|Genus & Species: Hypseleotris Compressa|
|Common Names: Empire Gudgeon, Australian Empire Gudgeon, Australian-Carp Gudgeon|
|Temperature: 72 – 86ºF (22 – 30ºC)|
|pH: 6.0 – 8|
|GH: 6.0 – 20 dGH|
|Max Size: 12 cm (4.72 inches) in length|
|Lifespan: 5 – 8 years|
|Depth Preference: Bottom dweller|
|Tank Size: 40 gallons|
The empire gudgeon is one of around 11 species in the most widely distributed genus found in Australia, Hypseleotris. Their present family, the Gobiiformes, was previously a suborder of the Perciformes, which once contained 2,211 species but has since been divided into seven families.
Origin & Habitat
The Empire Gudgeon is a freshwater species of fish endemic to Australia, New Guinea, and Indonesia. It has also been discovered in the Torres Strait, close to Horn Island, Fraser Island, Moreton Island, Bribie Island, and Stradbroke Island. Though they are mostly found in Australia’s coastal regions, particularly in the northern and eastern regions from the Chapman River to the Genoa River.
Slower moving coastal rivers, streams, swamps, ponds, and the upper reaches of estuaries make up their native habitat. Few species of aquatic plants are normally found in these waterways, although the waters are surrounded by dense forestation.
Soft sand, stones, branches, leaves, and fallen trees make up the substrate; as a result of excessive runoff and an accumulation of organic decomposition, the waters are often stained brown.
Empire Gudgeon Care
Empire Gudgeons are easy to care for since they are tolerant of broad-ranging water conditions, including those with high salinities, temperatures as high as 35 °C, and pH levels ranging from 5.0 to 9.1. Despite this species’ hardiness and capability to adapt, it is not recommended to raise them within the extremes of each parameter.
A tight-fitting lid is definitely needed for this species because they have a tendency to jump out of aquariums without a lid, especially when first introduced, during thunderstorms, or when startled.
Place tall decorations or plants that can reach the middle or the top layers of the water columns to provide plenty of hiding places for the fish. The goal is to break up lines of sight so that less dominant individuals may evade the ongoing attention of dominant males.
Empire Gudgeon Diet & Feeding
Juveniles are planktivores that almost exclusively eat zooplankton up until they reach a length of 2 centimeters. After that, they transition into omnivores, and their diet becomes more diverse and evenly distributed, consisting of varying sources of macroinvertebrates, zooplankton, algae, and plant matter.
Empire gudgeons have a voracious appetite and will readily accept most forms of food that you offer. Their diet should consist of high-quality tropical flake and pellet foods that have equal proportions of protein and plant-based ingredients.
They do, however, favor meaty foods, so providing them with at least one or two sources of food that are high in protein will be necessary for a balanced diet. Offer them live, frozen, or freeze-dried food sources that contain beef heart, blood worms, brine shrimp, insect larvae, daphnia, and artemia.
Tank Mates & Temperament
Empire Gudgeons are peaceful shoaling fish that do best when kept in schools of six to eight fish or more. Males are able to change colors rather quickly, in part because they visibly brighten their color when they are near females to attract their attention.
Because they frequently swim in the lower portion of the aquarium and are not at all timid or easily startled, species that swim at the top of the tank and in the middle of the tank will be a good fit for these fish.
Larger species of angelfish, danios, tetras, discus, gobies, sleepers, rainbowfish, sunfish, livebearers, corydoras, catfish, and labyrinth fish make excellent tank mates for empire gudgeons. They make the ideal tank mates for almost any species that isn’t overly aggressive and requires similar water parameters.
It’s important to remember that Empire Gudgeons will consume fish fry and any other smaller fish that can fit in their mouth; having said that, it’s not a good idea to introduce smaller fish, such as neons or rasboras.
Male & Female Differences
Sexual dimorphism is evident in empire gudgeons, with adult males having a large forehead hump that extends from above the upper end of the opercular edge to the snout. Two dorsal fins; males often have dorsal fins that are closer together, a taller first dorsal fin, and more elongated posterior second and anal fin rays.
Male empire gudgeons exhibit beautiful, bright colorations during breeding seasons. Their anal fin and dorsal fins both display vivid bands of red and black with a blue-white outline; additionally, the color of their head and underside brightens. The females lack the vivid colors of a male and are typically olive-brown in appearance.
Breeding & Spawning
Empire gudgeons rarely reproduce in aquariums, which is certainly due to their complex breeding strategy, which involves migrating from fresh to salt waters at different stages of their life cycle.
Aquagreen has made numerous attempts unsuccessfully to spawn them in an aquarium. However, recently, while attempting to cultivate atyiid shrimp in pond culture using natural planktons from northern estuaries, a few pairs of adult fish were placed in the pond with the shrimps, and soon after, fry was discovered. From an initial starting point of approximately 17 ppt when the fish were originally integrated, salinity dropped to 10 ppt after early seasonal rains.
During the warmer months, males build breeding territories and exhibit vivid colors to entice a female mate. From January to March, spawning occurs every 2 to 7 days over a period of many weeks.
Up to 3000 tiny adhesive eggs (0.26 – 0.32 mm in size) are subsequently laid by females onto prepared solid surfaces like rocks, sand, driftwood, or weeds, where they are continuously guarded and fanned by the male.
Approximately 14 to 24 hours after fertilization, the larvae hatch at 1.0 mm in length and start swimming shortly after. The larvae are born without an intestinal system or rayed fins. After spawning, the male takes sole responsibility for the brood and rejects the female. The fry reaches full maturity within one year at lengths between 5.5 and 7.5 centimeters.
After James F. Wilcox’s discovery of the empire gudgeon, it was initially described as Eleotris Compressus by Gerard Krefft in 1864.
Empire gudgeon’s old family Goboidei was reclassified in the Fishes of the World 5th Edition as the order Gobiiformes, and the families within the order were likewise rearranged from the previous edition.
The Gobiiformes are subdivided into the following families using this categorization scheme: Rhyacichthyidae, Odontobutidae, Milyeringidae, Eleotridae, Butidae, Thalasseleotrididae, Oxudercidae, and Gobiidae.
The following characterizations are used to identify them: Body somewhat deep, depth at pelvic fin origin 4.2 – 5.9 in SL, head, and body clearly compressed. Adult males have a noticeable forehead hump that extends from above the opercular edge to the snout. A small, slanted mouth that extends to around the middle of the eye; both jaws have small teeth arranged in many rows; with a truncated tongue tip.
Gill’s aperture is quite wide and extends beneath the back of the preoperculum. Except for two pores joined by a brief tube above the dorsoposterior corner of the eye and two to five preopercular pores, the head is devoid of pores. There are often few vertical rows and lengthy longitudinal rows of cheek sensory papillae.
Scales on the belly and neck are frequently cycloid; predorsal scales extend forward to above the middle of the eye, with 14 – 18 scales on the dorsal midline; body scales are broad and ctenoid, with no lateral line; longitudinal series are 25 – 29; cheek coated with medium-sized cycloid scales and 4 – 6 rows of small embedded cycloid scales.
G. Allen, S. Midgley, and M. Allen. Field guide to the freshwater fishes of Australia. 2002
S. Sharma and J. Hughes. Genetic structure and phylogeography of two freshwater fishes, Rhadinocentrus ornatus and Hypseleotris compressa, in southern Queensland, Australia, inferred from allozymes and mitochondrial DNA. 2011
Shaun Meredith, Vladimir Matveev, and Paul Mayes. Spatial and temporal variability in the distribution and diet of the gudgeon (Eleotridae: Hypseleotris spp.) in a subtropical Australian reservoir. 2003