Pregnant Bloodfin Tetra getting attacked?

[Jobin13]

Hey all.
I recently got a bloodfin tetra that rounded out my community tank, so I have 6 bloodfins, 6 cobra guppies, 6 rummy nose, etc. etc. So my fish should all feel safe and secure, it is moderately planted so they should feel safe and secure... however this last bloodfin that I added appears pregnant or atlas carrying eggs. since adding it to the tank the other bloodfins have been nipping at her lower fins excessively. Prior to adding her these all of my fish seemed fantastic yet since adding this last fish the bloodfins have gotten quite aggressive.

The behavior is not stressed based due to cycling issues... I have no nitrites or ammonia and my nitrates are very low.

Is this normal behavior? will it pass once she releases the eggs/fry? thoughts?

 

[idol1]

two senarios come to mind on theory. You only added one bloodfin in a school that already sorted out the pecking order making that bloodfin the target. If you added two the chances would of been greater of a new pecking order to start. second is the other fish sense something wrong with the new fish and it is weaker than the others. There is a method you can try but it does put stress on the fish! SO BE WARNED! set up some lg glass jars with your tank water. take four of your bloodfins out put them in separate jars for half an hour so they cant see each other fish are smarter than we think. Then reintroduce them to the tank one by one. If you have decorations in the tank or plants you have to move them around only slightly. This should trigger a new pecking order. If the last fish you purchased is weaker than the others the targeting will continue.

 

[Jobin13]

So it turns out that All of the bloodfins received nipped fins... and They weren't doing it to each other. The nipped fins came directly from Whisker shrimp... I went to Petco looking for some shrimp and the "aquarium specialist" directed me to these shrimp for my community tank. After a quick google search resulting from loosing 8 fish in a 24 hr period I found out that whisker shrimp are too aggressively for my nano/tiny fish community tank and that Basically all but one species of fish was prone to being eaten or attacked! I was livid and brought back the 8 dead fish that I didn't even buy from petco and they gave me a full refund on all of the killed fish. Since removing the whisker shrimp I've had no issues.