Unknown Tetra ID

[FJB]

My 3 were in a 6-foot tank, with other fish and many plants. Never aggressive. However, very assertive and always swimming back and forth, possibly harassing to slow pokes. Tremendously assertive at feeding. Pectoral fins shaped very similar as in true hatchets, like wings, and they are excellent jumpers. I would love to have some again but no space currently,
I have these for now.... (Hemiodus!).

 

[Omrit]

My 3 were in a 6-foot tank, with other fish and many plants. Never aggressive. However, very assertive and always swimming back and forth, possibly harassing to slow pokes. Tremendously assertive at feeding. Pectoral fins shaped very similar as in true hatchets, like wings, and they are excellent jumpers. I would love to have some again but no space currently,
I have these for now.... (Hemiodus!).

View attachment 1490864

Those look nice! Is the black dorsal stripe a gender difference or ?