Picture of the week: Arborek Jetty

Arborek Jetty in the Raja Ampat archipelago West Papua Indonesia  is famous for the huge schools of fish that shelter beneath it, and also for the colorful soft corals that cover its piles. Often  schools are  a mix of  one spot snappers (Lutjanus monostigma), diagonal-banded sweetlips (Plectorhincus lineatus), lined rabbitfish (Siganus lineatus), or vermiculate rabbitfish (Siganus vermiculatus, shown in picture above). Taken in December 2019 with Olympus 8mm fish-eye and E-PL5 in Olympus  PT-EP10 housing, 4 inch dome. @8.0, 1/80, ISO 200, dual DS 161 strobes.

Highlighted: Shane Gross

Shane Gross is the author of a new photobook, Bahamas Underwater, entirely devoted to pictures taken in the Bahamas, whose revenues will benefit  an  organisation called BREEF (Bahamas Reef Environment Educational Foundation). Shane moved from the Canadian prairies to the Bahamas in 2012, focusing mostly on pictures of  sharks and rays. The book is organized in 11 chapters, each devoted to specific species such as squid and octopus, reefs and fishes, conch, Nassau Grouper and many more. Chapter 4,  my personal favorite,  focuses on  pictures of  Mangroves and Lemon sharks, all  taken  in the mangroves of Eleutheria. It contains many  lovely  photogenic shots of the vulnerable  juvenile lemons moving and hiding the  in their nurseries  that project them from being eaten by the larger sharks.

Highlighted: Snapping lemons

These  pictures  were taken while kneeling on  the diving platform of the boat  and holding the camera just below the surface.  Taking care to keep my hands with gloves close to the camera housing, behind the dome. Lemon sharks in particular have the habit of congregating in large numbers behind  the boat hoping to catch some left-overs of the bait.   ''Lemon snapping'' is based on the  simple practice of  shooting along with your fish-eye lense without having  the sharks in focus, and picking out later the pictures that are not too bad. Taken with  natural light with Olympus 8mm fish-eye in E-PL5 housing and PT-EP10 housing,  4 inch dome strobes ant Tiger beach in 2019. More spectacular results can be obtained by using a small Gopro video camera on a pole, allowing to get much closer to the mouth of the shark.

 

Highlighted: Born to be with the Great white sharks

Ocean Floor Cage 02 Courtesy of Andrew Fox.

An interesting  in depth interview by Don Silcock of Andrew Fox, the son of Rodney Fox, the  Great White shark pioneer from Australia who started the famous cage diving tours of Great Whites. Rodney was the first ‘famous’ victim  and survivor of the Great whites  bites  while he was spearfishing   along the coast  of Australia as a young man.  After initially hunting sharks, Rodney later became their devoted protector

News: Cape Cod great white shark tours

A white shark swims across a sand bar off the Massachusetts' coast of Cape Cod. Photographer: Charles Krupa/AP

Three summers after Cape Cod  Massachusetts witnessed two great white shark attacks on humans this popular tourist destination south of Boston is showing signs of changing its attitude towards the great white sharks by stimulating shark tourism. A small but growing group of charter boat operators are offering great white shark tours in a region where whale and seal watching excursions have long been a tourist rite of passage. 

 

 

News: Throwing by Octopuses

Left: The throwing material is held in the arms preparatory to the throw, while the mantle is inflated preparatory to ventilation during the throw. The siphon at this stage may still be visible in its usual position projecting from the gill slit above the arm crown. Right: during the actual throw the siphon is brought down over rear arm and under the web and arm crown between the rear arm pair and water is forcibly expelled through the siphon, with contraction of the mantle, as held debris is released, projecting debris through the water column (Illustrations by Rebecca Gelernter)

Throwing of objects to others seems to be distinctively human, although targeted throwing has also been observed in some non-human primates (especially chimps and capuchins) and elephants. Recently investigators, found that wild Octopuses  (Octopus tetricus)  in Australia also throw objects like shells, silt, and algae through the water by releasing these materials from their arms while creating a forceful jet from the siphon held under the arm web (see insert). So actually it is not throwing with the arms (tentacles) but rather 'shooting' debris by applying hydraulic pressure of the body using the siphon as a gun. Some (not all) throws appear to be targeted on other individuals and play a social role, as suggested by several kinds of evidence. Throwing in general is more often seen by females Octopuses who were hit included other females in nearby dens, and males who have been attempting mating with a female thrower. High vigor throws were significantly more often accompanied by uniform or dark body patterns.

 

E-Book. Click on the Icon to download the PDF file

 This ‘E-book’  contains an updated collection of around 80  blog articles from the last three years.  I here provide two separate content lists, a list in which the articles are ordered according to the five most often recurring themes, and a chronological list. A simple click on the title will hopefully guide you to the article of your choice. For download,  click  next to the  PDF icon 

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