Dear Lora:

Pete Giwojna

Dear Lora:

I’m sorry to hear about the problem that the lawnmower blenny cost for your seahorses.

Unfortunately, they cannot be trusted with seahorses as you’ve discovered a little too late.

This is what I usually advise home hobbyist regarding the lawnmowers, Lora:

Lawnmower Blennies

For starters, I can tell you that you must not take a chance on keeping a lawnmower blenny with your seahorses. That’s an experiment that has been tried many times, and it often results in the death of the seahorses. There are some types of blennies that do quite well with seahorses, such as the Midas blenny and often the scooter blenny, but, unfortunately, the lawnmower blenny (Salarias fasciatus) is not one of the compatible blennies. They can be problematic with seahorses and must always be regarded with caution.

For example, Kevin Frenzel and Renée Hix categorize lawnmower blennies as a “3” on their scale in their seahorse compatibility guide. A reading of 3 indicates the following:

“3 – I wouldn’t keep any of these critters with my seahorses, but you’re welcome to try. 3’s are on the dangerous side. The fish will not only be in the water column but often have a distinct presence. There is a good chance for food competition and aggression.”

I would agree with that assessment, Lora, and I typically advise seahorse keepers to avoid lawnmower blennies. Just a few weeks ago, I received a report from another hobbyist (Katie) who had lost two of her Ocean Rider seahorses to attacks from a rogue lawnmower blenny. Katie’s seahorse tank is a 92-gallon aquarium with lots of live rock and she had a dreadful time capturing the aggressive blenny because there are so many hiding places in the rockwork. She eventually had to systematically remove the live rock temporarily so that she could remove the blenny before more damage was done to her other ponies.

I recently also received a report from David and Sheena Mikesell, who had just introduced four Ocean Rider seahorses into their home aquarium, and lost two of them for no apparent reason in the next few days. The only discovered the reason for the deaths later that weekend when they witnessed their lawnmower blenny viciously assaulting another of the ponies. This time they were able to intervene, but the seahorse unfortunately died several days later from its injuries. In less than a week, their lawnmower blenny managed to kill three of their four new seahorses without being detected doing its dirty work until both Dave and Sheena were home on the weekend and observing the remaining seahorses closely for any sign of a problem…

And I had another hobbyist (Deborah) who contacted me asking about the behavior of her lawnmower blenny, which wasn’t viciously attacking her seahorses, as happened with Katie and the Mikesells, but rather was “mouthing” them the same way it did when cleaning algae off of the rockwork or decorations. In other words, Deborah’s lawnmower blenny would periodically clean one of her seahorses as if it were part of the aquarium decor.

As you can imagine, her seahorses were always somewhat traumatized when the lawnmower blenny would do his cleaning, and would be very apprehensive and reluctant to feed afterwards. Of course, the unwanted attention of the lawnmower blenny was also compromise the seahorses’ protective slime coat, which left them susceptible to disease problems, and the seahorses were very intimidated by the blenny, and she also had to remove her lawnmower blenny, even though it didn’t seem to intend any harm to the seahorses directly.

Those are only a few most recent examples of the type of reports I hear regarding lawnmower blennies all of the time, Lora.

Whatever you have any questions or concerns about the compatibility of specimens that were not specifically mentioned in Lesson 6 of the seahorse training program, which is devoted to suitable tank mates for seahorses, just go online and check out the following webpage:

Tankmate Guide for Seahorses by Kevin Frenzel and Renée Hix

The only thing I can recommend that might aid your seahorses to get back to normal and bounce back following their experience with your lawnmower blenny, would be to treat them with a good antibiotic to prevent any secondary infections from stress or any injuries that the blenny may have caused. The antibiotics that work best for most home hobbyists when treating seahorses are Furan2, which can be used all by itself, or a group of medications by SeaChem that can be used together and mixed with frozen Mysis in order to administer the medications orally.

The SeaChem medications that work best for this purpose are SeaChem, KanaPlex, SeaChem NeoPlex, and Focus by SeaChem.

The active ingredient in SeaChem KanaPlex is kanamycin sulfate, a potent aminoglycoside antibiotic that is a very broad spectrum, and which can be combined with the neomycin sulfate (another aminoglycoside antibiotic) in SeaChem NeoPlex to create a synergistic effect that is more effective than either of these antibiotics used by themselves.

The SeaChem NeoPlex contains neomycin sulfate, a good aminoglycoside antibiotic that is very effective when ingested, and the SeaChem Focus contains a good nitrofuran antibiotics and is the perfect medium for mixing medications with frozen foods. I will explain more about how to use these two products together for you below.

Both the NeoPlex and the Focus come with little scoops for measuring out the proper dose of the medication, Lora, and preparing the frozen Mysis with the medications is actually pretty easy. First, you want to find out how much of the Mysis you are using amounts to a tablespoon. I imagine that several of the cubes of Mysis would be needed to fill a tablespoon after you have thawed it out as usual, if that’s the form of frozen Mysis you happen to have. (It’s important to find out how much of the thawed Mysis constitutes 1 tablespoon because the correct dosage for NeoPlex is one scoop or measure per tablespoon of Mysis.)

Once you have thawed out 1 tablespoon of the frozen Mysis, you then measure out one scoop of the NeoPlex and five scoops of the Focus and mix the two medications thoroughly so that they bind together. (You always add five times as much of the Focus as the amount of antibiotic you are using.) Once you have mixed the powdered NeoPlex and Focus together very well, you then add the resulting mixture to the tablespoon of thawed Mysis you have prepared and very gently but thoroughly mix the powder and Mysis together so that the medications bind to the shrimp. You can then either feed the medicated Mysis to your seahorses immediately or freeze it for later use.

