AEFW Archives - Coral Ever After

Coral Inspection, Dips, and Quarantine

reefdup How To, Rehabilitation February 25, 2022October 16, 2022acclimation, AEFW, coral dip, CoralRx, diagnosis, Dying Coral, gluing coral, grow-out, hydrogen peroxide, quarantine, Rehabilitation, Rescue Coral, superglue 7 Comments

A blog on coral rehabilitation is quite useless without a discussion on basic coral evaluation; a proper coral inspection, dip, and quarantine procedure deserves recognition. While there are many differing views on how and what to quarantine, this is my approach. If it seems a bit neurotic and obsessive, well, that’s because I’m taking in some of the most sick corals in the hobby. Hopefully learning from the worst case can help for the best. Find what works for you, and stick with it.

The Preparation:

Before bringing home dying coral, I have an established reef aquarium that I keep running continuously with no fish (this helps prevent Cryptocaryon irritans infestations or other outbreaks in my aquariums). Contrary to popular belief, long-term survivability of a reef tank without fish is quite easy (I’m measuring success in terms of years without fish). Lighting must also be adequate for what you intend to keep. A good skimmer should not be overlooked as well. If the tank will be a hospital tank, then a carbon reactor is essential to help remove coral mucus. Basically, this aquarium system does not have to be fancy or have all the frills. It just has to work. I’ve had many different quarantine setups over the years, and the best were always the ones that were the easiest to maintain. Honestly, most of my quarantine tanks just received the “hand-me-downs” from my other tanks. The coral rehabilitation system fish room shown was circa 2012.

The Acquisition:

I obtain my corals from everywhere, but I only recommend purchasing them from reputable vendors/hobbyists. Each of my coral acquisitions is worked out individually with the owner (e.g., sometimes I pay, trade, or make other arrangements) on a case-by-case basis. Regardless of the source, I inspect every coral visually for pests, nuisance algae, or hitchhikers prior to purchase to assess probability of survival. Depending on the coral species, I may look for pest-specific parasites (e.g., Acropora-eating flatworm bite marks (AEFW), red bugs on Acropora, Montipora-eating nudibranchs). Once the coral arrives home I acclimate it into the quarantine tank.

Coral Dips and Inspections:

Acclimation:

Acclimations are short (approximately 15 minutes for temperature adjustment), unless I have a specific reason for a prolonged drip. These corals are often damaged through poor water conditions in their previous home, so it is typically best to remove them from the cause as quickly as safely possible. If they were damaged from other causes (e.g., high light, stinging), then a short acclimation is not as important. After the coral is acclimated, I open the bag and put the coral in one cup of tank water in a separate container. For this part, I absolutely love my Magnetic Stirrer Coral Dip Station and my DIY face shield.

Coral Inspection and Diagnosis:

At this point, I perform a more thorough inspection to provide me with a usable “diagnosis” (again, I’m not a medical professional, but having an idea of what is wrong is still critical.) This “diagnosis” helps me determine how to treat the coral. For example, if the coral is bleached, I try to look for other markers to determine why (e.g., high light, extremely low light, poor water quality, disease), so I can arrange the most appropriate treatment (e.g., correct husbandry, additional feedings, disease treatment). The flowchart below depicts my typical “triage,” where I try to determine the most appropriate reaction as quickly as possible. This process helps when I bring home a cooler full of dying corals; I have to prioritize treatments and move fast.

The coral is then removed from the plug/base, and all dead skeleton is removed as much as possible. I find this especially critical for rescue corals. In my experience, corals have an easier time growing new skeleton rather than growing over old, especially if the old skeleton has sharp edges. If the coral was placed in strong current, the coral’s tissue could catch on a sharp edge of its old skeleton and rip. In cases where removing all excess rock/ skeleton would harm the coral further (example below – the coral’s tissue was not stable enough to cut the skeleton with a band saw), I just trim down any sharp points.

