This article appeared in Volume 4, Number 1, 1996 of The Breeder’s Registry’s Journal of MaquaCulture. The article is reproduced with the acknowledgment and permission of the author. All rights reserved, 1997
by Stanley D. Brown
The Suborder Gobiodei is one of the largest groups of fishes (Order Perciformes) encompassing 3-7 families, 263-270 genera and approximately 2000 species. Reference material can be confusing because of contradiction from one source to another, not only with respect to number of families and Genus, but even the spelling of (which is sometimes a typographical error,(1)). The Decorated FireFish (or fire-goby) Nemateleotris decora is placed by some in the Family Microdesmidae, while other references list it as a member of the family Gobiidae. Common names further add to the confusion; the Mandarin Fish, Synchiropus splendidus, a member of the Dragonets, (family Callionymidae), is often sold as the Mandarin Goby. The Convict blenny, Pholidichthys leucotaenia, is commonly offered as a Convict goby and the juveniles are sold as Engineer gobies!
The family Gobiidae (True Gobies) are typically defined as small fish (Trimmatom nanus, total length (TL) 1 cm, to the largest goby, Oxeleostris mamorata, TL 66 cm (26 inches). They have a first and second dorsal fin,, pelvic fins which are often fused to form a cup-shaped disk, the lateral line is lacking and most, but not all species, have scales. Many have developed symbiotic relationships with sponges, sea urchins and burrowing shrimp, and some demonstrate “cleaning” behaviors for larger fish. Many of the gobies are hermaphrodites, either protandrous (male to female) or protogynous (female to male).
Gobies have been bred in captivity but have not received the attention that clownfish have received. This may be due in part to their typically small size, limited appeal, and often inexpensive price. Their generally peaceful demeanor makes them especially well suited for the reef type aquarium. Many species spend most of their time “on” something (rock, sponge, coral, etc.,). Their modified pelvic fin serves them well for this posture. Other species, however, spend time in the “mid” water column as long as shelter is not too far away.
The Neon goby, Gobiosoma oceanops, was the subject of commercial efforts during the “early days” of propagating marine “ornamentals”. It was also among the first captive reared species to be offered for sale. It is a small Atlantic species which has the advantage of producing larvae which can be reared using rotifers, Plicatilis branchionus, as a first food. It has been reported as having hybridized with another Atlantic species G. evelynae which looks very similar and is quite possible offered for sale under the same common name Neon goby.
The Neon goby has been reported to the Breeder’s Registry database three (3) times to date. Longevity is at least 3 years, with spawning occurring after 1.5, 2 and 3 years. The female was always listed as being larger, ranging from 37 – 80 mm and the male ranging in size from 32 – 57 mm. Other than size differences, the only noted difference between the sexes was the females fuller abdomen. Pairs were maintained in small aquaria (10 – 20 gallons). Diet was varied and included both prepared and live foods. Spawning occurred in “nests” which ranged from the underside of a bivalve shell, small hole in a rock, to a 1 x 6″ PVC tube.
The egg mass is described as whitish, adhesive and approximately 2 mm in diameter. Spawning frequency ranged from 8 – 28 days. Incubation was reported as 7 – 10 days at water temperatures of 76-81 F. Specific gravity was 1.021 – 1.022. pH 8.2 – 8.3. Nitrate levels were not reported; however, it has been stated that ” The neon goby spawns readily in the aquarium…in non-choice aquarium situation.”(2)
Hatching occurs at dusk and larvae are ~3.0 mm in length with a small yolk sac and no pigmentation except eyes. They are phototaxic (attracted towards light) and can be easily collected using a Larval Snagger(3) or using a “mini-mag” type flashlight and collecting the larvae in a glass, bowl, or slow siphoned. Larvae should NOT be collected with a net. Larvae can be fed rotifers and newly hatched artemia can be introduced between the 9th and 14th day. Initial food size is in the 56-200 micron range(4). Metamorphosis occurs around 26 days after hatching. Coloration begins 26 – 42 days.
The Citron or Clown goby, Gobiodon citrinus and the Lemon or Yellow Clown goby, G. okinawae, have both been reared on a commercial basis. Spawning is reported to take place as frequently as every 4 days. A nest site is prepared, but these species seem to be less secretive than the Neon goby, depositing eggs on the upper outside edge of a clay pot. I have observed G. okinawae using the “crotch” area of a large acroporid coral in an area of strong light and current. G. citrinus has been described as a consecutive hermaphrodite(5). (The same authors have listed several of the species discussed in this article as having not been successfully bred)
Diet for the adults is broad and they readily accept a variety of live, frozen and prepared foods. The sexes are similar in size, with the female being reported as being pale in comparison to the male. Both reports for these species had the specimens in captivity for 1 year with size being equal at 62 mm (~ 2.5 inches). Incubation is only 4 days, much shorter than the Neon goby. Eggs hatch just after dark and larvae do not appear to have any yolk sac meaning a first food must be available. Rotifers are fed for the first 25 days at which time Artemia nauplii and copepoda are introduced. Metamorphosis occurs at about day 33. Success rates of 50% were reported.
I think it noteworthy to mention that during the late 70’s and early 80’s retailers were offering Gumdrop gobies (G. atrangulatus or G. rivulatus) as female Lemon/Yellow gobies. Whether this stemmed from reports of breeding (hybridization) is unknown. Likewise, G.okinawae was marketed as the Lemon or Yellow goby.
The Yellow Prawn goby, Cryptocentrus cinctus, has also been reported to the Breeder’s Registry database. Information is not as complete for this species, but the pair was maintained in captivity for 2 years and were moved to a new tank 6 months before spawning. No physical differences were notated aside from the possibility of size which was 80 – 90 mm (~3 – 3.25 inches).
Hatching was typical, occurring after dark. The larvae were ~2.0 mm in length and some yolk sac was visible. The larvae were fed with rotifers enriched with SELCO. After the first week the larvae settled to the bottom of the tank. At day 15 Artemia nauplii and copepoda were introduced (again enriched with SELCO). Metamorphosis occurred at 20 – 25 days and high mortalities were experienced.
Other goby species have reportedly been reared but data is not available in the database. These include (and these are only those species related to me); The Golden Headed Sleeper Goby or Ladder Glider, Valencienna striguata; Two-spot or 4-wheel drive Goby, Signigobius biocellatus; Catalina goby, Lythrypnus dalli. I encourage anyone with information about the spawning and/or rearing of these or ANY other marine organism to please submit the information so it can be included in the database. Remember, ANY DATA IS BETTER THAN NO DATA!