HCA: Hermit Crab Association

Leeko wrote:Is this a first? Baby straws bred in captivity? Man this is exciting stuff! I will be watching your progress like a hawk!

as far as I know it's not even been done in a lab yet, and thanks, I'm pretty excited too, maybe a bit too much

Curls/Nat, how do I tell which ones are dead and should be removed? I've only seen one kind of white, Would they float or sink with the bubbler off?

edit: another question! Can I just add brine shrimp eggs to my 1 bottle every 12 hours to get fresh baby brine shrimp every 12 hours?

Or do I have to clean out the bottle and do a new batch every 24 hours? If so, I think I need another hatchery setup

I've added some phytoplankton, just a few drops, but I also tried frozen baby brine shrimp. I'm not sure it worked but me and my wife are both convinced they are grabbing stuff off the floor and swimming away with it to eat. I let them have at this food for about an hour before I sucked it all out. You can see them doing this in the video below.

I've really got the hang of water changes and cleaning up the stuff on the bottom now, I use the small tip suction tube for most of this and I use the big hole one to move zoea between jars. I'm changing the water around 30% of each jar every 12 hours. So 60% water changes per day. I just hope I can keep this up, I can get it done fairly quickly now. I use a measuring cup so the tip sits over the jar edge so I don't drop ay in the main tank.

The setup is coming along nicely now, I really wish I was more ready when she dropped them but it was under a month, most like 25 days. I still have no live brine shrimp to feed them but they are still not dieing at all, so hopefully things are still ok. There's a pump/filter to keep the outside tank clean and moving. Then there's 4 Jars for Zoea, and 2 jars for water changes. I'm currently hatching my brine shrimp in a DIY contraption, i hope it works, but I have to wait 24 hours to find out. I did an NO2 test today and the levels are great even an hour after putting in the frozen baby brine shrimp.

Latest full setup:


And the video of it:


here's the zoea doing what we believe is eating off the floor but it's so hard to tell. Maybe someone can tell me if this is just normal and they aren't eating at all;

With bubbler on, not as easy to make out the details:


Bubbler off, much easier to see;


thanks for viewing!

Good luck with this, kuza! It does look like they are trying to pick up food off the bottom of the jar.

During my anesthesia induced haze, I've overlooked this update until just now and I... am... SPEECHLESS!

Way to go on the zoea! Unlike Dennis Rodman, you deserve a Nobel Peace Prize

thanks! And my brine shrimp have hatched and I'm doing the first feeding now! they hatched in like 20 hours, maybe less I may have missed the first ones.

Here's the video of the zoea possibly eating the baby brine! It's all so tinny it's hard to tell.



Ihave no idea what I'm doing here, I don't know if I need to switch the brine shrimp hatchery or keep feeding them from the same batch, or I guess after 3 hours they are too big? arg!! I feel so helpless..

ok so on top of my question from the post above, how did you both manage to do 2 brine shrimp feedings per day, did you have 2 hatchery's? And I've fed mine 3 times from 1 batch of eggs at different time and they seem to have either killed them all or eaten them all, I just clean up the mess at the bottom of the tank every few hours. Are the brine shrimp really useless after 3 hours?

I have been putting eggs in my hatchery randomly, maybe I should remove them all, clean it out and redo the eggs every day and only get one feeding in?

Either way, the zoea are turning darker color from eating, it's pretty amazing!! I've still only seen a couple of pale/white dead floaters in all 4 jars, so somehow I'm not losing any after 2 days. Should I take even more out than I have now? i have wayy more than 50 per jar, but I think doing water clean ups / changes every 4-6 hours is keeping up with the cloudiness.

And should the water be cloudy? I mean it's looking pretty nasty, even though my NO2 levels are good.

Haven't been here for a long time!
Wow, it amazing what your up too!
A late congrats Kuza, and all your vids where amazing!

Kuza, there is a lot here about their nutritional value, but it's a very good read!
http://www.advancedaquarist.com/2004/1/ ... #section-0

Basically it's that they use up their yolk sac in the few hours after hatching, which is the most nutritious part of them. Until the brine shrimp babies molt (yes, they molt to grow too!) they aren't physically able to eat so they have a lower nutritional value. Once they molt they start eating and with an enhanced food source then become more nutritional again. The problem becomes (if you can even find a good food source for them locally) their size once they molt. They may become too large for the zoea to be able to catch!

thank you kuza


sorry to say but I think there are still too many larvae in the jar!
You will never get them all feeded. It is a "survival of the fittest" but if there is not enough food, even the fittest will loose after a time.
And there is too many dirt on the floor.

