My adventures with Sargassum Shrimp and Penaeus aztecus shrimp

[Betta132]

Penaeus aztecus are brown shrimp, AKA Gulf shrimp. They're that big shrimp you see for sale in markets, usually as jumbo shrimp.
I've got a few now... I was in Galveston over the weekend, and I took a boat tour with a marine biologist. He put a small net out the back of the boat to catch critters, which was neat. We caught silversides, scats, two cute little fat squid babies, a handful of mean crabs, some comb jellyfish, an ADORABLE little baby sea robin, a few other small fish, and a bunch of shrimp. I took three shrimp with me in a bottle full of seawater, and I put them in a bait bucket with an air pump. Unfortunately, the air pump's batteries ran out way sooner than expected, in the middle of the night. I lost two of the shrimp, but one looked okay.
When I went back to the bait shop for more batteries, I got five more shrimp, which all did fine due to my keeping a close eye on the airstone's batteries.

I also picked up 8 or so (forgot exactly how many) sargassum shrimp. I would have liked a few more, but I couldn't find more due to going to the beach when the tide was going out. Fresh, critter-filled sargassum is best found when the tide is going in.

We just got back yesterday, and I mixed up some saltwater so they could have nice clean water. All of the shrimp are now in a 6g tank, which I'm hoping will be enough for something with such a small bio-load. I need my spare 10g to mix saltwater in.
I haven't fed them yet, not with processed food... Wasn't sure how much to feed them, or what. I put a dirty filter sponge in there for them to eat, and all of them have dirty-sponge-colored spots in their stomach areas.
They aren't incredibly active, but they're moving around and picking at stuff with their little claws. The Gulfies are a bit more active, swimming around, and the sargassums are mostly just sitting. I gave them a fake plant, and the sargassums are mostly hiding in it. I suspect the not-moving is normal for them... They spend all their time in floating seaweed, so I doubt they do too much moving.
The smallest Gulfie has a problem, though... His tail is turning the color that shrimp turn when dead, and he doesn't react to touches there. He also isn't as active as the others, and he doesn't protest if I catch him. I think his tail is dying... Possibly the rest of him is gonna follow. Any clue what happened? He's one of the ones I got at the bait shop, so he could have been injured.

I'm gonna keep updating this thread as I go on, just in case anyone's interested in them.

I'll post some pictures in a few minutes.

 

[Betta132]

This is the smallest sargassum shrimp, a cute red one with some white on him. He's in the hatchery because he's small and I want to keep track of him.


This pic is the biggest orange one, and I think it's a female. It's fat, for one thing. She's missing a claw, probably just because of shrimp fights.


Here she is again, from the side. I looked, and I think the speckling is just speckling and a fat tummy... She doesn't seem to have eggs.


Next we have the sick one, and as you can see it didn't protest being held. It just sat there... When I let it go, it swam down and landed on its side, then it sort of tipped over and got upright.


Last is a larger, healthier one. I'm not sure why its antennae are both cut off neatly like that, but it doesn't seem upset or bothered. It just crawls around on the bottom, sometimes swims around.

 

[Calappidae]

Wow keep us updated with these!

 

[Betta132]

I am an idiot.
I figured that the filter sponge was enough to take the bio-load from the shrimp.
I put some bits of seaweed in there for them to eat on.
The filter sponge couldn't handle the seaweed
I saw one shrimp repeatedly jumping, figured he was a derp and put a lid on.
Another one started jumping, I figured they were cold (the Gulf is warm) and gave them a heater.
I thought the sargassums were okay because they were all sitting in place.
Went to check on them, poked a sargassum. It went limp. Somehow it was still holding onto the mesh while apparently dead.
Tested for ammonia.
There's ammonia.
More than a trace, quite a bit.
Mixed a new batch of saltwater and put them in. I think it's too late, though. None of them are moving or reacting to anything.
They were moving and falling over and jumping and trying to get out while I was mixing, but not any more.
Too late.
I think I just killed six Gulf shrimp and seven sargassums.
I'll wait and see if they revive, but I doubt it.
I'm sorry, shrimpies...

 

[Calappidae]

I heard these shrimp are very very messy and some people actually have used them to start cycling tanks. Possible they "nuked" themselves.

What type of sponge filter? Any carbon, biomedia, live rock, anything?

 

[gnasher]

I would love to keep some larger shrimp like these. Does anyone know of an online vendor that sells ones that can live in warm water?

 

[Betta132]

It wasn't a sponge filter, just a sponge. I'd had it in my main tank's filtration since last year, and I figured that would be enough.
I also had a pump in there to keep the water moving, of course.
No carbon... I've heard mixed things about carbon in reef tanks.
I didn't add any live rock because I wanted to be able to keep track of all the shrimp in case one keeled over and croaked on me. I was planning to add a few small pieces in a couple of days, since they'd probably be out of the random-travel-stress-keeling-over stage by then.
You really think they managed to nuke themselves without any added food? They were just eating the stuff off the sponge... It wasn't even a gunk-catching sponge, it just sat in the filter.
I'm trying to find out what happened so that I can (hopefully) bring up some sargassum shrimp from our next beach trip. They're very pretty, and they don't seem territorial like most shrimp.

@gnasher, I know it's colder in California, but the Gulf gets pretty warm down by Texas. I bet Gulf brown shrimp would do fine in warmer temps... I don't know an online source, though. Maybe you could get someone by the Gulf to ship you some bait shop shrimp?

 

[Calappidae]

Why wouldn't anybody add carbon? Carbon takes out any toxins in the water and such. It's highly absorbant of anything bad and leaves good bacteria alone.

 

[Betta132]

I'd heard that it can adversely affect the biofilter, and that the dust can be harmful for invertebrates. Something about it getting caught in their spiracles.
I'll remember that for next time and just put a bunch of carbon in....

 

[Calappidae]

In my refugium I have amphipods crawling all over the carbon socks, sometimes in!

Carbon won't remove anything good, infact it'll remove anything you forgot to rinse off your hands and stuck in the tank accidentally (but of course don't get crazy just cause carbon is in there rinse your hands)

 

[DEFCLONE80]

Man I wish I lived near a ocean

 

[Betta132]

I actually don't live all that close, I'm several hours away.
Closer than you, I suppose.

 

[rbla51]

I find the sargassum shrimp all the time when we get a strong south/ southeast wind in so fla. They go missing in my tank quickly as everything seems to eat them. What's more impressive are the file fish and sargassum anglerfish that are in the weeds. Its a shame to because most die with the weeds when the waves push them in