New tank and fish identification.

[Iminit]

Started up this 40g to move the shrimp out of my 15g and the hillstream loaches and shrimp out of my 36g.139073. Picked up these tiny tetras this weekend.139074. These guys are small. Here they are next to a cherry shrimp139075. Any idea what they could be. Look fully developed and was told they were adults. Up close pic139076 and the first hillstream in the tank. He wanted to be first and hitched a ride on a piece of drift wood.139077

[Discus Fever]

Tank looks great tom, cherry shrimp will be happy in there for sure.

[jwcarlson]

They look almost like black neon tetras, but washed out.

[Second Hand Pat]

I'm pretty sure they are gold tetra. A beautiful little fish when you can find the WC ones. Beautiful gold color. I do not think they maintain the gold color in a tank but could be wrong.
Pat

[For100]

Hi Tom,

Pat is right in the money! These are gold tetras, very fun to watch shoal. From my experience, not a shy fish despite their small size.
You can find a bit more about them here:

https://www.fishkeeper.co.uk/fish/freshwater/characins/gold-tetra

[Iminit]

Yes that’s what the seller told me gold tetras. My asking what they are is just because of the size. They look like adults but could be juveniles. I’ve no clue. The seller said these were full grown. But it does seem like gold tetras will double+ in size. These guys are at best 3/4”. So I was wondering if it could be a different species. So I guess now only time will tell.139079

[gimaal]

They'll get a tad bigger. Picking up on Pat's point, the metallic color won't fade, but if these gold tets spawned, the fry would not be metallic gold. The golden coloration is the skin's reaction to a harmless infection with a parasite, a trematode, that can only be passed on in the wild (by birds whose droppings are eaten by fish.). The presence of the trematode causes the production of guanine, the metallic golden color in the skin of the fish. Wild 'gold tetras' (Hemigrammus rodwayi) are pretty much defined by this, but many other species can be affected. "Brass Tetras" used to be commonly sold and they were various species of Hyphessobrycon affected by the same parasite. I've also seen different species of Nannostomus and various Hemigrammus so affected. Again, it is harmless to your tetras and to any other species in the tank.

[brewmaster15]

They'll get a tad bigger. Picking up on Pat's point, the metallic color won't fade, but if these gold tets spawned, the fry would not be metallic gold. The golden coloration is the skin's reaction to a harmless infection with a parasite, a trematode, that can only be passed on in the wild (by birds whose droppings are eaten by fish.). The presence of the trematode causes the production of guanine, the metallic golden color in the skin of the fish. Wild 'gold tetras' (Hemigrammus rodwayi) are pretty much defined by this, but many other species can be affected. "Brass Tetras" used to be commonly sold and they were various species of Hyphessobrycon affected by the same parasite. I've also seen different species of Nannostomus and various Hemigrammus so affected. Again, it is harmless to your tetras and to any other species in the tank.

Learned something new here...thank you!
What a cool parasite host relationship.

Al

[gimaal]

Learned something new here...thank you!
What a cool parasite host relationship.

Al

It becomes even cooler, Al. The gold colored H. rodwayi, because of that shiny gold color, become easier prey for the birds. Once the birds digest the affected fish, the parasite becomes active again and the circle is complete. Nature gave this one a lot of thought.

[Iminit]

Great info! More than I expected! Now of these 9 tetras only 2 are actually gold the other 7 look silver. Next went to another shop and found this tiny rasbora. This is smaller than the tetra. I think it’s a dwarf rasbora. Another great little fish. Both of these fish are about the size of a cherry shrimp. The shrimp as well as the hillstreams do seem to be enjoying the tank. So far 139120so good. 139118139119

[gimaal]

Your dwarf rasboras are Boraras maculatus or Boraras merah, two similar species in the genus. My money is on B. maculatus. That's pretty much it for size. The gold tets have a bit more to go. As for the varying shades of metallic on them, I've noticed that before and have never seen an explanation. Perhaps due to how many of the trematodes are present. Unaffected Hemigrammus rodwayi look like this:

139121

[AquaticNerd]

I was going to say they look like Silver-Tip Tetras to me. :D