One for Cali.

[Gawdzilla Sama]

618px-Glaucus_atlanticus_1_cropped.jpg (62.75 KiB) Viewed 1865 times

[pErvinalia]

That looks like a Glaucus atlanticus to me.

[Gawdzilla Sama]

That looks like a Glaucus atlanticus to me.

It looks like that's what the file is named.

[Blind groper]

This is right up my alley, as a scuba diving lover of nudibranchs. Glaucus atlanticus is a pelagic predatory nudibranch. A wonderful creature, and I wanna take its photo!

Most nudibranchs are grazers, and bottom dwellers. Here is a photo of such a beast (Tambja verconis) - well actually two of them, getting up to naughty things. This I took at The Poor Knights Islands, which are close to where I live.

[Calilasseia]

Ah, Glaucus atlanticus. One of several species of Aeolid nudibranch in the Genus. All of them make their living in a very interesting way.

The Glaucus nudibranchs feed on the tentacles of ocean-drifting siphonophores, particularly the Portuguese Man'O'War, Physalia physalis. These tentacles contain powerful stinging cells known as cnidoblasts, but evolution has bestowed upon Glaucus some rather elegant features. Not only is the nudibranch capable of feeding upon the tentacles without triggering the cnidoblasts, but it passes the cnidoblats undigested, through blind cavities in the gut, and transports the cnidoblasts, still alive and ready to fire, into its own external appendages. In effect, it steals the defences of the Portuguese Man'O'War and uses them for its own defence.

As a consequence, this nudibranch is very dangerous to handle. The cnidoblasts are powerful, and being stung by the cnidoblasts constitutes a medical emergency for humans, and is life-threatening to smaller animals such as dogs or cats. The nudibranch maintains a constant live population of sequestered cnidoblasts, and is consequently extremely well defended against attack.

As the Portuguese Man'O'War has tentacles containing cells arranged by division of labour, with some tentacles being cnidoblast-armed defensive tentacles, and some being equipped with other cells (such as the shorter tentacles equipped with cells for food processing), the nudibranch obtains its nutrition by digesting immature cnidoblasts and food digesting cells, and sequesters mature cnidoblasts for its own defence. It's not the only Aeolid nudibranch to possess this sequestering feature: for example, small nudibranchs of the Genus Berghia feed upon Aiptasia anemones, and sequester cnidoblasts from the tentacles thereof. Other Aeolids feed upon other anemones, and again sequester cnidoblasts for defence. Another example is Flabellina trilineata, featured here, along with more details about the biology of these fascinating organisms.

Some other nudibranchs sequester other types of cell from their food. For example, Tridachia crispata, recently renamed Elysia crispata, is a nudibranch that feeds upon various seaweeds, and sequesters chloroplasts from its food. These chloroplasts are then maintained, alive, within the fronds on the dorsal surface of the animal, where they continue photosynthesising and providing food for the new host. This species is featured here. It's not the only solar powered sea slug, by the way, merely the best known.

[Gawdzilla Sama]

It's cute!

[devogue]

Not only is the nudibranch capable of feeding upon the tentacles without triggering the cnidoblasts, but it passes the cnidoblats undigested, through blind cavities in the gut, and transports the cnidoblasts, still alive and ready to fire, into its own external appendages. In effect, it steals the defences of the Portuguese Man'O'War and uses them for its own defence.

That's fucking mental.

[Calilasseia]

It's cute!

Oh, it's certainly one of the catwalk stars of the marine invertebrate world looks wise, but if you touch those feathery looking bits (technical term is 'cerata'), then you're going to find yourself eating into your health insurance in a big way. Those things pack a serious punch. Imagine Anne Hathaway turning up for a date with PMS and a minigun, and you get the idea.

[Calilasseia]

Not only is the nudibranch capable of feeding upon the tentacles without triggering the cnidoblasts, but it passes the cnidoblats undigested, through blind cavities in the gut, and transports the cnidoblasts, still alive and ready to fire, into its own external appendages. In effect, it steals the defences of the Portuguese Man'O'War and uses them for its own defence.

That's fucking mental.

And now you've moved to NZ Dev, you get to see some washed up on your nearest beach every now and again. Don't try picking one up though, because it'll knock you flat like an uppercut from Mike Tyson in his heyday, and will probably hurt even more.

[Gawdzilla Sama]

It's cute!

Oh, it's certainly one of the catwalk stars of the marine invertebrate world looks wise, but if you touch those feathery looking bits (technical term is 'cerata'), then you're going to find yourself eating into your health insurance in a big way. Those things pack a serious punch. Imagine Anne Hathaway turning up for a date with PMS and a minigun, and you get the idea.

I know nudibranchs are evil, one tried to kill me off Puerto Rico. They replaced my entire blood supply twice.

[devogue]

Not only is the nudibranch capable of feeding upon the tentacles without triggering the cnidoblasts, but it passes the cnidoblats undigested, through blind cavities in the gut, and transports the cnidoblasts, still alive and ready to fire, into its own external appendages. In effect, it steals the defences of the Portuguese Man'O'War and uses them for its own defence.

That's fucking mental.

And now you've moved to NZ Dev, you get to see some washed up on your nearest beach every now and again. Don't try picking one up though, because it'll knock you flat like an uppercut from Mike Tyson in his heyday, and will probably hurt even more.

Pick it up? I'll run screaming from the fucking thing like a Palestinian as it fires its rockets at me.

[Calilasseia]

Of course, one fun aspect of possessing defences such as this, is that quite a few Aeolid nudibranchs possess some insane looking colour schemes. Almost as if someone decided to let a three year old loose with unlimited supplies of acrylic paint.

Here's some ...









Then there's this one, which will take your breath away, along with this one and this one.

[Gawdzilla Sama]

This looks like the one that got me, but the spines were white.

[Calilasseia]

A couple more ...

[Calilasseia]

This looks like the one that got me, but the spines were white.

Interesting. That image depicts Hermissenda crassicornis, which is very variable in colour, but this species is a Pacific Coast one. Don't think it's found in Puerto Rico. However, it's one of several Facelinid nudibranchs, and this Family (Facelinidae) has a wide distribution. If the species in question sequestered any cnidoblasts from certain hydroids or fire corals, that would explain why it did for you. Even worse, if it fed upon certain venomous Zoanthids, being stung by the nudibranch afterwards would be a serious medical emergency, because the cnidoblasts of some Zoanthids deliver a toxin called palytoxin, which is lethal to humans in very small doses.