This dying Acanthastrea (“Acan”) coral came out of a hobbyist’s tank that had been neglected due to an impending move. Notice the lack of tissue between the polyps. Luckily, corals in poor water conditions usually recover quickly in a mature, well-maintained aquarium. Rehabilitation should be easy with just proper, basic care. (Photo taken 9 June 2012)
Preparation for Quarantine:
Since the coral just needed a healthy environment, there wasn’t a whole lot I could do. There was some nuisance algae on it, so I cut those sections off. I gave the coral a dip in Coral Rx to check for pests just in case. Within less than a month, the polyps were already expanding out more and growing larger. (Photo taken 30 June 2012)
Quarantined Coral:
Within a month, the previously dying Acanthastrea coral looked almost like it had never had a problem. Unfortunately the remaining skeleton kept growing nuisance algae, so I kept having to remove it to facilitate its rehabilitation (white areas in the photo, taken 7 July 2012.)
Coral Grow-Out:
After a month in quarantine, I was able to re-dip the coral and place it into a grow-out tank. In a grow-out tank, I can continue to monitor the coral for any remaining issues while not exposing it to other incoming quarantined corals.
Within only two months the polyps were fully expanding and growing tissue between them (14 August 2012). Around this time I purchased a band saw, so I cut off the part of the disc that kept growing nuisance algae.
Rehabilitated Acanthastrea Coral:
Not too shabby! All this coral needed was a bit of TLC and some good water to make a full recovery within six months. (7 October 2012)
I had this coral for several years, during which time I fragged it many times to pass along to other hobbyists. For all I know, I may still have some of it, but I’ve lost track of which Acan coral it may be in my tank after a few moves and having several similar corals (what a great problem to have!)
A local fish store (LFS) called me to ask if I wanted to try to save some of their corals. An employee had overdosed their reef tanks with a chemical used to treat flatworms (I was not told what chemical it was). When I arrived, honestly, I was shocked at how bad many of the corals were. I don’t know if these corals were dying from an overdose of some unknown chemical or if the flatworm toxins were killing them. Either way, something was poisoning these corals to death. I picked up two “chalice” corals, amongst others. These dying Lithophyllon coral mouths were gaping open, the tissue was falling off, and what tissue did remain was barely hanging on. Rehabilitation was going to be dicey. (Photo of Litho#1 taken 11 May 2013)
Dying Lithophyllon Coral Inspection and Dipping:
When I brought them home, I temperature acclimated them to my quarantine tank and prepared the dips. Like most of my rescues, I dipped the corals for pests. (Photo of Litho#2 taken 11 May 2013)
*NOTE: This post tracks the corals as “Litho#1” and “Litho#2” to show individual progress.
Coral Quarantine:
After the dips, I placed the two dying Lithophyllon corals into my quarantine tank in a low light, low flow area. I made sure that no crabs would bother the coral, especially with all the decaying tissue. Since the corals were poisoned, I made sure the quarantine tank had new carbon to help absorb anything that the corals might leach. Both corals did start to quickly recede, so I tried to stop it by smearing a bead of superglue gel along the receding edge (white lumpy band in the photos below). Rehabilitation was definitely already proving rough. (Photo of Litho#1 taken 11 May 2013)
Receding Lithophyllon Coral (Photo of Litho#1 taken 9 June 2013)
The corals also refused to eat until about a month after I received them. I started them on fish food pellets (shown here and above) since they are quite processed. In my experience, sick corals seem to digest fish pellets better than whole foods (like mysis, etc.) This helps them recover faster. (Photo of Litho#2 taken 9 June 2013)
Coral Grow-Out:
After stopping the recession with superglue and maintaining regular feedings, the corals started to heal quickly. And how great they started looking! After 30 days in quarantine, I inspected, re-dipped, and placed them into the grow-out tank. (Photo of Litho#2 taken 4 August 2013).
