Donya's Pico Experiment

[xxBarneyxx]

Edit: Sorry, looks like I missed a whole page before replying with the below!!

Scooter Blennies (and dragonets in general as its not actually a blenny) will eat isopods. However they eat a lot of them so unless you have a large tank or a lot or rockwork you can rotate (on at least a weekly basis, if not more) then you will have to end up culturing pods as well to feed it.

What size and type of food do the hermit larvae need? Would it not be easier to go with a sterile setup (i.e. no live rock, bare tank, regular water changes) and culture the food? That way you know there is going to be any predation going on. If they will eat rotifiers or pyhto it would be easy to culture a constant food supply for them. If they eat anything smaller then these though then I guess a sterile setup wouldn't work due to the difficulty of culturing the food (though I did read somewhere about someone culturing Zooplankton that was smaller than rotifiers, will try and find it if you need it).

Tanks looking cool. Makes a nice change to see a critter tank and its very interesting to learn more about them (my knowledge of inverts is limited to say the least).

 

[Donya]

Scooter Blennies (and dragonets in general as its not actually a blenny) will eat isopods. However they eat a lot of them so unless you have a large tank or a lot or rockwork you can rotate (on at least a weekly basis, if not more) then you will have to end up culturing pods as well to feed it.

My 20gal is literally a wriggling mass of munnid isopods on every surface (rock, sand, glass). This is because it's my gastropod tank and gets a big bunch of nori to keep everyone happy. While the snails are chowing down on the nori, sizeable masses of isopods are also busy making more isopods out of it at the same time and nothing in there eats them. It would be easy to rotate rocks daily into/out of that tank even daily to collect pods, so I have wondered if the populations are high enough to sustain something like a dragonet. However, that is the only tank producing massive amounts of pods and also my largest sw tank, so I do get uneasy about the idea. Will clown gobies or any other small, peaceful fish also have a munch on isopods, or is it pretty much down to dragonets?

What size and type of food do the hermit larvae need?

Hermit larvae pretty much need a combination of phyto and small zooplankton. Large larvae from species like Clibanarius vittatus are easier to feed (the ones I had took cyclopese). I've read some anacdotes that even small larvae will take rotifers, so my guess is that the mix of beasties in my phyto tub is probably sufficient.

Would it not be easier to go with a sterile setup (i.e. no live rock, bare tank, regular water changes) and culture the food?

The main problem in my case is limited size and the need for quick nutrient export; not sure WCs alone would keep things stable enough. Chemical filtration might compensate, but another complication is that there also needs to be a source of sufficient small food immediately after metamorphosis - something which I have no information on unfortunately. I've also read that an adult needs to be present to trigger faster metamorphosis (more anacdotes, so I'm not sure how much I trust it just yet), which would pretty much necessitate rock for hiding.

Of course, I imagine I have a few months to sort this out so I can probably test the stability of different setups in the mean time. The pair I have nearest to breeding are a couple of native Pagurus longicarpus, but I don't hold out too much hope there, since its been a couple of months of the female slapping the male in the face and running off just before he can manage to do the actual deed lol.

 

[xxBarneyxx]

The pair I have nearest to breeding are a couple of native Pagurus longicarpus, but I don't hold out too much hope there, since its been a couple of months of the female slapping the male in the face and running off just before he can manage to do the actual deed lol.

lol sounds like some of the relationships I have been in in the past!

My clown goby will sometimes take a copepod if it runs right by it but it doesn't actively hunt them. I have seen my orange false perc clown fish actively hunting pods before but not sure if this is normal as my Black and white false perc clown doesn't seem to do the same. Can't think of many other fish off the top of my head that will actively hunt pods but also still take prepeared foods.

Interesting what you say about needing an adult in there with them. I have spoken to people who are attempting to raise cleaner shrimp larvae (they go through loads of different metamorphosis stages) and there is similar anecdotal evidence there to show that the adults have some effect on the development of the larvae. I know some people have kept the adults separate and used water from their tank (put through a very fine micron net) into the rearing tank which has shown some success (its all still very experimental at the moment though).

