Saving the best for last: Mating rituals of the carribean reef squid

 

 

a pair of squids mating

a pair of squids mating

 

 

Imagine the idea of remaining celibate your entire existence right until the last day of your life where you engage in a massive orgy of sorts. Intrigueing? The carribean reef squid(Sepioteuthis sepioidea)does just that! A torpedo-shaped squid that averages in length at about 20cm, belongs to the Cephalopod family and can be found in the shallow reefs of the carribean sea in schools of 4-30. If you think this is going to be just another boring entry extolling the biological traits of this cephalopod– think again! One of the most interesting aspects about this squid is that, like other cephalopods, its is semelparous. Semelparous organisms reproduce only once in their lifetime, thus explaining the title of this entry you are reading. The crux of this entry, will thus focus on the mating ritual of the carribean reef squid.For the most part of their lifespan, the Sepioteuthis sepioidea are perfectly content having no sex at all, swimming around in schools in the day and hunting alone for food at night, consuming up to 60% of their body mass with their voracious appetites. However, this all changes as they approach the last weeks of their lifespan, and their voracious appetite for food translates into an overwhelming sex drive. During mating season, these squids are known to mate for hours at a time, and their mating ritual precedes a courtship process, which can be a very interesting sight indeed. During the courtship ritual the Sepioteuthis sepioidea change their colouration, shape and texture via nervous control of  their chromatophores. Males do this to enhance their attractiveness to the opposite sex whereas females do so to indicate their interest.

 

 

Male squids sparring, sporting a spotted mantle, a sign of aggression and competition

Male squids sparring, sporting a spotted mantle, a sign of aggression and competition

 

 

 

In the first stage of the mating game, a male will compete with about 4 other squids. Upon emerging victorious, it would then approach a female. One interesting effect about these male squids to note is that unlike our human counterparts, these reef squids are actually attracted to females of larger proportions! They will however, eventually settle with a same-sized female. The game begins when the male “flashes” and pulsates, gently sticking its tentacles onto her skin just below the eyes. A willing female often turns pale and the pair swim fairly quickly side-by-side in a rocking motion. Then he darts around in front of her and sticks the spermatophores in place. Females play games too! A female squid might play “hard to get” by putting an agonistic pattern of rough vertical zebra stripes on her skin and swimming away quickly. More often than not, this is being done to assess the male squid’s agility in “chasing” her. In the meantime, other male contenders might intercept by displaying neat zebra stripes across their mantle. If the male proves worthy, he will then be allowed to inseminate a sticky cluster of sperm into her, displaying a pulsating pattern, like a victory routine.

courting pair squids                                                 Picture depicts a pair of courting squids

 

All good things must come to an end however, and this vibrant display of courtship and vigour has to eventually end too. The impregnated female squid searches for little protected cracks and crevices in the reefs. She squeezes her way in and moves eggs out past the spermatophoric gland to fertilize them, gives them a gel coat and attach them in small clusters. The female turns into a dark brown shade whilst doing so. Shortly after, the female dies. The male squid also dies, becoming frail and susceptible to predator fish, such as tuna and yellowtail. Nevertheless, this intricate display of colour and marine art is indeed a sight to behold. If you happen to be snorkeling around shallow Caribbean waters in the morning, do look out for the Caribbean reef squid. If you are lucky enough you’d be able to witness first-hand this wondrous spectacle of Mother Nature!

 If you wish to view videos of the Sepioteuthis sepioidea, please click on the following link :

http://www.oceanfootage.com/stockfootage/Squid_Caribbean_Reef 

 Done by: Melissa Lim Ying Pei, U098708N

References: 

Second source- 

Science Direct- Encyclopedia of Ocean Sciences: Cephalods

http://www.sciencedirect.com.libproxy1.nus.edu.sg/science?_ob=ArticleURL&_udi=B77C6-4B0FVKG-GP&_user=9185724&_coverDate=11%2F12%2F2003&_alid=1284550175&_rdoc=11&_fmt=high&_orig=search&_cdi=14570&_sort=r&_docanchor=&view=c&_ct=398&_acct=C000008700&_version=1&_urlVersion=0&_userid=9185724&md5=3e1266a744f21ef2e3d5d627f73d6c13

other references:

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

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

 

http://www.thecephalopodpage.org/Ssepioidea.php

 

http://www.thecephalopodpage.org/Mather.php

The Pebble and the Penguin

The Edinburgh Zoo is recently providing and laying out pebbles to help its male Gentoo penguins (Pygoscelis papua) find a mate. The keepers place large doughnut-shaped nesting rings in the enclosures during the mating season for the Gentoo penguins to build their nests in, and then pebbles are gathered and placed within the ring as a blanket for the eggs to be laid on. Pebbles are useful materials for nest-building especially in areas without plants; such nests could possibly save an egg or a chick from drowning if there is a flood.