Regular feedings likely helped the coral recover. (Photo of Litho#1 taken 12 October 2013)
Here is Litho#2 on 3 November 2013.
A month later (8 December 2013), Litho#2 was growing down its skeleton.
Fully Rehabilitated Lithophyllon Coral:
Nearly a year later, both previously dying Lithophyllon corals were growing rapidly. This Litho#2 is shown on 1 May 2014, when it was fully rehabilitated. Below is a close-up shot showing the corals’ beautiful patterns.
Lithophyllon Coral Close-up
Conclusion:
I had very little hope for these dying Lithophyllon corals due to their poisoned state. However, the fast reaction of the LFS along with continued care over a year fully rehabilitated these two corals. Shown below are the before/after photos of the dying Lithophyllon coral rehabilitation. One coral was nearly immediately rehomed, and the other coral was rehomed a couple years later.
Before and After: Dying Lithophyllon Coral Rehabilitation (Litho#2 shown)
Cyphastrea coral are usually very hardy and prefer low light (and sometimes do best partially shaded) but can be acclimated to higher-light areas. They also adapt well to a variety of flow conditions. I received this dying Cyphastrea coral from a reefkeeper who was getting out of the hobby. Good husband would likely be key to this coral’s rehabilitation. (Photo taken 22 May 2012)
Unfortunately, most corals in the tank were suffering from poor water quality, and this Cyphastrea was no exception. The reefkeeper did the responsible thing by recognizing that the corals needed proper care and attention.
Note how some of the polyps still have tissue while there is no tissue between the polyps. This is a good indication of poor water quality (in addition to actually speaking with the previous owner). Regardless of the damage root cause, I still dipped and checked it for pests.
Coral Quarantine:
As mentioned, the coral was declining due to poor water quality. After the initial dipping process, I placed the coral into my quarantine tank for observation and acclimation. Here, the coral was fairly low in the tank to allow it to adjust to the lighting. Notice that by less than a month later (15 June 2012), the coral was already regrowing!
Just another 15 days later (30 June 2012) and slightly over a month total time with me, and the coral was gaining coloration and growing rapidly! Given the proper light and water conditions, this coral grows extremely fast.
Fully Rehabilitated Coral:
This previously dying Cyphastrea coral was completely rehabilitated in less than three months (pictured at 14 August 2012). The coral had completely covered the old skeleton and had encrusted onto the base. In fact, it started to grow so quickly, that I had to frag it several times. Coral reproduction via fragmentation reduces hobbyist impact on the oceans.
Troubleshooting Dying Cyphastrea Corals
As mentioned above, if the Cyphastrea coral has started to lose tissue between the polyps, then there is probably a water quality issue. If the coral is bleaching, then it’s likely in too high of light (or might’ve been in absolutely no light.) If the coloration isn’t great (too brown), then it may need more light or less nutrients. Or, if there’s recession from one side to another, then it may be a pest, bacterial/fungal infection, or a sudden water quality problem.
A single dot, a squiggle of white, a floating orange ball – marine eggs come in all shapes, sizes, and colors! Of course, the easiest way to tell what it could grow up to be is to find mom nearby, but that’s not always possible. These are just a few of the most common eggs found in an aquarium to help you with the identification of marine eggs.
Anyone plagued by Aiptasia sp. anemones needs to know about Berghia nudibranchs. These nudibranchs only eat Aiptasia anemones, and they produce an egg sac like the one pictured every few days. Below, a microscope image shows the developing nudibranchs, along with grown adults.
Nerite snails are a great snail, but I only know of one person who had nerite eggs hatch and grow successfully to adults (in other words, most eggs do not become adults…or even make it to juveniles.) The eggs look like white sesame seeds and are sometimes found singularly or in small groups (like the four in the photo below). Read more about snails here!
Ok, so maybe the taxonomy isn’t entirely straightened out on this snail yet, but regardless of name, they’re great snails. As you can see by the multiple egg sacs, they reproduce faster than rabbits. If you’re sick of buying snails, then these are your best choice in my opinion. They graze over rocks and on glass, stay small, and their population waxes and wanes with food supply. Read more about snails here!
