Aquaculture Notes – Elacatinus oceanops, The Neon Goby

It seems only fitting that our first creature feature focuses on one of the first marine ornamentals to have been raised successfully in captivity, the Neon Goby, Elacatinus oceanops, (formerly Gobiosoma oceanops). First reared in the 1970’s the neon goby is a popular aquarium fish owing to its general hardiness, attractive appearance, and abilities in picking ectoparasites off of other fishes.

Size and Appearance

Neon gobies are small and typical gobiioid in shape. Most Elacatinus spp. are less than 5cm (2 inches) total length. Neon gobies are black overall with a neon blue stripe extending from front of eye to the base of caudal fin.

Broodstock Care

Omnivorous and hardy they will do well in nearly any species-only or reef aquarium situation, but due to their size should not be kept with larger predatory fishes. Neon gobies do best in water temperatures below 26.5 decrees C (80 degrees F). Foods should include a variety of grated frozen shrimp, squid and fish, as well as commercial gelatin or pellet diets. Multiple feedings daily will condition neon gobies for spawning.

Pair Formation

Hermaphroditic sexual patterns are common in the family Gobiidae. I am not aware of a definitive classification of Elacatinus oceanops, but experience in our lab suggests that they are sequential hermaphrodites rather than simultaneous hermaphrodites.
Males are often larger and more slender. Females will possess a swollen abdomen, particularly when ripe with eggs.

Neon Gobies may be kept as groups of 6 or more individuals when provided with sufficient hiding spots, as these gobies can be quite quarrelsome. If they are to be kept as a pair, they should be observed closely during the first week after introduction. If fighting is excessive, one member of the pair should be swapped until marital harmony ensues. Groups of fewer than 6 individuals are not suggested, as pairs will begin to try to “evict” other gobies in their territory. Larger groups dampen and disperse these aggressive tendencies.

Spawning and Hatching

Spawning can occur as often as every fourteen days with plenty of feeding and warm water conditions. In their natural environment, demersal eggs are laid in small holes and crevices in the reef and under discarded bivalve shells. In captivity, small Tridacna sp shells serve well, as do halved clay flowerpots and short sections of half inch PVC pipe. Both parents tend eggs. Depending on temperature, hatching will commence in 6-8 days. Hatching occurs after dark.

Larval Rearing

Neon goby larvae are slightly shorter and substantially slimmer than clownfish larvae. The larval period ranges from 18-25 days depending on temperature and food type. The first diet is rotifers, followed by Artemia nauplii. The transition period is variable between these foods. Elacatinus larvae can be transitioned to Artemia as early as day 6, and while growth is more rapid, mortality is often high. Waiting until day 12-15 to begin Artemia feedings will delay metamorphosis by a few days, but will also significantly increase survivorship. We have successfully reared batches of neon goby hatchlings through metamorphosis only on rotifers, but metamorphosis took 30-35 days.