Firefish, are the breeding? Is that even Possible???

I have two firefish gobies, one is a Nemateleotris magnifica the other is a Nemateleotris decora. Originally my fear was that they wouldn't get along even though the owner of the LFS said that with the size of my tank they should be fine. To my surprise not only were they "fine" they were immediately attracted to one another. For about a month or maybe a little longer they have shared a cave and have been swimming in a pair with no signs of aggression. for the last 3 or 4 days they magnifica (which is the larger of the two) has been staying in the burrow and only coming our to feed while the decora stands guard outside the burrow. when the magnifica emerges the decora is not aggressive and does not try to chase the magnifica back into the burrow so I don't think its a bullying thing. But Im a little confused. I didn't think it was possible for these two to breed. There is very little info online about them. and I'm not sure is it possible that they have eggs in the burrow? if they cannot successfully breed is it possible that they have become a mated pair? any other ideas on what might be going on?



tank specs.

75 gal.

3 GSPs

1 lawnmower blenny

2 firefish

1 filefish



ammonia 0

Nitrite 0

Nitrates 15-20

Phosphates 1



running a sump system with skimmer and refuge tank.