View Full Version : Ostracos (seed shrimp) and shrimplets?

10-24-2017, 07:42 AM
I have a 10L species only tank with about 10-12 cherries. Many of the little shrimpy ladies molted and sent out the call, resulting in at minimum two dozen shrimplets. A month later, I can find perhaps three.

Is it possible for seed shrimp to starve out shrimplets? My husband had been told by a salesperson to 'feed several pieces of food, 3-4 a day'. He always buys Azoo brand (whatever the one for Crystal Red shrimp is called), and it comes in those 'big' flat pieces... you can see where that's going. Long story short, he dropped way too much food in right on top of the substrate. When I realized what was going on (a shrimp died), I vacuumed what was left out of the substrate (plants prevent full vacuuming) and did several water changes in quick succession.

So, the water quality is fine. No adult shrimp deaths since then (husband is forbidden from feeding shrimps). I haven't fed the shrimps for two or three weeks short of dumping some leaves in the tank (boiled 5 mins before adding). The micro invertebrate population has exploded; in the attached picture you can see the seed shrimps all over the algae on the sides of the tank, and detritus worms are being flung around by the water flow all day long (I don't know if that's important, but it strokes my schadenfreude to see them struggle).

I'm arranging to borrow a few guppy fry and do a thorough vacuuming, but I have no idea what's going on, as water parameters are fine, adults are molting normally, and shrimplet corpses are much harder to find than adult shrimp corpses.


10-24-2017, 09:03 AM
I don't think that they can, at least not in my experience. My painted fire reds have a gazillion (not really but I feel like it sometimes) seed shrimp in the tank and I remove at least 40 shrimplets of 1/2" size weekly to a grow up tank where I can decide grade and where their permanent home will be. There's only 9 breeding age females in the tank making babies and two quality males so I don't think the seed shrimp have an effect.

How long has the tank been established? It may be too new for the little ones to find enough to eat? You may also try a different shrimp food, Bacter AE is spendy but has a great reputation, I use CSF foods and have seen a significant difference from the Fluval stuff I'd fed before.

Temps can also play a part, higher temps speed up growth a bit but I have found my best shrimplet survival around 74. It can also take a few weeks for them to get going again after a big change. I also fish up anywhere from 4-12 teeny shrimplets I can't even see just by running the net through the wc bucket before dumping it every week, and that's in addition to the ones I can see and pick out. Little tiny translucent swimmers I'd never spot in the slightly tinted water on my own. You may have vacuumed up a bunch in the frenzy.

Might try giving them a couple weeks, make sure your filter intake is covered so you're not sucking them up. Try not to vacuum the substrate, I stir up the low spots that collect muck with a bamboo meat skewer and suck it up the syphon about mid tank (misses some gets a lot). Also may need to narrow down the feedings a bit too, I feed every other day and not as much as is listed on the directions. It took me a while to narrow down the right feeding and they are picking scraps around an hour after I drop the food with no remaining food by two hours.

Also might be worth checking to be sure you're not getting any pH swings in between water changes.

I'm definitely not a shrimp guru, but thought I'd share what I've learned in the past few months. Someone else will probably come along with some other better ideas for you as well. :)

10-24-2017, 05:32 PM
Just a thought, I'm no shrimp guru either, but you mentioned a microorganism explosion. Have you seen any hydra?

Your tank looks nice, I like it a lot. What is that algae on the glass? I'm not always convinced it's diatoms if I see it in my tanks. Is there an odor to the algae?

10-26-2017, 05:29 PM
When I first posted, nitrates (everything else was zero) registered 12 mg/L, so I did a 20% + 20% change (this brings it down to a 0 in testing), and popped in a bunch of small pothos cuttings sitting nearby in a vase. Found two little corpses and water again tested 12 mg/L, so I did another 20%+20%. No evidence of disease, trauma, or molting problems on either shrimp. It's fine if they can't tolerate much nitrates, but where is it coming from? (the baby dwarf tears never really took and might be slowly wasting away :T)

How long has the tank been established?
Tank finished cycling at least two weeks before adding the cherries.

It may be too new for the little ones to find enough to eat? You may also try a different shrimp food
The feed I've always used is Azoo Max Breed. It's specifically formulated for the making of many shrimpy babies. Also, it's what my husband always buys even if I tell him to buy something else. (ten times the price of Hikari crab & lobster)

You may have vacuumed up a bunch in the frenzy.
My vacuum has a strainer that pretty much only lets detritus particles through. I checked the bucket anyway ofc.

make sure your filter intake is covered
Prefilter sponge; its a small HOB but has about a 60L/h max flow.

