Pairing up fish

[ryan115]

I recently added a tailspot blenny (Ecsenius stigmatura) and a Randall's goby (Amblyeleotris randalli) and wanted to pair each on with another. My questions are:
1) are there anyways to sexing these two fish?
2) are there any special methods to pairing them up besides just adding the opposite sex to a tank?

 

[FishNutzBoi]

Is it even possible to pair fish of different genuses together?

 

[ryan115]

sorry, to clarify...
I dont want to pair these 2 fish up, I want to get a mate for each one.
But to answer your question, as far as I know different genus wont pair (Im sure there is an exception) but different species are commonly known to hybridize