Impurest's Guide to Animals #136 - Yapok

It’s the last week of August and things are looking grim and gloomy as I head into a five day cycle of bat surveys. Last week the peace was shattered by the Paradise Flying Snake, an animal that surprised us all by taking to the skies. This week a mammal follows suite, this time taking the plunge into the streams and pools of the rainforest. Hope you guys enjoy.

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Issue #136 - Yapok

Kingdom – Animalia

Phylum – Chordata

Class – Mammalia

Order – Didelphimorphia

Family – Didelphidae

Genus – Chrionectes

Species – minimus

Related Species – The Yapok or Water Opossum is one of over 90 species of marsupial found in the order Didelphimorphia (1)

Range

Marsupial Otter?

The Yapok is a medium sized marsupial, with a body length of around 30cm, with an additional 40cm long tail. The Yapok’s dense waterproof fur has a marbled pattern of grey blotches against a dark background that runs from the base of the tail to the base of the animal’s ears. Whilst the animals back feet are webbed to aid in swimming, the fingers of the front feet are fully mobile and are used to grab and manipulate prey. To aid in the detection of submerged obstacles, the Yapok has sensory bristles (in addition to the whiskers) mounted in tufts above each eye.

Yapok are carnivorous and do the majority of their hunting in water, using their long nimble fingers to grab frogs, fish, snails and other freshwater invertebrates to consume on shore. While the exact predators of the Yapok are undocumented (outside a few species of birds of prey) it can be assumed that cats such as Ocelot (Leopardus pardalis) and Jagurundi (Puma yagouarpundi), along with the larger species of snake such as the Bushmaster (Lachesis muta) are potential predators. To reduce the risk of predation the Yapok spends the entire day in its burrow and only emerges to hunt for prey at night.

Yapok are solitary, only coming together to breed during the months between November to Feburary, with the exact date varying from country to country. After breeding the female will give birth to a litter of up to five joeys which remain in the mothers pouch for the first month of their lives (2). Due to the species aquatic habits, certain modifications to protect the joeys are in place, and the females pouch is able to seal itself with a ring of muscle to prevent flooding. Young Yapok mature quickly, and once they’ve grown their adult teeth they are able to leave the nest and establish their own territories.

Five Fun Yapok Facts

The name Yapok comes from the local name of the Oyapock River in Northern Brazil, and is possibly where the species was first seen by Colonial Europeans

The Yapok is one of two aquatic masupials, the other being the Lutrine Opossum (Lutreolina crassicaudata) although the species isn’t as adapted to riverside life as the Yapok

The Yapok is also the only extant species of marsupial where both the male and female have pouches. The male’s is less waterproof and is used to store his genitals whilst swimming and diving (3)

In addition the Yapok is the only species of Opossum that doesn’t have a cloaca.

Fossil remains of the Yapok date back to the Pliocene Epoch (5 to 2.75 MYA)

Bibliography

1 -www.arkive.org

2 - Julien-Laferriere, D., M. Atramentowicz. 1990. Feeding and Reproduction of three Didelphid Marsupials in Two Neotropical Forests (French Guiana). Biotropica, 22: 404-415.

3 - Nogueira, José Carlos, et al. "Morphology of the male genital system of Chironectes minimus and comparison to other didelphid marsupials." Journal of mammalogy 85.5 (2004): 834-841

Picture References

1 - https://s-media-cache-ak0.pinimg.com/736x/48/51/b9/4851b925501b0b3c89e144f5e37e7940.jpg

2 - https://upload.wikimedia.org/wikipedia/commons/d/d0/Water_Opossum_area.png

3 - https://66.media.tumblr.com/e20685d1c699583ae46a92d0ec167381/tumblr_mlfjljaJnN1qd1zpno1_500.jpg

4 - http://www.reservacostanera.com.ar/wp-content/uploads/2011/06/comadreja-colorada-JST-06-11.jpg

Hmm all these animals in weird situations, it’s kind of confusing no? Next week we’re beach bound as we relax and enjoy the last days of summer, until then make sure to critic, comment and suggest future issues as well as making sure you check past issues in Impurest’s Bestiary.

Many Thanks

Impurest Cheese

Want more IGTA? Click here for more marsupial madness with the tenacious Tiger Quoll. Or if you like river creatures click here to meet the murderous monster the Mata-mata

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Semi Aquatic Marsupial of Action

It looks a bit like a small possum.

@cpt_nice: Well that's because it is an opossum, one that's about 60 to 70cm in length

Interesting! A possum with webbed legs.

There seems to be more stuff lurking in South America than anywhere else

@rocketraccoonthingy: Only its back feet it still has nasty little grabbing fingers on the front ones

@blueecho:Well it does have the largest range of habitats for any one continent. It has everything from polar wastes to tropical forests and savannas as well as everything in between

It's much cuter than the opossums we have where I live.

@xwraith: Hmm, never put opossum and cute in the same sentence before TBH

Lol cute not likely. Interesting animal though many north american possum's here when little I chased a mother protecting her young (not my brightest moment). She kept turning and hissing at me. I was just curious and followed her back to a tree were she hung upside down. I was just curious did not mean harm. Yeah anyway that's my possum story

If I remember my class about that correctly, its name means something like "the smallest among those that swim using paws".

I have a friend who researches on South American marsupials. And he loves to emphasize the fact that we have a relatively large diversity of marsupials despite the general idea that they are restricted to Australia/Oceania.

@destinyman75: Thanks for the comment. And no harm no foul I guess. Possums are cute, opossums not so much.

@anna_karenina:Huh never knew that, thanks for the assist. :-) And yes Neotropical Marsupial Diversity is quite astonishing, plus my favourite species lives over there, the Monito del monte, everything I've seen on them makes them look adorable

Opossums may not be cute, but they are fabulous mothers. And great article again :)

@jamiewolfe7: Yes they are (to both). Thanks for the comment

Yeah. That shot reminds me of an iconic moment.

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@risingbean: Wow that's kind of cool

@impurestcheese: I have read that a lot of mini-ecosystems exist within the rainforest, thus incrasing diversity.

@blueecho: Indeed, you have different ecosystems within all main biomes but the additional spacial dimension (height) that forests provide increases the amount found over relatively flat biomes such as deserts and grassland

@impurestcheese: I also heard the Joey's can endure low oxygen partial pressures during dives in the pouch too. I love South American Marsupials, so this was a nice read.

@laflux: Ah that's cool too

@impurestcheese: Cool- never heard of this one. ...Not that this is the first time I haven't heard of the animal you picked. lol

@ficopedia: Thanks, I aim for obscurity 9 times out of 10 :-)

Count me as one of those people who associated anything with pouches and offspring referred to as joeys belonging to only Oceania. Or, I used to, until I read this. Learning is awesome.