Diamond Gobies Breeding Journal

Fish Think Pink

Club Secretary
Staff member
Board of Directors
This journey was not intentional. It began by purhasing a small diamond goby, often referred to as diamond 'watchman' gobies though their behavior differ from other watchman gobies. Original small diamond gobie spent week or longer in QT, then added to main tank. Disappeared without trace in main tank for 3+ weeks. Decided goby died. Found healthy large full-size adult diamond goby at DFWMAS partner LFS, bought and brought home. A week after large diamond goby in main tank, spotted small diamond goby peeking from behind zoa arch.... I *NEVER* intended to have two diamond gobies. EVEN AFTER READING BELOW, I DO NOT RECOMMEND HAVING TWO DIAMOND GOBIES (but I'm going to ride this out and see where it goes...)
For several weeks they ignored each other. Adult full sized diamond goby took left front side of my 180 gallon, small diamond goby took center front of my 180 gallon. In the wild, diamond gobies reported to take 36 square feet of ocean floor as cleaning sand area ... have no scientific reference for this statistic, but it made me worried as now I have TWO in too small of space for one diamond goby (lots of aquascaped rockwork arches, caves so less clear sand than one might think with 180 gallon)
Then, gobies began to fight. Worst was when large goby grabbed small goby by its middle and severely shook repeatedly! As I was strategizing how to remove for rehome either one, fighting stopped (about 2 weeks of fighting). Small one would sometimes instigate fight - going to large one and biting either its tail or its middle! Has no fear! I feared small ones' death... 
Lately, gobies are inseparable, acting like mirrors of each other, seem happy but both occasionally like to bite the other. Wonder if bitings impact mating or sex changes. Haven't yet found how to sex them. Adult goby developing significant pot belly - is it finally eating enough (loves the CBB black worms and finally eating thawed Reef Frenzy but only if it directly hits in face... occasionally will swim an inch to grab large thawed bit (but rare)). Doubt pregnant, but can't help but wonder. Gobies have gotten so cozy over past few weeks they are sleeping together in middle front of tank where they daily create huge sand pile (mess) around one large flat rock. 
I'm following other website post where someone has breeding pair (and significant problems raising fry but they are changing pod types). I don't expect to raise baby diamond gobies but IF breeding is in my/their future likely their babies will 1) be super cool to have such healthy fish and 2) contribute to food for others in my 180g main tank
Anyone with info on diamond gobies please post here.
RIP small diamond goby - you will be missed. 
No fighting observed earlier this evening, but found small diamond goby dead after lights out. Back when they did fight, know large diamond goby was able to do serious shaking to small diamond goby, so suspect something like that happened. After death examination found no outwards signs of injury observed in small goby but whiplash or concussion possibly don't show. 
Had I known this was coming, I would have rehomed one. I thought aggression had settled and looking forward to possible breeding. Did not intend to have two and will be sure to only ever have one in future. I'm sad. 
Closing this breeding journal.