Once you have prepared the medicated Mysis, you feed it to your seahorses twice a day for at least five consecutive days or as long as is takes for the symptoms to clear up.

Of course, you can prepare more than 1 tablespoon of the medicated Mysis at a time in order to make it more convenient, Teresa. For example, if you wanted to prepare 5 tablespoons of medicated Mysis’s at one time, you would thaw out 5 tablespoons worth of your Mysis in advance. Then you would take 5 scoops of NeoPlex (one scoop of NeoPlex per tablespoon) and 25 scoops of the Focus (5 times as many scoops of Focus as the antibiotic) and mix it together thoroughly with the five scoops of NeoPlex so that they blend together and bind. Finally, you would take the mixture of powders and gently but thoroughly combine the powdered medications with the thawed Mysis so that the medicine also binds with the shrimp.

If you want to prepare extra medicated Mysis in advance, it’s best to spread it out on a piece of Saran wrap or Glad wrap or aluminum foil, or something similar, so that you can cover it completely to protect it from freezer burn until you’re ready to use it.

Here is some additional information on the Focus by Seachem Laboratories, which explains how to use it to combine medication with food:

Seachem Laboratories Focus – 5 Grams Information

Focus ™ is an antibacterial polymer for internal infections of fish. It may be used alone or mixed with other medications to make them palatable to fish and greatly reduce the loss of medications to the water through diffusion. It can deliver any medication internally by binding the medication to its polymer structure. The advantage is that the fish can be medicated without contaminating the entire aquarium with medication. Fish find Focus™ appetizing and it may be fed to fish directly or mixed with frozen foods. Focus™ contains nitrofurantoin for internal bacterial infections. Marine and freshwater use. 5 gram container.

Types of Infections Treated:


DIRECTIONS: Use alone or in combination with medication of your choice in a 5:1 ratio by volume. Feed directly or blend with fresh or frozen food. Feed as usual, but no more than fish will consume. Use at every feeding for at least five days or until symptoms clear up.

Contains polymer bound nitrofurantoin.

Active ingredient: polymer bound nitrofurantoin (0.1%). This product is not a feed and should not be fed directly. Its intended application is to assist in binding medications to fish food.

And here is an excerpt from an e-mail from another home hobbyist (Ann Marie Spinella) that explains how she uses the NeoPlex together with the Focus for treating her seahorses, Lora:

“When I bought the NeoPlex yesterday I also picked up a tube of Focus. According to the instructions, it says it makes the medication more palatable to fish and reduces the loss of the medication once it’s in the water.

So I followed the dosing instructions exactly. I used regular frozen Mysis instead of Piscine Energetics frozen Mysis. I figured it was softer and smaller. I was thinking along the lines of more surface area for the medication to adhere to, and with the softer shell, hopefully it would absorb into the shrimp a little better.

I used 8 cubes which came to just about 1 tablespoon. I thawed and rinsed the shrimp thoroughly in a little colander and let it sit on a paper towel to remove as much water as possible.

Then I put in it in a small dish and added the Focus and NeoPlex in the recommended ratio which is 5:1 (5 scoops Focus / 1 scoop NeoPlex). I mixed it thoroughly and added a few drops of Garlic Power.

Then I measured out 5 – 1/4 tsp. servings and 4 servings I placed on a sheet of Glad Press & Seal, sealed them and put them in the freezer, since it says in the instructions that you can freeze what you don’t use right away, and the remaining 1/4 tsp. I split in half and fed to them this morning. The rest I’ll give to them this afternoon and I’ll do this every day with the remaining shrimp that I already prepared and froze.

In the video you can see that the seahorses are eating it. Yea!!

Thanks for all of your help & I’ll keep you posted.”
Ann Marie

Okay, Lora, that’s the rundown on using the NeoPlex together with the Focus so that you could administer the medication in the NeoPlex orally after adding it to the frozen Mysis for the seahorses daily meals. If you got the KanaPlex instead of the NeoPlex, it can be combined with Focus and administered in exactly the same way as outlined in the instructions for the NeoPlex above.

You can feed the medicated Mysis to your seahorses twice a day until they are back to normal again and all is well.

If you obtain the Furan2 instead of the SeaChem medications, Lora, then I would recommend administering it as follows:

For best results, I would suggest gutloading live adult brine shrimp with the antibiotic and then feeding the medicated adult brine shrimp to the seahorses twice a day for the next 10 days. This will allow you to treat the ponies in your main tank, where they are most comfortable, which is the least stressful way to administer the medication. I would suggest using Furan2 for the antibiotic, since it is readily available at most local fish stores and is most effective when it is administered orally, as explained below:

FURAN-BASED MEDS (oral) Dosage and Preparation Instructions
Active Ingredients: Nitrofurazone and/or Furazolidone
Indication: bacterial infection
Brand Names: Furan-2, Furanase, Binox, BiFuran+, FuraMS, Furazolidone Powder
Feed adult brine shrimp gut-loaded with medication to the Seahorse 2x per day for 10 days.
• Add a small amount of the medication to one gallon of water and mix thoroughly.
• Place the amount of adult brine shrimp needed for one feeding into the mixture. Leave them in the mixture for at least 2hrs.
• Remove the adult brine shrimp from the mixture and add them to the hospital tank.
• Observe the Seahorse to be certain it is eating the adult brine shrimp.

Hopefully, your seahorses will recover from the aftereffects of your aggressive blenny and be back to normal again before you know it, Lora.

Please let me know if you are still having a problem with the hair algae and I would be happy to provide you with some tips for controlling and eliminating nuisance algae.

Pete Giwojna, Ocean Rider Tech Support

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