Is this what you mean by a 'dojo loach'?
http://www.seriouslyfish.com/species/misgurnus-anguillicaudatus/
If it is, it looks like BettaBeau is correct in its unsuitability as a tank mate for a Betta splendens.
You have to remember Betta splendens are a solitary fish. The increase in activity levels in your fish could be because he (rightly) believes that the loach has intruded on his territory.
Bettas don't need to be physically attacking a fish to be behaving in an aggressive manner towards it. Often aggressive behaviour can be very subtle, and I'm not so sure that the betta resting on top of the loach is necessarily a benign behaviour. It seems rather an intimidating/threatening gesture to me.
http://www.seriouslyfish.com/species/misgurnus-anguillicaudatus/
If it is, it looks like BettaBeau is correct in its unsuitability as a tank mate for a Betta splendens.
You have to remember Betta splendens are a solitary fish. The increase in activity levels in your fish could be because he (rightly) believes that the loach has intruded on his territory.
Bettas don't need to be physically attacking a fish to be behaving in an aggressive manner towards it. Often aggressive behaviour can be very subtle, and I'm not so sure that the betta resting on top of the loach is necessarily a benign behaviour. It seems rather an intimidating/threatening gesture to me.