April has been unseasonably cold, almost as if Mother Nature was playing a sick joke on the British countryside. Another sick joke is when evolution created the Amazonian Giant Centipede, a venomous land train of terror and destruction. This week’s animal is not as horrifying, but I still wouldn't trust it anywhere near my toes. Hope you guys enjoy.

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Issue #118 – Mata-Mata

Kingdom – Animalia

Phylum – Chordata

Class – Reptilia

Order – Testudines

Family – Chelidae

Genus – Chelus

Species – fimbrata

Related Species – The Mata-Mata is the only member of the genus Chelus (1)

Range – Mata-Mata live in shallow pools, swamps and marshes across the majority of tropical South America.

Sneaky Swamp Dweller

The Mata-Mata is a medium sized dark brown water turtle which has a carapace length of approximately 45cm and an average weight of 15kg. The shell of the Mata-Mata has a series of narrow ridges running along its length, and the whole animal has barbells and loose flaps of skin covering its body which act as camouflage from both prey and predators. The turtle’s nose features a tube like structure that, coupled with the animal’s long neck, allows the Mata-Mata to breathe from the surface whilst standing on the river or lake bed.

Like the majority of the other rive turtles, the Mata-Mata is carnivorous, with the name translating to ‘I kill’ in Spanish (2). While not particularly fast, Mata-Mata’s are active hunters, often sweeping their neck laterally through the water to detect prey such as fish or amphibians. When a food item has been located the turtle lunges forward and opens its mouth creating a change of water pressure that sucks the prey item into the turtle’s throat. Since water is also sucked in, the neck of the Mata-Mata often ballons out until the excess water is leaked out through the side of the closed mouth. Predation of Mata-Mata is limited since it sticks to shallow water, thus avoiding the large river predators and most terrestrial preadators can’t crack the animals shell, although Jaguars (Panthera onca) feed on turtles and tortoises of all types within their range and have a strong enough bite to puncture the Mata-Mata’s shell.

Mata-Mata are solitary outside the breeding season, which occurs in October, and involves the male extending his head towards the female as she opens and closes her mouth. Eventually the pair mate, although the female will mate with multiple males before her eggs are finally fertilized. Unlike the majority of Amazon River turtles, the Mata-Mata forgoes nesting on open sandbars, and instead creates a nest of vegetation on the edge of the forest where she lays up to twenty eight eggs (3). After an incubation period of two hundred days, the hatchlings emerge unaided and race to the relative safety of the water,

Five Unusual Animals of the Amazon River

The Amazon is home to two species of freshwater dolphin; the Tucuxi (Sotalia fluviatilis) and the Boto (Inia geoffrensis). While the former is almost identical to Oceanic dolphins, the Boto is very different in appearance, being pink in colouration and having the uncanny (and unique among cetaceans) ability to turn its head thanks to the unfused vertebrae in its neck.

Among the many fish in the river, one of the largest are the Arapaima (Arapaima gigas) which reach 3m in length. Obligate air breathers, the fish reaches a length of up to 3m and is said to make a coughing sound when it comes up for air.

Another large fish is the Tambaqui (Colossoma macropomum), a meter long predominantly fruit eating piranha. Unlike many fish, the species is highly resistant in changes in water pH, with the fish able to survive in pH conditions as high as 3.5, despite normally living in far more basic water conditions then that (4).

While on the subject of piranha, the Payara (Hydrolycus scomberoides) feeds predominantly on piranha using its 15cm long fangs. Known colloquially as the ‘Vampire Fish’, the Payara has special holes in its upper jaw to prevent its own teeth from stabbing into its brain.

As gruesome as the Payara is, one fish above all others is feared in the Amazon Rainforest. The parasitic Candiru Catfish (Vandellia cirrhosa) uses chemosensative organs to track urea in the water back to its host, where upon it enters the victims gill cavity and cuts into one of the arteries. Feeding takes only around two minutes, with the Candiru dropping off when fully engorged. Attacks on humans, whilst rare, have been reliably reported, with Candiru having to be surgically removed from both male and female genitalia.

Bibliography

1 - www.arkive.org

2 - http://animaldiversity.org/accounts/Chelus_fimbriatus/

3 - http://eol.org/pages/795410/details

4 - Val, Adalberto L; Wood, Chris M; Wilson, Rod W; Gonzalez, Richard J; Patrick, Marjorie L; Bergman, Harold L (1998). "Responses of an Amazonian Teleost, the Tambaqui (Colossoma macropomum), to Low pH in Extremely Soft Water". Chicago Journals 71 (6): 658-70

Picture References

1 - https://adlayasanimals.files.wordpress.com/2014/12/t407.jpg

2 - http://whozoo.org/Anlife99/diegoben/MataMouth_112003_093.JPG

3 - http://cdn1.arkive.org/media/51/519450C2-64A4-4916-9F3A-FF0213D3D7F4/Presentation.Large/Boto-playing-with-fruit-at-surface.jpg

4 - https://s-media-cache-ak0.pinimg.com/736x/ff/87/37/ff8737239aeb51e09973eb481affbe33.jpg

Maybe it’s best if we all stayed out of the water for a while. So instead of swimming, let’s try sailing like next weeks animal. 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. For out other turtle related issue click here to learn about the Big Headed Turtle, or if you want to look at another kind of ‘shellfish’ click here to check out the Noble Sea Pen