LSM1303 Animal Behaviour

After watching a documentary on parasites on Animal Planet, I learnt about Tumbu Flies from Central Africa.

To summarise, scientist Karl Loren spent 3 years in Africa, and he realised that he was getting pimples on his skin. After a while, these pimples grew itchier and itchier. At some point these pimples grow bigger, redder, and turned to sores. Some time later, these lumps on his skin began to move. By then it was already too painful, and he stopped work and tried to dig the sores open.

“The tumbu fly is found in many parts of East and Central Africa. It lays eggs on clothing – especially clothes that bear traces of urine or sweat. Clothes hanging outdoors on the washing line and clothes laid out on the ground to dry are the usual target.”

“The eggs hatch on contact with human skin. The larvae burrow into the skin and produce a characteristic boil, which contains not pus, but a developing maggot. The boils are usually multiple and are most often over the back, arms, scrotum, and around the waist.”

“The breathing apparatus of the maggots can usually be identified at the surface of the boil as a pair of black dots. A maggot can be removed by placing water or oil over its breathing apparatus and gently squeezing it; the maggot will pop out. This is a rather unpleasant spectacle to witness.”

This condition is known as Myiasis, which is the infestation of live animals with larvae, which at least for a period, feed on the host’s dead or living tissue. Fortunately for Loren, he got the help of a native African doctor, who covered his sores with coconut oil until the maggots came to the surface of the skin and they dug out the maggots one by one. I can’t imagine being eaten alive like that.

References:

Animal Planet: TV With Teeth – Nature’s Vampires

Karl Loren (2003). The Bite? of the African Insect? That lays egges that burrow. http://www.karlloren.com/biopsy/p47.htm

James AS, et al; Cutaneous myiasis due to Tumbu fly. (Arch Emerg Med, 1992 Mar, Abstract available) [MEDLINE]

A picture to get your attention! Well, if you have watched Disney’s “Finding Nemo”, you might remember the fish on the right of the picture – the Deep Sea Anglerfish. This however, is the female, which gets all the “limelight” (well, light… see the thing sticking out its head? get it? light…? alright, lame jokes aside…)

The male anglerfish is the lead of this post. In comparison, the male anglerfish does not look like its female counterpart. It does not have the light-producing component (which is actually part of its spine) and is much smaller in size.

Male Anglerfish

The interesting thing about the Deep Sea Anglerfish is its method of reproduction – with particular focus on the male. The male gradually loses its digestive ability as it matures. In order to survive, the male then searches for a female and bites onto the female. The male then releases an enzyme that dissolves the skin around its mouth and the body of the female. Eventually, their bodies become fused together for the rest of their lives.

Its role then becomes a gonad (or testicle) for the rest of its life, releasing sperm when the female is ready to reproduce. Did I already mention this is for the rest of its life?

You could catch a video from the link below, particularly from 3:00 onwards…
http://www.youtube.com/watch?v=RitJe16c3sM

Citation

1. Deep Sea Anglerfish – Deep Sea Creatures on Sea and Sky http://www.seasky.org/deep-sea/anglerfish.html

2. Theodore. W. Pietsch, 1976. Dimorphism, Parasitism and Sex: Reproductive Strategies among Deepsea Ceratoid Anglerfishes. Copiea, Vol. 1976 (4): 781-793

Kangaroos have an amazing reproduction system. The young is usually born after a tremendously short gestation period of 33 days and is embryonic in appearance.Its size is minute, usually measuring around 2.5 centimeters and weighing less than 1 gram! The baby is hairless at this stage and looks nothing like a kangaroo. It looks more like a piece of jelly because of its translucent skin, vague outlines (because it is not fully formed yet) and red body. Immediately after its birth, the tiny newborn starts climbing up its mother’s legs and into her pouch. This journey takes less than 3 minutes in spite of the baby’s tiny size.