Nassarius snails produce various egg patterns, depending on species. Some of them produce some of the most beautiful “fan” patterns of marine eggs, but others leave these small individual sacs. Read more about snails here!
Cerith snails are a beneficial part of a reef tank clean-up crew. They reproduce in captivity to some extent (some aquarists have more success than others, and the juveniles make it to adulthood in small numbers). The egg pattern is very distinctive, as shown with the mother (and possibly father). The egg pattern will vary by species, but most have something similar to this white swerving pattern or the fuzzy white string below. Read more about snails here!
Stomatella snails are hands-down my favorite snail. They come in nearly all colors (like the black one and speckled one below, but also in red, silver, green, etc.) They frequently enter an aquarium as a hitchhiker, scour the tank for algae, and then reproduce prolifically. They’re broadcast spawners, so they reproduce by climbing high in the aquarium and releasing small puffs of sperm and eggs which look like smoke.
Although the stomatella snail can’t be seen in the photo with the Scolymia coral, there is one hiding under the coral releasing either sperm or eggs (white smoke-looking mass to the left of the Scolymia). This event lasted about 3 minutes. Unfortunately, I’ve had a hard time determining their life cycle times since they constantly have new batches of babies. Read more about snails here!
I had (what I assume to be) a mated pair of fighting conchs that regularly laid eggs. Unfortunately, I never had success raising these in captivity. Read more about conchs here!
Acropora-eating Flatworms (Amakusaplana acroporae) – Not Reef Safe:
As the common name implies, these flatworms only eat Acropora corals. Although they usually lay their eggs directly on the Acropora corals, the eggs can sometimes be found near Acropora corals, like on a frag plug in the photo.
These massive flatworms are not reef safe due to their predatory behavior. I found one of these flatworms inside a hole in the live rock attached to a coral along with the marine eggs shown. Although I am not 100% certain the eggs are from the flatworm, there were no other large invertebrates within the live rock. Additionally, the eggs resembled very large Acropora-eating Flatworm (AEFW) eggs, another polyclad flatworm species.
There is quite a bit of debate over whether gall crabs are reef safe, but I, personally, have not experienced any issues. The female builds a small hole in live rock, and corals grow around the crab. Since sick corals often contain gall crab inhabitants, the crabs are often blamed for the coral’s ill health. I should note that extremely large, healthy corals in the wild house gall crabs with no noticeable problems. The female shown is carrying eggs (in yellow).
A fellow hobbyist in my local reef club at the time contacted me about his dying Pectinia coral. He said no matter what he did, the tissue kept receding, and it was just a brown color. Knowing the hobbyist and his system, this was out of the ordinary. So, after much discussion, I took it in to attempt a rehabilitation of this dying Pectinia coral. (Photo taken 8 March 2014)
Inspection:
Upon inspection, I noticed that the tissue recession was slow (notice the coralline algae growing on the old skeleton). I also noticed it was covered in very tiny, moving, white dots (and majano anemones!)
I wanted to take a closer look at the “white dots,” and found that they were Ostracods – seed shrimp. This was the first coral I’ve encountered that had a massive pod population covering it during the day. Typically I’ve only seen ostracods out at night.
Although a microscope isn’t ideal for examining seed shrimp, it was still neat to see.
Treatment:
As with all my dying corals, I started the coral out with a series of dips.
During the dipping process, I trimmed off all of the excess skeleton to expose any hidden issues, reduce the likelihood of pests, and allow the coral to regrow a skeleton unencumbered.
I didn’t really believe the ostracods were the source of the problem, but dips are always wise.
Quarantine:
After three dips and a skeleton trim, the Pectinia coral was quite stressed, but it went into my quarantine tank for observation.
