Loach like thing. identify?

I don't think it's a loach. There are sometimes darters? that come with ghost shrimp, cute whatever it is. Maybe a swamp darter?

its a darter Probably, but I don't know what type. could be a swamp darter but I am not sure. they are cute lil active fish

Yea i say swamp darter but yours is looking kinda thin well a darter anyway maybe not swamp

http://www.fishbase.org/summary/speciessummary.php?id=3424

I say swamp darter as well. They're very common with shipments of feeders.

Definately a swamp darter. And yes it looks a bit thin, but unless they have other problems they plump up very quickly with feeding. It seems to go with different breeding seasons in different areas. Around here they become VERY common in shrimp shipments in fall (winter seems to be bullfrog tadpole season :swear.

Some stores will give away darters for free. Other times they give you the feeder-fish price. Either way very cheap fish.

2g is a bit small. Their activity area is entirely the bottom of the tank (no swim-bladder). As a result gallons isn't really the measurement to use for keeping them, bottom surface area is. I've kept wild swamp darters in a 1.5g hex quarantine, but they are much less active. They are rather low bioload, so you could get away with it, just won't be ideal.

Well if you don't mind it in the 10g that would work.

The 20g may be a bit too aggressive for it. They are pretty tough for their size but can find it difficult to compete for food if the food doesn't get to the bottom of the tank. Not sure if Malawi's would eat the darter. I'm pretty sure my Pictus Catfish has eaten some and my girlfriend's Jack Dempsey seems to have eaten the one she tried in her tank. Not sure how big Malawi's are on eating fish.

If it will fit in their (Malawi) they will eat it. If it won't they will kill it.