Donya's Pico Experiment

[Donya]

Recently put in a new, much smaller C. strigatus. Following the removal of the other one that ultimately died, I noticed that the female started sitting around like a lump and not doing much. Water checked out and the behavior continued after a couple WCs, so not a pollution issue. I saw some similar behavior from a female small Clibanarius that lost a mate and even stopped eating for quite a long time until I put another "buddy" in. I don't usually subscribe to the idea of most hermits needing "buddies" all the time (since it certainly doesn't work out for all species), but it seems like sudden dissappearance of one memeber of a content pair or small-ish group causes a fair amount of distress in the remaining individual(s). With the new Ciliopagurus strigatus in, the original female is right back to normal activity.

Another tank mod: replaced the home-made filter cover with the bottom portion of a Fluval Edge prefilter (one of these dealies: http/www.petco.com/product/111694/Hagen-Fluval-Edge-Aquarium-Pre-Filter-Sponge.aspx ). It has a conveniently snug fit even though it's not even from the same brand. The female hermit was starting to rip apart the hot glue I'd used to hold the older foam slabs together, so a continuous piece of foam should hold up better.

Also, the broad-leaf Caulerpa seems to be out-doing the grape Caulerpa. It's still having a bit of a stuggle getting established with the periodic beatings and stompings that the hermits inflict on it, but it's making progress slowly. The female hermit keeps snipping all of the balls off of the grape Caulerpa every time she gets a hold of it so that species is probably doomed in the long run since I can't keep propping it up. I'll try to get picks of how the other species is establishing as soon as my camera stops telling me the card isn't formatted.

 

[Donya]

An unusually large Cladonema that's been swimming around the tank recently:

Also, the video might be too cruddy to see (I have no idea why it's so dark), but I was able to observe events leading up to a massive Amphipod spawning today:



If you click the image above it should play in another window.

This species of amphipod doesn't usually free-swim, but individuals and sometimes pairs kept shooting up from the rocks and doing a weird squiggly swim around the tank. After some reading, I gather that the single individuals were males and the rest were male-female pairs with the larger male doing most of the swimming. As I type this, a big, loosely-connected floating bundle of them is making quite a cloudy mess.

 

[Donya]

After some more bumps, I am back to the same principals I've used on my other picos: more bubbles = safer. The new foam thing I added got clogged with amphipod boddies following the spawn, the filter turned into a skimmer churning up some nice orange goop inside (erg! ), and the the Nassariids in the tank were very, very unhappy as a result. Changes as a result:

- raised the filter so it can't suck up sand as easily and removed all foam.

- swapped the air pump that came with the package to a hefty Whisper one that is equally quiet but is intended for 20gal tanks if I recall right. Not doing this sooner has probably been half the problem as far as getting enough surface aggitation, since it massively boosted the filter flow in addition to letting me have a backup source of aggitation should the filter clog.

- added a 4" air stone along the back as a backup surface aggitator and to more evenly distribute flow around the tank.

- additional 4.5W LED lamp to get more light towards the front of the tank and encourage the macro that's taken hold there.


The new light:

More flow, more bubbles, and more macro (another clickable video):


Please excuse the changes in light level - that's purely camera issues.

Also, cost tally for equipment + animals in case anyone is interested:
tank = ~$25 (tank, original pump, and main light)
LR = ~$8 for just over 1lb
additional LED lamp = ~$10
hermits = ~$30 (for 3 total, counting the one that died)
snails = ~$15 including those that ultimately had to be moved. There's only ~$2 of snail there now lol.
airstone and additional tubing = ~$3
Total = ~$91 if I counted right ($45 for animals, $46 actual equipment)

Would be a bit more of course if everything was new, since I already had the sand, macro, and spare pump. Ignoring the livestock (I know that species of hermit is cheaper in some areas, but not here), it seems to have fallen not too far from my $50 ideal bound for no-frills pico equipment.

---

EDIT: Corrected the type of new pump. Had it as Rena before - for some reason I get those two mixed up a lot.

 

[seffieuk]

Fasinating as always, but i cant get the video to play

Seffie x

 

[Donya]

Huh....perhaps photobucket was having some issues. It has occasionally punked out in the past. Tested both just now and they opened up new windows and played for me (in IE anyway - haven't tried with firefox and such).

It looks like the extra LED was all the grape Caulerpa needed to grow faster than the rate of being destroyed. It's given a massive boost to the plolifera too, so I will probably be able to have a nice wall of macro and bubbles along the back very soon (maybe even without a plastic plant ). I'm wondering if it's a spectrum difference? I did a brief bit of looking for info along those lines but didn't turn up much useful. The new LED has more red, more like the lamps I've used to grow macro on other tanks. While it could just be a light intensity difference that's led to the macro boom that's currently happening, it would seem odd to me if that was the only thing. I recently swapped out a similar spectrum bulb on my 20gal for a "bright white" bulb closer to the blue side of things, and so far I've observed the reverse: significantly less Caulerpa/Chaeto growth, but much faster hair algae growth.

 

[Donya]

Beauty is that thing that's not known for happening fast right? There's a very lonely corner now where one of the plastic plants was ousted to let the macro take hold in its place. The prolifera finally sent runners over in that direction so I thought it best to free up the space before it became a tangle. I predict it'll have little leaves poking up in a couple weeks based on the current growth rate. However, I do rather miss the red...

