Horseshoe Crabs Mating

Horseshoe crab mating on YouTube

Horseshoe crabs often referred to as a living fossil, is one of the most interesting creatures on earth because it’s origins dates back to millions of years ago. The video shows an interesting shot of the mating behaviour of the horseshoe crabs.

Background information of Atlantic Horseshoe Crabs

The horseshoe crab or Atlantic horseshoe crab, Limulus polyphemus is found along the eastern coast of North and Central America. It belongs to the Limulidae family which consists of three other species. It is a misconception that horseshoe crabs are crabs. In fact, they belong to the phylum of Arthropods, which consists of animals having an articulated body and limbs (The Horseshoe Crabs). Horseshoe crabs are now considered endangered animals due to the loss of habitats.

Mating behaviour

The female Limulus give off chemical attractants called pheromones, which the males can detect (The Horseshoe Crab). Once the male Limulus detects a female offshore, he grasps her with his specially modified claws, and the attached couple crawls toward the high tide line. Once copulation is over, the female, with the male still attached, digs into the sand and lays thousands of eggs which the male fertilizes externally (Rudloe, 1980). It was found that some male Limulus remain attached to the females for as long as 2 weeks!

Horseshoe Crabs mating

Horseshoe Crabs mating

However, there is strong competition between males for females because it was found that females tend to reach sexual maturity later and they return to the nest less frequently than males (Rudloe, 1980). Because of this, there is a difference in ratio between the males and females therefore leading to an intense competition for females as seen in the video. Even if a male is attached to a female, other satellite males will still “join in” to mate with the female by pushing away the current attached male.


H. Jane Brockmann. Mating Behavior of Horseshoe Crabs, Limulus polyphemus. Behaviour, Vol. 114, No. 1/4 :pp. 206-220.

“Horseshoe crab mating,” by solatia. YouTube Channel, 3 April 2007. URL: (assessed on 4 March 2010)

Natural History:Spawning Behaviour. URL: (assessed on 4 March 2010)

Rudloe, A.E. 1980. The breeding behavior and patterns of movement of horseshoe crabs, Limulus polyphemus, in the vicinity of breeding beaches in Apalachee Bay, Florida. Estuaries 3, p. 177-183.

Duck + beaver + otter =?

I’m pretty sure you’ve heard about cross-breed animals, like the maltese. But a mixture of animals… probably the platypus is the first of its class! Never heard of it before? One might recall the Sydney Olympic Games 2000, where an animal named Syd (obviously short for Sydney) was one of the 3 mascots for the event – and without a doubt that animal is a platypus. Or perhaps you’ll recognize it as the animal minted on the back of an Australian 20-cent coin. (accessed on 3rd April 2010) (accessed on 3rd April 2010) (accessed on 3rd April 2010)

Background on the platypus:
The platypus (Ornithorhynchus anatinus) is a venomous, egg-laying, duck-billed, beaver-tailed, otter-footed, semi-aquatic mammal. In fact they are the ONLY mammal known to lay eggs and the ONLY venomous mammal known to humans. They are the oldest surviving branch of mammals known to date. They are one of five extent species in the Monotremata order; others include four species of their cousin, the echidna. They can only be found only at two places on Earth – namely, Eastern Australia and Tasmania.

Platypus Parts

The first appearance of the platypus dumbfounded many people as they thought it was impossible to have the platypus’ phenotype. After some years of research and questions, scientists have confidently concluded that they have reptile and mammal traits. Examples include the coat of fur they have to help them adapt to an aquatic lifestyle; the fact that their females lactate and yet lay eggs; and how males have spurs on their hind legs containing venom similar to that of many reptiles.

Scientists have also discovered that the platypus’ beaks contains a lot of receptors, which are used when the platypus dives down into the water to forage for food (their diet include small invertebrate animals found at the bottom of rivers or lakes – as they have no teeth to chew) as they tend to close their eyes and their nose when doing so.

Both genders are born with venomous spurs located at their hind legs, but after being a few months old, the females’ spurs will drop off, while the males’ keep their spurs intact. These spurs will enable them to protect themselves against predators. During mating season, these spurs will come in handy when there are male-male battles for both territories and mates.

