ID a fish

Question

ID fish   QUESTION: Hi Matt,

I asked for help before, but didn't have very good photos. The fish I'm trying to identify is starting to get just a little aggressive toward my ottos. It's a little bigger now, so would you mind looking again? I want to be sure it doesn't hurt my other fish (betta, 2 ottos, 4 japonica shrimp) 30 gallon long tank, Thank you very much for your time! Janice

ANSWER: Hi agian Janice,
Yes I remember :).  It looks like a Madagascar Rainbow fish.  At first my other options are Chinese and Saimese Algae eaters but the red fins rule those out.  And Madagascars usually have red striking fins.  I rarely see these fish around my area, but I remember they are quite a peaceful fish and know they are a schooling fish that require 5+ or more of its kind.  They also get up to 6 inches I believe.  Let me know if you agree with the fish identification that I picked.
-Matt-

---------- FOLLOW-UP ----------

QUESTION: Hi Matt, Thank you! I actually looked at a Madagascar Rainbows on-line yesterday, and I thought it was the closest I had seen! Though the tail on mine seems more rounded. I am getting nervous, as I found another otto dead tonight, and it was clearly eaten, though I don't know if it was killed or was sick. I first spotted 2 of these weird fry, end of April. After a live daphnia feeding, I found half of one, and I thought the Betta fish may have gotten it while chasing daphnia. (daphnia is only thing I'd actually seen those babies eating) I had five ottos mid-May. I could only find two ottos left yesterday (no traces of three), and now one left, and I don't know if I should get any more. The water quality tests good, and the japonica shrimp and betta have not been affected. I had seen the weird baby (who is now affectionately known as daemian), flare at the ottos. Maybe I should get the last otto out of there and into another tank with more ottos? I'm leery of trying to accommodate this daemian because it might be tough finding others of its kind, and find out it's really not a peaceful fish? And, also, it's really tough to get it any food, because that betta fish, Jarvis, eats EVERYTHING! There is algae in the tank. If I were to put daemian in another tank, I don't know what would be safe with it? Should I just wait until it gets a little bigger to be sure what it is? Thank you so much for your kind patience, Matt!! I certainly appreciate your advice.
Best wishes, Janice

Answer
Hi again Janice :),
Theres only two reasons that I can think of that is happening to your otos.  It is either the compatibility issue, or the otos themselves.  There is one thing to keep in mind, ALL oto cats are all caught from the wild and brought in.  They are not bred anywhere because they are so hard to breed in captivity.  A lot of the otos that are bought from stores have a high death rate depending how long they have been in the stores.  The longer they have been there, the higher the mortality rate.  When I buy otos, I make sure to buy them the day they arrive to the store or 1-3 days after.  They can easily starve because the tanks at local fish stores do not provide any food for the otos.  When you buy them, try to buy the plumpiest one, the underside of the body should look like the size of a head of a Q-tip.  Or ask them when they are going to get a new shipment of oto cats.  

The compatibility issue would be my last choice because all of your fish seem compatible with each other.  IF that fish is indeed a Madagascar Rainbow fish, he is generally peaceful toward other fish.  The betta, if it is a male, is usually only aggressive towards his own male kind or any fish that has similar fins such as guppies with the colorful tails.  The betta attacking the oto cats would be a little awkward to me.  It is possible though, that the otos died on their own and then get fed on by the other fish.

Otos love live plants and greatly benefit from a planted aquarium.  If you want to, try to go to petco or petsmart near you and look for a plant called Anubias Nana.  It has small thick green leathery leaves.  It should be in a clear plastic tube or near the rest of the aquatic plants if they have any.  They are low light requirement plants and are extremely easy to grow which I recommend to anyone keeping small fish.  They dont even need any special nutrient rich soil and can even be grown attached to driftwood or decorations.  The roots can be underground but the rhizome shouldnt, or it will rot.  

Again, hope I helped and let me know if you need anything else.
-Matt-