Once it reaches her pouch, the baby attaches itself to one of its mother’s four nipples and immediately starts suckling. It attaches itself to the nipple permanently for about 70 days and continues to grow and develop during this time. Usually after this period, the joey learns to detach itself from the nipple and reattach itself as and when it likes. During this time too, the joey leaves the pouch for occasional forays outside. The mother carries her joey for more than 200 days!

The most interesting thing about the reproduction cycle of the female kangaroo is that she is able to freeze the development of any embryos in her womb until the joey in her pouch has reached a certain maturity. This means that the female kangaroo is able to keep herself permanently pregnant! When the joey in her pouch is mature, she will start gestation for another joey and suckle both together.

Another amazing fact is that, the mother’s nipples can produce 2 different kinds of milk for the joeys who are in different stages of development. The nipple that the newborn attaches itself to will contain milk rich in fats necessary for its development, while the nipple that the older joey suckles from would be rich in carbohydrates to provide it with energy as it is more active.

A kangaroo can have as many as 3 joeys together, one that is mature and has left the pouch, one that is a newborn and permanently being suckled and another embryo that is in a state of suspended animation waiting for its siblings to mature! You can watch a video on this amazing animal by clicking on this link: Working Mums by National Geographic

Citations

http://www.outback-australia-travel-secrets.com/kangaroo-facts.html

http://animaldiversity.ummz.umich.edu/site/accounts/information/Macropus_rufus.html

http://animals.nationalgeographic.com/animals/mammals/red-kangaroo.html

http://www.zoo.utas.edu.au/RR/pdfRose/Growth%20in%20the%20red-bellied%20pademelon.pdf

http://www.reproduction-online.org/cgi/reprint/14/1/129.pdf

http://www.zoo.utas.edu.au/RR/pdfRose/Repro%20and%20evol%20of%20Macropodidae.pdf

A  Misfit?

Well, before stumbling upon an animal planet show about the playtpus, the only time I heard about this creature was during my science lesson in primary five.  Of course, many of us would have heard about this creature and how though it is a mammal, it lays eggs and you would have thought wow, cool.  Well, after the animal planet show and more research, the platypus came across as more than wow.

The Duck-billed platypus is an animal that grasps one’s attention because of its odd appearance. While having the webbed feet and a bill of a duck, the platypus also has the tail of a beaver and the body of an otter.  However, the apparent ‘misfit’ clearly does not stop there.  In all aspects of its behaviour, the platypus has stunned scientists who thought it would be a myth when drawings of the animals first appeared.   For example, while it has been classified as a mammal, it lays eggs.   Secondly, while it spends a large amount of time underwent foraging for food; it prefers living in burrows near a pond.  Despite its docile appearance, the duck-billed platypus is also an aggressive animal which males engage in combat which may result in fatal injury.

A female platypus can lay up to three eggs at a time in her burrow which she incubates by placing the eggs on the belly fur using her tail.  Thereafter, the mother nurses her young with milk that comes directly from her belly skin.  This is due to the fact that the female platypus has no nipples.  This is again inconsistent with the characteristic of a mammal where the mother nurses her young with milk from her nipples. 

http://www.youtube.com/watch?v=QNoQvjlmGdk 

(The link from youtube provides more insights into the behaviour of this creature.)

The platypus largely hunts underwater using its beak which is a very complex feature of its anatomy.  The skin surface of the bill which contains 40,000 electro receptors, or specialized sensory nerve endings allow the platypus to detect tiny, underwater bursts of electricity from the muscles of its prey.  This is instrumental in enabling the platypus to be able to obtain food at the bottom of the waterbed among the rocks where it is seen to be searching for food using its bill.  Well, talk about being sophisticated, thats sophisticated technology the platypus uses.  In addition, the platypus also does not hunt under water with its eyes open, instead it relies solely on its bill the sensory nerves on it. And yet, he gets his catch.

