New baby fish?

[Smiles1969]

After doing some vacuuming and a water change today, while waiting for the tank to settle I noticed a new fish that I did not purchase and hadn't seen before. The little one on the lower right with the red tipped dorsal fin and anal fin? It's pretty small and I'm having a hard time getting a really good photo of it. The upper left has one of my firefish for scale. Any thoughts on what it could be? I'm just curious if it's going to be a problem when it's older/bigger.

 

[C4ctus99]

That’s crazy, do you have any spawning fish or get live rock? I’m just wondering where it came from…

 

[C4ctus99]

Either way, I’d think you’ll be fine till it develops more and you can get a more accurate id

 

[littlefoxx]

Woah!! What is that?? Thats so cool!! If I didnt know better I would think thats a freshwater fish with how it looks. Maybe a chromis or some kind of damsel?

 

[vetteguy53081]

After doing some vacuuming and a water change today, while waiting for the tank to settle I noticed a new fish that I did not purchase and hadn't seen before. The little one on the lower right with the red tipped dorsal fin and anal fin? It's pretty small and I'm having a hard time getting a really good photo of it. The upper left has one of my firefish for scale. Any thoughts on what it could be? I'm just curious if it's going to be a problem when it's older/bigger.

This is a Gambusia which is related to guppies and Can survive in saltwater. It likely was a hitchhiker from coral or fish purchase and is often a result of LFS using same nets for capture and not rinsing. This guy will be a good algae eater but could become a meal for a fish in the future

 

[-JoJoReefing-]

That is cool! I have never seen a fish as a hitchhiker!

 

[Smiles1969]

That’s crazy, do you have any spawning fish or get live rock? I’m just wondering where it came from…

I have 3 blue/green chromis and 3 firefish. I don't think this is either one of those. I did get live rock when I started up my tank in December. I also got some macroalgae in February but it's almost May. I have no idea where it came from lol

 

[littlefoxx]

This is a Gambusia which is related to guppies and Can survive in saltwater. It likely was a hitchhiker from coral or fish purchase and is often a result of LFS using same nets for capture and not rinsing. This guy will be a good algae eater but could become a meal for a fish in the future

Huh thats cool! I guess I was right on my intuition saying freshwater fish lol. Either way the little guy is cute!

 

[Smiles1969]

This is a Gambusia which is related to guppies and Can survive in saltwater. It likely was a hitchhiker from coral or fish purchase and is often a result of LFS using same nets for capture and not rinsing. This guy will be a good algae eater but could become a meal for a fish in the future

Thank you so much. I have 3 firefish and 3 blue/green chromis currently so I hope they won't bother it. I do have algae a plenty for it.

 

[vetteguy53081]

Thank you so much. I have 3 firefish and 3 blue/green chromis currently so I hope they won't bother it. I do have algae a plenty for it.

He'l be safe with them

 

[Smiles1969]

He'l be safe with them

Could this be a Rainwater Killifish? After you said it could be a freshwater fish related to guppies I did some searching and killifish can live in saltwater. I found a photo of a female Rainwater Killifish. Thoughts?

 

[Tired]

Honestly, I thought this was gonna be a mysis shrimp or something, but no! That's a fish!

Some species of freshwater killifish can live in saltwater- not all. That does look rather killifish-like, though. Update when it grows some, and maybe we can find out.

 

[vetteguy53081]

Could this be a Rainwater Killifish? After you said it could be a freshwater fish related to guppies I did some searching and killifish can live in saltwater. I found a photo of a female Rainwater Killifish. Thoughts?

This is a much clearer photo and does look like a killie which has same habits as a gambusia. They are prone to flukes but risk is lessened in salt

 

[Anemone_Fanatic]

This is either a killifish or gambusia, as others have said. This isn't as uncommon as you might expect, I've seen a few other posts about this before. Not entirely sure where they come from, but it seems probable that it snuck in as a baby in rock/macroalgae or as an egg. Killifish eggs can stay dry for a while (over a year and a half), so it could have come in as an egg on used equipment from another tank. Should be reef safe, but some people have problems with fin nipping from them.

 

[Dog Whiskey]

I have this fish. Let me tell you my saga....

Best I can tell, mine came in on something (cheato or live rocks) as an egg and hatched. I'm fairly sure it's a male rainwater killi because of the strong red, orange, yellow, and black coloration. It's supposed to live for a year. 15 months later he is still going strong.

He was so cute and charming at first. That lasted about two months. Then he evolved into the spawn of Satan.

As a youngster he started hanging out with the blue/green chromis gang I had. Then he apparently decided he was actually the alpha chromis and needed to bump off everyone else in the gang. He was very successful in this effort.

As a baby with the chromis and clowns.

When I caught on to what was going on in around May 2022, I was able to catch the killi. He was in my isolation tank solo for MONTHS. Two chromis are left in the DT at this point. But he was a model citizen during a month-long observation period with a fang blenny and a blackcap basslet. So I figured he was safe to go back into the DT.

BIG mistake. He immediately started terrorizing the chromis, bullying one to death. Tried to catch the killi for a week. Impossible. It's fast and smart and now it knows what's a trap and avoided it like the plague. And while I have no proof of his guilt, three shrimp mysteriously disappeared during this same time period. I finally just removed the last chromis standing (or swimming???) to the iso tank. This is early October 2022.

In December I got a pavo damsel from Biota who the chromis seemed to like hanging with in iso. I thought it could be the two of them against the killi. The damsel is super bold -- a perfect dither fish. And it had been like three months after the last killi terror attack. That would work, right?

Wrong. Pop both the damsel and chromis into the DT with lights out. It took approximately a minute (tank dark) for the killi to start chasing the chromis, who then laid down on the sand in the corner wedged by a rock totally stressed. Chromis goes back in the iso tank where it's been since early January.

The killi then tried to terrorize the damsel, but fortunately the damsel is having none of it. It's actually kind of funny. Damsel chills with everyone else but goes on the offensive with the killi. BECAUSE THE KILLI IS A TURD.

The turd today.

The weird thing is that the killi ONLY chases fish shaped like damsels and chromis. Everyone else is left alone, even fish that are closer in color, size, or shape.

At this point I'm hoping for one of three things: 1. the cat goes fishing and catches the killi 2. the damsel eliminates the problem or 3. the killi will just die because it's already basically 150 years old in killifish years.

But I fear I'm going to end up with the longest-lived killifish on record.

And if I had it to do over? Killi in iso tank or fuge but not in DT.