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Posts Tagged ‘octopus’

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.

Have sex and die – the octopus way!

When I visited Lembeh in September/October there were flamboyant cuttlefish around in numbers that I have never seen before. On more or less every dive, we saw one or more flamboyants. Blue ring octopus were not as common, but still there was hardly a day when we didn´t see them. This is very much in contrast to the situation now, at least considering adult octopus and cuttlefish. We have seen some, but while still here, they are not nearly close to the densities experienced in September/October. Where did they all go?

A surviving flamboyant cuttlefish, that probably was out of luck mating in September

A surviving flamboyant cuttlefish, that probably was out of luck mating in September

Actually, cephalopods, the group that octopus and cuttlefish belong to are quite short-lived. Not only that, they only reproduce once and then die! This pattern of reproduction, where an individual grows for almost all its life, mates and then die, are called semelparity.

Mating coconut octopus in lembeh

Mating coconut octopus – not something they will do a lot of times!

Other animals continue living after reproduction and produce other litters some time after. Such a strategy, with multiple reproductive events after the onset of maturity, is called iteroparity.

Giant frogfish, an iteroparous species mating several times during its life cycle

Giant frogfish, an iteroparous species mating several times during its life cycle

The answer is that all life histories, that is the allocation of energy over time, consist of trade offs. Food is seldom unlimited, and if it where, time or developmental rate would limit the options available for an animal. The first ting that needs to be realized is that reproduction, having offspring, is expensive. Experiments have time after time verified that reproducing individuals of a lot of different species die earlier than non-reproducing individuals. That is the first trade off, choosing between a long life or offspring. And having no offspring is a fundamental screw up in nature, as your genes get lost for the future, so choosing long life rather than reproduction is not an option for animals looking for success in life.

Hairy shrimp carrying eggs

Hairy shrimp carrying eggs

The second trade off is that costs are related to the effort that is put into reproduction. Everything else equal, the more offspring that is produced, the less survival or future growth rate an individual will experience.

Baby broadclub cuttlefish that never will meet its parents!

Baby broadclub cuttlefish that never will meet its parents!

The third important trade off is that an individual need to keep significant amounts of energy reserves in order to survive over long time in the future. Up to around 90% of the energy budget might have to be allocated to future survival if that is the goal. Thus, an individual can produce a vastly higher amount of offspring in one reproductive event if no energy is saved for future survival. Thus, if an individual irrespective of reproduction faces quite high mortality rates, it could obviously be advantageous to “go all in”, reproduce with all the effort you can, and save nothing for a very uncertain future. And that is exactly what cephalopods do, invest all they got in one single “big bang” litter instead of saving themselves for another day.

Young blue ring octopus

Young blue ring octopus

The cool effect of that here in Lembeh is that there now are quite a number of minute, fully colored flamboyants around. The young flamboyants are really cool, brightly colored and have a lot of attitude.

Newly hatched flamboyant cuttlefish

Newly hatched flamboyant cuttlefish

Blue Ring Fever Reaches a Climax

Blue Ring Octopus have been everywhere form months now, which is unusual to have them around for so long.  The guests have seen them mating, feeding, fighting and now we saw a beautiful specimen with eggs.  Blue Rings doing normal behaviour are a Top 10 Critter for Lembeh, where would you place one with eggs?!

'Pregnant' Blue Ring Octopus carrying Eggs

‘Pregnant’ Blue Ring Octopus carrying Eggs

Blue Ringed Octopus have a life cycle of 2 years, however, for this female her time is nearly up as once the eggs hatch she will die.  She will not have eaten for the entire pregnancy (which lasts around a week to 2 weeks). This beautiful girl has moved away from where we found her, hopefully to live out the rest of her days in peace without any photographers! Hopefully in a few months we will start to see her offspring out feeding.

This was a first for me and as such the video is probably not as clinical as it normally would be.  I also left the clip in of the Octopus leaving the bottle without being abused.. Although to be honest I am sure he would not have left the bottle if there were no divers around.

Hairy Octopus Video

I finally got around to posting my Hairy Octopus video, we’ve seen 3 in 3 days now here in Lembeh!

Categories: Critters Tags: , , ,

Johan, Marnes and Indra shoot their first Hairy Octopus

We’ve been having fantastic diving recently, and we have been having some fun with the guys taking pictures and also annoying out yearly repeat guest, Mood.
Mood has been to Lembeh every year for the last 5 years and still does not have the hairy octopus, he always missed it.  We see it when he has a bad ear, when he skips a dive, or they find it on the same dive he is on but he has gone off looking for something else and is too far to call over.

The other day the boys took me to try to find the Hairy Octopus for the first time, and they found one on each of the first 2 dives – they haven’t found one for a while so there was quite a lot of excitement, and obviously a lot of bravado beforehand, and even more afterwards.

I was pretty amazed by this creature, so i thought it only fair that I let them click off a few shots whilst we were waiting for the guides to find Mood.

Here are their shots!

Tiny Baby Octopus

Juvenile octopus

On yesterday’s second morning dive our guide Stenly found (amongst other things) this little baby Octopus for his three Japanese guests. The little fellow had the size of a fingernail or a small coin and was still transparent … you could even see his internal organs working. Its colouration was a little bit like a pygmy squid or a bobtail squid. We think it is a newly hatched Coconut Octopus – this would also explain his preference for little objects and shells … it was grabbing anithing it could find in the sand and tried to hide in it. This picture shows two little shells that i offered him as a little present.

Creature Feature: Mototi Octopus

Lembeh Strait is the Mekka for rare Critters – but even here, there are some creatures, that are even rarer than other ones. Like the Mototi Octopus (Poison occelate Octopus, Octopus mototi). This rather small Octopus can be easily identified by its two blue Rings (one on each side) that it displays when excited or threatened. The normal colouration is brown/beige and in addition to the spots it can also show a white-yellow/brown stripe pattern. The Mototi Octopus is usually found in Black Sand and preferrs to stay in places where it can hide: Shells, Cans, Bottles, Sponges etc.

The Mototi Octopus is poisonous and can have the size of a Blue Ringed Octopus or also grow to a Body size of 10cm.

Best place to find Mototi Octopus in Lembeh: Muck Dives like TK Bay, Hairbal, Jahir, Pante Parigi and others.

Photo Tips: Best lens to use is a 60 or 100mm Macro Lens (specially if it is a smaller Mototi). Stick with the Octopus for a while and see how it reacts to the Camera. Often it will start to display its blue rings after a while and raise his front tentacles.