LSM1303 Animal Behaviour

I love animals. I love them most when they are furry and warm, with whiskers and cute paws and small legs. Who can resist a bunny rabbit hopping around your legs begging you for food? Or a kitty cat snuggling into your arms for a rest? They’re simply irresistible. To do a write up about these cute animals, I might as well be setting up a website like cuteoverload.com, with pictures of baby rabbits, puppies and puggles. So on the contrary, I have decided to do a write up on the most disgusting creature I came across. This creature is by far the most heinous and repulsive, in all aspects, from its physical appearance, to its feeding habits, reproduction and most of all its defence mechanism! I present to you, the Atlantic Hagfish, also known scientifically as Myxine Glutinosa

The hagfish looks like an eel. In fact, it is very often mistaken for an eel and scientists have even debated whether or not it belonged to the fish family or the lampreys. It is the only animal with a skull but no backbone. Picture it as an underwater snake, if you will, with barbels (whisker like organ) instead of fins and a single nostril. Its colour ranges from grey to pink or brown, depending on the species and is found at a depth of 4000 feet underwater, making it a deep sea creature. The Atlantic Hagfish, as its name might suggest, is found on both sides of the North Atlantic Ocean and can go as far up as Norway.

If its appearance is not enough to repulse you, it’s feeding habits might. Albeit relatively small (16 -32 inches), the hagfish possesses a very barbaric and monstrous way of feeding. The hagfish starts off by attaching itself to another healthy fish. Unlike the Remora, the Hagfish does not stay at the sides or underneath its host, feeding on its remains, but bores its way into the host fish. The hagfish then feed on the host fish’s flesh with its tongue, literally eating its host inside out. There are instances where deep-sea fishermen found thousands of hagfish (instead of flesh) inside their catch! Be careful the next time you’re eating a Cod.

Sex with the Hagfish can be confusing. This is because some are hermaphrodites. Yes, they have both male and female sexual organs. A study conducted by Scott I. Kavanagh et Al in 2004 revealed that the production of gonadotropin-releasing hormone is highly seasonal and differs in relation to its size class and stage of gonadal development: “In the medium and large class hagfish, there was an increase in GnRH concentrations during April and May that correlated with male and female gonadal maturity. Also in these size classes of female hagfish, there was a similar rise in GnRH in November and then again in January that preceded the highest incidence of large eggs.”

What is known is that the hagfish’s eggs attach together and the Hagfish will curl itself around the eggs but it is not known if they are taking care of the eggs.Sexual Reproduction in the Hagfish is rarely documented and further study is much needed to those who can withstand its slime and grime.

Yes, the most disgusting fact about the Hagfish? Aside from its confused sexual orientation, its beastly eating habits and its unsightly appearance, the Hagfish is known for its defence mechanism. The slime. When provoked, the Hagfish excretes a whitish substance that, when in contact with water, will develop into a thick, slimy substance that reminds you of your own mucus! A Study by S.Subramanian et Al., discovered that a major constituent of the hagfish extruded slime are trypsin-like proteases. They found that stress induced slime of the Hagfish contains “various innate immune parameters in comparison to its epidermal mucus”. The slime excreted from the hagfish not only protects it from its predators (thickness of the slime clogs predators’ gills), but also from other diseases and micro organisms that might cause infection! Interestingly, the hagfish escapes from its own slime by knotting itself up and pushing this knot through its body.

The video below shows a scientist and his research animal: the hagfish.

If the video doesn’t load, click here to view: Hagfish Slime

Look at how just a teeny bit of excretion did to a beaker of distilled water! Do not underestimate the power of slime.

References:

Scott I. Kavanagh, Mickie L. Powell, Stacia A. Sower, (2005) “Seasonal Changes of Gonadotropin-releasing Hormone in the Atlantic Hagfish Myxine Glutinosa” General and Comparative Endocrinology, Volume 140, Pages 136-143.