Coral Dips:

Hydrogen Peroxide Coral Dip:

First, all LPS coral receive a dip in a mixture of hydrogen peroxide and tank water. This helps kill off some nuisance algae and some pests. Hydrogen peroxide isn’t great for the coral tissue itself (prevents calcification), but it isn’t immediate death either. I just use the normal 3% pharmacy-grade type, as the high-strength hydrogen peroxide is very dangerous (can cause blindness in humans). The ratio I use depends on the coral’s condition, but a 10:1 tank water:hydrogen peroxide (3%) is fairly safe on LPS corals for about 20 seconds. In severe cases, I go up to 4:1 for 60 seconds, but I rarely recommend this.

CoralRx, Iodine, and Other Dips:

Second, all corals except smooth-skinned Acropora (they die frequently) are treated with one milliliter of CoralRx mixed with the one cup of tank water (or scaled to the size of the coral). Smooth-skinned Acropora are instead treated with Lugol’s Iodine mixed to manufacturer’s instructions. There are other suitable coral dips, but CoralRx is what I prefer (no real reason – it works, and I haven’t found a reason to switch).

The small amount of water volume limits where pests can hide after the dip draws them out. While the coral is sitting in the dip, I use a pipette to gently baste the coral to blow any remaining pests out of the crevices. I also use a magnifying glass to identify the hitchhikers.

If I find any pests or evidence of them (bite marks or eggs, like this Acropora coral with AEFW), then I will do an additional pest-specific treatment. I keep all treatment medications on hand so I never find myself looking for drugs at an odd hour (hmm…that sounds bad…).

Aquarium Medications (circa 2012 – oh, how this has grown over the years!)

After dip time is completed, the corals are rinsed with quarantine aquarium water (NOT the bag water.)

Final Coral Preparation:

After the peroxide dip, if there is any ripped or cut tissue, I place a small amount of superglue gel along the line (as shown on the Fungia coral). This helps prevent water flow from literally ripping the tissue off the coral. Superglue gel reacts with water to form a type of plastic mesh. However, this reaction is exothermic, which means it releases heat. This can cause cell death, so extreme care should be used. That’s why I prefer wound-grade superglue gel, like Liquid Skin or Vetbond (this is pricey, especially considering when I get my regular superglue gel from the dollar store, but the medical type is worth it in these cases). I also seal any remaining skeleton or base rock in regular super glue. This way, if there are any remaining pests or algae spores, they will have a hard time getting past the glue barrier. The coral will quickly grow over the super glue, and within about a month the super glue should not be noticeable.

Coral Quarantine Tank:

Corals are then transferred to the quarantine tank where they will stay for at least 30 days. During that time I visually inspect each coral about every three days for pests/bite marks/and overall health.

During this time, it is essential to keep hermit crabs, cleaner shrimp, and the like away from the coral. These critters will go after the dying tissue and often take away healthy tissue in the process, which can quickly lead to the coral’s demise. It is especially essential to keep them away during feeding, as the process of stealing food from a coral’s mouth can be extremely damaging.

Lighting and flow should be kept low to allow the coral to acclimate. However, the flow rate must be high enough to keep the coral mucus from building up on the coral.

Coral Grow-out Tank:

After the 30 days, I go through the entire dipping process again. Also, if the corals weren’t stable enough to have the excess skeleton/ base cut, I do that at this point. The corals then go into a grow-out tank/secondary quarantine where they live for another 30 days. After those 30 days, I repeat the dipping process a third time. But, I leave the entire base of the coral or a nice fragment of the coral in the grow-out tank. This allows me to have a healthy backup in case I lose my main colony. The main colony is moved to the main display after the dipping process or fragmented for sharing.

Grow-out Aquarium for Rehabilitated Corals

Coral Inspection, Dips, and Quarantine Conclusion:

Yes, it takes a whopping 60 days for a coral to make it to my main display. But, through a proper process of coral inspections, dips, and quarantine, I can rest assured that I minimize pests and nuisance algae. I will not have to rip out my corals to treat for AEFW or go almost two years without Montipora corals to treat for Monti-eating Nudibranchs. “An ounce of prevention is worth a pound of cure.” I can also sell my coral clippings knowing I’m providing a very healthy specimen to another hobbyist.

No matter where you buy a coral from, always quarantine. Do not trust anyone, even me. Everyone makes mistakes, and sometimes even a backup safety fails. You do not have to quarantine like I do, but any amount is better than nothing. I hope this post provides some insight on how to improve your procedures.

