This lot is a BAP donation of a group of six Melanotaenia sp. Kali Tawa (three pair).   These fish are currently about 1" long but will get to about 2-1/2" making them one of the smaller of the rainbowfish.  I hatched and raised the eggs starting in May of 2025.   A very desirable fish that is currently traded between rainbowfish enthusiasts and hard to find in shops.   The link I included from Dans fishroom is a good read.   Scroll down past his fishroom construction news to read about the Kali Tawa.  The only ones I could find for sale right now are on Aquabid and are $100/8 plus shipping.  They are the same size as mine.