Also may need to narrow down the feedings a bit too
I actually haven't fed them in a month, other than adding some leaf litter because reasons.

pH swings
I didn't even think of this.

Have you seen any hydra?
Thank goodness, no. Just a minor scutariella outbreak that was quickly resolved.

What is that algae on the glass? I'm not always convinced it's diatoms if I see it in my tanks. Is there an odor to the algae?
Pretty sure it's just diatoms? Shrimps will pick at it but don't seem to eat it. I tried fighting the initial post-cycling outbreak but just gave up. I don't notice any odor other than the usual WOW AQUARIUM smell. I tend to leave the light on for overly long periods (6am-10pm) out of negligence.

Would adding more plants help deal with the nitrates? Too many tree leaves in the tank? I'm considering duckweed because not being able to vacuum everything is irritating.

10-26-2017, 06:03 PM
In tanks that small, it is very difficult to have stable water parameters. Not impossible, mind you, but difficult. There simply isn't enough volume to help buffer against variables that wouldn't be noticeable in a larger tank.

Yes, adding more plants will help with the nitrates. I can't tell for sure, but it looks like you are using an active substrate, like Amazonia or something similar. Those substrates are notorious for leaching out ammonia for several months. This could explain why you are battling nitrates despite not feeding the tank anymore. I also had a breeder tell me that the leaching ammonia could kill off shrimplets as they are sitting right on the substrate as the ammonia is wafting off. Your filter may be cycled and converting all that ammonia to nitrates, but it won't help the little shrimpies that are sitting in the ammonia before it can get sucked up by your filter and processed.

I'd suggest getting a tiny pump to create some more flow across the substrate, but I can't think of anything that would be gentle enough for a tank that size. You may just have to wait for the substrate to sort itself out and stop giving off ammonia, if that is indeed the case.

I say this all from recent experience with a caridina tank. My shrimp were berried for about a month and a half and I was never seeing a single shrimplet despite everything coming back normal. That's when I went to some breeders and they told me about the issue with the active substrate. Sure enough, after a couple of months the substrate stopped leaching ammonia and bam, I started seeing babies everywhere.

10-28-2017, 02:25 AM
Yes, the substrate is apparently active. The packaging is in Japanese, but I can read enough to make that out (there's also a nice diagram of substrate layering witchcraft on the back). Out of curiosity, is it possible for ammonia leeching to kill adults?

I removed the leaves last night during another partial water change, and nitrites test as 0>12ppm, ph is stable and ammonia/nitrites are 0. Also, I tied my anubias to my ornaments with cotton string, which has fallen apart after two weeks and now the anubias are floating around. That'll teach me to be lazy and not look for the right tool...

Is duckweed easy to grow? The baby dwarf tears are all slowly perishing anyway...

10-28-2017, 02:56 AM
My bad, NITRITES are 0ppm, NITRATES are testing again at ~12ppm (about 12 hours after a water change to reduce them to 0ppm). Gonna see about buying sand substrate after all (which is what I originally wanted because 1. inert 2. bag was $2).

10-31-2017, 06:17 AM
I'm blind. It seems to have been a molting issue. All the shrimps got a salt bath to deal with a parasite infection, and molts were repeatedly removed as follow-up. I guess the shrimp food didn't have enough supplement minerals, and thus the deaths.

Regular spinach is hard to find in my area, so I added a few leaves of gai lan, parboiled. Most of the shrimps seem to be molting properly now.

10-31-2017, 06:50 PM
Glad to hear things are going better.

I use this for my shrimp that need a specific gH for shell health. It's very clean (doesn't raise TDS levels by much) and doesn't affect your carbonate hardness (kH).


11-03-2017, 12:45 AM
Glad to hear things are going better.

I use this for my shrimp that need a specific gH for shell health. It's very clean (doesn't raise TDS levels by much) and doesn't affect your carbonate hardness (kH).


Thanks for the recommendation, another thing to add to the shrimp wish list :)

I actually need to buy a feeding dish. I've been dropping the food tabs on a decoration, but as the shrimp struggle over them, it gets dragged into the substrate. I feel like I got lucky and the tank didn't re-cycle/mini cycle when I switched over gravel.


