Wednesday, September 25, 2013

Wednesday search challenge (9/25/13): What IS that thing? Another undersea mystery.

Diving in Bonaire was immensely satisfying, it also led to multiple mysteries, each perfect for a search challenge.  I'm trying hard to not turn SearchResearch into a long series of "Mysteries of the Deep!"   

While there I took several hundred underwater photos, and when I was going through them this past week for the parrotfish problem (more on that later), I ran across a few snapshots of something I couldn't identify.  

In around 30 feet of water (10 m), I found several instances of this... 
These spheres are a remarkable sight.  They're not pearls, although they definitely have that kind of pearly, opalescent quality to them.  They're about 2 inches (5 cm) across, slightly bendable when you press on one, but firm too.  They're strongly attached to their substrate, in this case, sponges, but I saw them attached to other things as well.  

When I finally figured out what they were, I learned they're kind of a pest in saltwater aquariums, and aquarists look for ways to control them.  (Although they are fairly remarkable in appearance.)  They're certainly not a pest in Bonarian waters; I'd always see a few per hour while swimming over the reef.  

These wonderful things lead to today's challenge: 

1.  What IS that thing?  (I'm looking for the genus/species scientific name, although the popular names are interesting too.) 
2.  What biological agent might you use to control them in your salt water aquarium?  
3.  (Extra credit)  Why does it now seem that the use of this biological agent might be a really bad idea?   

Let us know HOW you found the answer.  For SearchResearchers, the search method to get to the right answer is as important as the answer itself!  It's how the rest of us learn to be better searchers.

Search on! 

Parrotfish update:  I hope to finish my update to the "parrotfish poop" problem from two weeks ago.  

It turns out that (much to my surprise) figuring out a credible answer to "how much sand does a parrotfish make in 1 year?" is pretty tricky.  I've been on the job, though, reading lots of scholarly papers on fish, and yes, how parrotfish process what they eat.  Fascinating stuff.  (But it's also really busy at work these days, so I haven't had nearly the amount of time I'd like. Ah, the irregular, but joyous life of a researcher!  I'm enjoying having a reason to read through ichthyology papers.) 


  1. 1. It's valonia ventricosa, aka "sailor's eyeball algae" or "bubble algae." I figured that other people diving in Bonaire probably took pictures of similar creatures, so I threw a bunch of terms at a Google image search: Bonaire diving coral reef pearl pest. That didn't turn up anything useful, so I added the word "algae," since the big bubble thing in your picture looks like it has something algae-ish on it. Not much there. I removed "pest" and tried again, and got a bunch of image results that looked like a match. ATJ's Marine Aquarium Site ( confirmed the scientific name. A quick Google search of the scientific name provided more common names.

    2. A Google text search for "valonia ventricosa control aquariums" (no quotes) turned up a common biological control agent: the emerald crab. One of the earliest hits was a 2008 article in the Journal of the Marine Biological Association of the UK entitled "Efficiency of using emerald crabs
    Mithraculus sculptus to control bubble alga Ventricaria ventricosa (syn. Valoniaventricosa) in aquaria habitats." Subsequent searches of "emerald crab bubble algae control" (no quotes) confirmed it.

    3. It seems like introducing emerald crabs to your tank is a trusted way to get rid of the bubble algae, but searching "emerald crab problems" (again, no quotes) turned up a couple of accounts of emerald crabs being so good at eating all of the algae that they ran out, got hungry, and started munching on the coral in the aquarium.

  2. still not working for me...I hit publish and nothing happens except a tiny triangle with yellow in it and an exclamation mark appears over the comment box jon

    This is weird. I can send this but not my answer............hmmmmmmmm

  3. Well done RI Curmudgeon!

    I tried a lot of queries, reverse dictionary. crop Dr. Russell picture, asked to Terramar Project Google Plus page (not answer yet) and many other searches. Found nothing.

    Searched RI answer on images and it looks like the answer is correct.

    With RI answer tried [Valonia ventricosa saltwater aquariums]

    Found "Bubble" Algae: Selected descriptions... in there found these algae has new Genus "Ventricaria". "the much-cited 'Valonia' of our nightmares is no longer Valonia, but, thanks to Olsen & West (1988) now has its own Genus, Ventricaria. "

    [Valonia ventricosa genus] Found confirmation of new Genus: Article Citation:
    Jeanine L. Olsen and John A. West (1988) Ventricaria (Siphonocladales-Cladophorales complex, Chlorophyta), a new genus for Valonia ventricosa. Phycologia: March 1988, Vol. 27, No. 1, pp. 103-108.

    Search Lesson for me: I need to learn more! I couldn´t resolve this challenge

  4. I think there is something about my answer that this comment system does not like. So, here is a much abbreviated Readers Digest version.

    The thing is thanks to Olsen & West (1988) its own Genus, Ventricaria. So yours is Ventricaria ventricosa

    Biological controls in aquariums are urchins, herbivorous fish, crab mithrax sculptusm, snails, some algae, all have shortcomings so physical removal is best

    These bios can do a partial job or be too thorough

    Original comments available on request,

    jon 10 minutes to do and 2 hours troubleshooting; now with fingers crossed - here goes

  5. Busy day today so I thought I would try a different approach this week.
    I phoned a friend that I know is an avid diver. I sent him the image.
    He recognized it but didn't know what it was. He was going to contact
    friend he sees as an expert.

