plume, which flows westwards to the Guianas coastline and favors the dispersion of the freshwater species. The Amazon plume functions as a large estuary-like system that provides an ecological continuum from the Amazon River mouth to the disconnected waterflows of the Guianas, which deserves status as a special conservation area.
|
|
Bibliography and Index of the Sirenia and Desmostylia 