Skunk cleaner shrimp spawning log

[DaJMasta]

A preface: I know these guys are really hard to raise and I don't expect to be able to do it early or easily, but I've got two shrimp, they're spawning, and it's way more interesting to try.

 

 

I've seen them with mature eggs a couple of times, but shortly after dark it looked like the one carrying eggs today was going to release them, so I shut off the flow and had a look.  I saw a couple of whitish dots in the water column with jerky movements, and shining a light on them, they had shiny, long limbs going out from the dot.  I set up my Vossen larva trap for the first time, covered up the moonlight with a sheet of paper, turned off the other lights in the place, and then searched around with a flashlight.  I was very fortunate to have the camera going during the first big burst of released larvae.

 

Got a few hundred in the larva trap, transferred them to a breeder box stuck in one of the fry aquariums (taking space from those baby cardinals).  Originally had an extra pump pushing into the netting of the box, but decided it was probably too much flow, so I removed it and then put an always on low power light over the tank.

 

Flow is lower, added a couple hundred mL of phytoplankton to the tank, and while I may add a bit more, we'll basically see what's there in the morning.  I'm pretty sure the white dots are the egg yolk as their first food source, but in the morning I'll give them a dose of the zooplankton I feed the fry (mixed species and stages of development) and see if I can keep some larva going.

 

Part of the pessimism getting into the project is that I know their larval stage is supposed to be around 150 days (5 months) before settling into juveniles, and especially in just 'spare space' in a fry tank, I can only wonder if it will be even close to adequate for a real attempt.  But I won't know unless I try, and I know they've spawned a few times in the tank before with no sign of the larva the next morning, so at least these ones have a better chance than with all the stinging things, hungry mouths, and powerheads.

[cpeguero]

Awesome! Good luck with this. Always wanted to raise these, but never had time, space, and 2 shrimp all at the same time. Excited to see how this goes!


Sent from my iPhone using Tapatalk

[YHSublime]

Neat! Tagging along for progress

[Cris]

That's really cool-keep us updated

[DaJMasta]

Well unfortunately, it seems to have been a rough night for them, it took me some time to find any drifting around in the box this morning, and while there are certainly some still alive, it's clear that the breeder box is not a good choice for this kind of larvae.

After catching them I added a total of 400mL of phyto, then after reading they needed to eat in the first 24h and that while they could eat phyto in that time period, it alone wasn't sufficient, I harvested about 12oz of my zooplankton cultures and fed it to them.

 

I think the critical issue overnight was flow - I had reduced it to a slow drift around because I didn't think them being pushed into the walls was going to be good, and while that may still be true, it meant in the morning a lot of them had collected in a pile on the bottom (I had seem similar piling up on the side in the collector and then in the box), and I think since they are not all that mobile, they probably need to be fully in suspension.  I've adjusted the flow this morning and it's better, but they seem a bit less active than before, so I don't know how many are still going or if they're now too weak to really make it.  In either case, I'll feed them and make an effort until it seems like there aren't any.  There's also some chance that the collection method was too rough or there was some parameter shock transferring to the new tank - though at least the latter shouldn't have been too far off.

 

(the blob of them that collected in the collection vessel)


There are some worthwhile observations that should help in the future, too:
The newly hatched shrimp don't really seem to swim (or at least, they didn't after the transfer to the new vessel), they sort of move around and then they jump when they run into something, but I presume the jump back (characteristic of many shrimp) is probably just an escape mechanism.

 

Live and dead larvae look pretty similar (especially without much movement), but it seems the live ones have a yellow yolk dot, while dead ones have a white one or have gone clear altogether.

 

 

 

I've been thinking about it for a while, but I will definitely prioritize designing some sort of holding vessel for them and printing it.  I'm thinking more or less a vertical kreisel arrangement, but something that holds on to the front glass of one of these tanks, a viewing window on the glass side, a mesh cover on the other.  Then there's an open top (and the top of the circle is cut off by the water line, so it's maybe 230 degrees worth of a circle), and some sort of flow mechanism (probably a column for air driven flow with a flat spillway for it to be laminar along the inside edge of the circle to keep things spinning).  Just keeping them from settling I think will be big, but it would be much easier to observe than shining a flashlight into the side of a breeder box.

