River/stream tank experiment

[josu2]

I've always wanted a river setup and I was oh-so-close to having one. Unfortunately, my mystery snail breeding necessitated using the tank I designated as river tank for growing out the snails instead. Well I have finally wrapped up the mystery snail breeding, so the tank is finally ready for business! I hadn't decided what exactly I wanted to do with it until I was watching some Chris Lukhaup YouTube videos of Caridina shrimps in their natural habitats. I was struck by how much water flow characterized some of these habitats. With that in mind, I decided to make my tank a (mostly) shrimp tank.

 

This does, of course, go against a certain conventional wisdom. Google around about dwarf shrimp care and you'll see lots of matter-of-fact statements that they should be provided an environment with minimal water flow. And it is true that some shrimps tend to be found in stagnant waters. But I wasn't convinced that this was so important, so I decided to try this.

 

Here's the setup, which was first put together 2 years ago:

 

• 20 gallon long tank (30" long, 12" tall)
• AquaClear 50 filter placed at the end (not back) of the tank to send the flow longways. An additional Rio 90 powerhead for more flow. The AC50 has a Han stainless steel mesh intake cover and the powerhead has a sponge pre-filter.
• Light-colored sand came from Home Depot.
• large (mostly) rounded river rocks from LFS, which cost me a fortune...never think you can eyeball how much something will weigh.
• smaller river rocks from Home Depot
• large-ish spiderwood
• several pieces of cholla from a now-defunct shrimp tank, one with Xmas moss on it (just added)
• Marimo ball that has been in there for 2 years
• 6" pleco cave covered in Xmas moss
• Cryptocoryne undulata 'red', C. wendtii 'red', C. becketii
• Heated to 70-72F
• Custom-cut plexiglass lid with additional plexiglass piece to fit around filter and cords

 

 

Since I took this pic, I've added a hanging light fixture instead. The green algae is there by design (for food!). I also did some DIY moss shelves suctioned to the wall after this pic.

 

Here's the extra piece of plexiglass around the filter:

 

 

So who's going to live in here?

 

The biggest beneficiaries are some of the shrimps I already owned, because they're filter feeders:

 

• 3 bamboo shrimp (Atyopsis moluccensis)
• 1 vampire shrimp (Atya gabonensis)

 

Then I added some new shrimps:

 

• 8 tiger shrimp (Caridina sp.). They're a pretty varied group, some quite blue, one or two more like the "super" tiger with orange tails, and at least one with rather red stripes.
• 2+ blue velvets (Neocaridina sp.). I say "+" because I only bought them because one was berried at the LFS. One of the eggs actually hatched while I was drip acclimating them and my spouse actually watched the hatching occur. I'm not sure how it ultimately did. By a few days later, all the eggs had been released. Now about 10-14 days later we're starting to spot little tiny blue shrimplets around the tank. Success!

 

Next are some nerite snails, one of which is an "onion" snail. Another is a very young, compact species that is probably a Clithon sp. (horned nerites) but has an interesting brown color pattern that's hard to describe. And then on a whim I got a rarer variety of nerite that turned up at my LFS, which I have since gathered is Vittina waigiensis with no consistent common name. The best common name IMO is "tire track nerite." I haven't gotten a great pic of mine yet, but this photo from a site selling them shows you what I mean.

 

 

Last but not least, I've added a river fish that I'm confident won't bother the shrimps: hillstream loaches, in this case the variety often sold as "Borneo suckers." They are Gastromyzon species, in my case I think one of G. ctenocephalus and the other G. scitulus. They tend to be mixed species groups in sellers' tanks (and the wild) and are not bred in captivity. Sadly, my LFS did a really terrible job getting them out of the tank—these guys are much more dedicated to being suctioned than suckermouth catfish are. The employee, who had never caught any before, was pushing the fish with his net on one side and then trying to pry the fish off with his finger/fingernail on the other side. It took a long time to net it and then took a long time again to transfer from the specimen container to the fish bag. One of them in particular lost a lot of its skin in the process, as you'll see in the picture below:

 

 

We're calling that one Harvey (like Harvey Dent from Batman). I'm peeved with the LFS but I know they didn't realize how damaged the fish was. It took me a few days to notice how extensive it was. They can get very pale and when they do, these injuries are really hard to see. These fish like high flow (well, very high oxygenation moreso than actual flow) and I'm excited to give them a tank that meets their needs and shouldn't stress them with much serious competition for food. As a side note, you can see my biggest bamboo shrimp there. The two hillstream loaches were doing all kinds of hijinks on that big rock, carefully avoiding the bamboo shrimp who acted as if he didn't care or notice them at all.

I may ultimately add one or two more hillstream loaches, but I don't have too many more plans for the tank. I'm hoping the tiger shrimps will breed, but they're more finicky than the neos and I'm not sure how eager they will be to breed at this temperature. We'll see how it goes.

[Wygglz]

So cool! Thanks so much for sharing.

[josu2]

So far, so good here. I'm seeing blue shrimplets whenever I look in the tank, so I'm feeling confident that the gamble is paying off. Maybe at some point down the line I'll add some more to diversify the genetics, but for now I'm happy to have started a colony with just two shrimps.

 

And even more encouraging news (IMO) is that I spotted two berried tiger shrimps today. I haven't bred any Caridina sp. before, though in my past experience their demise was mostly due to bad stocking decisions. But I couldn't know for sure whether they would find my tap water and other aspects of the tank acceptable until they bred. Maybe they'll change their mind before the eggs mature, but I think this is a very good sign that the tank will be thriving with even more shrimp activity in the near future.

 

The tank is more for enjoyment/aesthetics than breeding, but I'll probably start culling and trying to make everybody look nice once their numbers are sufficient. My starting stock of tigers isn't exactly impressive so there's lots of room for selective breeding to improve their appearance. I'll probably select more for the "super tiger" type of appearance than the darker body color; I prefer the striped look because it looks more natural to me. Plus, the neos I have in the tank are blue anyway.  As for them, the mother is a nice "blue velvet" while the other female I purchased is much more of a "blue dream" type, with a really nice navy color over almost the entire body. Of course, I don't have a clue what shrimp fathered the shrimplets other than I can say with some confidence that it must have also been a blue since the shrimplets are already clearly blue.

 

I should get some more pics sometime soon, but for now I'm letting the glass continue to accumulate green algae for the benefit of the fish and snails (and the shrimps, who occasionally try to feed from it).