Assessing Coral Health: An Introduction

reefdup DIY, How To, Rehabilitation June 26, 2021October 16, 2022AEFW, bleached, brown jelly disease, Coral Health, disease, Dying Coral, fragged, fragmentation, husbandry, infected, infested, parasite, poison, starvation, Stung, Tegastes acroporanus 9 Comments

Even on a smaller scale than global reef decline, the ability to assess coral health is essential. I am often asked how I know where to even start to rescue corals. In my opinion, determining how healthy the coral is, or what the problem might be, is usually the first step. This is an introduction on assessing coral health to determine what might be causing the coral stress.

Assessing Coral Health for Stung Corals:

Corals stung by another coral are probably the most easy to save. These corals are healthy overall, but a portion of them is damaged. As long the coral avoids infection and no further damage occurs, then healing is rather quick. When a coral “stings” another coral, the stung coral is sometimes actually “digested.” When corals have to compete for territory, they expel their digestive organs, called mesenterial filaments, and use them to digest a nearby coral. This typically results in one area of severe damage and no damage elsewhere. A coral stung this coral shown, but the remaining tissue was very healthy. You can read more about the Trachyphyllia’s recovery here.

Lack of Proper Husbandry:

A lack of proper husbandry is typically a slow process. It can result in the tissue between polyps receding first. As shown here, portions of recent die-off right are beside healthy tissue and coralline-encrusted skeleton. With these corals, good water parameters are essential. Removal of invasive algae is also critical. These corals typically do not need much additional care. You can read more about this Lobophyllia’s recovery here.

Assessing Poorly-Fragmented Corals:

When a coral is improperly fragmented, various outcomes are possible depending on damage. Sometimes the tissue rips apart improperly, or the skeleton is crushed underneath intact tissue. As long as there is about half the polyp left, the coral typically survives with the natural healing process. This Euphyllia coral unfortunately became infected and died.

Corals with Pest Damage or Parasites:

Attempting to rescue an infected coral is risky, as it may infect other corals. This type of rescue requires a proper quarantine tank and medications on hand. Typically, once the pests and any eggs are removed, the coral will heal quickly on its own. Here, this infected Acropora has both Acropora-eating flatworms and red bugs (Tegastes acroporanus). With proper treatments to remove both pests, this coral made a full recovery.

Assessing Coral Health due to Infections:

Attempting to rescue infected corals can be dangerous, complex, and expensive. Any attempts require a dedicated hospital tank, proper supplies (including a microscope), and extensive knowledge in coral diseases and treatments. Furthermore, keeping a low expectation for coral survival is key. These infections vary by cause (e.g., bacterial, viral, fungal, ciliate, etc.), so the owner must tailor treatment to the cause. Determining the cause can be nearly impossible without the proper equipment. Any attempts also require the utmost caution, as some infections are transferable to humans. This coral shown had “brown jelly disease.”

Bleached Corals:

Coral bleaching also has a variety of causes, and knowledge of the cause can help determine possible solutions. Assessing a bleached coral’s health can be challenging as high light, chronic low light, high temperature, low temperature (rare cases), lack of oxygenation, and some infections can cause bleaching. Since a bleached coral is lacking its typical zooxanthallae population (the symbiotic algae that lives inside the coral’s tissues and produces food for the coral), it will need regular feedings. Unfortunately, in my experience, sometimes these corals never thrive again, even with coloration return.

The photo below shows several corals that were poisoned with household bleach. An angry customer poured it into a local fish store’s tanks, which killed all the livestock. I attempted to save everything that still had tissue, but even these corals eventually died.

Starved Corals:

Although starvation is more commonly seen in non-photosynthetic corals (NPS), it is still possible in photosynthetic corals as well. This is more likely to occur in in ultra-low nutrient systems, also known as ULNS. Here, a Dendrophyllia coral is starving, shown by the algae-encrusted skeleton. Regular feedings are essential in these cases.

