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

(picture courtesy of Nadia Kamil)

Elephants, one of the most sociable animals around have often been assumed of their communication merely through loud trunk calls. How do elephants then achieve this over large tracts of land in the wild? Surely the distance would impede communication?

Studies carried out following the Asian Tsunami in 2004 showed that ‘trained elephants in Thailand had become agitated and fled to higher ground before the devastating wave struck, thus saving their own lives and those of the tourists riding on their backs’. (Rodwell, 2005). The elephants were observed to have picked up seismic warnings of oncoming tidal waves and to have retreated to safety.

Elephant talks apparently go beyond trunks-in-the-air-calls and have been observed to be transmitted across vast distances via seismic signals! This secret unravelling has been recorded in Namibia, across vast acres of land where Africa’s wildlife roamed.

Through a study conducted , it was observed that in the herd, ’suddenly, and for no apparent reason, the four males step away from the water and freeze in unison, as if posing for a group action shot’ (Rodwell, 2005), where one of the elephants, unlike the rest, had its trunk ‘flat on the ground, the tip pointing inward toward his front feet’ (Rodwell, 2005). Synchronized freezing is a common behavior in the wild even amongst herds of 20 or more animals. Such synchrony enable the elephants to focus their senses of smells and hearing on unfamiliar noises and odors in the air. However, scientists have observed that in addition, elephants do also sometime stick their trunks close to the earth whilst staying motionless for a brief period of time to detec vibrations in the ground for signs of danger or activity.

Elephants in the wild travelling in herds also transmit vibrational signals through the ground—long-distance seismic messages that could play a crucial role in their survival and reproductive success. (Rodwell, 2005) Scientists have postulated that perhaps these vibrational sounds are sent out to attract potential mates far away, or to warn of oncoming predators in the vacinity through the distress signals from other herds.

Oncoming tides? Look out for trunk calls!

References:

1. W.R. Langbauer Jr, Elephant Communication in Zoo Biology, 30 Nov 2002, Volume 19, Issue 5, pp 425-445.

2. Scientists Unravel the Secret World of Elephant Communication – http://www.physorg.com/news4211.html. Retrieved on13 April 2009.

3. The National Elephant Centre, http://www.thenationalelephantcenter.org/en/art/23/, Vibrations ‘Could Save Elephants’, 14 Feb 2009. Retrieved on 13 April 2009.

4. Kraynak, Cherly,. http://zoology.suite101.com/article.cfm/seismic_communication_in_elephants, 28 Feb 2009. Retrieved on 14 April 2009.

Yes, you will see cuteness personified in this highly vocal relative of the rabbit, the pika (Ochotona sp.). And David is pretty charming too…

A very amusing collection of cat vocalisations which sound like words! Domestic cats may vocalise more to owners than to each other due the reinforcement they receive from the former.

As for cat chirping and chattering:

“Subtle chemical signals, or pheromones, have long been known to draw pairs together within the same species. In mice, for example, experiments showed that pheromones acted as attractants between males and females who were genetically similar except for a difference in a certain type of immune system gene – the HC (major histocompatibility locus). This pairing gives their offspring an advantage in beating back disease organisms.”

So the question is, can humans smell out complimenting partners?

See Teacher’s Domain for the background essay.