In addition, despite its docile appearance, the platypus possesses a deadly venomous spurs on the heels of its hind legs.  This spurs are used in male to male combat where males fight to assert their dominance.  The spur is so venomous that it can result in the death of one male in the course of the combat and has the ability to even kill a cat or a dog. 

So, a misfit? well in my opinion it is truely a misfit.  However, while studies on the platypus are pretty limited and while certain behaviours are yet to be explored, the playtpus remains a mysterious animal and an anomaly on many levels.

Citations

“Duck-Billed Platypus: Ornithorhynchidae- Behaviour and Reproduction”. Mammals and other Warm blooded Animals, Volume 1.

“Platypus Profile” by National Geographic.

Incest!! Taking motherly love to a whole new level

Animals need to mate in order to reproduce. That is the law of nature, and one that ensures the continued survival of the species. Yet during mating rituals, there will be someone left out, be it male or female. Either the male was not strong or attractive enough or the female was not seductive enough that they ended up lonely. Yet one bug has managed to go against all that by creating sexual partners for reproduction.

The Histiostoma murchiei mite goes against most mating laws and rituals that we have learnt in class. Instead of the usual sexual selection that animals go through in order to determine a mate, the female Histiostoma murchiei copulates with her offspring! And this is after creating them from scratch. ie. She lays eggs that can hatch unfertilized into males, and then have sex with them to breed more females.

This is such a weird from of reproduction, but I guess it does help make things a lot simpler. Gone are the days where males had to fight each other for the attention of females, or vice versa. With the Histiostoma murchiei, you are guaranteed a mate! If you don’t have one, create one! Sick as it may sound, it does seem to ensure the continued survival of the species, and keeping everything within the family to boot!

<!– /* Font Definitions */ @font-face {font-family:”Cambria Math”; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:-1610611985 1107304683 0 0 159 0;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1610611985 1073750139 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:”"; margin-top:0in; margin-right:0in; margin-bottom:10.0pt; margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:”Calibri”,”sans-serif”; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Calibri; mso-fareast-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:”Times New Roman”; mso-bidi-theme-font:minor-bidi;} p.MsoBibliography, li.MsoBibliography, div.MsoBibliography {mso-style-priority:37; mso-style-next:Normal; margin-top:0in; margin-right:0in; margin-bottom:10.0pt; margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:”Calibri”,”sans-serif”; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Calibri; mso-fareast-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:”Times New Roman”; mso-bidi-theme-font:minor-bidi;} .MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Calibri; mso-fareast-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:”Times New Roman”; mso-bidi-theme-font:minor-bidi;} .MsoPapDefault {mso-style-type:export-only; margin-bottom:10.0pt; line-height:115%;} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.0in 1.0in 1.0in; mso-header-margin:.5in; mso-footer-margin:.5in; mso-paper-source:0;} div.Section1 {page:Section1;} –>
/* Style Definitions */
table.MsoNormalTable
{mso-style-name:”Table Normal”;
mso-tstyle-rowband-size:0;
mso-tstyle-colband-size:0;
mso-style-noshow:yes;
mso-style-priority:99;
mso-style-qformat:yes;
mso-style-parent:”";
mso-padding-alt:0in 5.4pt 0in 5.4pt;
mso-para-margin-top:0in;
mso-para-margin-right:0in;
mso-para-margin-bottom:10.0pt;
mso-para-margin-left:0in;
line-height:115%;
mso-pagination:widow-orphan;
font-size:11.0pt;
font-family:”Calibri”,”sans-serif”;
mso-ascii-font-family:Calibri;
mso-ascii-theme-font:minor-latin;
mso-fareast-font-family:”Times New Roman”;
mso-fareast-theme-font:minor-fareast;
mso-hansi-font-family:Calibri;
mso-hansi-theme-font:minor-latin;}

<!–[if supportFields]> BIBLIOGRAPHY \l 1033 <![endif]–>10 Craziest animal behavior. (2006, May 6). Retrieved from 2spare: http://www.2spare.com/item_55014.aspx

Oliver, J. H. (1962). A Mite Parasitic in the Cocoons of earthworms. The Journal of Parasitology , 120-123.