I know people who use sterile setups for marine fish larvae that have had no issues with just doing regular (daily) water changes while keeping the tank tinted with phyto and rotifers. It is difficult to judge though (getting enough water volume to dilute the waste between water changes but small enough to keep the food density high). Like you say chemical filtration (such as ammo lock) might work but there is a risk of it effecting larvae development in unexpected ways.

What about an air power sponge filter (with a very low flow rate and covered by small micron mesh)? This might work but depends on larvae size and free swimming ability (i.e. if they could avoid getting sucked into it).

None of that solves the problem of needing small food (smaller than rotifiers) to be in place. I have been trying to find the article about the new food source that has been used recently but I can't remember for the life of me where I read it or even what it was in relation to (I though it was mandarin breeding but might have been about shrimp). I think it was something Tim Hayes from midlands reef wrote but not 100% sure.

One thing I did think about was using Cheato in the rearing tank. It would need to be treated first to kill off any pods populations (maybe a short soak in RO water would do this). But would act as a nature filter as well as a source for micro food sources.

 

[Donya]

Can't think of many other fish off the top of my head that will actively hunt pods but also still take prepeared foods.

Bummer. Even if I go the sterile growout tank rout, I'll still be scouting pod-eating possibilities for that 20gal. I love having a tank that grows such healthy gastropods, but it's a bit much when what looks like a thick layer of diatoms and other gunk covering the entire back wall can actually run off when startled.

What about an air power sponge filter (with a very low flow rate and covered by small micron mesh)? This might work but depends on larvae size and free swimming ability (i.e. if they could avoid getting sucked into it).

Big species larvae would do fine, but smaller larvae not so much - they'd probably get stuck if they got too close to it. When my Clibanarius digueti spawned recently the larvae were even getting hopelessly trapped in stray bits of snail slime.

One thing I did think about was using Cheato in the rearing tank. It would need to be treated first to kill off any pods populations (maybe a short soak in RO water would do this). But would act as a nature filter as well as a source for micro food sources.

Hmmm...I'll see if I can give this a test once I do some tank rearranging. I've never observed macro to make much of a dent on ammonia levels duing cycling, but that could be because the rate of production was way over what the macro could handle. Would be nice if I could just use a big heap of macro to avoid fouling from any phyto dieoff.

 

[Donya]

Time for another small mod. I have established that the filter, although air driven, pumps water fast enough that it gradually fills itself with sucked-up sand if left to sit too close to the substrate (hard to avoid in this tank). The problem is that it's rather open on the end:

A bit of foam over the end solves the sand issue. I don't have a well-fitting such foam cover, so I had to make one by cutting slices of foam and hot gluing them together. Hopefully I'll find some thinner foam soon to make a less-clunky cover. Fortunately it's not too visible from most angles.

...and it comes with a photobombing hermit.

 

[sorgan]

Donya my pipefish hunts pods and also takes frozen food, they love to live in algae and love tanks with lowish flow, convinced yet.

 

[xxBarneyxx]

Donya my pipefish hunts pods and also takes frozen food, they love to live in algae and love tanks with lowish flow, convinced yet.

Oh yeah, brilliant idea!! I never thought of these, would probably work very well!

Regarding the macro algae. It can consume a lot of ammonia, however the limiting factor is usually light. I think cheato is probably the best option due to it being able to grow more rapidly then most other macro algaes and being easier to control.

 

[Donya]

lowish flow

Is there a good turnover guideline for this? I did a quick look around on pipe fish but am not seeing much on that yet (having never searched on pipefish before, I probably just haven't spent long enough). While I would guess most of my picos are <10x, my 20gal has somewhere around 15-16x turnover.

