Strange Nudibranch behavior

Hi guys,

Found these two colorful fellows in Alor, Indonesia. Do you know what they are doing? Cannot seem to figure it out...

Cheers

Daniel

Hi guys,

 

Found these two colorful fellows in Alor, Indonesia. Do you know what they are doing? Cannot seem to figure it out...

 

 

Cheers

 

Daniel

I'm assuming that the orange one is the second one. If so, it may be "trailing": "Also known as queueing or tail-gating, all species of the chromodorid genus Risbecia exhibit this behaviour where they seem to play "follow the leader". Perhaps its a behaviour which has evolved amongst relatively uncommon animals to ensure they find each other for mating. When tailing, one animal appears to follow the mucous trail of the other until they actually make contact. Then the following animal, as can be seen in thse photos, keeps contact by touching the 'tail' of the leader. Sometimes 3 or 4 animals can be seen together."

I've seen it in a Caribbean slug

Fact Sheet - Trailing

The orange one looks like Gymnodoris inornata which is a predator of other nudibranchs. Looks like it is in the process of making a meal of the other nudi similar to this:

http://www.seaslugforum.net/find/15816

The orange one looks like Gymnodoris inornata which is a predator of other nudibranchs. Looks like it is in the process of making a meal of the other nudi similar to this:

 

http://www.seaslugforum.net/find/15816

Thanks guys for your quick answers!

I always assumed that nudibranchs would follow a chemical trail left by its own species or at least genus, but two different species from different genuses attracting each other does seem odd.

Gudge, i must admit i rulled out the predator theory as i tought the orange one was from the genus Nembrotha that to my knowledge aren't predators of other nudis. Next time I 'll research better before asking. Thanks for the link!

Such a big prey for such a tiny predator. It does seem that in the world of nudies it is not always the biggest who eats the smallest...

Cheers

Daniel

Such a big prey for such a tiny predator. It does seem that in the world of nudies it is not always the biggest who eats the smallest...

Like we keep telling you guys, size isn't everything!

According to the ever-informative Sea Slug Forum Gymnodoris inornata usually attacks its prey from behind, makes a hole in the prey's skin, and sucks out the internal organs. The prey shrivels away until it is an empty husk at which point the G. inornata will swallow what's left. So as long as it can stay attached it will be a successful predator on animals much larger than itself. http://www.seaslugforum.net/showall/gymninor

Thanks Leslie.

From what i know after reading some books, some Gymnodoris species munch/graze on the gills of other Nudis as opposed to eating them whole. So from the position that might be the case here?