Distributors and species names: Regional variation. Urchin sel.  6/13/08
Hello, WWM crew.
<David>
I am hoping that with some of your people having experience with the distributors in the Pacific that perhaps they will know something about this.
I have been trying to get an Astropyga radiata via my LFS, but the two times he has ordered one (or three), what have arrived were Tripneustes gratilla. The second time he even sent a picture of what we wanted. The two species don't look that similar, so I'm left with wondering if there is some common name that those in the eastern Indian Ocean / western Pacific Ocean call this urchin, because the scientific name isn't doing it.
Any thoughts?
<Mmm, yes... for one, the trade is composed of "disparate players"... the actual collectors/divers are not often in the employ of the folks who gather, sell, ship livestock... So there is likely a disconnect here. Astropyga are rarely "used" in the trade, owing mostly to their long spininess... and difficulty in shipping therefrom... costing more to put in larger bags, screened, with more water (shipping is more money than livestock per se in most cases). Whereas Tripneustes are more compact, easier, cheaper to ship... Both animals are not that rare in the wild, easily collected. At any length, what I suspect is that these two influences, the fact that you're not communicating with the actual collector/s, and the social inertia of folks dealing with the Tripneustes is working against you. I would keep sending the images, asking whomever you're dealing with, to show same to their source/collectors. Bob Fenner>
Thanks in advance.
David

Hair Algae Vs. Our Urchin 10/14/07
Hello!
<Hi there!>
We have a 125 G. reef tank, 1 hippo tang, 1 blue damsel fish, 2 clarkii clowns, 1 clam, lots of corals: zoas, Monti caps, frogspawn, hammer, SPS, etc. Oh and 5 pyjama cardinals. Anyways, several months ago, we brought home some LR we bought off of a guy that was downsizing. Big mistake. We no longer have bubble algae (different story), but we have hair algae, which came on the LR we bought. We figured that it would be no problem to get rid of what was left, after most of it was scrubbed off. So now there is a hair algae problem in the tank, along with Cyanobacteria. It seems that the hair algae is slowly receding, but the cyano is becoming more prevalent. We have a pencil-urchin, maybe 3". We also have lots of snails, emerald crabs & hermit crabs. Suggestions on eradicating the rest of the hair algae & the Cyanobacteria?
<This is more than the rock introduction. Yes the rock can introduce spores of nasties like hair algae and other unwanted guests, but nutrients need to be present for them to flourish. The use of Activated Carbon and an iron based phosphate resin will help dramatically over time. The resin should be changed out every 30 days. An increase in water change schedules will help also.>
Every few days, we use a turkey baster to blow off the LR from the cyano & push it into the sump & thus filter it out. Yeah, this hasn't helped. We use RO water for changes. We've also recently added a larger sump, about 75 G, for a total (approximate) water volume of 200 G. The pH is maintained at 8.2. Alkalinity is normal. Dose phytoplankton. once a month. Haven't supplemented the tank with Kalkwasser for a while (used to have it in a separate dosing tank).
<The use of a dual DI canister after the RO unit will bring the TDS (total dissolved solids) to zero. This will help in reducing any nuisance algae. Returning Kalkwasser to the system will aid in the precipitation of phosphates and increase Calcium levels. I would return to dosing Kalkwasser.>
Do we need another urchin? If so, what type? We've tried lawnmower blennies, but they seem to love to commit suicide by jumping out & attracting our cats, who, in turn, love to chomp on them. After much searching, it doesn't seem that this precise case has been covered on WWM, and so have decided to post this question (actually these questions.) to you!
<The use of the Black Long Spined Sea Urchins of the Diadema family work very well. Orange Scribbled Rabbitfish are also very good herbivores but are hit or miss on small coral polyps. It's worth a shot.>
(Yes, just for you, as we know
you have nothing better to do) :-)
Thanks all!
<Bob and the Crew appreciate your confidence! Thanks Rich-aka-Mr. Firemouth>
Anna & Eric Z

