My Bleeding Heart Tetra Is Being Attacked?

[jordanelizabeth]

Hey everyone, I had a quick question.

I set up a fresh water aquarium about 8 months ago, everything has been going pretty well, it contains:

1 Bleeding heart tetra
1 Cherry barb
2 Cory Cats
1 Prawn

(had two neon tetras but they died suddenly, no symptoms.)

When I first bought my fish, the store said the barb would be alright with the other fish, recently im hearing this is not the case? My poor bleeding heart lost most of his tail and dorsal fins from nibbling by the neons, but recently hes been getting red spots, almost like bites. My barb (who is usually very peaceful) has started charging at my bleeding heart, they go back and forth. I don't know if I should take the barb out if he is causing this, or if my bleeding heart is sick.. help!

The two have been happy tank mates for 8 months, what changed?!

 

[waterdrop]

If you've ever gone snorkling, in the Caribbeans or whereever, you might have noticed that many, many fish can be found shoaling in very homogenous groups. Shoals are depended upon by these fish as their major defense against predators. When a predator appears, the shoal can move and shape in ways that will fool the predator into thinking there may be a single fish bigger than it and that it shouldn't attack. The shoal, for the members of it, is a great stress reducer.

So, as it happens, out in nature, most of these tetras and barbs are members of large shoals. Neon tetras for instance, are usually in shoals consisting of thousands or tens of thousands of individual fish. Fish do not have the extra brain structures that humans have and are tightly bound to a life lived within their instinctive behaviors. When shoaling fish find themselves somehow separated from their shoal, by themselves or in a number less than the hundreds or dozens that they are used to, they instinctively show behaviors of stress, related to their perceived lack of defense from danger.

Personally, I think one reaction to this stress from low shoaling numbers is to want to drive away or otherwise harass any fish that look or are different, a behavior that all shoaling fish would have normally to some extent. I think that behavior can greatly increase when the fish are without their minimum shoaling numbers.

For small tanks, you can see this presents major problems. Each of the shoaling fish you mention, bleeding heart, cherry barb, neon tetra.. wants to be in a shoal of its own kind, ideally with dozens or thousands of others. Over the years, fishkeepers have determined some rough minimal numbers at which they perceive some of the worst of the stress and aggression behaviors to diminish enough that a particular shoaling type will live peacefully in the aquarium. Six is one of the most popular such numbers.

Sorry! lol, all that just to mention one potential explanation for what you observed and that's not neccesarily the only explanation! There are also dominance behaviors -within- shoals and groups of fish and they, like lack of shoaling numbers, can take a while to show up in a tank. Perhaps the reason it takes a while is that at first a "new territory" (which is what the aquarium is for a fish that would normally live its whole life near its birthplace in the wild) must be explored and grown used to and there are perceived dangers in that process that may be greater than the known tankmates nearby. Anyway, hope that's not just a rehash of things you've already thought about long ago!

~~waterdrop~~

 

[jordanelizabeth]

Personally, I think one reaction to this stress from low shoaling numbers is to want to drive away or otherwise harass any fish that look or are different, a behavior that all shoaling fish would have normally to some extent. I think that behavior can greatly increase when the fish are without their minimum shoaling numbers.

For small tanks, you can see this presents major problems. Each of the shoaling fish you mention, bleeding heart, cherry barb, neon tetra.. wants to be in a shoal of its own kind, ideally with dozens or thousands of others. Over the years, fishkeepers have determined some rough minimal numbers at which they perceive some of the worst of the stress and aggression behaviors to diminish enough that a particular shoaling type will live peacefully in the aquarium. Six is one of the most popular such numbers.

I'm very shortly upgrading them to a 20gal tank, will adding a few of each help them out? I'm VERY new to fish keeping! When choosing my fish, I basically walked into the store and said "which do well together?" and they advised my small group. Ive realized that at the store, the advice you get changes DRASTICALLY from one worker to the next, so I joined this fourm hoping to learn a little. Thank you so much for your response!

 

[waterdrop]

You're Welcome! Glad we could start being a help!

~~waterdrop~~