Placentation in Amazon River Dolphins
Author Information
Author(s): da Silva Vera MF, Carter Anthony M, Ambrosio Carlos E, Carvalho Ana F, Bonatelli Marina, Lima Marcelo C, Miglino Maria Angelica
Primary Institution: National Institute of Amazonian Research
Hypothesis
What morphological transformations occurred in the lineage of cetaceans regarding their placentation?
Conclusion
Placentation in Inia and Sotalia is similar to that described for other toothed whales, supporting the view that cetaceans are nested within the larger clade Cetartiodactyla.
Supporting Evidence
- The umbilical cord branched to supply a bilobed allantoic sac.
- The interhemal membrane of the placenta was of the epitheliochorial type.
- Two different types of trophoblastic epithelium were observed.
- The endometrium was well vascularised and supplied with actively secreting glands.
Takeaway
The study looked at how dolphins from the Amazon give birth and found that their placentas are similar to those of other whales, showing they are closely related.
Methodology
The study involved examining the placentae of three specimens of Inia geoffrensis and one of Sotalia fluviatilis, using histological methods.
Limitations
The study was limited by the small sample size and the condition of the specimens.
Participant Demographics
The study focused on two species of dolphins from the Amazon River Basin.
Digital Object Identifier (DOI)
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