THE STEINHART AQUARIUM - Gulf of Guinea Science ...

Spotted Gar
Lepisosteus oculatus ( Lepisosteidae)
Gars
Distribution: Lake Erie and south Lake Michigan
drainages; Mississippi River drainage from
Illinois south to East Oklahoma, East Tennessee;
Gulf Coast streams from West Florida to
Central Texas.
Habitat: Clear pools with aquatic plants in
streams, swamps and lakes; may enter brackish
water on the Gulf Coast.
Appearance: Length to 1.1 m, weight to 4.4 kg.
Body cylindrical, colored dark olive to brown
above. All fins with dark spots; belly whitish;
snout short.
Diet: Voracious predator on fishes and benthic
crustaceans.
Reproduction and Development: Spawn during
the spring in shallow water over vegetation.
Like all gars, the larvae have an adhesive
pad on their heads, by which they affix themselves
to plants.
Mortality/Longevity: Live to at least 18 years.
Remarks: Minor commercial fishery. Also
taken as a gamefish.
Longnose Gar
Lepisosteus osseus (Lepisosteidae)
Gars
Distribution: Saint Lawrence River drainage;
freshwater systems along Atlantic coast from
south of New Jersey to Orlando, Florida; Southern
Great Lakes and Mississippi River system,
south to Rio Grande in Texas.
Habitat: Backwaters, large creeks, lakes; may
enter brackish water; live near aquatic vegetation
when young.
Appearance: Length to 2 m. Weight to 22 kg.
Snout more than twice as long as head. Body
cylindrical; dark olive-green to brown above,
lighter on sides with dark spots, usually on
posterior; belly whitish.
Diet: Voracious predators. Piscivorous; also
feeds on crabs and other crustaceans. Catches
prey by swinging jaws back and forth, impaling
fish on its sharp teeth.
Reproduction and Development: Non-guarding
egg scatterers. Eggs demersal and adhesive.
Eggs are protected from potential predators by
being poisonous.
Mortality/Longevity: Live to at least 36 years.
California Academy of Sciences
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Parasitized by the sea lamprey Petromyzon
marinus.
Remarks: Considered a nuisance by fishermen
because it damages gill nets and feeds on
game fishes. The longnose gar is caught but
rarely eaten.
ORDER OSTEOGLOSSIFORMES
(BONY TONGUES AND ARAPAIMAS)
Pirarucu aka Arapaima
Arapaima gigas (Osteoglossidae)
Bonytongues
Distribution: Amazon River and its tributaries.
Habitat: Freshwater, enters flooded areas dense
with aquatic vegetation and shore plants, avoids
the acidic waters of the “black water” zones.
Appearance: Length to 2.3 m, weight to 133
kg. In the 1800s specimens 4.5 m long and 200
kg were reported. Heavy, elongate body has
very large scales.
Diet: Specialized for surface feeding with their
upturned mouths. Adults prey on fish at the
surface; suck smaller fish into the mouth, then
crush prey against the roof of its mouth with
its tooth-covered bony tongue. Juveniles consume
smaller organisms, especially shrimp.
Like its close relative the arawana, it can leap
from the water to snatch a bird or even a monkey
from an overhanging branch.
Reproduction: Spawning occurs in April
and May in shallow lakes of flooded regions.
Builds a nest of about 15 cm depth and 50 cm
width in sandy bottoms. Male guards the eggs
and the young. Once hatched, young fish follow
their father.
Mortality/Longevity: Preyed upon by humans.
Conservation status: CITES Appendix II. Heavily
exploited as a commercial fish throughout
the Amazon. Populations have been greatly
reduced during the past 200 years.
Remarks: Obligate air breather, well adapted
to oxygen-deficient waters. Gulps air into its
gas bladder every 10–15 minutes when oxygen
levels are low.
Indigenous people utilize the scales and bones.
The tongue was once used as a seed grater
to make drink powders. Scales were used as
scrappers.
Often referred to as the largest freshwater fish;