<!–[if supportFields]><![endif]–>

While we are eating our sambal sotong at a seafood restaurant by the beach, enjoying the sea breeze, it is a harsh world out there deep under the sea. The ’sotongs’ have a tough decision to make, either they lay their eggs deep in the sea on the ocean bed leaving them vulnerable to predators, or they carry the eggs around and after hatching, the exhausted mothers themselves are left vulnerable to predators. The catch: the eggs comes in thousands, often the combined size of all the eggs are way larger than the body of a single mother squid.

Most species of squid opted for the first. During mating season, they dive deep into the sea and lay their eggs on the ocean floor, leaving them to hatch on their own. However, scientists discovered recently, that the Gonatus Onyx decided to trade their own survivability for that of their young.

This squid, Gonatus Onyx, was discovered to be taking care of its eggs instead of leaving them lying around the ocean bed, waiting to be eaten up.

“Laying eggs on the ocean floor is quick and costs little in terms of energy; the penalty is a lowered chance of survival for the young.

Carrying the eggs around is far more expensive in energy terms, and does seem to affect the mothers severely. “

Links:

The link to the article on BBC News – Science\Nature: First images of baby squid care

A short one-page scientific article published on Nature: Post-spawning egg care by a squid (requires logging on to NUS account)

The full scientific paper on Gonatus Onyx: Life history of Gonatus onyx (requires logging on to NUS account)

Analysis:

This behaviour that we’re looking at actually comes from the fight for survival. Because the Gonatus Onyx is one of the most common squid in the Pacific and Atlantic ocean, they are also being highly predated on. This became a cost vs benefit situation, which over time, has evolved into the current state.

Cost: mother squid spend more time and energy taking care and protecting the eggs by carrying them around. After the the eggs hatched, the mother squid herself became weak and thus more vulnerable to predators.

Benefit: The chances of survival of the thousands of baby squids increased greatly.

Conclusion: The mother squid sacrificed itself for the survival of its babies. She traded her own life for thousands of her offsprings to survive. In this case, the benefits of this behavior greatly outweighs the cost, hence the population of Gonatus Onyx will continue to thrive.

References:

• “First Images of Squid Care” by BBC News, Science/Nature. 15 dec 2005. http://news.bbc.co.uk/2/hi/science/nature/4530980.stm
• Seibel, B.A., F.G. Hochberg & D.B. Carlini. 2000. Life history of Gonatus onyx (Cephalopod: Teuthoidea): deep-sea spawning and post-spawning egg care. Marine Biology 137(3): 519-526.
• “Post-spawning egg care by a squid” Brad A Seibel; Bruce H Robison; Steven H D Haddock. Nature, Vol 438: pg. 929
• Picture from: http://tolweb.org/onlinecontributors/app?service=external/ViewImageData&sp=11834

Giant squid (genus: Architeuthis) is one that lives in the deep ocean. Research has suggested that they can live at an approximate 1.5kilometre down in the water.

Their physical size can grow to a size of approximately 13metres long for the females and 10metres for the males.

Giant squids have very unique  sexual behavior where the male ejaculate sperm under the skin of the female’s arms and she carries the sperm around with her until she is ready to lay her big jelly mass of a million eggs (Hoving, 2004). As we know, Females giant squid are relatively one third larger than male giant squid, hence this size differentiation makes the reproduction process difficult; especially when the female is not keen on being injected.  Male giant squid might experience detriments during the conflict.

To overcome the size barrier, male giant squid has a penis that can grow up to 8 FEET long! According to Randell “This is no ordinary eight-foot penis. It is hypodermic, and hence able to pierce the female’s arm and impregnate her”. With its length, male giant squid can remain at a fairly safe distance away from the female during injection. 

