New owner, molting issues?

[nonik]

Hi all,

New shrimp owner here! After a recent trip to Hawaii where I did NOT get the chance to see these guys in the wild, I decided to take the plunge after lurking here on and off for a year or so. I recently got 15 shrimp and 10 snails from Mustafa and couldn't be happier with my little guys! I love these creatures! Snails are great, too.

However, I'm starting to have a few concerns so I thought I'd tap into the communal wisdom here. I've already had one shrimp pass away and another is probably on his way out. To elaborate--I got the shrimp about 1.5 weeks ago after following Mustafa's instructions. Before the shrimp were ordered, I had set up my tank and gotten a macroalgae from Mustafa, then after ~2.5 weeks had tested the tank's water with a saltwater test kit, tested the gravity, and also waited for noticeable algae growth on the walls of the tank--everything checked out. When I got the shrimp, I fed them a little BB sized fish pellet. After I few hours I tried taking it out as it wasn't finished, but it sort of disintegrated so I tried to just jam the rest into the substrate with a chopstick, fearing I was going to overfeed them. Given the amount of algea on the tank now, I won't be feeding again soon. Anyway, about a week after introducing the shrimp to their new home I started noticing that a few of the shrimp had molted as I had found a few floating exoskeletons. I figured was normal given the shipping and water change.

However, a couple nights ago, I saw one of the shrimp laying on the top of the substrate and apparently in the middle of a molt! He'd lay dormant a few seconds and then sort of shake and curl himself in a violent fit before settling down again. For the next hour or so, I checked on him to observe his molting process before I eventually went to bed because it was taking too long.

I woke up the next morning and found that now I had two shrimp apparently going through "molting fits". I wasn't sure if the molting process was supposed to last this long, considering at least 2-3 other shrimp had molted without me noticing. But, I also thought I saw a few more molts floating around, so one possibility I thought was that these were new shrimp molting and the ones I saw earlier had finished and I was seeing those molts now. Unfortunately, later that evening, I saw that one of the shrimp had passed away, belly up on the substrate. There was another shrimp that looked like he had molted since I didn't see any obvious loose molt on his body. But, he was really struggling to move around and didn't seem like he had full dexterity of his limbs as he was completely unable to swim. He's been like that for over a day now so I'm not sure how he is going to fare. He's still alive but is just occasionally twitching now as he can't really move outside of flailing his limbs. So hard to see.

At this point, I am not sure if I should take a wait-and-see approach or if there's something I should do? Is it normal for a few shrimp to have issues molting? I've owned mantids before and molting is always a risk for them as well as it doesn't go well occasionally. I'm planning to get some water conditioner (prime) because I'm starting to get paranoid about possible contaminants now. It's my new life goal to get a berried female so I am very invested in this.

Here's a quick summary of my setup:
- 2.9g glass tank (rinsed with fresh water before use, then wiped down and completely driedwith clean towel...but not distilled water now that I think of it)
- CaribSea Arag-Alive Hawaiian Black Sand
- Lava rocks (boiled in distilled water for 10-15 min to sterilize and clean)
- Instant Ocean Sea Salt (water is at 1.010 gravity)
- Glass lid (not airtight)
- LED light

I also attached a picture of my tank. Dead shrimp visible on left, struggling shrimp is the one on the right. Most of the others are hanging out in the rock crevice (but not all the time).

Thanks for your help! Crossing my fingers that these 2 guys are the last...

[Varanus]

Have you tested the water for ammonia, nitrate and such? What's the PH of the water? I would think having aragonite sand would provide plenty of calcium (a lack of which could effect molting).

You mentioned the sand is "arag alive" so I assume it is "live sand" that you used. This could be a source of the problem, as live sand can have any number of contaminants caused by creatures in the watery sand that have died after the sand is packaged. But then I would think most such contamination would show up on a test kit as a ammonia spike.

[nonik]

Yes, I tested the water a few times, including today, and everything checks out. Gravity around 1.010, pH is around 8.0, and ammonia, nitrate, and nitrite are all 0 (as far as I can tell, attached picture of results).

I was debating whether to initially use the live sand/arag alive but I had found another user here who had also used the same kind I got and had no apparent issues. I also measured the ammonia around a week after staring the tank, and saw no real spike then either (as well nitrate, nitrite).

Is there any behavior I could observe in the remaining shrimp that could possibly indicate something is wrong? They've been more passive than the first few days in the tank--but there's not really a lack of food given the amount of algae visible so that would seem normal.

Thanks!

[Varanus]

Others may be able to help more, I myself have never had an issue with my shrimp molting so its hard to advise. Perhaps it is simply a problem with those two shrimp, stress from shipping or something else. Mustafa does great but he can't control everything that could potentially happen during shipping, so its not unheard of for a couple shrimp to pass away shortly after their arrival (none of mine died, but other users have had it happen and their tanks have continued healthily and successfully otherwise).