Purple Spined Sea Urchin... Arbacia punctulata   7/30/07
Hi Crew.
<Hi Rick, Mich here.>
I was walking the beach in Florida the other day on the Gulf of Mexico side and found a purple spined sea urchin.
<Lucky you... the walking on the beach part... I seem to be good at finding urchins with my feet! Ouch!>
I did a web search on them and they are, according to them Arbacia punctulata- purple spined sea urchin.
<Is endemic to Florida, and generally live on rocky bottoms as opposed to sandy bottoms.>
I was thinking about putting him in my FOWLR tank. Is he safe?
<Mmm, I doubt that you will be able to provide suitable nutrition for him. These animals typically eat sessile invertebrates which he will likely consume your current tank population quite quickly. Gut content analyses have show bryozoans, hydroids, barnacles and tunicates and limited algae. The algae are typically only those growing on the rubble. but the diet is usually more heavily weighted with animal matter>
I have a coral shrimp and a tang. goby and clown. Right now I have him in my QT tank. Would he benefit my tank?
<I don't think the tank would benefit nor do I think it the urchin would benefit. I think it would be best to return him to where he was found.>
I also found some large hermit crabs, about 2 1/2 inches and was wondering if these would be good substrate cleaners?
<A big no go there! Usually any large hermit crabs are highly predatory, capable of killing fish and even well protected animals such as urchins.>
Those I didn't bring home
<Wise.>
but the urchin was too pretty to pass up and they do sell them locally.
<I do not have personal experience with this species, but from what I have read, I obviously have concerns, perhaps those in your local market may be able to guide you better, but with the information I found describing the typical diets of these urchins, I would be concerned about starvation.
More here: http://www.int-res.com/articles/meps2005/295/m295p171.pdf >
Thanks for all info past and present you guys are great and make my hobby so much easier. Rick
<You're welcome and thank you for the kind words. Mich>

Algae Control, Urchin selection 6/22/07
Chris,
<Hello>
Thanks for your quick response. <Sure> I had a follow-up question. <Ok> While my 110g display is running fallow, the algae is starting to grow and grow and grow . . . This was all being kept in check by my lawnmower blenny and yellow tang before I removed them to the HT (neither survived). I have lots of hermits and snails, but they aren't really doing much. <Can be picky eaters at times.>
Someone has suggested an urchin to control the algae, but I'm wary of that because I intend to introduce a few easy-to-keep soft corals once I get everything running and back into shape. <Some can be troublesome with corals.> Are there urchins that are reef safe, or do you suggest some other organism to help control algae during the fallow period? <As always I suggest the main organism for algae removal is you, manual removal will help lots here, both removing the unsightly algae and in the same step remove fuel for future algae to metabolize. But there are some urchins that can be utilized here, although bringing problems of their own. Some may sample corals while just about all are known to be bulldozers, knocking loose corals are rocks about, not particularly agile creatures for sure. Several suitable species are available, specific species are found in the FAQs.> Btw, in searching the urchin FAQs I came across the picture of the yellow goby with an urchin spike through its head. That is one of the coolest pictures ever. <Quite, although not a great day for that goby.>
Although my tests show 0 phosphates, I imagine that there are some phosphates present--just being used up by algae before they register on test. <Yes, most likely.> I'm saving for a RO/DI unit, which should help in the long run, but until then I have ordered some PhosBan to run in the sump. <The RO/DI will probably help more than any livestock you add to the tank. I would probably not spend the 20 or 30 dollars on the urchin and apply it to the RO/DI unit, more long term benefit here.>
<Chris>

