Gobies are the largest group of marine fishes, and fresh, brackish and salt combined; and the dominant element in small-fish bottom fauna on tropical reefs. Laugh if you will at the comical, shy gobies; it is they that will have the last chuckle. Yes, someday (soon) you will plunk down your hard earned cash to buy them.
Most species live in, on, or near the bottom and are of small size. One super goby species attains a gargantuan eighteen inches, but almost all his kin are less than four inches in total length. The family contains the world's smallest fishes and vertebrate. Trimmatom nanus of the Indian Ocean females reach a mere 8-10 mm. There are other goby species only slightly larger.
Many of the gobies live in close association with invertebrates such as sponges, shrimps and sea urchins; regardless of goby size, they become the center pieces of an aquarium when maintained with them.
Take ten big breaths Dear Reader; if the sheer diversity and size of such families as the Butterflyfishes, Cichlids or Damsels was impressive, "you ain't seen nothing yet".
In recent times the Suborder Gobioidei has been divided into as many as six separate families. "Clarity is pleasurable", and for simplicity's sake we will stick with the historical two, the freshwater loach gobies, family Rhyacichthyidae of the Indo-Australian archipelago, & the humungous family Gobiidae. Alternatively you may find numerous families and subfamilies of "true" and fancifully named gobies in the literature and real life; the Odontobutidae, the sleeper gobies, family Eleotridae, sand fishes or sand gobies, family Kraemeridae, the obscure Xeristhmidae, worm- or Dartfishes, family Microdesmidae, and the family Schindleriidae. You'll forgive me if we don't list all the subfamilies.
All told the gobies number some 267 genera and 2,100 described species with many more to come. All but about 200 are marine; mostly tropical and subtropical reef.
We will definitely be highlighting just the most common and available types of interest to marine aquarists here, but I trust the above gives you pause to consider just how vast your possibilities are.
What's A Goby?:
The gobies are grouped together on the basis of several hard to discern characters; bones of the head, a family-unique sperm gland... but let me simply state some of the traits that are of use to us as identifiers and keepers of marine life.
Most live in or on the bottom and are aptly adapted for a demersal existence. They are roughly torpedo-cylindrically shaped, and have reduced lateral line systems coupled with enhanced vision. Generally gobies lack swim-bladders and display degrees of fusion of their pelvic fins that are located anteriorly under their pectorals and used as a sort of suction disc to help them stay in place.
In case you're asked, gobies can be readily distinguished from the numerous fellow bottom-dwelling blennies on the basis of dorsal finnage. Most gobies have two distinct top fins; Blennioids have a single long one.
Because of their diminutive stature and bottom orientation you have to look closely at these animals before purchasing. They really come in two qualities; sterlingly fit, and dismally doomed.
Examine the stock carefully for bloody or white markings; tanks with bloodied or dead individuals should be passed on.
Check their breathing, it should be regular and not labored; for most species kept 60-90 gill beats per minute.
Is the fish looking around, aware of it's environment and you? Gobies are heavily predated on; they are never "asleep at the wheel". If the specimens aren't alert, leave them.
Territoriality can be a big problem with some species, individuals. Make and use clear, seal-able containers if you don't have extra tank space to move bullies, bullied.
Predator/prey relations; oh yes, except for the species that have natural bad-tasting slime immunity (a term I just made up), like the coral, clown gobies, this group is like bite-size candy bars. Triggers, large angels, basses... most anything with a big enough mouth will suck them down.
Acclimation; maybe just a general note to place all the "colony" type species individuals all at once to reduce the likelihood and intensity of aggression.
Gobioids for the most part are relatively disease resistant, with the exception of one type of disease, environmental. Though they have cycloid or ctenoid scales, they have about the same intolerance of harsh chemical treatments as "naked" fishes. Many more are bumped off from copper, malachite and formalin- containing medicants than from the infectious diseases they're used against.
Key Species, Groups:
Genus Bryaninops: Whip and Coral Gobies; most often found on Black Corals and Gorgonians.
Genus Eviota: Small and often beautiful. Thirty five described species, with many more to go.
Genus Gnatholepis: Seven species of great sand sifters.
Genus Hazeus: Two species
Genus Istigobius: Good looking reef sand-dwelling fishes. The genus comprises eleven species.
Genus Lythrypnus; pretty, but most cool to cold water: Eighteen species
Genus Pleurosicya: Tiny host gobies
Other Goby Genera/Groups:
You betcha. This is a mere smattering of the industry's currently most often varieties. Baensch and Debelius (1994) have almost 100 pages dedicated to this group. WEB, HRA & REH (1990) 41 goby pages in their tome.
Heck, we didn't even mention the "land" Gobies called Mudskippers that spend more time out of the water on mud flats than in.
Foods, Feeding, Nutrition:
Bibliography/Further Reading: (See sub-groups pages for their bibliographies)
Goby Groups In General:
Baensch, Hans A. & Helmut Debelius. 1994. Marine Atlas, vol.1. MERGUS, Germany.
Brown, Stanley. 1996. Gobies. V.4, #1 96 The J. of Maquaculture, The Breeder's Registry.
Burgess, Warren E. 1975. Salts from the seven seas; gobies. TFH 2/75.
Burgess, Warren E., Herbert R. Axelrod & Raymond E. Hunziker. 1990. Atlas of Aquarium Fishes, vol. 1, Marine Fishes. T.F.H. Publ., NJ.
Colin, Patrick. 1975. The green band goby (Gobiosoma). Aquarium Digest International 3:3, 75.
Damian, Sorin. 1993. Breeding behavior of the sand goby, Pomatoschistus (Bubyr) caucasius. FAMA 2/93. Cold water example.
Delbeek, Charles & Scott W. Michael. 1993. The substrate sifting Gobies: Fishes that earn their keep. AFM 5/93.
Fenner, Bob. 1999. Gobies. Notes for the new saltwater hobbyist. FAMA 9/99.
Hunziker, Raymond E. 1985. Gobies for freshwater and brackish aquaria. TFH 12/85.
Nelson, Joseph S. 1994. fishes of the World, 3rd ed. John Wiley & Sons, NY. For systematic reviews.
Coral Gobies, Genus Gobiodon
Debelius, Helmut. 1986. Gobies in the marine aquarium, pt. 3: Coral gobies. Today's Aquarium 1/86.
Esterhaus, Hans. 1995. The citron goby, Gobiodon citrinus. TFH 12/95.