Continued Care:
The coral started to regain color, but the ostracods came back. Interestingly, they only covered this one coral during the day. I decided to perform the dips again.
Final Results:
After the second set of dips, I never saw the ostracods again, and the coral started to recover. By 1 May 2014, the coral was turning a beautiful blue and starting to grow. Shortly after this photo was taken, I gave the coral back to its owner. Below, you can use the slider to see rehabilitation of a dying Pectinia coral from beginning to end!
Although sea spiders are certainly creepy and may have eight legs like land-dwelling spiders, sea spiders are only distantly related. The sea spiders identified here are more interested in eating coral than eating pods in a reef tank, which makes them all the more scary!
Acanthastrea-Eating Sea Spiders: Not Reef Safe
Here’s another one for your nightmares! For years I had heard rumors of a stealthy Acanthastrea predator, but I had yet to find one (to my relief.) A while back, I attended a coral fragging demonstration, and along with my frag freebie, I also received these lil buggers.
Rumor has it that these spiders tend to prefer Acanthastrea (typically called “acans”) corals, but they have also been found on other large polyp stony corals (LPS). Thankfully I eradicated these spiders before I had a chance to find out if they would infect my other LPS corals as well.
This Acan-eating spider shown below (hereafter referred to as AES) has (or had, I should say) eight legs. This is likely a female as the males have a specially modified leg (called an oviger) for carrying eggs (unless I knocked that leg off accidentally too) (Cowles, 2009). As you can see, there is practically no body – it is mostly legs. On the left side of the AES in the photo are the chelicerae (mouth parts) and the proboscis (tubular mouth part for ingestion). As mentioned – these are not true spiders! (Although they still give me the heebie jeebies!)
Acanthastrea-Eating Spider
How to Identify AES:
AES are nearly colorless, so they blend in quite well with the coral. Even after a thorough visual inspection of the coral prior to dipping, I only found these after they fell off in the dip. The ones I found were about 1 cm in diameter (nearly half an inch). So, I recommend a good coral dip prior to introducing the coral into your tank. As they can rapidly eat Acanthastrea corals, proper identification of sea spiders is critical.
How to Treat AES:
Various dips may be effective against AES; however, multiple dips may be required to eliminate any recently-hatched eggs (most dips are not effective on marine pest eggs).
Hydrogen peroxide dip: This is my preferred method for AES. This dip creates bubbles that will actually lift the AES off the coral – they usually can’t hold on! Use this dip with caution as overdoing it can cause serious coral damage. Also, only dip LPS in it. Soft corals and small polyp stony (SPS) corals do not typically respond well.
CoralRx, Lugols, and other commercially-available dips: Although I haven’t used these dips on AES, they should work…possibly with varying levels of effectiveness. Several brands tout effectiveness against pycnogonida (sea spiders).
Natural predators: Certain wrasses and other typical pod-eating-vertebrates may eat AES, but I’m not aware of any definite natural controls.
Manual removal: If your eyes are good enough (or are helped with a magnifying glass), you may be able to manually remove AES with tweezers or a pick. However, you may miss some and end up with a worse problem down the road.
Other: I am not aware of any in-tank treatments (other than possible natural predators). Additionally, Bayer insecticide is a common hobbyist treatment for marine pests; however, it was not designed for reef usage. Please read the label.
AES Conclusion:
Although Acanthastrea-Eating Spiders are quite creepy-looking, they are not a horrible pest to eradicate. They are highly susceptible to coral dips and can even be manually removed. If you know you have AES, please be a responsible reefkeeper and do not pass your coral on without at least notifying the new owner.
Note how different the AES above is from the Zoanthid-Eating Spider (ZES) shown below. The AES is much larger and has a much smaller (proportionally) body. Both have eight legs.
The photo below is of a zoanthid-eating spider that came off a zoanthid colony during a dip in CoralRx. It is in a water droplet on the top of a water test card for size reference.