The male penguin basically sifts through the available pebbles to find the smoothest (slightly flat) one — these pebbles tend to sit the best in the nesting rings — to present to its intended mate, and if the female penguin accepts the pebble and puts it on the nest she’s sitting on, a marriage would be formed — she has accepted the male penguin. Zookeeper Roslyn Talbot mentions that this courtship process also provides an opportunity for the penguin couple to bond. And ‘pebble envy’ could even occur, where the male penguin actually steals pebbles from other penguins, but naturally not without some defensive behaviour from the pebble owners.

Pebbles in Gentoo penguin enclosure at the Edinburgh Zoo

Gentoo penguin with pebble

Gentoo penguin with pebble

This courtship/mating ritual is not only evident in the Gentoo penguins, but also in the Adelie penguins (Pygoscelis adeliae) of Antarctica. In fact, this rather cute courtship behaviour inspired the production of an animated musical film The Pebble and the Penguin back in 1995!

I guess this gives new meaning to “picking someone up”!

————

References:

Gentoo Penguin nesting,” by M. Pettitt. Flickr, 10 Jul 2006. URL: http://www.flickr.com/photos/mdpettitt/186727159/

LT Ronald J. Koss, 1963. Report of dental officer for Antarctic support activities for operation deep freeze ’62. Rubicon Foundation, 415: 1-41.

“Pebbles help penguins mate,” by BBC News. BBC News, 31 Mar 2010. URL: http://news.bbc.co.uk/2/hi/science/nature/8597520.stm (accessed on 3 Apr 2010).

Stone, L.M, 2002. Penguins. Google Books, URL: http://books.google.com.sg/books?id=qws0gwkvc4gC&dq=gentoo+penguins+and+pebble+and+mating&lr=&source=gbs_navlinks_s (accessed on 7 Apr 2010).

“The Pebble and the Penguin family fun edition DVD,” by FunkMonk. Wikipedia, 11 Dec 2008. URL: http://upload.wikimedia.org/wikipedia/en/8/80/PEBBLE.JPG (accessed on 6 Apr 2010).

“The way to a Penguin’s heart… a pebble?,” by P. Dickinson. Zoo News Digest, 31 Mar 2010. URL: http://zoonewsdigest.blogspot.com/2010/03/way-to-penguins-hearta-pebble.html (accessed on 6 Apr 2010).

It’s a car! It’s a chainsaw! Wait… IT’S A BIRD!

Imagine you’re walking through the forest and you suddenly hear the sound of a chainsaw nearby; the thought of a tree falling on you is enough to make you scramble for your life. But if you’re in an Australian forest, hold your thoughts and calm down for a bit; you will be pleased to know that the sound of the chainsaw might just be coming from a bird instead – the Superb Lyrebird.

Superb Lyrebird

Superb Lyrebird

Scientifically known as the Menura novaehollandiae, the Superb Lyrebird (above) is a songbird whose specialty is to mimic any sounds that it hears. This is one of the two species of Lyrebirds which exist, with the other being the Albert’s Lyrebird. In a YouTube video from BBC Wildlife, a male Superb Lyrebird can be heard performing amazing mimicries of a Kookaburra, car alarm, chainsaw and camera shutter sounds – mimicries so convincing that you would think they’re the real deal. (Check the video out here!) This vocal mimicry is usually prominent during male displays where male Superb Lyrebirds stand on a “platform” to perform a courtship song which includes its own song as well as imitations of other species and surrounding environment to attract females. While doing so, the male Superb Lyrebird will spread out its tail (above), showing off a stunning display of its feathers.

The Superb Lyrebird’s syrinx (vocal chords) is “the most complex of all songbirds” (Birds.com, 2007) and this gives the bird its astonishing ability to reproduce sounds accurately. The accuracy of vocal mimicry in Superb Lyrebirds is also an “indicator of male age” (Zann & Dunstann, 2008). Although vocal mimicry plays a clear role in the selection of mates, not many studies have been done regarding the relationship between the complexity of vocal mimicry and the level of mating success (Kelly et al., 2008).

