A pic or two of my Opae Ula

[Rob in Puyallup]

One more thing, Andy.

I like, most folks, have been mixing "communities" in my aquariums for a many years. I can guarantee you 100% that opae ula do not live alone in their native waters. It may be easier to keep them in simple man made homes devoid of critters big enough for us to see aside from a snail or two, (and I DO understand why we do that!)but why not push it, and aim for something that may simulate a bit more of a natural home for them, and add interest for us? It may take more work, may add a challenge or two, but if you're willing to face these things... go for it!

[Rob in Puyallup]

Hi Harry,

It's a Blue Legged Hermit. Stays very tiny. Eats anything it can find including cyanobacteria (which is also a native food of opae ula). My guys mow across the live rock, gnawing on things they find growing there. I don't feed them anything else.

I also have some red legged hermits in the other tank. They are a bit larger, still tiny, and graze the live rock too.

Most shops that carry these guys charge less than $2.00 each, so it's a very small investment. I'm thinking that one or two is more than enough for a 10 gallon tank. Buy extra shells for them, too!

[KenCotigirl]

Rob your tanks are nice and I like the experimenting you are doing. It makes a wonderful community. If you succeed in the long run I will do the same in one of my tanks. Right now I am sticking with the Opae, snails and macro algae (and my hair algae) I am not an experimenter. These shrimp are pretty foolproof when you keep it simple.

I feel compelled to correct you on a previous post to Andy. There are almost no other creatures in the Opae's native anchialine environment. There are 5 other shrimps known to live with H. rubra. None are even remotely as abundant. The only shrimp to co-occur with any frequency is Metabetaeus lohena. Other inhabitants are Cyanobacteria,filamentous algae and diatoms. No snails, no crabs nothing. Are Opae found in some tidal pools and with more marine creatures, yes I sure they are but these tidal pools are not their native environment. Oh well sorry for preaching. Please keep experimenting and breeding. Shrimp breeding.

[Rob in Puyallup]

Hi Ken,

Back in November an acquaintance from the Big Island of Hawaii collected some snails from an archialine pond not far from his home. He wasn't aware of the species but it resembles Theodoxus cariosus (a native nerite, and not the typical Pipipi snail), the most.

Pipiwai
Theodoxus cariosus

Appearance: The shell is high, smooth, and dark-colored like its marine cousin, the pipipi.
Size: Shell diameter up to 1 inch.
Habitat: Brackish water species found in estuarine areas and pools near the seashore.
Diet: Feeds on algae growing on rocks.
Distribution: Endemic to Hawaii.
Interesting Facts: The pipiwai was also used as a food source by early Hawaiians.

[Rob in Puyallup]

Reference material- http://www.hawaiiecoregionplan.info/anchpoolNC.html

"Characteristic anchialine pool species include crustaceans (e.g., shrimps, prawns, amphipods, isopods, etc.), some of which seem restricted to anchialine habitat. Hawaiian anchialine pools are often occupied by small endemic red shrimp (Halocaridina and others) called ʻōpaeʻula. Other species are restricted to the surface waters of the pools, and include a few fish species, crustaceans and other invertebrates. Two endangered waterbirds (Hawaiian Stilt and Hawaiian Coot), and several species of migratory waterfowl also use these pools."

Reference material 2- http://www.nationalparkstraveler.com/20 ... eature5481

"Some scientists find anchialine pools like those at Kaloko-Honokohau endlessly fascinating because they are home to interesting fish, mollusks, and crustaceans. Some of these species are abundant, a good example being Halocaridina rubra, the little red shrimp that native Hawaiians named the ʻōpaeʻula. Others are regionally or globally rare species, including some that exist nowhere else on Earth. Hawaii is famous for its endemic species -- about two-thirds of Hawaii’s native species are unique to the islands -- and anchialine pools are great places to look for them."

[Mustafa]

Ken is more or less correct. Although there are other species in anchialine pools, if there are species such as fish, Macrobrachium shrimp, crabs , birds etc. that may prey on the H. rubra, they just disappear underground for the most part. Remember that a large portion of their population is mostly likely just living underground in caves and crevices...not much lives down there..maybe the occasional cave isopod or cave amphipod. Most "other critters" were introduced, such as exotic fish and the "prawn" Macrobrachium lar. That's why you don't see these shrimp in most anchialine pools anymore. There are some other shrimp that live alongside the H. rubra, as Ken mentioned, but they are few in number. Only on ponds where the Supershrimp are the dominant species, do you see large aggregations of them. Part of the reason why this shrimp is so dominant in such pools is because these pools don't really have much to offer in terms of food for pretty much any other animal (AND they are lacking predators). Just biofilm, bacteria, algae..and not too much of it, either. Because this species is literally a "Supershrimp" it can survice, grow and even thrive on *very little* food. That situation should be emulated in captivity. That means that you can't keep most animals with these guys as they would just starve to death only being fed a tiny amount every two or three weeks.

I mean it's great to experiment in general (to learn and find out new things I presume), but this is not the right animal for an intensive brackish (or marine) setup. There are much more suitable animals, including many beautiful shrimp, that could live alongside hermit crabs, various macroalgae and even corals in a full marine setup. The Supershrimp are comparitively tiny, aren't even suitable for such setups and are nowhere nearly as beautiful as many marine crustaceans. What's so special about them is that they have *special* capabilities...

If your goal is to find out what marine animals can live under brackish conditions, than that's a different story altogether. The scientific literature is full of descriptions of usually marine species that can live in brackish water (including typical marine fish species like some damselfish...I saw them in brackish estuaries myself). But again, I just don't see where the Supershrimp fit into that equations.

[Mustafa]

A white one. Some of these are nearly transparent: (Need to figure out how to sedate these guys sometimes!)

That's not a white Supershrimp, Rob. That's just a pale normal red one that's barely red. You can still see the red hue on it. Compare it to the real white shrimp picture I posted.

[Mustafa]

A couple of the yellow orange...

Although that shrimp does seem to have some yellowish orangish undertone, I suspect that it's, again, a pale red shrimp with a yellowish undertone. See all the red on the shrimp? Especially the head area. I wouldn't be surprised if that shrimp turns full red once it decides to color up. Again, if you compare it to the true yellow/orange shrimp picture I posted you'll notice that it has absolutely no red whatsoever. It is interesting that it has the yellowish undertone, though.