Zoanthid-Eating Spider
How to Identify ZES:
ZES are extremely tiny, so they hide quite well in the coral. And, they are able to attach themselves very well inside the zoathid polyp. Even after a thorough visual inspection of the coral prior to dipping, I only found these after they fell off in the dip. The ones I found were about 3-5mm in diameter. So, I recommend a good coral dip prior to introducing the coral into your tank. Since they can devour Zoanthid corals, proper identification of sea spiders is critical.
How to Treat ZES:
Various dips may be effective against ZES; however, multiple dips may be required to eliminate any recently-hatched eggs (most dips are not effective on marine pest eggs).
Hydrogen peroxide dip: This is not an ideal treatment for ZES, as soft corals (zoanthids) do not typically respond well.
CoralRx, Lugols, and other commercially-available dips: These ZES photos were taken after removal with CoralRx, so these preparations may have varying degrees of effectiveness based on brand/solution.
Natural predators: Certain wrasses and other typical pod-eating-vertebrates may eat ZES, but I’m not aware of any definite natural controls.
Manual removal: If your eyes are good enough (or are helped with a magnifying glass), you may be able to manually remove ZES with tweezers or a pick. However, you may miss some and end up with a worse problem down the road.
Other: I am not aware of any in-tank treatments (other than possible natural predators). Additionally, Bayer insecticide is a common hobbyist treatment for marine pests; however, it was not designed for reef usage. Please read and follow the label.
Zoanthid-Eating Sea Spiders Conclusion:
Although Zoathid-Eating sea spiders are quite creepy-looking, they are not a horrible pest to eradicate. They are highly susceptible to coral dips and can even be manually removed. If you know you have AES, please be a responsible reefkeeper and do not pass your coral on without at least notifying the new owner.
A friend of mine asked about this dying Echinophyllia coral’s rehabilitation, “How did you even know there was any living tissue on that one?” That’s a really great question, because this Echinophylliasp. (also known as a “chalice”) coral was in a really bad shape and dying.
There was a local fish store (LFS) near me back in the day that used to have massive coral runways with massive runway sumps below. If any corals died, the employees would just throw the pieces into the sump. I used to take a UV-light and run it along their sump to see if there was anything with the tiniest hint of life clinging to it. Although I didn’t get this particular coral there, a UV pen was what gave me hope. This coral might be brown under regular light, but it fluoresced a beautiful green under UV.
This dying Echinophyllia coral got its start with me on 22 May 2012. Of course, I dipped it to check for parasites and placed it in a low light, higher flow area.
Coral Quarantine:
Just a little over a week later, on 3 June 2012, the transformation was amazing. With regular target feedings, this previously dying Echinophyllia sp. coral was no longer clinging to its skeleton, showed off its orange mouth, and it developed what can only be described as “glitter” throughout its tissue (notice the specks around the mouth). I was getting excited! Its rehabilitation was coming along!
By the end of June (30 June 2012), just a little over a month later, and the Echinophyllia sp. coral had nicely filled out. It was time to transfer the coral from quarantine to the grow-out tank, so it was dipped again and inspected to ensure it was clean.
Coral Grow-out:
This photo was taken on 14 August 2012. The grow-out tank’s lights were much stronger, so this coral started out in the sand again. Even down in the sand, the coral began to develop some beautiful coloration, with blues, greens, and orange mouths.
Fully Rehabilitated:
By 19 February 2013, the coral looked as if it had been beautiful all along. There were no signs of fragging, and the coloration was fantastic. This previously dying Echinophyllia coral was rehabilitated!
After about a year-and-a-half recovery (2 November 2013), the coral was ready for a permanent home (excuse the oversaturated photo!) This coral went from essentially the “trash bin” to having a new start.
The before and after an Echinophyllia rehabilitation
This dying elegance coral (Catalaphyllia) came in on 24 November 2012 covered in aiptasia anemones and flatworms. Although I believed the flatworms were just Waminoa (nuisance, but not parasitic), but the previous owner was convinced the flatworms were actually parasitic. At the time, reports of LPS-eating flatworms were becoming more prevalent, so I wasn’t about to take chances.