S. Subramanian, N.W. Ross, S.L. MacKinnon, (2008) “Comparison of the biochemical composition of normal epidermal mucus and extruded slime of Hagfish (Myxine Glutinosa)” Fish & Shellfish Immunology, Volume 28, Pages 625 – 632

http://www.seasky.org/deep-sea/atlantic-hagfish.html

http://en.wikipedia.org/wiki/Hagfish

Truly the stuff of Hollywood ‘animal horror’ flicks, the red-bellied piranha (Pygocentrus Nattereri), with its bulging eyes and razor-sharp teeth, have gained enough notoriety to rival the shark as the most-feared fish in the sea (aside from the fact that they don’t actually live in the sea, but rather in the rivers of the Amazon). Seen in a trailer of Discovery’s Animal Planet Series, River Monsters, a shoal of piranhas swarm and finish off half a duck carcass in a scarcely a minute. Definitely not something that you would like to find in your bathtub!

The scent of blood and the thrashing of an injured animal (or human!) in the water typically triggers off a feeding frenzy in the shoal, which results in several dozens or even hundreds of piranhas descending upon its hapless victim, completely devouring it in a matter of minutes. The piranhas can accomplish this scary but amazing feat mostly because their jaws of interlocking teeth tear easily into flesh, which they literally rip off and swallow without chewing. Once tearing off a chunk of meat, they move out of the way to make way for the next fish in line to get its bite. As a result the shoal efficiently demolishes off the unfortunate creature, leaving behind little more than skeletal remains.

Paul A. Zahl/National Geographic/Getty Images

Thankfully, such frenzies only occur when there is easy prey (old, sickly or injured animals) to be had, or when the piranhas have been starved and are really, really hungry. Under normal circumstances they rarely attack large, healthy animals (such as people), and mostly feed on other small fish and carrion. In fact, their role as scavengers(and not predators) is paramount to the Amazon’s ecosystem, as they very efficiently clean up any dead creature long before decay sets in, keeping the waters habitable for other marine life.

Contrary to what Hollywood would have us believe, piranhas are actually pretty wimpy creatures, considering that they live in the big bad (and very wild) Amazon. Originally thought to form shoals in order to effectively overwhelm and take down large animals, it turns out that the piranhas huddle together for predator defence instead; to take advantage of safety in large numbers, just like normal fish. And who would predate on the jaw-chomping, frenzy-feeding piranha? Just about anyone bigger than itself, it seems. Piranhas make tasty snacks for river dolphins, caimans, aquatic birds, and larger fish.

Looks like there’s always a bigger fish in the sea, isn’t there?

Claus Meyer/Minden Pictures/Getty Images

References:

“Can Piranhas really strip a cow to the bone in under a minute?” by Julia Layton. Howstuffworks. Accessed April 2009.

“Piranha Devours a Duck“. AnimalPlanetTV. April 2009.

Pauly, D. 1993. “Quantitative analysis of published data on the growth, metabolism, food consumption, and related features of the red-bellied piranha, Serrasalmus nattereri (Characidae)” Environmental Biology of Fishes, 41: 423-437.

Queiroz, H. & Magurran, A.E., 2005. “Safety in numbers? Shoaling behaviour of the Amazonian red-bellied piranha” Biology Letters, 1 (2): 155-157.

Pan Kun is not an ordinary Chimpanzee. He was raised by a Japanese researcher as a Japanese boy and has undergone learning of human behaviour as he was brought up as if he was a boy and he probably thinks he is. This is commonly known as social imprinting, with the evident extreme expression of filial piety towards human.
He is often featured on the NTV television show "Tensai! Shimura Dōbutsuen" and the TBS program "Dōbutsu Kisō Tengai!" (Unbelievable Animals!). Most of the segments feature him and his bulldog friend, James, embarking on a variety of "human" tasks, like buying groceries, planting a rice paddy, or catching insects.