The other notable is that since these shrimp are simultaneous hermaphrodites, I think both shrimp have actually been carrying eggs.  About 11 days ago one of them had a clutch of eggs that disappeared late at night (after like 2:30am), and since their gestation period is longer than that, I may have another attempt before the year is out if I can't get any of these ones to stay with me.

[DaJMasta]

Well it's 24 hours in, and while there are a few alive still, it's gotta be a dozen or less, more likely less than that.  A few dots still are on the sides/bottom of the box, and I can see them jumping when a light is shined in, but the majority are definitely gone.  Fed some pods twice today and hoped, I think water quality is staying up, but flow and bumping into things is really seeming to be the problem, battering the little guys who aren't really able to swim much.

I have seen a few during the day drifting and sort of waggling their legs, in a more coordinated fashion than yesterday's basically thrashing, but not to the point of real locomotion aside from their little escape maneuver jump.

I will see what is around tomorrow, there is at least some chance that babies that are on the mesh in low flow aren't actually being hurt and may still be getting needed circulation.... I'm not totally sure, though.

Took some video and didn't get much in focus, but you can see some pods and debris floating around.

[DaJMasta]

Unfortunately, my first attempt is already over.  I didn't see any in the box this morning, took a few more looks during the day, and emptied it (of copepods) this evening to return the tank to the cardinal babies.

I see yellow (and when they swim upside down, very pale teal looking) eggs under both of the shrimp, one a ways farther along, so I hope a next attempt is on the way.  I also felt inspired and had a bit of time, so my first trial version of a magnet-on kreisel for this tank is a few hours into printing.

 

 

The idea is a circular tank with one side that is tank glass and one side that is a fine mesh (probably 250um, but maybe smaller, smaller keeps more copepods in) that is held on by the retaining ring that looks like a tie fighter cockpit.  The odd piece on the right clips onto either side of the main chamber and *hopefully* is an air powered pump that can be turned down to very low levels of flow and dump it right along the inside edge of the tank.

[DaJMasta]

I will be more ready for the next one!  I've got a working prototype of the in-tank kreisel, though I need to buy some narrower magnets to mount it a bit more evenly and securely.

 

 

On mid-high flow settings, it will keep TDO B2 in suspension and push TDO XS slowly along the edge, and while there's a bit of sticking to the output mesh, there's not a ton (currently using 250um mesh).

 

The pump for it (slightly visible on the left), uses air to drive water up a tube and over the top edge, so it can flow down the left side (but it can be moved to the opposite side).  The flow rates seem to be in the right ballpark and can be adjusted by air amount, but it does introduce some small bubbles - not sure if they will be a problem.  There definitely would be a way to extend the drop inside the vessel and then vent the air around the surface, since the air only needs to push it over the edge, but I'll make that modification if it seems to be helpful - a lot of larva devices seem to be air driven without ill effects.

[DaJMasta]

Second shrimp spawned this evening, much earlier than any I noticed before, probably around 11:10 or 11:15.... but I was busy and missed the moment it happened maybe by 10 minutes.  I think the clutch was smaller, the egg mass under the shrimp definitely seemed smaller, but when I got the pumps off all I saw was a few dead ones near the top, the remainder were already food.

 

My assumption is that with the full flow in the tank going, I've got a few minutes - at best - to turn off the flow so the babies can survive.  I'm starting to get a good estimate of when they will hatch - the egg mass goes tawny and gets larger in the 2-3 days before, and the day of it seems larger/individual eggs are more pronounced - and I had a feeling from the look that it would have been tonight or tomorrow, but I missed it.

Definitely have a yellow egg mass under the other shrimp, who I think was the one who spawned on the 30th, so I will probably turn off the powerheads and just leave the rear chamber pump on the night it seems like it will spawn.  May have to rig up a bright, narrow beam light through the top of the water column or something, so that I can see larger particles at a distance, but the simplest solution would just be to watch carefully starting from 10:30 or 11pm.