 

[Donya]

Nnnnooooo my lovely update post...it's gone! Great, so I've either put it in some other random part of the board or I hit "preview" instead of "post" and then absent-mindedly closed the window. You'd think after 1k posts I'd have figured out not to do that.

Alright...take #2, the abridged version.

HYPOTHESIS TESTING TIME.

I have observed Ciliopagurus strigatus eating zoos more than once now, but that is the only type of softie I have seen them eating and it seems shrooms are able to grow quite happily in a tank with them at an LFS. This makes me wonder if the species is somewhat selective in its softie-destruction tendencies.

And so, a brave mushroom appears in the name of science:

(Somehow having the bubbles on is giving my camera a bit of difficulty focusing...will have to work on that)

Hardly a controlled experiment, but in such a small environment I'll at least get to see how the hermits interact with the mushroom, since it's sort of hard for them to not find it. And, of course, if things go less than ideally and even one snick gets put in the shroom, I have a backup tank waiting for it.

Also, I have no doubt that if placed into true starvation conditions these hermits would probably have a go at just about any softies and probably other corals as well in a desperate search for food. But, that would also hold for most moderately-sized hermits that are normally considered coral-safe.

 

[seffieuk]

Interesting, so are you going to feed the hermits or starve them to see what happens?

Seffie x

 

[Donya]

Won't be cutting back on food too much since I don't want the whole tank ripped up. When stressed for food, many animals will resort to pretty bad behavior that normally would never show up. I have seen other hermit species get pretty rough trying to pry open polyp's mouths when desperate for food (even sticky/stinging polyps like white ball corallimorphs) so I don't want to head that direction.

The mushroom has been getting quite a bit of attention from the hermits so far. Despite that, they really go out of their way not to touch it much - despite the fact that it's attached to a shell that they're rather interested in. They go up, sniff it, and then usually back away (one exception being the female hermit losing her balance and accidentally sticking her leg in its open mouth...that led to a couple minutes of chaos since it sucked right on and didn't want to let go). The hermits will even stay in their shells if the mushroom leans over in their direction and touches them. They wait until it tilts back up before they're willing to come out again. Borneman briefly mentions in "the book" that there may be chemical reasons that mushrooms don't have many predators, although I can't seem to find much more detailed information on exactly what chemicals are in question.

 

[seffieuk]

(one exception being the female hermit losing her balance and accidentally sticking her leg in its open mouth...that led to a couple minutes of chaos since it sucked right on and didn't want to let go).

I take it the hermit managed to get her leg out?

Seffie x

 

[Donya]

Good grief - it's been ages since I got back to this thread. All is well between hermits and shroom, although I can't say all has been well between hermits and hermits. Not long after my last post, I had added a third to see if it would change any interactions...and it did, it just waited ages peacefully until I was confident that there was no effect and went off to an all-day conference. When I came home, and my husband told me of all the awful things that went on in the tank while I was out. The new one molted, and somehow set the original female off on a rampage. My husband reported that the original female was unrelenting in trying to brutalize the new hermit despite his attempts to intervene. She hasn't done this to the male when he has molted, which has happened twice now - once before the event (but after the third one went in) and once after. The newest hermit was minus two legs when I got to it, but I suspect it was either a bad molt or a rushed molt due to harassment rather than legs being ripped off later. The goniopores on the molt did show that the new hermit is another female; I removed her to a breeder net in my 20gal until the legs are back, and will probably keep her in that tank or another one to avoid further nonsense. Either the event was the result of introducing a competing female (might not have gone the same if it was a male or gender-undecided), exceeding some population density threshold, or these guys are just picky about who they're willing to share a territory with.

New pics soon hopefully...gotta recharge my camera's batteries first. The darned things always go dead just when I want to use them.

 

[seffieuk]

Sounds like carnage, I didn't realise that hermits are born asexual - so, what influences which sex they become?

Seffie x

 

[Donya]

The literature has been a bit vague about that from what I've read to date. At least once they've reached a reasonable size (not sure what happens in the larvael or very small juvenile stages yet - I've seen breif mention of gender determination at those stages, but don't know the detail), there can be three categories of individuals in some species: male, female, and those showing goniopores for both genders. In some species like Clibanarius vittatus, I've read that the individuals with both types of goniopores will usually become males (at least in behavior - from the diagrams it looked like the female goniopores started to close off as well, although they didn't dissappear). However, I don't know if it holds for other species. If pleopods were missing or stumpy as they are in some males, then it would make sense to assume a male role to reproduce successfully, since carrying eggs would be difficult/impossible. However, I don't know if pleopods are something that can change drastically with successive molts. It's a shame I lost that hermit when I did, since I've wondered if it's a mechanism to balance gender ratios.

 

[seffieuk]

Donya, do you have a diagram that shows what you are talking about - I'm getting a bit mixed up

Seffie x

 

[Donya]

Not currently, but in progress. Since I'm going to add a section on sexing hermit crabs to the next version of that big messy document of mine, I have been working on some extra diagrams to toss in (I haven't seen many good ones floating around the web or in publications; usually it's rather difficult to make out what's going on in them) and I'll post them up here once I get them inked and scanned in.