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Posts Tagged ‘Cephalopods’

Octopus camouflage – how does it work?

Meat, being high quality food, is a scarce resource in nature. The available amount of meat for any consumer is many orders of magnitude less than the amount of vegetation that is available. If you don´t believe me, just take a look out the nearest window and do a quick calculation over how much animal weight and how much tree or other plant weight you see out there. With notable exceptions such as my home area (where all you will see right now is a lot, and I mean a lot! of snow) and a camel market in the middle of a desert, meat will be extremely scarce and often not even around. Where I sit right now I see probably hundreds to thousands of tons of trees. I see one (very annoying) fly representing available meat.

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Octopus are essentially soft globs of meat living in a world where meat in general is extraordinarily scarce and needed. Octopus will face a never-ending struggle to keep their meat to themselves, and not let anyone else use it for food. It is no wonder that octopus have a number of defenses to actually accomplish monopolizing their meat. Once being seen by a predator, octopus have several defenses. First of all they will try to escape, either by swimming quickly away from the predator or by getting into a small crevice or hole that the predator cannot penetrate. Second they can let go of an ink cloud in order to confound the predator, or, best-case scenario, have the predator attack the ink cloud as the octopus escapes. Third, some octopus can let go of limbs when threatened much like lizards loosing their tail, leaving the predator with a meal but keeping most of the octopus unharmed. Fourth, some octopus can use warning coloration advertising a highly venomous bite when threatened.

Young algae octopus a couple of seconds later

Young algae octopus a couple of seconds later

However, octopus go a long way to keep from having to use their active defenses. they do so by blending in in the environment, that is being camouflaged, in a way that is highly efficient and also very adaptive. One problem with using camouflage in general is that camouflage is site specific. Once out of the area the camouflage pattern is adapted for, the camouflage stops working. A Swedish soldier in his very efficient camouflage for Swedish winter conditions would, if transferred to tropical rainforest, stand out as a huge boil on the forehead of Naomi Cambell! As octopus are highly active, they have to be able to adapt their camouflage to changing environments, which they solve in a way very few other animals do.

Young algae octopus a couple more seconds later

Young algae octopus a couple more seconds later

Texture and color are the two major components of an environment that a camouflaged animal must handle. Octopus handle texture in an impressive way. They can change from looking like a smooth coral to a piece of broken rubble in a matter of seconds. They do this by using muscles in their outer layer of skin, using their very acute eyesight to map an exact picture of the surrounding environment in order to match the texture of the environment with that of the outer surface of the octopus. Some octopus can go from smooth to looking like a hairy piece of decaying sea floor in mere seconds.

Young algae octopus yet some seconds later

Young algae octopus yet some seconds later

Octopus are even more impressive when handling colour matching of the environment. First of all, their sense of sight is excellent, enabling the octopus to know what they have to match. Second, the outer layer of octopus skin has a number of different specialized skin cells, which can change the colour, brightness and reflectiveness of the octopus. These cells are under control of the nervous system of the octopus, enabling extremely fast responses to outer stimuli.

In this way, octopus and many of their allies can live their life being highly successful despite inhabiting a very dangerous environment.

NAD Night Safari in 02/2012

Porcelain crab on Seapen / Night dive in lembeh Strait

Lembeh offers not only excellent Muck Diving the whole day long – the night dives are actually the most spectacular ones. And they are versatile: Coral, Rubble or Muckdive … there are lot’s of different styles of Night diving to experience here in Lembeh Strait. With so many critters to see – either things you don’t get to see in the daytime or things that are easier to take pictures of at night. Crustaceans, nudibranchs, cephalopods, fishes, and other weird creatures in the sand, in sponges, in coral, in seapens, in anemones or just floating in the water column. So actually people often not even have enough nights here in Lembeh to experience all the different Night dive sites …

That’s why we are repeating our “NAD Lembeh Night Safari”: One week of diving only when it is dark – with 3 dives every Night. This event will take place in February 2012 and some few spots are still available.

Orange Bobtail Squid in Sarena Besar / Lembeh Strait

Schedule:
18th Arrival Day: 6pm Night Dive19th Transition Day. 3pm Afternoon Dive, 5pm Dusk Dive, Dinner, 10pm Night Dive
20th Dusk Schedule: 5pm Dusk Dive, Dinner, 10pm Night Dive, 1am Night Dive
21st Night Schedule: 6pm Night Dive, Dinner, 10pm Night Dive, 1am Night Dive
22nd Super Night Schedule: 10pm Night Dive, 1am Night Dive, 4am Night / Sunrise Dive
23rd Night Schedule: 6pm Night Dive, Dinner, 10pm Night Dive, 1am Night Dive
24th Transition Day: 11am Day Dive.
25th Departure Day: Departure or continuation on a different package.

Total Dives included: 17

Breakfast will be whenever you wake up after the night diving nights (from last years experience, around 12noon). Lunch is usually with the other guests that are on the typical day schedule. Dinner is planned to be with the other guests at the typical time. On the Boat we serve snacks and tea / coffee between the twin tank dives. On returning from the dives in the middle of the night there is a light snack available (toast, noodles, etc – let us know what you prefer).

Dives will be conducted throughout the Lembeh Straits, on both Black Sand sites and Coral Sites because we are doing twin tank Night Dives in the middle of the night we will go further and explore the less (night) dived areas – where it will be VERY unlikely to meet other divers!

How and How much:

Book directly with NAD at info@nad-lembeh.com.

Price per person based on twin sharing in an Airconditioned room: $1056USD. Bungalow: $1122USD