[DaJMasta]

Another spawn, and I caught it!   The shrimp looked like it would release them today or tomorrow, so I had only the rear chamber pump on at about 10pm.  I put some paper over the moonlight and setup the larvae trap and light, and basically hovered around the tank with a flashlight, looking every so often.  Around 10:20pm I saw the first zoeae released, and around 10:45pm was the biggest release of them.  The shrimp stayed high, on the top side of the rockwork, and didn't move around much, but at the point where the most came out at once, it actually climbed all the way to the water's surface, actually trying to hold on to it, and after releasing the zoeae in a burst, walked back down to where it usually hangs out.

The cardinals and the sharknose gobies were awake and definitely got a snack, but I think I still got 100-200 in the bucket.  I put them in the new kreisel, now with smaller magnets to seal better, put the light from before over it, and got some video.  I added a bunch of unsorted apocyclops copepods and about 400mL of phytoplankton to the 3.5G tank its in, and found that either because of warping of the part, the shape of the front wall of the tank, or something else, there were small (<1.5mm) gaps in a couple parts around the kriesel... and some got into the main tank.  I tried to plug them with some fine mesh and it may be somewhat effective, we'll see.

 

Already, from the way they are drifting around and the movement they are showing, I have much higher hopes for this batch.  I can see that in the lesser flow and without impacting the sides, there's more leg movement and small swimming motion - mostly backwards and sometimes in corkscrews.  There are a few collecting on the mesh in the back, but it's probably not the majority - I don't know if they are resting, stuck, or otherwise injured/dead, but there are enough that seem to be in good shape that I am expecting better than 48 hours this time!

[DaJMasta]

A lot has happened with this since the last post, but I'm happy that tonight I have zoeae here that are more than 48 hours old!

 

 

 

So to start from the last post:
The zoeae only lasted about 30 hours or so, the same as in the breeder box the first time, but in the first 12 hours or so, a few major issues came up which needed a revision of the kreisel.  First, the 250um mesh on the side clogged with debris quickly, enough so that the top was overflowing by 12 hours.  Second, the kreisel didn't seal well against the glass, there were little gaps from the shape of the glass or warping of the print, which when coupled with the higher water pressure internally because of the clogged mesh, forced some larvae into the gap between the kreisel and the glass, usually trapping them there.  The placement of the tabs for the magnets also meant it was a tad bit to big to fit properly on the front when the size of the magnets were included.

 

After the second batch of larvae had died (second day), I set to work redesigning the kreisel to fix these problems.  I moved to having the whole back side be open with mesh and I built in a channel to the print for a piece of silicone airline tubing to use as a sealing gasket.  I also extended the top a bit so It could sit lower in the tank and redesigned the air driven pump to fit in the new space (and to reduce the splatter and microbubbles added to the kreisel).  I started printing it, realizing another spawn was imminent, and when I assembled the new design the evening of the 25th, I realized the outer retainer for the mesh was too big to fit properly.  While I did redesign it and start printing, the print time was about three hours... and I had about an hour until the second shrimp started releasing larvae.  When I saw them coming out, I swapped over to the old part and just super glued the part on, and so far, so good.

 

I had some trouble catching this third batch of larvae, there were somewhat fewer of them released over a longer time, but I eventually found out how strongly phototaxic these are.  I had the Vossen larval trap setup and the pumps off, and the fish weren't acting too hungry, but when I looked, there were maybe a dozen in the trap and dozens over on the side of the tank, near the surface.  I realized they were being attracted to the light on my desk (mostly obstructed from POV of the tank), so I shut it and a few other dim/distant lights off.  Then I found a bunch near the bottom on the same side, this time attracted to the moonlight of a neighboring tank, so I put a piece of black foam in between, shined my flashlight in the tank from the base of the trap, and eventually caught 100-150 of them.

