Mystery underwater sand circles are actually puffer fish art

If you thought crop circles were strange, odds are you haven’t seen these:

crop circles

The underwater version of crop circles!  Some of the intrigue with crop circles faded once people stopped thinking they were made by aliens, but these sand circles are even more interesting to behold once you know where they do come from.

So who or what makes these enigmatic sculptures where they are doomed to fade into nonexistence once the ocean erodes them away?  No, not an alien race, nor a group of people from of the legendary Atlantis, but Puffer fish!

Male puffer fish craft their detailed sculptures by using a single fin to push the sand around, working day and night to finish the job, topping it off by cracking shells and placing them along the inner grooves of the circles.  Similar to bower birds, the puffer fish creates these structures to attract females.  However, the marine art serves a greater purpose than to look pretty to impress the ladies.  The puffer fish constructs his art with great care because it will become a nursery ground for his future offspring!  Watch him here:

Once the female has found the grooves, she will follow the ridges to the male in the center, mate with him, and lay her eggs.  The more ridges the circle contains, the more likely it is that the female will mate with the male, because she knows that the ridges will buffer the eggs from currents, thereby protecting the eggs from disturbance and exposure to predators.  Furthermore, the seemingly decorative seashells provide nutrients to the eggs and newborn puffer fish.

The artist at work

The artist at work

Next time you get annoyed by the sand that gets in every orifice after a day at the beach, or think humans are clever for using sand to make glass and concrete, think about how the puffer fish makes art out of sand to attract females, protect its young, and provide sustenance to its offspring just by using the raw stuff-and you might find new appreciation in sand, and the ingenuity of animals, a little more.

References:

Discovery: http://news.discovery.com/earth/oceans/puffer-fish-makes-elaborate-undersea-sand-circles-120925.htm

This is Colossal: http://www.thisiscolossal.com/2012/09/mysterious-underwater-crop-circle-art-discovered-off-the-coast-of-japan/

Dress to impress: bird courtship rituals

AIX GALERICULATA

Mandarin duck

Birds exhibit some of the most elaborate and bizarre courtship rituals of any animals on earth.  Here are a few of the more beautiful and zany examples:

The marvellous spatuletail hummingbird exhibits one of the most extreme courtship rituals (see video below).  The male bird has two elongated tail feathers that end in a large violet-blue disc, or spatule.  The male bird hovers in the air, waving his spatules in front of the female and making a snapping sound with his beak.  To the hummingbird, which is the size of a ping-pong ball, this display costs a lot of energy.  Spectators of this courtship ritual have reported that after he’s done dancing, the male will have to flop down on a branch, exhausted, and sit still for over an hour to regain his strength.  This species of bird is rare and endangered, and lives in only a few places in Peru.

The bird of paradise is equally stunning:

The frigate bird puffs up a large red balloon on its chest and dances about, calling to the female in question to impress her:

Mandarin ducks, both male and female, bob in and out of the water to seal their partnership, which is for life.  In Chinese culture these monogamous ducks symbolize love, marital fidelity and relationship respect.

Red capped manikins do a sort of funky moonwalk reminiscent of Michael Jackson:

The white-throated bee-eater is a rakishly plumed bird that engages in the “butterfly display,” in which the male and female both hold out their wings while calling to each other.

References:

Mandarin duck:  http://birding.about.com/od/Waterfowl/p/Mandarin-Duck.htm

Marvellous spatuletail hummingbird: http://news.bbc.co.uk/earth/hi/earth_news/newsid_8338000/8338728.stm

White-throated bee-eater:  http://en.wikipedia.org/wiki/White-throated_Bee-eater

Dragon dance

sea dragon

Meet Nessie the sea dragon.  No, she’s not the monster that has popularized a certain Scottish loch, but is in fact a very real animal related to seahorses and pipefish that roams the weedy beds off the coast of Australia.  Like a dragon, Nessie has a plated body to protect herself.  She is one of the masters of camouflage, a method of crypsis many animals use to conceal themselves from predators.

There are two types of sea dragons, the leafy sea dragon and the weedy sea dragon. Nessie is a leafy seadragon, and indeed she looks just like a leaf to blend into her seaweedy surroundings, swaying in the water to heighten the masquerade.