Urchin for algae control   6/16/07
Hello, crew. Here for a post-research sanity check prior to purchase.
<Okay>
I have a 20 gallon tank containing a very happy and vigorous peacock mantis shrimp (4"). Despite frequent (usually weekly) five gallon water changes, I am struggling to fight off amazingly vast quantities of hair algae and Cyanobacteria. Presumably this predator's messy feeding habits are more than this tank's nutrient exports can handle. The tank has a productive Remora skimmer and a small hang-on-tank refugium with a mud/sand substrate, live rock rubble, and Chaetomorpha (harvested biweekly). I also employ mechanical filtration with PolyFilter and PhosGuard. The total water turnover in the tank is > 20x/hr. Lighting is about 80W PC (50/50 10K and actinic). I have yet to try black-out periods with the lights due to the presence of soft corals (xenia, mushrooms, zoanthids) that I understand are significantly photosynthetic.
<Mmm, yes... Does sound/read like a very nice small unit... and I concur, with much more nutrient than the gear can outcompete pest algae for...>
I added a serpent star, which adds some movement to the tank, but hasn't done much else. I am strongly considering adding an urchin to try to attack some of the algae. I think an urchin has a good chance of survival due to the mantis' diurnal habits (and the urchin's nocturnal ones).
<Good point>
Snails/hermits are just so much aqua-popcorn. Food will NOT be a problem -- the tank looks like a jungle despite all efforts. After reading a lot, I am debating between the "Purple urchin" (Echinometra viridis) and the "Blue tuxedo urchin" (Mespilia globulus). Both are relatively small, are purely herbivores, etc. I am leaning towards the former, because it appears from what I've read that it will leave corallines more-or-less alone (at least, more so than the tuxedo). Also, it looks like the tuxedo is a little more picky about its habitat ("shade areas" are rather sparse in my tank).
Do you guys think this might work?
Thanks,
Dan
<Well... worth a try... I like the Mespilia for looks... Bob Fenner>

Collecting Sand Dollars... Best Left at the Beach.  - 6/7/07
If I bring live Sand dollar from the beach, and quarantine it, can I put it in my reef tank?
<Greetings, Mich with you tonight.
Can you or should you? Sand dollars generally don't do well in home aquariums typically starving after a few months. They require a lot of sand, approximately 10 sq ft of surface area for a sand dollar 4 inches in diameter. They also need a sand bed at least 4 inches deep, and can be suffocated by fine sediment and aragonite sandy muds found in some reef aquariums. Subtropical sand dollars will not survive at normal reef tank temperatures either. Generally, I think it's best to leave the sand dollar at the beach. Though I am glad you mentioned the quarantine part! Mich>

Re: Collecting Sand Dollars... Best Left at the Beach.  - 6/7/07
Thanks Mich. I'll leave them at the beach!
<Welcome! Another dollar saved! Yay! Mich>

Urchin in Mud Refugia/Sump Area?   3/1/07
Dear Bob,
<Actually Adam J with you tonight, hello.>
Can a pencil urchin survive in a mud sump environment.
<Urchins are largely rock dwelling in nature, but with some rock for hiding, etc.., a light and food source I don't see an issue. Though I would surmise it would partially be an unwanted organism in any type of refugia. Not only being clumsy and destructive but being an opportunistic omnivore, feeding indiscriminately on algae and other benthic life forms.>
I have a lot of algae growing in there
<Why are you concerned with algae in your sump/refugia area...is this not it's designation...would rather in colonize here than is the display or this refugia intended for other types of life?>
and could use the hitchhiker to keep it clean,
<If it is filamentous algae, smaller less destructive herbivores such as small snails would be a far better choice.>
Also will the Aiptasia anemones harm the urchin?
<No, though a large population of Aiptasia is usually indicative a larger nutrient issue.>
Best regards,
<To you as well.>
Jason
<**AJ**>   

Mespilia globulus   11/19/06
I have a 25 gallon with 12 bumble bee snails, a Hawaiian feather duster, a colored feather duster, an Arabian Dottyback, 12 dwarf blue leg hermits, 5 Nerite snails, 5 Tonga snails, a Bi-color Blenny, and 5 Scarlet hermits. I'm planning on adding a Fire shrimp and a cleaner shrimp.
<Only one or the other... and not a Stenopid...>
I've been looking into a Mespilia globulus. Do you think it would be compatible with everything else?
<I would not add an Urchin of any species here... too small a volume, too crowded with organisms that fill about the same niche>
What about some small mushrooms?
<Could be tried>
I've never kept them before but was thinking about them as well.
My tank has been running for 10 months and has a large amount or algae growth (I just added the blenny and the Scarlets).
<Ahh. I would wait on them...>
Parameters are good, and filtration is high (Emperor 280, SeaClone 100), 2" sand bed, and standard fluorescent lighting.
Rich Chen
<Bob Fenner>