Pteronura brasiliensis is the Latin name for giant river otter, in which Pteronura means wing or feather, and brasiliensis means Brazilian. The reference to a wing, or feather, refers to the giant river otter's tail, which helps to propel it through the water, and what a coincidence! The giant river otter inhabits Brazil!




Two baby river otters lying on each other. Image provided by Nick Gordon via Arkive.

Kingdom- Animalia
Phylum- Chordata
Class- Mammalia
Order- Carnivora
Family- Mustelidae
Subfamily- Lutrinae
Genus- Pteronura
Pteronura brasiliensis




Here is the breakdown of the taxonomic levels to which the Pteronura brasiliensis belongs to.



 Giant river otter during the dry season. Image provided by Pete Oxford via Arkive.Domain- Eukarya
Eukarya have cells that contain organelles and also a nucleus that holds its DNA. An interesting fact: eukaryotes went through endosymbiosis to obtain their mitochondria and chloroplasts; this means some Eukarya are photosynthetic.

Kingdom- Animalia
    Animals are multicellular organisms that are motile at some point during their lifetime and lack cell walls. They are also heterotrophs, so they can't use sunlight to produce their own food.

Phylum- Chordata
    Be aware of the Chordata! This phylum consists of the lurking amphibians, reptiles, and mammals, as well as colorful fish and birds. They all possess muscular tails and pharyngeal gill slits, and don't forget the notochord that runs along their back, attaching to muscles in many chordates and enabling them to move. All chordates have a dorsal hollow nerve chord that lies just above the notochord. If you find the Chordata interesting, visit this webpage to learn about the great white shark, one of many representatives of the chordates.

Class- Mammalia
    Mammals are classified as endothermic because they maintain body heat internally. Along with their inner metabolic functions that produce this heat, they also have a soft coat of fur to keep the warmth in. A little advice, don't try to sneak up on a mammal. They're always listening! Mammals also have mammary glands that are used to produce milk for their young.

    If you want to learn more interesting facts about the anatomy of mammals, visit Dr. Jon A. Baskin's Biology website for Texas A&M University of Kingsville here!



Family of giant otters running along the river. Image provided by Keith and Liz Laidler via Arkive.Order- Carnivora
Carnivora is Latin for "flesh" and "to devour." As you can tell from the root meanings of the Latin term, these mammals eat meat, which means that they require razor sharp canine teeth and claws. Like most other mammals, carnivores give live birth rather than laying eggs. If you would like to learn more about mammals that belong with the Carnivora, take a look at the cougar here!

Family- Mustelidae
The mustelids consist of weasels, otters, wolves, and martens. All members have an elongated, tube-shaped body with stubby muscular legs and five retractable claws. Their small rounded ears are the only innocent-looking characteristics they have, for as soon as they open their mouths and show their menacing pointed canines, it's enough to send anyone running for their lives. They also have delayed fertilization, in which the embryo can remain dormant for up to a year (Encyclopedia Britannica 2014). Check out this sea otter to learn more about Mustelidae!

Subfamily- Lutrinae
    The Lutrinae are a subfamily of Mustelidae, and they are considered to be semi-aquatic otters. Their diet consists mostly of fish, and they live near any freshwater land forms.

Genus- Pteronura
    The Pteronura brasiliensis belongs to the genus Pteronura and is the only species within this genus. Pteronura brasiliensis brasiliensis and Pteronura brasiliensis paranensis are claimed to be subspecies of the giant river otter because of their larger skull and varied dentition, but there is not enough evidence yet to support this claim (Pickles et al. 2011).



Phylogenetic tree of the Mustelidae family. Image by Alyssa Patten.    This phylogenetic tree shows the phylogeny of the subfamilies belonging to the Mustelidae. This representation is based on the data received from molecular testing of five nuclear genes within species in each subfamily. However, it must be noted that this is just one of many representations that could be created. Rapid species radiation makes it difficult to test these species (Yu et al. 2011).
    Within this phylogenetic tree, the giant otter would be part of the Lutrinae within the Mustelidae. It shows the relationship between otters, weasels, badgers, wolves, and martens. See this website for more information on the relationships between the giant otter and these species!

  Figure 1. Phylogenetic tree of the Mustelidae. Image by Alyssa Patten.


Phylogenetic tree of families belonging to the Carnivora. Image provided by Alyssa Patten.



     This phylogenetic tree compares fossils of different species among the families that make up the Carnivora. The placement of taxa were determined by the morphologies of dentition, mandibles, and skull size and shape (Prevosti and Ferrero 2008). As you can see, the Pteronura brasiliensis is shown to share a most recent common ancestor with the Satherium piscinarium based on similar morphologies.





                                                                                                                                                                                                        Figure 2. Phylogenetic tree of families within the Carnivora. Image by Alyssa Patten.



As you can tell from the classifications, the Pteronura brasiliensis is a very intriguing species! What's even more interesting is its habitat. Continue on to learn about where the giant river otter lives.





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