Leafy_sea_dragon_by_Ta-graphy

Nessie spends much of her life floating happily in the seaweed beds, sucking up microscopic food out of the water with her long snout.  In fact, sea dragons have been observed to remain in one location for up to 68 hours, just eating.  But when it comes to courting a male, she departs her rather mundane life of plankton-slurping and embarks on an epic romance.  Well, epic for a fish.

When it comes time to find a partner, sea dragons perform a special courtship dance in spring under the fading light of sunset.  In the video below, Nessie and her mate mirror each other’s every movement in this elaborate courtship ritual.

Perhaps you wouldn’t normally think of fish as being hopeless romantics, but it gets even stranger.  After the courtship ritual is complete, the male is “pregnant.”  Like the sea dragon’s cousin, the seahorse, the male protects and provides for the eggs during their development.  You see, the dragon dance is not just a dance.  During the courtship ritual, the female lays 150 to 200 eggs in an area under the male’s tail called a brood patch.  The father’s blood feeds the eggs for two months, then the eggs hatch and fully formed baby sea dragons emerge, ready to brave the world completely without aid from either parent.  Seahorses, sea dragons, and pipefish are the only fish species in which the males carry and raise the young.

Leafy_Seadragon

These special fish are subject to many threats, but the sea dragon is an example of a conservation success story.  In the early 1990s the Australian government placed a complete protection on sea dragons (the leafy sea dragon is the official marine emblem of the state of South Australia), and since then their numbers have risen so that they are now classified as “near threatened.”  To raise awareness and celebrate these strange yet beautiful animals, a biennial Leafy Sea Dragon Festival is held in South Australia and an animated short film was made in 2006 and distributed to all primary schools in the state.  Weedy sea dragons’ populations are monitored in Australia as well.  Because of their uniqueness and the intrigue they provide for many people, sea dragons could become “flagship” animals, which are animals that humans have an emotional attachment to, such as panda bears and elephants.  Flagship species are often used by conservation efforts in order to encourage more people to join their cause.

Hopefully, with the efforts of Australians and other conservationists, Nessie the sea dragon will enter the hearts of more people around the world.  Perhaps then we can focus more of our attention on preserving unique and special animals like sea dragons than the other, admittedly more enigmatic but fictional loch-dwelling Nessie.

References

McCall, Gerrie.  Weird and Wonderful Fish.  Nature’s Monsters, Water Creatures Series.  Gareth Stevens, 2005.

Wikipedia.org: http://en.wikipedia.org/wiki/Leafy_sea_dragon

Ghostly “Dance of a Sea Dragon,”  BBC:  http://news.bbc.co.uk/earth/hi/earth_news/newsid_8330000/8330705.stm

“Sea Dragon,” National Geographic:  http://animals.nationalgeographic.com/animals/fish/sea-dragon/

“Phyllopteryx,” Wikipedia.org:  http://en.wikipedia.org/wiki/Phyllopteryx

Sticks and tricks: Bowerbirds use interior design and optical illusions to attract females

Human men aren’t the only ones to show off for the ladies.  In fact, their stabs at romance seem a bit shabby when compared to the courtship displays bowerbirds put on for females they are trying to charm.

Imagine if a man built you an entire house and put all of your favorite things in it to get you on his good side?  A male bowerbird does just that, building a shelter or “bower” of sticks and elaborately decorating it with anything he can find to impress the female in question:

Bowerbird 1

Bower of a Vogelkop bowerbird (Amblyornis inornata) decorated with natural and man-made objects

But that’s not all – it turns out that bowerbirds are very particular about the type and arrangement of objects they place in and around their bowers.  Apparently, female satin bowerbirds prefer the color blue, which is perhaps why they have evolved such strikingly blue eyes (see picture below) so the males seek out blue objects over those of other colors.

Satin_bowerbird

Satin bowerbird (Ptilonorhynchus violaceus)

Furthermore, male bowerbirds construct their bowers to create an optical illusion.  Objects are not randomly placed around their court, but instead placed in a size gradient with smaller objects closer to the entrance of the bachelor pad and larger objects farther away.  This optical illusion is called forced perspective, and causes all of the objects to look the same size while the entrance of the bower appears smaller than it actually is.

bowernest

Satin bowerbird with female

12713-satin_bowerbird-cswHow does this help the male bowerbird snag a female?  If the bower entrance looks smaller than it is, then the male hopping and dancing around the bower entrance in his courtship display will appear larger than he actually is!  Males are very specific about constructing this optical illusion and will in fact recreate it in three days if it is disturbed.