 

[sorgan]

Well tbh pipefish can handle a fair bit of flow so long as they are shielded, my tank has 20x turnover and my PF is happy as larry, he sleeps in a red ulva leaf.

 

[Donya]

Uhoh - first unidentified wiggly. Looks like I get to do a bit more searching on worms than normal.

Two of these crawled out of the substrate in the pico today right after I put the light out. Haven't seen any others show their faces. Wormy features:
- somewhere between 1"/2.5cm to 1.5"/4cm in length.
- two black dots on the head that look like eyespots.
- glides along surfaces and doesn't seem able to free swim.
- no segments as far as I can see and they can contract into more of a leech-like shape. You can sort of see that in the picture where it's thickening in the middle.

They look a lot like Planarians, but if I'm wrong on the lack of segments then perhaps they could be some strange epitokes (although I've seen quite a few epitokes in my other tanks and none looked like this). I guess the first step in testing epitoke-ness is to wait and see if they miraculously get shorter or otherwise dissappear overnight from the cup of water I put them in.

 

[Donya]

Well, definitely not epitokes. Higher magnification just makes the worms look more like extra-long Planarians. However, they show no interest in scavenging, so I won't be putting them back into a tank just yet.

Also forgot to mention that I did a small bit of substrate worm harvesting recently from my 20gal to seed the tetra pico since it was showing pretty much zero life in the sand. While none of the worms that I saw go in looked anything like these two, it's possible that I could have the same mystery worms all over my 20gal and just not know it. Since the worm transfer there has also been an explosion of much smaller flatworms (probably something like Amphiscolops), and Cladonema jellies have started to show up. The Staurocladias dissappeared recently, so I'm not sure whether the tank has enough food to support a Cladonema population.

And finally, it had to happen eventually...

I've never really found Aiptasiids to be offensive and won't be putting corals in, so I doubt I'll be taking any drastic action.

 

[Donya]

More bad news. The hermit of uncertain gender,the newer, smaller one, decided to molt in a totally strange place last night with no room and may be lost as a result. Looks like it either got stuck very early on and pulled the skin back with it or didn't leave enough room to back out all the way. Lack of room seems most likely, since it dug itself into a pretty strange spot with the shell aperture blocked by a rock. Usually they have to slide out of the shell a ways and then back into it again as they leave the old skin. It's been isolated since it jammed itself too far back in the shell for me to do much else, but I don't see movement anymore this morning. The original female seems healthy but I'm keeping a close eye on things in case there was anything else fishy going on that I'm missing.

No tank is without its bumps in the road I suppose...ergh.

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EDIT update: Sadly I have confirmed that the smaller hermit did indeed cause his own demise. He didn't get stuck in the old skin, but rather crawled completely out it and then rotated at a right angle inside the shell. This caused serious deformation of the body. Even with the aperture up against a rock, there was probably enough room for him to back out straight given that the shell was proportionally very big (didn't realize just how big until I got the body out to compare), but for some reason he decided to twist as well. Makes you wonder sometimes how the molting method of growing can be adaptive when there are so darned many ways it can go wrong.

 

[Donya]

I think I may have solved the water quality & filtration vs. sterile environment problem for hermit larvae such that I should be able to have my cake and eat it too: fine mesh breeder net in the tank with the adults.

I gave this a test with some freshwater shrimp in a tank full of plenty of fish and things that would eat babies, and I have ~5 visible babies so far in the net. Of course, this test was a lot easier than it'll be with hermits since there was no need to dose plankton. But, it's nice to know that I can have a contraption with mesh fine enough to protect most larvae (perhaps not for the really small species, but should be ok on others I've seen) while keeping up with filtration and water flow. De-podding things will still be a good precaution, but at least a number of other issues would be solved with the net.

 

[seffieuk]

I'm sure I speak for others as well when i say this is fasinating

Seffie x

 

[xxBarneyxx]

Cool, that's a good solution. As Seffie says this is really fascinating. As much as I love everyones reef setups its the things like this that really keep my attention.