References

“Amazing! Bird sounds from the lyre bird – David Attenborough – BBC wildlife” by BBC. BBCWorldwide YouTube Channel, 12 February 2007. URL: http://www.youtube.com/watch?v=VjE0Kdfos4Y (accessed on 27 Mar 2010).

Kelly, L. A., Coe, R. L., Madden, J. R., Healy, S. D. 2008. Vocal mimicry in songbirds. Animal Behaviour, 76: 521-528.

“Superb Lyrebird (Menura novaehollandiae) by kookr. Flickr: Kookr’s photostream. URL: http://www.flickr.com/photos/kookr/3866749339 (accessed on 27 Mar 2010)

“The Marvelous Mimicry of the Lyrebird,” by Editor. Birds.com, 10 September 2007. URL: http://www.birds.com/blog/the-marvelous-mimicry-of-the-lyrebird (accessed on 26 Mar 2010).

Zann, R. & Dunstan, E. 2008. Mimetic song in superb lyrebirds: species mimicked and mimetic accuracy in different populations and age classes. Animal Behaviour, 76: 1043-1054.

The Best Way to Impress the Ladies

KUNG FU PANDA

Remember Po, the extremely clumsy yet skillful warrior in the movie Kung Fu Panda? Well, you will be amazed to know that pandas in real life can perform martial arts too – they can do the handstand!

panda doing handstand2

Research has shown that male giant pandas (Ailuropoda Melanoleuca) often perform such acrobatic acts to “impress the ladies” and intimate their rivals (National Geographic, 2010). When a male panda scent-marks an object, the height of the mark actually lets other pandas know their size and status. Thus, the males often go upside down on their front paws with the aim of pushing their urine as high up a tree trunk as possible. This is done in the hope of attracting the females and scaring off rival competition (BBC Science/Nature, 2004).

Known to be solitary mammals that have little visual and vocal contact with one another, the endangered giant pandas thus rely heavily on chemical communication through scent. Besides using scent to coordinate mating, these remarkable creatures also utilise it to mark their territory and establish social relationships.

On top of the aforementioned handstand position, there are three other distinct gymnastic postures which the giant pandas often adopt to deposit their individual unique scent: squat, reverse on vertical surfaces and leg cock (Swaisgood, Lindburg & Zhou, 1998). They will rub an acidic-smelling substance, secreted by glands surrounding the ano-genital area, on tree trunks and stones through these various methods (Wanglang Nature Reserve, 2001). The males scent-mark frequently year-round, though increasing significantly during the mating season, whereas the females’ marking behaviour occurs predominantly during the mating season (Kleiman, 1985).

Now, looks like the battle for women is no longer just based on looks.

Reference List

Images and Video

BBC Wildlife. (2008). “Giant Panda Bear Does Handstand!”. Retrieved 4 April, 2010 from http://www.youtube.com/watch?v=006ip4ndThE

Kjdrill. (2008). “Upside down Zhennie during the rainstorm”. Retrieved 4 April, 2010 from http://www.flickr.com/photos/kjdrill/2291858483/

Lynch, P. (2008). “Kung Fu Panda”. Retrieved 4 April, 2010 from http://www.thevastpictureshow.com/2008/07/kung-fu-panda-45.html

Articles/Journals

BBC Science/Nature. (2004). “Panda handstand makes its mark”. Retrieved 4 April, 2010 from http://news.bbc.co.uk/2/hi/sci/tech/4043105.stm

Kleiman, D. G. (1985). Social and reproductive behaviors of the giant panda (Ailuropoda melanoleuca). Bongo, 10: 45–58.

National Geographic. (2010). “Giant Pandas, Giant Panda Pictures, Giant Panda Facts”. Retrieved 4 April, 2010 from http://animals.nationalgeographic.com/animals/mammals/giant-panda/

Swaisgood, R. R, Lindburg, D. G., & Zhou, X. (1998). Giant pandas discriminate individual differences in conspecific scent. Animal Behaviour, 57: 1045–1053

Wanglang Nature Reserve. (2001). Panda Facts. Retrieved 4 April, 2010 from http://slack.net/~rd/wanglang/panda_facts.htm