Platypus Genome : by Nature Video

Probing Platypus Evolution

References :

“Platypus”, by Wikipedia, 28th March 2010. URL : (accessed on 3rd April 2010)
“Platypus Genome Reveals Secrets of Mammal Evolution”, Scott Norris, National Geographic News, 7th May 2008. URL : (accessed on 3rd April 2010)
“DPIW : Platypus : Introduction to an Iconic Mammal”, Department of Primary Industries, Parks, Water and Environment in Tasmania, Australia, 26th November 2009. URL :

“Syd, Olly and Millie – Olimpiade Sydney 2000”, by Marissa on WordPress, July 16, 2009 : (accessed on 4th April 2010)
The platypus featured on the Australian 20 cent coin”, on Hubpages :  (accessed on 4th April 2010)
“Platypus swimming under water” on Learnanimals : (accessed on 4th April 2010)
“Platypus Parts”, by National Geographic. Hosted on Youtube : (accessed on 4th April 2010)
“Platypus Genome: by Nature Video”, by National Video Channel. Hosted on Youtube : fvw (accessed on 4th April 2010)
“Probing Platypus Evolution”, by National Geographic. Hosted on Youtube : fvw (accessed on 4th April 2010)

Journals :
“Genome analysis of the platypus reveals unique signatures of evolution”, by Wesley C. Warren and colleagues. Nature 453, 175-183 (8 May 2008) Retrieved from :

Aye Aye… Creature!

Aye Aye

The Aye Aye (Daubentonia madagascariensis) is a badly misunderstood creature who is actually rather harmless!  In its native Madagascar, it is viewed as an evil omen and is killed on the spot; as such its species are highly endangered! There is a hypothesis that the word “aye aye” signifies simply a cry of alarm to alert others to the presence of this animal. Some of the other names the Madagascans call it by are “aiay”, “ahay”, and “hay-hay”.

Aye Aye 1

Aye Aye 2

Aye Aye 3

Some Interesting Facts

The Aye Aye, one of the most bizarre mammals, is the world’s largest nocturnal primate and spends 80% of the night foraging in forest canopies, whereas during the day, it curls up in a ball-like nest of leaves and branches. In addition, the male Aye Aye weighs approximately 2.5 kilograms, while the females are slightly lighter. Other than the weight and sex organs, Aye Ayes exhibit no sexual dimorphism. Last but not least, the most intriguing characteristic of the Aye Aye is the manner in which it locates its prey! Besides the Striped Possum, the Aye Aye is the only other animal species which hunts in this unique fashion!

As seen from the clip, when the Aye Aye is perched aloft, it uses its elongated and bony middle finger, which can be three times longer than the others, to tap on the tree up to eight times per second!  The Aye Aye listens for a tiny change in the resonance, which indicates the presence of a hollow spot within the trunk. It then gnaws into the wood and uses its middle finger to fish out the wood-boring insect larvae.  It takes about 4 years for a young Aye Aye to master this technique. As such, the Aye Aye is the only primate thought to use echolocation to seek its prey. Interesting aye?

A documentary on the Aye Aye from BBC “Life”

All in all, Madagascan folklore and habitat destruction have resulted in the Aye Ayes being one of the many highly endangered species.
What a pity! Perhaps more education and exposure on these fascinating creatures can be introduced to uncover their beauty and eradicate the myths.


Aye-Aye Daubentonia madagascariensis” National Geographic. URL: (assessed on 28 March 2010)

“Aye Aye Facts” by Rita Putatunda. URL: (assessed on 28 March 2010)

“Harmless Creature Killed Because of Superstition” by David Knowles. AolNews, 27 March 2010. URL: (assessed on 28 March 2010)

“Aye-Aye Eating” by LibrePL Youtube Channel, 14 April 2008. URL: (assessed on 28 March 2010)

“The Aye Aye” by BBC “Life” Domentary Series. Globalzoo Youtube Channel, 8 January 2010. URL: (assessed on 28 March 2010)

Mittermeier, R. A.; et al. (2006). “Lemurs of Madagascar” (2nd ed.). Conservation International. pp. 405-415. ISBN 1-881173-88-7.