Care
The Green Coral Goby is a small species known from lagoons and reef crests to depths of around 15m (49ft). Here this coral-commensal goby is found singly or in pairs, amongst branches of
Acropora. These fish are characterised by a green body colour with red to violet stripes, broken lines, or rows of spots on the flanks, 4-5 reddish bars on head, and an absence of scales. The modified ventral fins have fused to form a kind of suction cup that helps them to maintain position on coral branches in swift currents. Green Coral Gobies are generally of a peaceful nature and make a wonderful addition to mature reef aquaria containing established colonies of broad-branching SPS corals, which they very much enjoy hiding amongst. Although often recommended for nano aquaria because of its diminutive size, caution should be exercised for two reasons. Firstly, smaller tanks will limit the number of individuals you can keep together; only one specimen is recommended in small nano type tanks, otherwise there will be constant arguments over territory which could result in the untimely demise of the weaker individual. Secondly, the more space available in a reef setting, the chances are that there will be much larger, stable colonies of suitable SPS corals available, and so it is less likely that these fish will damage any one individual beyond repair as they go about their daily routines (hiding/resting amongst the branches, and feeding on the occasional mucous polyp). If these types of corals are not being cultivated in your aquarium, invest in several coral skeletons so that these fish have something natural to interact with and give them a sense of security. Green Coral Gobies may be kept in groups (but only in larger quarters where there is an abundance of hiding places/territories), and oftentimes these fish will pair up and spawn. With regards to tankmates, these should all be small, non-aggressive feeders. These gobies actually produce a thick toxic body slime that deters many species from trying to consume them. Having said that, obviously do not house these fish with large carnivores. In the wild, these gobies are most commonly associated with
Acropora nasuta, but they are also known to inhabit the branches of
A. millepora and
A. valida, and sometimes
A. tenuis. May also be seen on sale as Broad-barred Goby, Blue-spotted Coral Goby, Green Clown Goby, Green Gumdrop Goby, Maori Coral Goby, or simply Green Goby.
Feeding
Will consume a wide range of meaty fare including Mysis shrimp, vitamin-enriched brineshrimp, finely chopped krill/prawns etc. Feed small amounts 3 times per day, target feeding if necessary.
Breeding
It is fairly common for the Green Coral Goby to spawn in the home aquarium; however, raising the young is extremely challenging. These fish are bi-directional protogynous hermaphrodites (which is sometimes referred to as a bi-directional sex change), which is an uncommon trait among gobies, meaning that any two fish placed together are guaranteed to form a male-female pair. These fish tend to strip a small area of coral polyps in order to create a place to deposit their eggs, although other sites are not unheard of. The male fish will dance/quiver in front of the female and when she is ready to spawn, she will deposit her eggs on the coral branch, and these are immediately fertilised and subsequently guarded by the male. The eggs are very small (less than 1mm in diameter) and can number several hundred. The presence of the eggs on the coral may cause a small amount of tissue recession in that area, but this should recover quickly once the eggs have hatched (4-5 days, dependent on water temperature). The larvae are miniscule and require appropriately sized foodstuffs such as cultured rotifers and copepods.