    And that was the end of that search trail. I never heard back.

    Beginning again I searched [ saltwater aquarium problem pearl-like ] to
    go to Aquarium
    Corals: The Bubble Corals: Species of the Genera Plerogyra and Physogyra
    In the article they mention "pearl bubble" coral so I search for [
    "pearl bubble" coral ] and then [ pearl bubble coral ] and don't really
    find anything useful. I take a gamble at looking at the images. Way
    down on the page I found 1 picture that looked slightly similar to pics
    in the post. On a page of pics called Cozumel Shore
    and half way down the page I see a picture that is labeled
    "sea pearl" aka "sailor's eyeball" - a one-celled algae.

    Search [ "sailor's eyeball" ] and the knowledge graph shows it as
    Valonia ventricosa and the picture looks familiar. Search [ Valonia
    ventricosa ] going on to the Wikipedia page
    So I think I have the name.

    Search [ saltwater aquarium bubble algae treatment ] and find post on Bubble
    in Reefkeeping magazine. The article lists 3 controls. Only
    one of them fits biological agent 2. Suppression via appropriate
    herbivores. I went back to beginning of the article and something
    caught my eye "there is this added twist: the much-cited 'Valonia' of
    our nightmares is no longer Valonia, but, thanks to Olsen & West
    (1988) now has its own Genus, Ventricaria." Interesting!

    Search [ Ventricaria ] followed a few links but not much info gained.

    Back to finding a biological agent for controlling this aquarium
    problem.  Back to Bubble Algae article and it lists certain types
    of snails, crabs, fish and urchins. I went back to the SERP for [
    saltwater aquarium bubble algae treatment ] and take a look at the
    video where there is a lot with suction tubes and finally gets to a
    biological agent 8:19 mark 4 Ways to Remove Bubble
    Algae From Your Reef Tank - YouTube
    An Emerald Crab!

    Searched [ emerald crab ] and the scientific name matches the crab in
    the Reefkeeping Magazine. The article mentions that the crabs may eat
    other things in the tank and the video said that the pincers of the
    crab could pop or pierce the algae causing it to spread.

    1. Either Valonia ventricosa or Ventricaria aka sea pearl or sailor's

    2. Mithrax sculptus aka emerald crab

    3. Two possible problems - The crab eats other things in the aquarium
    you don't want them to eat or they can pop the bubble and spread the

  6. The key for this search was finding right keywords (terms). After trying words like "pest" "parasite" "sponge" "coral" I found a combination that worked.

    Image Search -
    Query [bonaire marine life "pearl"] Result- - Good image of "{Sea pearl} a species of Green Algae" - Good collection of images named {Ventricaria ventricosa}
    ------------ - It could be one of four possible algae
    "The four main forms of green so-called Bubble Algae (Chlorophyta) that we nowadays quite commonly encounter in reef aquariums are: Valonia, Ventricaria (usually ventricosa), Dictyospheria, some times spelled Dichtyospheria and Bryopsis"

    Valonia: deep green, not smooth, soft to the touch
    Ventricaria: lime green, hard, smooth***
    Dictyospheria: medium to darker green, soft, smooth, looking like individual bubbles agglomerated in one area.Bryopsis is round, looks like a ball, light greenish, soft skin easily pierced, rough not smooth.
    So I need to find a confirmation since above are personal webpages. I found 'Marine Species Identification Portal' and obtained a further image of the Sea Pearl and is identified as {Ventricaria Ventricosa} Answer #1

    Now on to controlling algae-

    Query [ how do coral reefs control algae] Result - Coral

    "While herbivorous reef fishes may prey upon some corals, the beneficial role they play in decreasing algae growth and allowing corals to settle and grow is much more important".

    List of algae eaters are Spotlight Parrotfish, Sea Urchins, Sea Stars, Crabs, Molluscs, Mesograzers.

    And " The take home message which can be gleaned from this article is that without grazers, coral reefs would not be able to exist. If algae were allowed to grow unchecked"

    Second website -

    And for the bonus we can look at algae controls in saltwater aquariums
    Query [ algae bloom control saltwater aquarium] Result 'Fish'

    List of algae grazers plus UV, manual removal and Algicides.

    Here's a list of instructions in managing a saltwater aquariums. The message at various websites was that its a fine balance between solving the problem and creating other problems such as marine grazers killing off ornamental fish and algicides killing all inhabitants

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  8. after some posting hiccups…

    aye matey, it not eye of newt; rather swabbies orb or naval gazer's eye or some-such gabbing… can't pass up a chance to go pirate. (Valonia ventricosa/sailor's eye/bubble algae)
    from Bonaire
    these were helpful too - from Panama, nice zoom feature on photos:
    toil & trouble (Bocas del Toro)
    Emerald green crab, can eat/damage the coral - hot topic of debate amongst saltwater aquarium keepers.
    another example
    emerald crab/reef tank
    started search with Bonaire, but switched and went with [salt water aquarium pest] which brought similar images and leads to names. 25 minutes