 

I transferred them over and into the new kreisel, then added 300mL live phyto to the tank and then a good dose of apocyclops (unsorted size) and a little bit of TDO A - throw everything I've got at them in case they can eat it.  I saw a few clustering on the mesh and in the top left portion of the kreisel, and I eventually realized probably the most important thing to getting better success this time: I needed to block out the stray light.  Basically, the larvae navigate by light almost solely in these early stages, and having other sources around when the lights are mostly dark just seems to confuse them.  I took some neoprene I had spare and wrapped it around the front of the tank, and now that they only had the always-on moonlight above them, they dispersed in the water column like one would expect, and I saw no more clumps of them and no more corkscrew swimming behavior.

 

The setup

 

This seems to be so critical that my next iteration of the kreisel will be printed in black plastic instead of clear.  It doesn't matter as much during the day, as the brighter overhead lights seem to be strong enough relative to other sources that they can stay oriented, but it really seems critical with the main tank lights off.  If you shine a flashlight into the kreisel, they will be attracted towards it, regardless of orientation, and when you shut it off they will go off and reset themselves.

Over the two days they've been going the numbers have definitely decreased, but this time at the 48 hour mark I've got dozens of zoeae exhibiting what appears to be much more natural drifting behavior, and with more identifiable and coordinated movement (though they are still far from good swimmers).  I hope that they can keep going and in a few days I'll be able to see a new larval stage.

[DaJMasta]

Took a look this evening and I still have at least a couple dozen, and I see a new larval stage!  Whereas the eyes were close to the carapace before, now they are distinctly stalked out to the side - the eyes are maybe 1/4 of their body length apart in total.  It's.... extremely difficult to discern with the video i've been able to get... but here's one of the more in focus stills from it:

Edit:
Looking at images of early stages in this paper: https://www.semanticscholar.org/paper/Feeding-early-larval-stages-of-fire-shrimp-Lysmata-Simoes-Ribeiro/f5ad0e2a89fea23d3980ff1d9ddeab1b223fe969 I can say that I definitely have seen the Z1 and Z2 stages, and that all of them appear to be at Z2 (or later?) development right now, 72 hours in.  It looks like Z3, 4, ad 5 are probably going to look similar without magnification (mostly tail development), but they may show some visible red color by eye by then.

Edited December 29, 2021 by DaJMasta

[JohnTheReefer]

Great work! These are seriously cool to be breeding and raising

[DaJMasta]

Thanks, they're certainly a fascinating one to try to get going!

I found out I was using my 16mm lens and not my 25mm lens for the last video stuff, so I swapped (and ordered a 50mm lens for later on...), so I got some clearer video and a bit of behavior from this morning:

 

[dipg]

This is pretty awesome. Great work!! 

[DaJMasta]

Thanks!  5 days in and I don't think there is much in terms of daily losses - the numbers seem about the same each day.  I moved the light a little more squarely over the tank and they seem to be on the mesh wall less, and I snapped a few pictures today after feeding (a more impressive copepod density than I had realized) and got a few good extra pictures:

 

The sharpest image in the middle actually shows a less developed zoea, as it has almost no red coloration showing, but most of the others show red in the claws and many show it on the top of their tail too.  They seem to generally be strong enough to swim against the current for 30s or so bursts now, and while I don't think they can actually grab much, they use those forward 'claws' to sort of shovel food particles into their mouths, while the 4 legs behind operate as pairs of feathery oars and are for swimming.  I see them swimming forward, backwards, sideways, sort of wherever now, and the clearest pictures I managed, by far, were when they were swimming against the current so they stayed still better.

[DaJMasta]

Today the little shrimplets are one week old!  They've come a good ways visually since the last update, probably to the Z4 stage, but maybe beyond which is the start of new sets of legs.  I think I have a few less than a few days ago, but it's tough to tell, as now that they have more control over their motion and more ability to resist the current, they seem to prefer to congregate where my camera isn't at least some of the time.  Still feeding apocyclops primarily (and you can see them go in the video/pictures I've been getting, pretty high prey density but only one feeding a day), but also trying TDO A and B1 - not sure if they can actually eat B1 yet, and while I can see feeding behavior already, I haven't seen actual eating happening.