Poisoned Corals:

Poisoned corals usually have retracted tissue with areas of white skeleton showing. Tissue colors are usually brown or white, depending on the toxin. Any other typical colors (e.g., blues, reds, greens) are muted. This coral was poisoned by either the flatworm treatment a LFS used, or by the flatworm toxins themselves. You can read more about this coral’s amazing recovery here.

As shown, coral health has a multitude of causes, and only a few examples were shown here. If you would like to continue learning about coral pathology, a more technical source is available on NOAA.

Dying Acropora Coral Rehabilitation

reefdup Acropora, Rehabilitation May 29, 2021May 29, 2021acropora, acropora eating flatworms, AEFW, brown coral, Dying Coral, red bugs, Rescue Coral, Tegastes acroporanus 0 Comment

Acropora Rehabilitation Before and After

Back in 2012, I took in several corals from a fellow reefkeeper, knowing they were all rescues. Included in the bulk were a few dying Acropora corals that desperately needed rehabilitation. However, rehabilitating small polyp stony (SPS) corals has its own challenges, and in many cases, these sensitive corals may experience a more rapid death than their large polyp stony (LPS) counterparts. Below I will cover the initial inspection, diagnosis, treatment, for a complete dying Acropora coral rehabilitation.

Assessing Dying Coral Health:

All dying Acropora coral were brown, not extending polyps, and had white marks on them. Upon initial inspection (and not shockingly), they had red bugs (Tegastes acroporanus) and Acropora-eating flatworms (AEFW). I treated the AEFW and red bugs with a series of coral dips as part of rehabilitation efforts. I also inadvertently subjected the tank to a reduced temperature (thanks power outage), which quite possibly killed the red bugs. (At the time, Interceptor was the normal protocol for treating red bugs, but there were also several other suitable treatments.)

Since AEFW lay eggs, it was critical to regularly inspect the coral and re-treat to completely eliminate the parasites. Thankfully, red bugs are live-bearers, so once they were initially eliminated, I no longer had to worry about them.

Quarantined Acropora Coral:

Of course, Acroporas require stable salinity, alkalinity, magnesium, calcium, etc. Given that I had over 50 corals undergoing rehabilitation at the time, my quarantine tank was not exactly a healthy aquarium. I had to focus particularly hard to make sure the other dying corals did not adversely affect the SPS. Water changes to remove excess nutrients were crucial. Once the Acropora parasites were gone, I maintained my alkalinity at 9 dKH, magnesium at 1350, and calcium at 450. I also performed 20% weekly water changes.

Previously Dying Acropora Coral Rehabilitated:

With stable parameters and a lack of parasites, this previously dying Acropora coral was quickly rehabilitated. They can heal quickly and add a beautiful touch to the aquarium. However, I don’t recommend Acropora rescues for beginners as they can have more severe pests than LPS corals, are sensitive to poor water conditions, and require careful monitoring of water parameters.

Red Bug Parasites (Tegastes acroporanus)

reefdup Identification, Red Bugs May 29, 2021October 16, 2022acropora, AEFW, Bayer, Coral, Interceptor, Milbemax, red bugs, small polyp stony, SPS, Tegastes acroporanus 4 Comments

Somehow back in the day, after over five years of having SPS-dominant aquariums, I got my first case of red bug parasites. A local aquarist was tearing down his system and gave me a few corals that weren’t doing well. Turns out, red bugs AND Acropora-eating flatworms (AEFW) infested the corals. Fortunately, I caught the red bugs while the Acropora was still in my quarantine tank.

Red bug parasites (Tegastes acroporanus) are extremely tiny copepods (as seen in the red circle in the photo) that solely infest Acropora corals (not Montipora, Pocillopora, etc.) They come into the hobby on wild or maricultured colonies (corals purposefully grown and harvested in controlled ocean environments), and hobbyist selling/trading of aquacultured corals further spreads them.

A good indicator of a red bug infection is a loss of Acropora tip coloration and browning that cannot be attributed to other factors. Red bugs caused the coral shown to lose nearly all coloration, while AEFW caused the white patches.

