Watchman Goby

[mark_]

I have a watchman Goby, he’s been in my Fluval 13.5 gallon nano reef tank for 2 years now. Initially with 2 clown fish, now with a single clown fish (the female clown became very aggressive and beat up the male until he wasn’t able to survive in a span of a few days, about 6 months ago) the Big female is going very strong and looks excellent and doesn’t seem to be missing her mate at all. However I noticed over the last month or so my Goby has shrunk and seems a lot smaller. No signs of damage on any fins at all or any signs of trauma, but his facial structure sunken, and he seems very skinny. At the same time Goby is very active and eats like a pig, like he always has. I’m very concerned because he’s visibly smaller and just doesn’t seem healthy due to his appearance although his behaviour hasn’t changed, he’s very fearless, he’ll perch on my rocks and patrol around the sand bed, sift sand from time to time. And is very comfortable and not very timid, he’s got a very cool personality and I’m concerned and just looking for some advice.

(2 photos are from when he was looking in better shape, blue light photos are from the other day)

Thanks to anyone taking the time to read my little story and offer some advice.

 

[Spare time]

I would try something for internal parasites if it were me. Something like prazi or (in a qt) general cure, and then move from there.