In any case, they're still going and progressing through their life cycle stages, and the kreisel design seems to be keeping up.  I made some tweaks to things and printed another one in black, and I think I'm a few days out from another spawn, so I may have two batches going at once come next week.

Here are some images from 6dph:

 

If you look at the tail, you can see some in the Z3 stage (split tail with 4 distinct sections) where the center right one seems to be Z2 (no splitting of the tail yet).

 

Then 7dph:

 

Here all of them have the split tails, but some of those outer tail segments are longer than the original ones, which seems to be characteristic of the Z4 stage.  According to the paper I've been basing most of my shrimp larva morphology on, Z5 will likely be hard to see where the new leg buds come in, but by Z6 they should visually have close to twice as many legs as I see now.

[DaJMasta]

Can no longer add it to the last post, but here's the first week in video so you can see behavior:

 

[DaJMasta]

Yesterday, during the day, I seem to have lost several of them, and now have three remaining of this spawn.  Not sure what happened, but I get the impression that the flow in the kreisel is too low, so I basically maxed out what the pump will do.  Especially with higher flow, this air driven pump puts in a lot of microbubbles into the tank, which even if it's not a problem for the larvae, isn't great for viewing.  Keeping up the same feeding regimen, printing a replacement in black, and I just designed a clip on spray bar to power it with an aquarium pump instead.  I don't see an obvious change in their physical shape, but they do seem to have a bit more red in their carapace.

 

Meanwhile, I started my first kreisel printed in black with some strange twig-looking larvae I caught last night which moved sort of like shrimp, but didn't visibly have legs and swam vertically in the water column (and pretty well for larvae), and tonight I added some more to it along with a new batch of skunk cleaners - this time 200-300 larvae and as many as 100 of those stick like guys - so the new color and higher base flow rate will get its trial in short order.  The parents seem to spawn every 3-4 weeks, each!

 

 

The yellow dots are the hour old larvae, the faint vertical lines with some dots along them are those stick critters.  But shortly after this image, I remembered I had a microscope and some larvae to spare, so I caught some of both and had a look:

Those little stick guys are also shrimp, but they're the mysid shrimp I found growing in my tank a couple months ago, just in a juvenile stage.  From their behavior, they're still pre-settling, and their eyes aren't stalked out and their body doesn't seem to be fully formed, but they may be farther along in their development since they have a cluster of legs (blurred in the image, but clear in motion) that they can stand on and are still pretty strong continuous swimmers, whereas the skunk cleaner larvae have four main legs for paddling around and have very little sense of direction or real capability of movement when they're so young.

[DaJMasta]

A surprising amount has happened since then - the day after the last post, I didn't see any live in the kreisel, but it also seemed that the air driven circulation pump had failed - some small air leak from between print layers, I think, that meant it lost the power to raise the water up.

 

I went to clean it up and in stirring up the debris, I thought I saw one, so I got it with a turkey baster and put it under the microscope.... and his legs were still going!

 

That's a 10 day post hatch zoea, at stage Z5 (hard to see the legs, but there are more than one pair of main legs in the video of this).  I transferred him to the newer started kreisel.

 

In the two days since, the numbers are decreasing in there, though there are still more than 50, but I also saw one of the seemingly quicker growing mysid larvae stuck to one of the skunk cleaners.  Since they are known for being cannibalistic and are better swimmers/are more well developed, I had feared that they may predate on the other larvae.... so I spent 10 mins with a pipette sucking out all the ones I could find into the main part of the tank.

 

Then I set up for catching another batch this evening, and while ultimately I was a day early and the shrimp didn't release any larvae, I setup the trap when I saw a burst of larvae, and I did catch.... something else.  In the trap they looked like a little ball at the end of a hair, and under the microscope, they look like a shrimp under sort of a helmet or shell, but with a huge unicorn protrusion sticking out the front.

