Gobioides broussonnetii

Common Names: Dragon Goby
Violet Goby
Synonyms: Amblyopus brasiliensis
Amblyopus broussonnetii
Amblyopus mexicanus
Gobioides barreto
Gobioides broussoneti
Gobius brasiliensis
Gobius oblongus
Family: Gobiidae
Category: OthersFW
Distribution: America - South; Southern USA (Florida through Louisiana to Texas), through western coastal Central America, to Caribbean coast of Colombia, thence to Venezuela and Brazil, reaching as far south as Rio Grande do Sul.
Main Ecosystem: River; The species is an inhabitant of estuarine waters, though can also be found upriver in wholly fresh water, and is also documented as having been found in fully marine environments.
Temperament: Territorial; Mature individuals are reported to exhibit territorial behaviour toward conspecifics, consequently multiple specimens require large aquaria to provide adequate space. Compatible with a range of other brackish water fish species such as larger Liverbearers (for example Velifera Mollies), Scats, Monos and similar sized fishes.
Diet: Carnivore; A planktivorous fish whose diet consists of small animal organisms sifted from fine particulate matter in the substrate. In the aquarium, it is advisable to supply foods as close to those found in the wild as is practicable in order to maintain the health of the fish. Suitable foods include live Bloodworm (for larger specimens), substrate dwelling crustaceans such as Gammarus or Crangonyx, with Brine Shrimp and Daphnia being possible foods if more suitable ones are unavailable. Large specimens may be capable of ingesting small fishes, and thus it is not advisable to keep this species with fishes small enough to be swallowed. Adapatbility to dead foods is likely to be variable, and live foods should be at least intermittently available to keep this relatively demanding fish in good health. This fish possesses very poor eyesight, and relies principally upon scent to detect food. For this reason, it is considered advisable to use 'target feeding' with this species, placing food close to it by some means such as tongs or a turkey baster. The fish has a modest but definite requirement for some vegetable matter in the diet, so algae or a suitable substitute should be provided intermittently.
Care: Although a brackish water community setup with carefully chosen companions is possible, the ideal setup for this fish is a species aquarium tailored to its particular needs. A soft sandy substrate into which the fish can burrow, furnished with a range of decor items that have been selected with care to eliminate sharp edges, is considered the best. Furnish in such a manner that the fish has a mixture of regions of secluded cover (e.g., bogwood root tangles) and some open foraging spaces. The fish is likely to appreciate shaded areas provided either by decor overhangs or floating plants. If provided with various synthetic alternatives such as PVC piping, the fish will make considerable use of these as hiding places, though if possible, natural decor formations providing the same security are preferred.

While the species is euryhaline, and can be found in environments ranging from fully fresh water to fully marine, the preference for this fish is of the order of 10% to 50% marine strength. Variations in salinity are reported (according to Tropical Fish Hobbyist magazine as quoted by to be a spawning trigger.

Note that while Fishbase quotes a size of 55.3 cm for this species, some sources report a larger maximum size, up to as much as 64 cm. In any case, this is a large fish, and the aquarium should be planned for the long term maintenance of a fish over 24 inches in length.

Additionally, the fish appears to have a definite preference for temperature stability in the aquarium. Excessive fluctuations make the fish  e to disease. Temperature changes made to an aquarium containing a Violet Goby should be gradual and conducted with especial care.

7.2 - 8.6
20°C - 28°C
68°F - 82°F
10 dH - 30 dH
Potential Size: Male: 55.3cm (21.8")
Female: 55.3cm (21.8")
Water Region: Bottom; A substrate dweller that frequently buries itself.
Activity: Diurnal; Likely to be active during the day, particularly if food is provided during the daytime and 'target fed' to the fish.
Gender: Visual differences between male and female individuals are few. Behaviour is the principal clue - males become more territorial and aggressive as maturity approaches.
Breeding: An account is cited in Issue Number 472 of Tropical Fish Hobbyist magazine, in which it is suggested that one male should be placed with three females in a suitably large aquarium, furnished with copious cover, to provide hiding places for the female and a choice of nesting sites for the male. Feeding should be wilhheld for a week, then restarted using copious live foods. Salinity should be lowered by 5 parts per thousand from the ambient value initially, then raised to 30 parts per thousand (around 90% marine strength). Once the male has spawned and is guarding eggs, the females should be removed. Fry hatch in 36 to 48 hours, whereupon the male should be removed from the breeding aquarium. Fry require infusoria (particularly rotifers) and "green water" (single celled motile algae) for up to a month, whereupon migration to Brine Shrimp nauplii can be attempted. It is emphasised that the chances of success are slim until more documentation is available from a wider spectrum of successful aquarists.
The species itself exhibits no major variation in colour or form. However, it is noted on one source (notably here) that specimens in US stores are usually Gobioides broussonnetii, whilst specimens found in UK stores are likely to be the related Gobioides peruanus, a closely related species that differs primarily in being unable to tolerate fully marine salinities but whose care is otherwise identical.
Comments: An unusual oddball that endears itself to a number of dedicated keepers. Be advised that large specimens in particular are capable of delivering a painful bite to human fingers.

Note that the fish is unusual in that the dorsal, caudal and anal fins are not separated as in most other fishes, but joined to form a single, continuous, 'wrap areound' unpaired fin.
Main Colours: Purple
Markings: No Markings
Mouth: Normal
Tail: Convex
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Submitted By: Calilasseia
Contributors: Calilasseia, ACIDRAIN, Natalie
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