Rember: more larvae = more food needed. More food (artemia nauplii) = more dirt.
As wodesorel already said: the molt aswell. And they poop, too. Very much animals in the jar to make the water dirty.

Better to use only round about 50 or less in a jar

I only know that artemia nauplii lost their substantia nutritional value after 3-4 hours.
I could watch that they catch bigger artemia but they release them directly and try to catch a 'better' one.
All Artemia which are older than round about 5 hours are useless. And has to be catched out of the jar. Because they are additional pollution.
So in my opinion there is no need to feed them nor to keep them!


I clean my artemia jar every day with very hot water. And than I set up a new jar to have freshly hatched nauplia the next 18 hours. (mine are hatching very fast because they are INVE 430)
In the first days I set up 2 jars. To have new nauplii in the morning and evening. (in the case of the ocean nutrion artemia will not hatch). As an emergency food option

In the video it looks like that the pick up something off the floor.
They have something like hairs in fron of their head. They touch the ground and than they jerk and swimm higher. (The jar bottom reflect the light. And they always swimm to the light.)

As I already said: the can't pick up things from the bottom. That's what I see in each of my experiments.
What can be is: that their swimming arms swirl up the food from the bottom and than they can catch it . For me ti is too risky to put in frozen food. I have read in a fishkeeping forum, that frozen food can have a lot of germs. And has to handelt with care.
When they are in the megalopa stage you have to feed frozen krill, frozen mysis and stuff. But this has to be a very samll portion and has to be remove very fast.


The freshly hatched artemia nauplii are sooo small, it is very hard to see the larvae eat them. A good camera with macro funktion may help.

They definetly will eat freshly hatches artemia nauplii. So do not panic

thank you both. I cleaned up the bottom right after the video and I do remove more zoea with each water cleaning. I will set up a second hatchery now.

kuza- This is AMAZING!!!!! Congrats to you and the mama crabbie!!!!

Curlz, my brine shrimp cycle is off so I won't have any for at least 17 hours, is it ok for them to go that long without food? They are all orange now so I believe they all at, like all off them, lol.

I am also getting another set of jars today to swap them out since they are so cheap, and I do water changes of 33% every 12 hours, do you think this is enough to keep up with the pollution?


And thanks Irene.

I consider that you would need fivefold of freshly hatched brine shrimp to feed them. And that daily!
But I believe this won't work... At the moment I have round about 45 larvae. I started with over 50. And this time I lost only a few. Even in the molting times (they molt up to 5 times to reach the next larvae stage - depending on the species.) they stay alive and fit.

In my opinion if you leave all of them all , you only increase the death rate. And at the end all did not get enough food and die. But you must try it by yourself. In my last tries I started with 300-150. And got big loss.
In my successfull experiment I started with round about 300 and till the 10th day I lost 230 larvae ... because I let the artemia hatch in the Kreisel and because of the kreisel stream they were able to catch enough food. I do not know.



I think they can stay some hours without food. Maybe up to 12 hours. But than they should have food.
So maybe set up 2 jars with artemia daily. One that will hatch in the morning and one that hatch in the evenig.


ah you've ask how to identify dead ones: the are white - rose and they are not transperant. The are curved and if there is no strong stream the stay at the bottom.

ahh ok, the reason I haven't been getting rid of them in large amounts yet is because I have the 4 jars so I'm waiting to see if one jar takes heavy losses, then I will take out that jar, clean it, and then split another jar up again into that jar and that will split the population down. I didn't think about losing all 4 jars at once, but I guess that could happen so maybe I should take 2 jars down to 50-60 now.

The good news is I have managed to feed them all i think, I put in A LOT of baby brine shrimp and they are all gone, they ate thousands of them and all the zoea are bright orange now.

As for the dead ones, if they do turn pale/white when they die I have had maybe 5 deaths so far, the other ones i got rid of during water changes, if I catch some in my dropper I just dump them in the sink with the water so I am bringing the population down with each water change.

I'm thinking of adding 2 more zoea jars since I have the room and the water changes are so easy with my setup.

i guess the next step is to figure out when they are molting, can you really see it clear if they molt, like do they continue to float around or do they try to get stuck somewhere to molt?