If it doesnt come as a pair... Better not try to get another one to try to pair up... They will fight... And they are not easy, die for no reason like yours even when feeding well...
It will hurt the fish... If unlucky, the fish will suffer from bacteria infection... Cos some parasitic isopods will have piercing and sharp teeth to allow them to hang onto the fish...
Isopod Parasite... So far I only encounter this once.. I hypo the fish.. Let the Isopod die itself... or you can FW dip the fish... But will be very stressed on the fish...
Most reefers wun wanna pay more for CB shrimp(smaller) when they can get WC shrimp (bigger) at that price too..
Singapore is too small a market to promote CB stocks... Not many ppl are willing to spend more money to get CB fishes and inverts...