However, having such a long penis does have its drawbacks. According to a Japanese scientist: “It seems coordinating eight legs, two feeding tentacles and a huge penis, whilst fending off an irate female, is a bit too much to ask”(citation).  News has reported that a few cases of male giant squid washed up shore were found with sperm packages inseminated on its own legs and body (CDNN, 2005).

This put us to ponder, does longer really means better?

References

CDNN, (20050925). Scuba diving. Retrieved April 13, 2009, from CDNN Web site: http://www.cdnn.info/news/eco/e050925.html

Hoving, H.J.T., Roeleveld, M.A.C., Linpinski, M.R., & Melo, Y. (2004). Reproductive system of the giant squid Architeuthis in South African waters. The Zoological Society of London, 264, 153-169.

Randall, David (20051002). Environment. Retrieved April 10, 2009, from The Independent Web site: http://www.independent.co.uk/environment/love-in-the-deep-sex-life-of-the-giant-squid-revealed-509302.html

It is widely known that the only way to get a sex change is to have a surgical operation, but for chickens, they change their sex naturally, saving the cost for an operation! However, the known occurences are extremely rare, happening only in 1 out of 10,000 cases. “Every once in a while you hear a story about a hen that changed into a rooster. Such stories are often meet with skepticism, but sex reversals do, in fact, occur, although not very frequently,” says a 2000 report published by the University of Florida’s Institute of Food and Agricultural Sciences.

In an egg-laying barns where no roosters are present, a common behaviour arising from the hens are one of them will start crowing like a rooster. Generally, the hens only have one functional ovary, the left one, hence, once it is damaged, testorone will soar and regeneration occurs in the right gonad hypertrophies, which then regenerates as an ovotestis which consists tissues of either the testes or ovary, or both. This change is known as a spontaneous sex reversal and is extremely rare, usually happening only in barns which have a lack of roosters. The sex reversal will also occur when a rooster dies off and there is no rooster or a drastically small number of roosters left in the barn.

It is interesting to note that the hen will develop the behavioural and physical characteristics of the rooster as well. It will stop laying eggs, grow new plumage, a wattle and comb and starts the crowing behaviour. The sexually altered rooster will also try to mate with their old female mates. Although there are reports of the ovotestes producing semen and is able to reproduce, most however, are unable to reproduce.

Chicken run: George (1st in the photo) with some of the females he used to look like. The bird has become bossy since he swapped sexes and became a male Source: Daily Mail Reporter (http://www.dailymail.co.uk/news/worldnews/article-1080049/Pictured-The-sex-swap-chicken-called-Georgina-turned-cockerel-named-George.html)

Although majority of the sexually altered roosters are unable to generate semen to reproduce, the occurrence of this phenomenon is most probably to ensure a sexual balance in the brood or perhaps to maintain the need for a ‘boss’ figure in a brood of hens. However, it is intriguing to note that there are reports of these ovotestes having the ability to reproduce and another possible reason for the sexual change is to ensure reproduction is possible with non or few roosters in the brood to ensure continuation of its species.

Freaky- The sexually altered rooster

  Source: Bristol Evening Post

 (http://i7.photobucket.com/albums/y286/helena_the_chicken_lady/eveningPostChickenSexChange.jpg)

References:

1. Jacob, J and F. Ben Mather, 2000. Sex Reversal in Chickens. Department of Animal Sciences, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, FACTSHEET PS-53.
2. “The Sex-Swap Chicken Called Georgina that Turned into a Cockerel Named George,” by Daily Mail Reporter. Daily Mail Online, 23 October 2008.
3. “Letters: Sex-Change Chicken,” by M. A. Crooks. New Scientist, 16 May 1992.
4. “Strutting Super-Rooster is a Real Gender Bender,” by Geoff Bennett. Europe Intelligence Wire, 18 April 2006.