11-03-2017, 01:26 PM
Dead berried female this evening. Not sure what's going on. Might have to look into pet aquatic rocks at this rate.

11-03-2017, 01:43 PM
What kind of test kit are you using to check water params?

Why the salt treatment?... I have never heard of using salt with shrimp.

No need to remove molts, it's actually better to leave them in there, additional source of calcium.

11-03-2017, 03:27 PM
What kind of test kit are you using to check water params?

Why the salt treatment?... I have never heard of using salt with shrimp.

No need to remove molts, it's actually better to leave them in there, additional source of calcium.

Scutariella japonica (https://www.reef2rainforest.com/2015/05/12/parasites-in-freshwater-shrimp/)

She's not kidding about infection rates in Taiwan populations. Everything I buy has them.

Dip shrimps in salt solution bath, adult parasites fall off. Parasite eggs end up in molts, so discard a round or two of molts immediately following to eliminate problem.

Ashamed to say I only have NO2/NO3 liquid tests (didn't buy others at the time because reasons). They are Tetra brand, and are less incrementally accurate than API test kits. Are there tests you guys recommend that aren't included in the API master kit? I'm just going to order it this week.

NO2 has consistently tested 0ppm, and NO3 at 12ppm (was panicking about it not being >0 ppm also, but meh).

Adding a parboiled gai lan leaf (common spinach and kale are not readily available to me) eliminates finding loads of shrimpy corpses with that awful white molting ring. Most have molted normally, but I am still finding a dead one every few days. I've head excess protein in the diet can also cause molting issues (i.e. growing too fast)? I'll take some water to get tested at LFS/LPS while I wait for the master test kit.

11-03-2017, 04:09 PM


11-03-2017, 04:18 PM
Sorry to hear about the loss of your mamma shrimp. Your link was quite interesting, thank you for sharing it.

Are you able to find IAL (Indian Almond Leaf) readily, where you live? My shrimp seem to like those quite well. I've read about a number of advantageous properties that IAL are reputed to give. I'm wondering if laying that upon your substrate would provide protection from the slight leaching that your substrate might be undergoing. IAL provide a good home to grow desirable infusoria as well. Shrimplets can eat those.

(I'm not any sort of shrimp expert in the least, by the way.) I do enjoy them, though!

11-03-2017, 04:35 PM
I'm familiar with ellobiopsis as I've seen a lot of members in FB shrimp groups posting about the parasite, but this is the first I've seen of the scutariella.

Failed molts are almost always attributed to a lack of calcium and other minerals in the water. When having molting issues, it is important to get a kH/gH test kit, like the one sold by API. For neos, you want to aim for 2-5 degrees of carbonate hardness (kH), and 6-8 degrees of general hardness (gH).

Some people prefer to put things like cuttlebone in the tank for a calcium source. Others who like to be more precise prefer to use remineralizer products like the one I linked above as it is very easy to hit specific targets and keep the water parameters exactly where you want them.

11-04-2017, 05:14 AM
IAL, probably. There are loads of avenue trees here, but I steal oak, maple, mulberry, magnolia etc. from the nearby college campus. Our first cold snap just happened so I need to go soon! (64 F really isn't that cold; hilarious to see locals triple layering with bubble jackets, scarves, snow clothing, etc, but still wearing flip flops)

Remineralizer seems like it would produce more consistent, more immediate results across the population vs cuttlebone or crushed coral.

I tried saving the female's eggs after posting last night. They were already pretty developed (eyes, spots of red coloration showing), and two hatched overnight. A few are goners, we are hopeful for a few more.


I can't figure out how to remove the wrong side up photo.

11-21-2017, 07:45 AM
Kind of a thread necro, but I wanted to thank everyone who responded and gave suggestion. Nitrate buildup and calcium deficiency were (as suggested!) the primary murder culprits.

I bought some (giant) duckweed online, that keeps the nitrates at close to zero, and added a piece of cuttlefish bone.

Unfortunately some pond/ramshorn snails snuck in with the duckweed (wasn't sure if the plants would survive a bleach dip), but I smash all the baby snails I can find with planting forceps. Plus side is the shrimplets love the fresh snacks.

Thank you, thank you, thank you, to everyone on this forum! I solemnly swear to stop killing the shrimps.

11-21-2017, 03:25 PM
Good news that you've determined the troubles and begun measures to counter them!