the lowdown on sea squirts

[fatkatx]

Does anyone have any experience culturing ascidians or sea squirts? what do they need to thrive? are they photosynthetic? or purely NPS? food...

Thanks!

 

["Umm fish?"]

I have some that came in as hitchhikers on a coral. I've managed to keep them going for 2-3 months so far. Some species are just spectacular. Mine are mostly transparent but still very pretty.

So, you know that as larvae they are chordates? That is, they have a notochord and brain. They are far more closely related to us than corals, for example. Once they find a good spot to settle, their brains and spines (and many internal organs) degenerate and they become completely sedentary.

The larvae glue themselves, nose first, to the substrate using the secretions of anterior adhesive papillae. This is followed by an exceptionally rapid, drastic and complex metamorphosis. Epidermal cells covering the animal's surface contract and within a period of 10 to 15 seconds they crush the tail and its inner notochord, muscles, brain, nerve cord, and sensory structures into a mass of tissue debris.

Once they get themselves settled they are filter feeders, though it's said that some have symbiotic cyanobacteria:

Several species of tropical colonial sea squirts contain symbiotic cyanobacteria growing in the branchial basket. These cyanobacteria, in the genus Prochloron, appear to function much like the zooxanthellae found in many other invertebrates.

As for care, it's supposed to be fairly difficult to get them small enough foods and to get enough food to them.

Very fine particulate organic material, mostly bacterioplankton or small phytoplankton, is filtered from the water and is caught on the mucous layer lining the branchial basket. Tunicates are awesomely effective suspension-feeders; even small ones can filter hundreds of liters of water per day and remove well over 95% of its bacteria.

I think I've likely kept them alive as long as I have because I feed my tanks a lot and, so, get a lot of small critters living in my water column.

All quotes are from here: http://www.reefkeeping.com/issues/2005-03/rs/index.php

 

[fatkatx]

thanks very informative

 

[ctenophors rule]

not to stel yo thread, but...... can the be fed bbs?

 

["Umm fish?"]

Doubt it. Much too large.

 

[ctenophors rule]

ok, so i guess rots would be better?

and what if it is a big tunacit, say 3 inches tall, could it eat bbs then?

 

[fatkatx]

"bbs"? rots=rotifers?

 

[greenbean36191]

In general, zooplankton, including rotifers and baby brine are much bigger than phytoplankton. They're not suitable for filter feeding inverts like tunicates which are size-selective feeders that utilize the smaller fractions of the plankton- phyto and bacteria.

 

["Umm fish?"]

Even the big ones with large siphons probably eat at the smaller end of the food range. Phyto, bacteria, ciliates, that sort of thing. The big siphons are to get more of the smaller prey through. That is what I've read.

 

[ctenophors rule]

ok, thanks!

kindof like the whale sharks throat, to small for anything larger than a foot to fit through, even though the mouth is massive.

 

["Umm fish?"]

Exactly!