This photo shows the coral in a dip to remove the flatworms and any other unseen parasites. I had to manually remove the aiptasia (chopping off parts of the old skeleton).
Only two days later (26 November 2012), and the coral was looking much better. (Only one piece of the Elegance is shown here.) With good water quality, I was hoping the coral would grow well.
Unfortunately, even seven months later (16 June 2013), the coral had not grown. Many rehabilitated corals often have stunted growth for about six months or so (some have had stunted growth for about two years). The coloration was significantly better though, with beautiful pink tips and fluorescent blue streaks reminiscent of lightning in the center.
Shortly after this photo was taken, the coral was permanently rehomed.
Move the slider to see the before/after coral rehabilitation!
“I’ll just feed my tanks before bed.” Famous last words. I spent the next two hours with a microscope and the glow of my computer screen instead of my nice, cozy bed. Even then, it took quite a while to find someone to identify them as likely the cercariae stage of fluke parasites in my reef tank.
A few minutes after feeding my reef tank, I noticed some rather large “pods” swarming around the top of the still water (all pumps were in “Feed Mode” – off). Odd, but nothing too weird. After all, I thought they were Ostracods at first (seed shrimp). On second glance, they looked too big. I paused, and then I realized what really caught my eye. They were red. Other than “red bugs” (Tegastes acroporanus), I’ve never seen red pods. I sighed in hesitation, then accepted my fate. Bed would have to wait.
I took a sample. There was no doubt; these were truly red. Ok, red Ostracods, right? I wouldn’t have to get out my microscope and prepare a slide, right? Wait. Ostracods don’t have tails. Noooooo.
Up Close with a Microscope: Fluke Parasites
I prepared a slide, and nothing could have prepared me for what I would find. I expected something in the definitive worm or pod realm. But not this. This was respiring. It was opening and closing its… mouth?
Closed…Opened…
Close-up of its anatomy… for what it’s worth.
Up until this point, they looked all cute. Like, little swimming strawberries, right? Nooooope. More like Sauron’s Eye (check out the video below).
So what are they? I have no idea. Every idea leads me down the wrong path. The closest I’ve landed is maybe some sort of larval sponge? (See update below.)
Identification: Fluke Parasites
Update (12/27/2020): Thanks to Reeffraff on Reef2Reef back in July 2020, it appears these are likely the cercariae of a trematode or fluke (in other words, they’re likely parasitic). Their life cycle probably involves snails and fish. I was right: these fluke parasites in my reef tank were the thing of nightmares! My treatment was to run fishless for several months (as the snails can shed for weeks/months). Another option, which I did not utilize, was to run PraziPro. I decided against that approach, as the number of worms (e.g., spaghetti, bristle) in my tank would probably cause a crash. I plan to quarantine all future snail purchases in a fishless system to avoid these.
On 14 May 2012, I received this bleached and receding Favia sp. coral. There was algae covering the exposed skeleton between the polyps as well. Although it isn’t shown, the back portion was mostly dead (and so was the front left area).
Here it is in the quarantine tank after the appropriate dips and inspections. Shortly after this photo, I decided to trim the dead portions off, which left mostly a flat piece.
By 14 August 2012, the coral had stopped receding and was regaining color. The algae was gone as well.
After five months (7 October 2012), the coral was starting to display a lovely “glitter” effect in its tissue.
Ignoring the bit of damage on the top (a coral fell into it – these things happen), by 6 January 2013, the coral was nearly recovered.
However, after another ten months (12 October 2013), it started to morph with these dark rings. Here, it is eating, which helped highlight its color ring.
By 2 March 2014 the coral was full morphed and healed.
After two years (5 May 2014), the coral stabilized and just continued growing naturally.
Two years may seem like a long time, but it was so worth all the effort!
