Showing posts with label Crown of Thorns starfish. Show all posts
Showing posts with label Crown of Thorns starfish. Show all posts

12 April 2013

Crown of Thorns


Chapter 3: Crown of Thorns starfish

page 40: starfish. Smithsonian has recently published a pleasant overview of some amazing features of starfish with photographs by Alexander Semenov including the one above, which shows wafting papulae (breathing organs) interspersed with spiky spine on Crossaster papposus. The Crown of Thorns has 15 madreporites while many starfish have only one. Who knew?

page 40: sea cucumbers.  Deep Sea News reveals sea cucumbers breath through their butts, and more:
In adult sea cucumbers the cloaca (a cavity already doing double duty for the release of excrement and genital products) rhythmically pumps huge amounts of water in and out. It is already known that this pumping brings oxygen rich water across a highly branched respiratory tree.  Thus the cloaca is now pulling a function trifecta.  But what about quadfecta?...yes, sea cucumbers can eat through their anuses...
Below: frontpiece to a life of Joseph Pujol (also page 40). His stage act "consisted of disciplined, odorless flatulence, a talent learned during his military service."




This is the fourth in a new series of notes and comments on chapters in The Book of Barely Imagined Beings. It appears around the time of the US publication, and adds to an earlier series that appeared around UK publication. 

22 October 2012

Death and life of stars

Ninth in a series of notes and comments on The Book of Barely Imagined Beings

Chapter 3: The Crown of Thorns Starfish
 

page 41: The press cried apocalypse: the crown of thorns starfish hit the headlines again earlier this month. [1] An analysis of data shows to inexorable decline in coral cover in the Great Barrier Reef since 1985. [2] According to the researchers, tropical storms and bleaching account for about 60% of this decline and the crown-of-thorns the other 40%. In the absence of the starfish, the researchers think, coral cover would grow by 0.89% a year, despite pressures imposed by bleaching and cyclones, rather than shrink by about 0.5% a year as it has been. The best way to reduce the infestation would be to reduce agricultural runoff, which provides nutrients for their larvae.

page 49: most reefs at risk of destruction by 2050: In July of this year, Roger Bradbury of the Australian National University published an article in The New York Times arguing the coral reefs have become "zombie ecosystems, neither dead nor truly alive in any functional sense, and on a trajectory to collapse within a human generation." The following day Andy Revkin hosted responses on his Dot Earth blog, all of them worth reading, from John Bruno, Randy Olson and others. Carl Safina concluded:
The science is clear that reefs are in many places degraded and in serious trouble. But no science has, or likely can, determine that reefs and all their associated non-coral creatures are unequivocally, equally and everywhere, completely doomed to total non-existence. In fact, much science suggests they will persist in some lesser form. Bleak prospects have been part of many dramatic turnarounds, and, who knows, life may, as usual—with our best efforts—find a way.
And, indeed, remarkable coral species such as Leptoseris troglodyta do find a way.