SCUBA News 179,
30 April 2015
SCUBA News (ISSN 1476-8011)
Issue 179 - April 2015
Thank you very much for subscribing to SCUBA News. This month a story about how a small reef fish disguises itself, infiltrates damselfish communities and once accepted kills their young. Plus, readers are looking for dive buddies and advice in Jeddah and Crete.
Should you wish to cancel your subscription to SCUBA News you can do so at http://www.scubatravel.co.uk/news.html. SCUBA News is published by SCUBA Travel Ltd.
Dahab, in the Red Sea, has some excellent diving. It is most famous for its Canyon and Blue Hole dive sites, but it has many others - some arguably better than these most well known dives. scubatravel.co.uk/redsea/
Clear water, dramatic scenary and wrecks - we've more on the Greek dive sites and dive companies at
Underwater photos taken by Tim Nicholson on Lady Elliot island, the Yongala, Lady Bowen and Agincourt Reef. Showcased on our Google Plus Community.
Diving Saudi Arabia
Looking for a dive buddy here in Jeddah, I'm a certified DM and dive every Friday, if any 1 is interested please let me know, I have logged over 130 dives in the Red Sea here in Jeddah
Diving Crete (via Facebook)
I'm going to be in Crete in early June - anyone any experience? I'd like to do one day of diving - and will organise my own accom. Where and with whom?
Annabel from AquaMarine Diving-Bali
Any suggestions for Sly or Annabel, e-mail [email protected]
A new study by researchers at the University of Cambridge has shown that the dottyback, a small predatory reef fish, can change the colour of its body to imitate a variety of other reef fish species, allowing the dottyback to sneak up undetected and eat their young. Its Latin name, Pseudochromis, means false damselfish - giving clue to its mimicry abilities.
The dottyback also uses its colour-changing abilities to hide from larger predators by colour-matching to the background of its habitat - disappearing into the scenery.
While using mimicry to hunt or hide from other species is commonplace in nature - from cuckoos to cuttlefish - scientists point out that if the same physical deception is encountered too frequently, species on the receiving end become more vigilant and develop tactics to mitigate the mimics.
The dottyback, however, is able to colour-morph depending on the particular colour of the surrounding species it is currently hunting: different types of damselfish being a popular target.
Scientists say that this flexibility of physical mimicry makes it much harder for the dottyback's prey to develop detection strategies and avoid getting eaten.
Dottybacks are generally solitary and highly territorial predators of around eight centimetres in length, commonly found in Indo-Pacific coral reefs.
While dottybacks can vary their colouration from pink to grey, the researchers focused on two colour 'morphs' - yellow and brown - that both occur on the reefs surrounding Lizard Island, off the coast of north-east Australia. This is because the area has populations of both yellow and brown damselfish, and habitat consisting of live coral and dead coral 'rubble'.
The scientists built their own simulated reef outcrops comprising both live coral and rubble, and stocked them with either yellow or brown damselfish. When released into reefs with damselfish of the opposite colour, scientists found the dottybacks (Pseudochromis fuscus) would change from yellow to brown or vice versa over around two weeks.
Anatomical study of dottyback skin cells revealed that while the level of 'chromatophores' - pigment-containing cells that reflect light - remain constant, the ratio of yellow pigment cells to black pigment cells shifts to move the dottyback from yellow to brown or back again.
The team conducted lab experiments with adult and juvenile damselfish to test whether this colour change affects dottyback hunting success. They found that once the dottyback matched the colour of the damselfish, they were up to three times more successful at capturing juvenile damselfish.
"This is the first time that an animal has been found to be able to morph between different guises in order to deceive different species, making the dottyback a pretty crafty little fish" says Dr William Feeney, co-author of the study from the University of Cambridge's Department of Zoology.
Photo credits: Christopher E Mirbach, Justin Marshall.
Activists are taking legal action to try and stop mining on the tiny Indonesian island of Bangka, a hotspot of marine biodiversity in the Coral Triangle.
It has long been known that whales were seriously endangered during the 20th century, but new research shows just how close we came to wiping them out completely.
Sunburn can ruin a scuba diving holiday, but you could soon know when to cover up thanks to an early warning sunburn indicator bracelet, developed by Queen's University Belfast.
The number of US fish stocks listed as overfished or subject to overfishing has dropped to an all-time low.
A population of the fish that was once one of the most disastrous examples of overfishing could be certified as sustainable within five years, according to new research
Tens of thousands of endangered turtles die every year in the United States when they are inadvertently snared in shrimp nets, an environmental group alleges, filing a lawsuit Wednesday against the government.
Conservationist group's four-month pursuit of illegal fishermen ended off west Africa, with the captain cheering and applauding as the boat went down, say rescue crew
The political and industry support is already there, but what systems are being put in place to make sure countries can be more effective against illegal fishing in the future?
Stretching 1,400 miles along the Australian coast and visible from space, the Great Barrier Reef is home to three thousand individual reefs, more than nine hundred islands and thousands of marine species, and has alternately been viewed as a deadly maze, an economic bounty, a scientific frontier and a precarious World Heritage site. New book out May.
Outside of humans, the most complex alliances known are found in a population of bottlenose dolphins in Shark Bay, Western Australia.
Surprising new short-circuit to the biological pump: dying phytoplankton release chemicals with a steroid-like effect on marine bacteria.
Scotland now has its first ever National Marine Plan, which sets out a single statutory planning framework for all marine activity in Scottish waters.
Oil catching coatings, inspired in part by lotus leaves, could aid the clean up of ocean oil spills
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Photo credits: Tim Nicholson; David Burdick
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