 

I had seen some similar protrusions in other invert larvae (sea urchin larvae tend to be spiky, but not urchin spiky), so I started looking around, and I was quick to find a match:

https://baynature.org/article/miniature-marvels/13-367-110418_47594/

 

My half a dozen or so porcelain crabs seem to be quite happy!

[YHSublime]

Oh wow! That's cool as! Rooting for getting them all the way, then happy to purchase a few if you get that far! 

[Origami]

Very, very, very cool! Keep us updated. 

[DaJMasta]

Thanks!  Shortly after that post I had the biggest spawn I've seen yet - hundreds of them, maybe close to a thousand, enough that it's amazing they fit under that shrimp!

 

I transferred them into the kreisels now both using the water pump driven spray bars and clamps to reduce flow... and immediately both looked too high a flow for the application.  One sort of swirled on its own, one had a small area in the center with very little movement but a swift current around the perimeter.  I had decided to try and be more disciplined about feeding schedule - not feeding any more, but making sure it was at least twice a day.  My initial thought had been that since the copepods can survive in the kreisel just fine, infrequent large feedings should stick around for long enough to feed them, but I think the copepod nauplii small enough for them to eat can also get through the netting on the side, so I wanted to keep a steadier supply of food.  The base daily schedule was phytoplankton and zooplankton in the morning, again both at night, and then a bit of TDO A right before bed.

 

I had a good number through day 3, but day 4 into 5, I lost a lot of them, and then there were none again.  I observed some drifting through the water without swimming, but still alive (and sometimes reacting), but this was different from previous runs, so I think this is another indicator that the flow was too high - and it seems to be challenging to really dial in.  I should be able to better control it with setups moving forwards, but so far the higher end of flow from the air driven pumps seemed to work best, but I think without bubbles and debris collected in the bottom should improve survival rate.  I will also try and do mid-day feedings to space them out a bit more and try to keep a more constant food density in the tank, but I'm also working on splitting the cultures to get a bit more food available.  I'd also like to get another species or two culturing (I've got mostly apocyclops, but have smaller, more difficult to harvest tisbe cultures I'm trying to increase the density on), but that's a longer term goal at the moment.

 

Another contributor could have been amphipods - a couple did eventually get into one of the kreisels, and while this coincided with the big population drop in both, it is realistic to think something as bit as an amphipod wouldn't have any problem catching and eating the larvae.

I managed to catch some more of the porcelain crab larvae (with just a flashlight and a turkey baster!) and put them in the lower flow of the two kreisels, and while the spawns are much smaller (maybe as many as two dozen), the larvae are much better swimmers.  As a result, of the maybe dozen I collected, I've still got at least one porcelain crab larva that is at least 5 days old in the higher flow.


I've taken a fancy to this work and knew my two 3.5G tanks didn't offer a lot of stability or grow out space, so I started planning an upgrade, and in the last week I've gotten the parts together and did the assembly, so the new setup has had water for two days now.

 

The top space will be grow out and 'display' for some critters I want to keep but which wouldn't be a great choice for the main tank, the middle rack will be bare bottom and have space for three kreisels, and the bottom level sump will be for filtration, a bit of deep sand bed, and lots of macroalgae.  All three levels are a standard 10 gallon, backs painted black, the bottom with some diagonal baffles, and the top two with a drain drilled in the back wall.  I'm not sure it will be fully ready to go for the next shrimp spawn, but hopefully at leas the one after that.  The plan is to use one pump to drive multiple kreisels, each with their own flow control clamp, and the larger system should offer better stability and somewhat simpler broadcast feeding and the like.  It will take a couple weeks to move everything in and make sure it's operating alright, but having established tanks I can just consolidate into it should give the process a jump-start.  Fits in almost the same footprint as the two small tanks and the plankton production, too!

[Origami]

Thanks for the update. Keep posting!

[YHSublime]

This is very cool. We had a member do something similar to this many years ago, but I believe it ran off her display tank sump and then gravity fed down from the top. It's been a long time since I've seen a hobbyist with the time and tenacity to tackle these fun types of things, so please keep us updated!