Perhaps we humans should take a leaf out of the bowerbird’s book – I’m sure the ladies wouldn’t complain!

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References:

“Bowerbird.”  Wikipedia.org.  http://en.wikipedia.org/wiki/Bowerbird

Photographs from Arkive site:  http://www.arkive.org/vogelkop-bowerbird/amblyornis-inornata/image-G66592.html.

Bowerbird optical illusions:  http://www.livescience.com/18015-bowerbird-mating-illusion.html.

Animal romance National Geographic page: http://newswatch.nationalgeographic.com/2013/02/14/wild-romance-weird-animal-courtship-and-mating-rituals/

Bowerbird informational video from National Geographic:  http://ngm.nationalgeographic.com/video/player#/?titleID=bowerbirds&catID=1

Bowerbird information from National Geographic:  http://ngm.nationalgeographic.com/2010/07/bowerbirds/morell-text

Bowerbird stealing man-made objects video from National Geographic:  http://video.nationalgeographic.com/video/animals/birds-animals/ground-birds/weirdest-bowerbird/

Satin bowerbird picture from Wikimedia commons is under a Creative Commons license.

Arkive photographs taken by:

© Tim Laman / naturepl.com

Nature Picture Library
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Tel: +44 (0) 117 911 4675
Fax: +44 (0) 117 911 4699
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Arkive pictures may be reproduced for educational, scientific, or conservation purposes.

From Marlin to Marilyn: Clownfish Change Their Genders! Bizarre Courtship and Mating Rituals in the Animal Kingdom

Clown_fish_in_the_Andaman_Coral_Reef

Clownfish in anemone home

It turns out Finding Nemo had it wrong.  When a barracuda ate mom in the first scene of the movie, Marlin would not become a single dad, because being a single dad clownfish is impossible.  Realistically, Marlin would have become Marilyn– a single mom!

Clownfish are protandrous sequential hermaphrodites.  In other more pronounceable words, clownfish start their lives as males and then change into females.  Why is this necessary?

Clownfish2

Clownfish live in sea anemones and have adapted so they are unharmed by the anemone’s stings.  Because of its unique mutualistic relationship with the anemone (the clownfish eat parasites off the anemone, effectively cleaning it), the clownfish is reluctant to wander too far beyond its tentacly home.  This becomes problematic when the clownfish wants to meet members of the opposite sex, so the clownfish has evolved an interesting mechanism – sequential hermaphroditism – to overcome this obstacle.

Nemo

Marlin and Dory from Finding Nemo movie

Instead of braving the dangerous open waters beyond the reef (no, neither Marlin nor Nemo would realistically breach the “drop-off” and make it back alive), all the clownfish living in one place are males except the oldest, which is always a female.  After the head female dies, the next-oldest male turns into a female!

I suppose Pixar would’ve had a hard time explaining why they turned Marlin into Marilyn after one scene – I would’ve been confused too.  But in reality, the animal world of romance hosts a plethora of bizarre courtship behaviors, mating rituals, and other such oddities that put human courtship to shame!

References:

Clownfish picture 1 by ecatoncheires on Flickr: http://www.flickr.com/photos/ecatoncheires/2335044473/.

Nemo picture: from Cthomasuscg on Flickr:  http://www.flickr.com/photos/cthomasuscg/3304908183/

Interesting animal romance behaviors:  http://www.care2.com/greenliving/animal-romance-they-have-sex-how.html?page=1.

“Sequential hermaphroditism.”  Wikipedia.org:  http://en.wikipedia.org/wiki/Sequential_hermaphroditism

Clownfish information at Shedd Aquarium:  http://sea.sheddaquarium.org/sea/fact_sheets.asp?id=72

Clownfish information at Visit Sea Life:  http://www.visitsealife.com/explore-our-creatures/clownfish.aspx

Clownfish information at Evolution Faq:  http://www.evolutionfaq.com/articles/sex-change-nature-coral-reef-fish