In the early 2000’s (now I’m dating myself), there was a general consensus in the reefkeeping hobby that red bugs only affected smooth-skinned Acroporas. Hobbyists assumed they did not bother corals like Milleporas or “the green slimer” due to the extra mucus they produce. Although red bugs do tend to prefer certain Acropora (especially Acropora valida, the “tricolor”), most every Acropora species is susceptible. Hobbyists also commonly believed that red bugs laid eggs and had a larval stage. This led to a consensus that three treatments were needed in order to eliminate the red bugs entirely. Although research eventually determined that red bugs are live bearers, I still recommend three treatments just as a safety precaution.

How to Identify:

On Acropora corals that have “browned out” due to red bug presence, the red bugs are rather distinguishable. They are mostly yellow (almost a gold color) with a bright red dot. They are also extremely tiny at around 0.5mm (think a little bigger than the size of the period at the end of this sentence). Unfortunately, they are not easy to see on healthy corals, and they have an ability to hide within the coral polyp itself without being consumed. In order to determine the presence of red bugs, I use a magnifying glass to look for them before placement into my quarantine system. After that, I observe the coral daily for a week. I also take a photo of each coral and zoom in to look for anything I’ve missed.

How to Treat Red Bug Parasites:

Unlike other serious pests (e.g., Montipora-eating Nudibranchs), there is a suitable in-tank treatment for red bug parasites.

Method 1: Control

Some hobbyists believe that blowing the corals off with a powerhead a few times for a couple weeks will rid the Acropora of red bugs since they may starve before finding their way back to the coral. Other hobbyists rely on natural predation (e.g., pipe fish, file fish, gobies, wrasses), but to my knowledge, no predators have a 100% success rate. I advise against natural control methods for aquarists who plan to sell/trade their corals.

Method 2: Coral Dips

Coral dips often help stun the pests so they can be blown off gently with a pipette or powerhead. Since red bug parasites are live bearers, this method can work as long as all the red bugs are removed. Since a succession of coral dips work for AEFW and red bugs, I dip all Acroporas daily the first week. After that, I dip every other day the second week, every third day the third week, and then once a week for weeks four through six. I have not lost a single coral with this method, and it saves me the hassle of treating with different medications for different parasites at different times.

I should note that I’ve never found a pest after week two, but I still go the full six weeks since the lifecycle of AEFW is quite long (and I always treat for both AEFW and redbugs). Also, some dips can be extremely damaging to smooth-skinned corals, so please use caution if you plan to treat one of these.

Coral Dip Treatment Protocol for Red Bug Parasites:

Follow dip manufacturer instructions.

Method 3: Prescription Flea Medications

Before the manufacturer discontinued it, hobbyists considered Interceptor (milbemycin oxime), a prescription canine flea medication, as the golden standard for red bug parasite treatment. However, as it killed all shrimp, crabs, and other crustaceans, aquarists had to remove them before dosing (the pod population recovered with time). This die-off would also spike ammonia levels, so reefkeepers had to be prepared for a water change and to run carbon. Many people had difficulty obtaining Interceptor from their veterinarians since treating for red bugs is an off-label use. However, the Veterinary Information Network (VIN) published information on red bug parasites for reference.

Once Interceptor was no longer available, reefkeepers began searching for a replacement. Currently, Milbemax is the most often recommended replacement. It is a prescription combination of milbemycin and praziquantel. (The latter medication is commonly used for fluke treatment in reef tanks (e.g., PraziPro); however, it is a much lower dose than would be effective for common marine flukes).

Providing proof of infection to a veterinarian and asking him/her to look up red bugs on the VIN should be enough to receive the medication (or at least it was for us.) Some veterinarians have recommended different medications with different treatment protocol (e.g., MilbeMite Otic), so those individual cases are not discussed here. Unfortunately, many aquarists are finding some red bugs have a resistance to milbemycin. If you try it with no success, work with your veterinarian to find an alternate medication or try one of the other methods listed here.

Interceptor Treatment General Protocol for Red Bug Parasites:

(This is provided for historical purposes only since Interceptor is no longer available, as it may be relevant to other treatments.) Dustin Dorton of ORA determined 0.025 grams of Interceptor are needed per 10 gallons of water. After that, the protocol is the same as Milbemax, described below.