And yeah, settling down and moving around less is a normal thing as the shrimp become acclimated.

[nonik]

OK, thanks for your help.

Continuing to monitor the health of the shrimp (and snails), and possibly will do a water swap if any more shrimps' health takes a turn for the worse. At this point, considering the other factors, can't rule out the possibility of a contaminant if things continue to go south based on reading around the forum.

[KenCotigirl]

First I would like to say you have good looking tank. Second it appears from your post you followed Mustafa's directions. I tend to agree with Varanus that it could be bad luck. Stressed shrimp could last a few days to a week before sub coming to stress and die. Making changes to your tank now can stress out the rest of the shrimp. It is hard to do but sit back and just observe.

KenP

[Mustafa]

When I got the shrimp, I fed them a little BB sized fish pellet. After I few hours I tried taking it out as it wasn't finished, but it sort of disintegrated so I tried to just jam the rest into the substrate with a chopstick, fearing I was going to overfeed them.

This may be the likely culprit here. Since the shrimp were already living in the tank for a week I highly doubt shipping conditions had anything to do with it. Shipping is almost never the issue. I would change 50-80% percent of the water and then leave the tank alone. Don't even bother with testing anything.

[nonik]

Thanks for response! Did a water swap this morning. Took no chances with any contamination...everything that the water touched was washed, dried, and then rinsed twice with distilled water. Regardless of the necessity of the swap, at least I know that any sort of contamination in the tank is at least at half the concentration now.

Do you have any thoughts on the actual cause of death in relation to the feeding? Was it a temporary ammonia spike from the leftover food? I tested the water after a few of the shrimp became symptomatic and read nothing usual. Maybe the spike had come and gone but the damage had been done to the weaker/less fortunate shrimp? Can an ammonia spike and decline happen in that short of a time span? Or was it that the shrimp ate too much for their own good?

Regardless, these guys are not getting fed for a while, especially seeing now that several other owners have gone several months to several years without feeding. Thanks again for advice!

[Mustafa]

You're welcome! This *should* solve the problem. As for causes of death....good question. You can't really measure anything unusual when you test after feeding too much. No ammonia spike or anything. But shrimp die. Way back when in the beginning when I was overfeeding I'd notice a shrimp or two dying or a dead body getting eaten by other shrimp. I measured everything and couldn't detect anything (that's why I usually say "no need to test for anything" because it usually doesn't help).

My best guess is that the nutrients introduced via the food cause some kind of invisible (and sometimes visible) bacterial bloom which then sets off a chain of events (like oxygen depletion or a continuous release of tiny amounts of ammonia (non-measurable) or a combination of both maybe) that leads to the death of of some shrimp. When you stop feeding the deaths stop. That's really all we need to know...overfeeding = death. Stop feeding = deaths stop. Of course it's intellectually interesting to know what mechanism causes such deaths, but unfortunately to really resolve that we'd need lab quality measuring equipment and a bunch of test tanks with shrimp that are exposed to deadly conditions.

[nonik]

Just here to give a quick update from last year--my tank now has several weeks-old larvae. It's been very interesting watching the little guys slowly develop over the past month or so, to the point where they are now starting to transition from the larval "bobbing around" to actually being able to swim with their developing bodies!

I'd actually had a few instances of berried females dropping their eggs in the past several months leading up to the larvae I have now. I had grown concerned that maybe I still had a low level of some contaminant or other similar issue that was somehow interfering with the eggs' development. But I looked around I found some helpful threads here that reassured me that dropped eggs are not an unusual occurrence. As such, I was able to stick to the "let it be" adage since the rest of the shrimp seemed happy and healthy, and finally last month I had a mom successfully release her eggs!

Just want to share my experiences to help reiterate to others to not fuss over smaller stuff if your shrimp seem to be doing well.

[i<3Opae]

Cool! Thanks for the update!

[Mustafa]

Thanks a lot for the update! Keep 'em coming!

[Malikta]

It is your substrate, I'm 100% sure. I've had my shrimp for over a year that I pulled out of an ecosphere. 6 months ago I bought some from Mustafa to add to what I have (perfect shrimp btw). Everything was going great until I went fancy, got a bigger tank and thought the lava substrate would make them feel at home.

When you describe the convulsions - they were actually dying but it takes awhile. I've seen one of mine stuck in a molt and it didn't take more than 5 minutes to free out and move on (completely different situation). More than half my shrimp died within days, it was terrible. So I went back to the basics and got a small beta tank setup and I'm slowly grabbing my remaining shrimp (the ones that survived despite me) and snails away from the black substrate. (I had used Fluval lava soil when I poisioned my shrimp - previously I just used sand and basic aquarium substrate which is what I returned to).

I do think the feeding may have been a factor but I feel strongly that the lava soil/substrate is the bigger factor.

Never doing that again, I cried for a week. Many of mine were saddled that passed

[skylorvivo88]

Great post with a lot of useful information. Hope everything goes good for you