[Video]: Sepioteuthis juveniles; 2 days +

And a few more from today...

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We had a power outage this evening (quite a large part of Auckland central was out), with all lights/power down for at least an hour.

... so there I was, peering into the tank to detect any movement (the aquarium we are based at, Kelly Tarlton's, is actually underground ... so there was ZERO light, spare an emergency thing down the corridor) when the lights went back on.

Well, if only I'd had a camera primed for that moment. Every squid had their chromatophores banded down their body, transparent/band/transparent/band, with their arms all curled backwards and similarly banded.

Never seen anything like this before; I'll have to get some extremely low-light-level camera in there, infrared or something, and see just what these animals are doing in pitch black (even at night I have a small fluorescent tube on in their room).

When the lights went back on four larvae hatched from eggs in an adjacent tank (the first hatching larvae from new egg masses in over a week). I didn't quite realise how big these animals had grown until I placed the 4 new ones in the tank (they were dwarfed!!!!, ~ 5 times smaller).

As an aside, I had Discovery folk here last week .... It looks like we'll have a web cam on this tank very soon (and a brand new tank in ~ a month to accommodate the larger animals).
 
They're certainly getting easier to photograph these days (as they're getting considerably larger)!

Cannibalism is proving to be a major problem, as the stocking density in the tank is way too high. Yesterday morn 6 large squid (not small ones) were being devoured by other squid; this morning there were about 15 dismembered corpses on the bottom of the tank. Every day I remove a few individuals that are swimming around with almost all arms/tentacles severed (probably happens when two individuals go for the same food item and simply keep chomping away until one realises that it has been eating the other, in addition to the shrimp).

The tank is being flooded with food thrice daily; there doesn't appear to be a shortage of food!!! However, although the squid keep devouring the shrimp at a fantastic rate, I'm no longer certain whether the particular shrimp that we are feeding them are appropriate in size or nutritional value. Looks like night trips with light traps to collect oceanic euphausids might be required now .....

These three of the present stocking density

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.... and three pics of the larger juveniles. I've lost track, but they're about 30 days old now

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Quite remarkable is that recently hatched (this morning) larvae (I'm running several systems) seem to tolerate a hexagonal tank (they don't like square/rectangular all that much).

I don't like experimenting with larvae, even though it is necessary to figure out how to keep these things alive, because it often results in instant death. As such, once a system is found that keeps them healthy I tend to stick with it (cylindrical tanks).

A hexagonal tank was handy, 5 larvae were placed into it (I've since added a protein skimmer, and removed the air stone), and all seemed quite ok; I'll leave them there for a day to see how things go.

The larvae are ather small (tiny in fact) compared to the ~ 30-day old juveniles, so look like little brown blips on the screen.

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might just be a natural instinct to eat everything else that moves regardless of species or size.. i think i would try putting in stuff to block some line of sight and provide distractions, i know that may mean more food to be added at more frequent intervals but that wont be bad..

how about cutting thin strips of plastic bags at 1cm wide and however deep the tank is and anchoring them to the bottom sortof kelp like??? that may provide a certain obstacle in the kill zone?
 
Colin said:
might just be a natural instinct to eat everything else that moves regardless of species or size.. i think i would try putting in stuff to block some line of sight and provide distractions, i know that may mean more food to be added at more frequent intervals but that wont be bad..

how about cutting thin strips of plastic bags at 1cm wide and however deep the tank is and anchoring them to the bottom sortof kelp like??? that may provide a certain obstacle in the kill zone?

I think I agree Colin, although i'm sure stocking density plays a part. When we had hatchling Sepioloidea ( I know not really the same....but) they went cannibalistic but it continued even when the stocking densities were low.

The "kelp bags" might help, I wonder if "out of sight out of mind" applies to such ferocious little beggars?????????

J
 
i'm 100% sure it does... my experience with sepia tells me that they may be full but seeing movement brings out the kill instinct and they attack... hence the bodies left behind. hungry squid wouldn't leave corpses.

my cuttles would attack each other during feeding, i put it down to overexcitement due to a feeding stimulus.. i lost two cuttles this way.
 
.... I'll give this a go (additional weed in there). You're right - if the bodies are only dismembered (not completely eaten), then it's not a food problem.

There's a small sacrificial sprat that's been swimmining around in that tank for the past few weeks. Every day I expect it to be 'gone', but they don't touch it (it's ~ 1.5 times their size, long, skinny and very silver). They don't like the glass shrimp (1 or 2 are eaten daily, in total, but they prefer the considerably smaller mysid shrimp, now considerably smaller than the squid themselves).

Jean, I've always wanted someone to look at tentacular club armature and diet. The three Sepioloidea species we get here (2 of them new species) have different tentacular club sucker armature. S. pacifica has the largest suckers (a few enlarged), and probably could take a 'colleague' squid (to eat), but those of the other two species are extremely small, and I wouldn't imagine that they were capable of restraining large prey (like a fellow squid).

It would be an exciting piece of work to look at diet and compare this to beak morphology, arm structure (relative lengths, sucker and/or hook morphology, protective membranes, photophores etc.) and tentacle structure, length, sucker and hook morphologies.

Jean, any chance any diver/vessel can get eggs of Sepioloidea right now is there?? I'd get a chiller unit shot down and pay for the same day courier to Auckland. I'd love to give these guys a go.
 

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