Milbemax Treatment General Protocol for Red Bug Parasites:

(Obtain actual procedures from a veterinarian, as this is for general reference only.) The recommended dosage is 23mg per 400g tank water, which works out to 0.0575mg per gallon tank water (or 5.75mg per 100 gallons if that is an easier reference point). Similar to Interceptor medication, pulverize and weigh the medication out as accurately as possible. Estimate the true volume of water as close as possible (subtracting live rock, sand, etc.)

Remove all crabs, shrimp, and other crustaceans from the aquarium before dosing. Turn down the skimmer so that water runs through it, but the skimmer doesn’t actually skim. Remove GFO and activated carbon. Add an airstone (or multiple, depending on the size of the tank) bubbling gently to help maintain the pH. Otherwise, allow everything else to run so that the chemical can spread throughout the aquarium. Dose the correct amount and let the system run for six hours.

After six hours, the red bugs should be gone, but if they are not, slightly adjust the dosage and try again in a few days. Perform a water change (~15-25%), turn the skimmer back up, and bring the GFO and carbon back online. As mentioned above, although red bugs are live bearers, three treatments a few days apart is still ideal. Once the red bugs are completely eradicated and the medication is removed, reintroduce the crabs, shrimp, and other crustaceans to the aquarium.

Method 4: Bayer Advanced Insecticide

WARNING: Per Bayer Advanced Insecticide’s labeling, “It is a violation of Federal law to use this product in a manner inconsistent with its labeling.”

Yes, this is the stuff you may have in your garage or at your local hardware store. Some aquarists use it as a dip only, not as an in-tank treatment. This website does not cover Bayer use as a coral dip, due to the warning above.

Method 5: Temperature Adjustment

With crazy heat in the summers, lowering the tank temperature may not be feasible. But for tanks located in basements during the winter, this may be the least expensive option. In fact, this method worked for me…accidentally! Right after I received the infested Acropora mentioned above, we lost power for about six hours. My quarantine tank got down to about 65 degrees (thanks to being in Utah in the middle of winter). After the power came back on, there were no signs of red bugs. I’m not the first to document this. I still continued treating for them just in case, but I never saw another one. This seems to work, but we still need scientific studies to back it up.

Experimental Temperature Treatment Protocol for Red Bug Parasites:

Slowly lower temperature to 65-66 degrees. If tank inhabitants start to show signs of stress, start bringing the temperature back up. Leave the temperature at 65-66 degrees for 4-6 hours. Note: this is experimental, and there is not enough data to determine if this treatment works 100% or is safe. Use with caution!

Conclusion:

Thanks to all the courageous mad scientist reefkeepers out there, there are several proven treatments for red bugs, including an in-tank treatment. The Acropora shown was saved from both red bugs and AEFW! Hopefully, with the increasing ease of treatment protocols, red bugs will be a thing of the past. Best of luck in your treatment!

Identification of Marine Eggs

reefdup Identification, Marine Eggs January 23, 2021October 16, 2022AEFW, Berghia, Cerith, Collumbellid, Crabs, Eggs, Montipora-Eating Nudibranchs, Nerite, Nudibranchs, Polyclad, Snails, Stomatella 6 Comments

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.

Berghia Nudibranch Eggs (Berghia verrucicornis) – Reef Safe:

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 Snail Eggs (Nerita sp.) – Reef Safe:

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!

Collumbellid Snails…AKA Hawaiian Strombus Snails…AKA Strombus maculatus – Reef Safe:

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 Snail Eggs (Nassarius sp.) – Reef Safe:

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 Snail Eggs (Cerithium sp.) – Reef Safe:

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 (Stomatella sp.) – Reef Safe:

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!

Conch (Strombus sp.) – Reef Safe:

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.

Polyclad Flatworm – Not Reef Safe:

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.

Gall Crab Eggs – Reef Safe with Caution:

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).

Coral Eggs – Reef Safe:

Coral eggs, like the Tubastrea coral eggs shown, are typically orange balls. The coral below actually started spawning while in a coral dip!

Unknown Marine Eggs

Marine egg diversity is vast, as shown by another pattern here. What eggs have you found in your tank?