Lepisosteus oculatus
Spotted Gar
SynonymsTop ↑
Lepidosteus oculatus Winchell, 1864; Lepisosteus latirostris Girard, 1858 (possible senior synonym); Cylindostreus productus Cope, 1865; Cylindrosteus agassizii Duméril, 1870; Cylindrosteus bartoni Duméril, 1870
Etymology
Lepisosteus: from the Greek lepis, meaning ‘scale’, and osteon, meaning ‘bone’.
oculatus: from the Latin oculatus, meaning ‘having eyes, eye-shaped’, in reference to this species’ spotted colour pattern.
Classification
Order: Lepisosteiformes Family: Lepisosteidae
Distribution
Known from Great Lakes Erie and Michigan with distribution extending south through the Mississippi River basin to the Gulf of Mexico drainages where it’s said to occur between the lower Apalachicola River in Florida and the Nueces River in Texas.
It may also be found in the Rio Grande which forms the border between Mexico and the United States further south where records include Falcon International Reservoir, for example.
Type locality is ‘Duck Lake, Calhoun County, Michigan, U.S.A.’.
Habitat
Found in various habitat-types, from large lakes and rivers to sluggish tributaries, backwaters and pools though it tends to show a preference for larger, low-altitude bodies of water.
Maximum Standard Length
1000 – 1250 mm.
Aquarium SizeTop ↑
Suitable only for very large public installations.
Maintenance
Relatively unfussy provided water flow is not too strong and lighting not bright.
Water Conditions
Temperature: 12 – 20 °C
pH: 6.0 – 8.0
Hardness: 90 – 357 ppm
Diet
Gars are ambush predators feeding on smaller fishes and aquatic crustaceans in nature.
It can sometimes be tricky to get newly-introduced captive individuals to accept dead foods though most will learn to do so following a short period of starvation.
After a short time most small individuals will accept meaty frozen foods such as prawns, lance fish, etc., while larger specimens can be offered whole fishes such as trout or sprats.
Feed every day when juvenile but as the fish grows reduce the frequency; an adult requires only one or two meals per week at most.
In extreme cases there may be no other option but to use live ‘feeder’ fishes for the initial period but it must be stressed that this is only advisable until an individual has built up adequate body mass to attempt a starvation period.
It’s highly receommended to buy such feeders in advance and quarantine them for at least two weeks to ensure they’re free of disease while feeding them a high quality diet so that the flesh is sufficiently nutritious.
This species should never be fed the meat of mammals such as beef heart or chicken since some of the lipids and other organic compounds contained in these meats cannot be properly metabolised by fishes, causing excess fat deposition and even organ degeneration over the long term.
Except for in the extreme circumstance described there’s also no real benefit in the use of feeder fishes due to the risk of disease or parasite introduction.
Behaviour and CompatibilityTop ↑
Best kept alone, or with similarly-sized, non-aggressive fishes it cannot fit into its mouth.
Reproduction
Unrecorded in captivity.
In nature spawning occurs between the months of May and July and eggs are simply scattered among aquatic vegetation with no parental care.
As many as 20,000 eggs may be deposited in by a single female during such an event.
NotesTop ↑
This species clearly shouldn’t be considered a home aquarium subject at all given its eventual size and the fact it can live for several decades.
We include it here only because some public aquaria are able to maintain it long-term and juveniles are occasionally offered in the aquarium trade.
Gars are among the most primitive fish species still alive today.
They have a modified, vascularised swim bladder that is connected to the pharynx and allows them to breathe atmospheric air to a certain extent.
