Wild tang with black spots seen scuba diving

[Peter Clark]

I was recently in Bonaire (Caribbean) scuba diving and saw many tangs with black spots. It was mainly the Ocean Surgeonfish that had it. Below are photos of 2 different ones (1 photo of the first and 2 of the second). Just curious what these spots are. I assume some sort of disease, which is sad considering how often I saw it.

 

[SeaJay]

Wow. That’s unfortunate. I went diving in Bonaire 20 years ago. Best dive trip I ever went on.

 

[danschoenherr]

Have seen this on occasion on Surgeon fish in the Carribean, but am unaware of what it is.

 

[Peter Clark]

Wow. That’s unfortunate. I went diving in Bonaire 20 years ago. Best dive trip I ever went on.

It was one of the best I have ever been on too. I loved the amount of staghorn coral I saw thanks to the Reef Renewal Bonaire organization (offshoot of Coral Restoration Foundation from the Florida Keys).

 

[SeaJay]

It was one of the best I have ever been on too. I loved the amount of staghorn coral I saw thanks to the Reef Renewal Bonaire organization (offshoot of Coral Restoration Foundation from the Florida Keys).

Being able to just walk out of your room at any time, grab a tank and jump off the dock into such a magnificent reef is priceless.

 

[Peter Clark]

Being able to just walk out of your room at any time, grab a tank and jump off the dock into such a magnificent reef is priceless.

5 of my 17 dives were just right there at the hotel. So simple.

And to have a happier photo, I have the below of an awesome area of the critically endangered staghorn coral. Restoration efforts work.

 

[discocaz]

I was recently in Bonaire (Caribbean) scuba diving and saw many tangs with black spots. It was mainly the Ocean Surgeonfish that had it. Below are photos of 2 different ones (1 photo of the first and 2 of the second). Just curious what these spots are. I assume some sort of disease, which is sad considering how often I saw it.

Sorry to revive an old thread but I'm on a team that researches this disease and found this post just recently!

That surgeonfish has Black Spot Syndrome (BSS) and is infected with a parasite called Scaphanocephalus expansus (below). Parasites like this usually infect fish through proximity or ingestion of a snail that was previously infected by the same parasite. The infected fish are then eaten by a predator, an osprey in the case of S. expansus, where they reproduce sexually. The eggs are released in the bird's feces, which then infect an new crop of snails. Ah, the circle of life.

Bonaire is currently the island with the most BSS anywhere we've looked in the Caribbean. We aren't quite sure why, but we are trying to understand the parasite's lifecycle and distribution in hopes of answering this question (among many others!).

If anyone sees this in aquaria or out in the wild and has more photos they think might be of BSS/Scaphanocehalus please send me a PM! If you're in for a more technical read you can find our article about BSS on Bonaire here.

 

[Jay Hemdal Verified Community Expert]

Sorry to revive an old thread but I'm on a team that researches this disease and found this post just recently!

That surgeonfish has Black Spot Syndrome (BSS) and is infected with a parasite called Scaphanocephalus expansus (below). Parasites like this usually infect fish through proximity or ingestion of a snail that was previously infected by the same parasite. The infected fish are then eaten by a predator, an osprey in the case of S. expansus, where they reproduce sexually. The eggs are released in the bird's feces, which then infect an new crop of snails. Ah, the circle of life.

Bonaire is currently the island with the most BSS anywhere we've looked in the Caribbean. We aren't quite sure why, but we are trying to understand the parasite's lifecycle and distribution in hopes of answering this question (among many others!).

If anyone sees this in aquaria or out in the wild and has more photos they think might be of BSS/Scaphanocehalus please send me a PM! If you're in for a more technical read you can find our article about BSS on Bonaire here.

Thanks for the great information! I think we run into other digeneans from time to time in aquarium fish that all get lumped into something called "Black ich" - a terrible common name, I know. Some of those cases are caused by Paravortex turbellarians. In others, the lesions seem more diffuse, like your images. I've just always called them "digeneans" and never went any further. Because of their complicated life cycles, they are almost always self-limiting in aquariums so I tend not to medicate for them (since the treatments are all fairly risky).

Jay