THE STEINHART AQUARIUM - Gulf of Guinea Science ...

free-swimming larvae hatch and leave.
Remarks: Mouth and gill openings are ventral;
despite this apparent “handicap” (always in
contact with mud or gravel) Loricariid cats can
feed and respire simultaneously.
Sucking mouth is used for propulsion,
adhering to the substrate in fast flowing areas
such as waterfalls, and moving forward cm by
cm with short jerky movements.
Dorsal fin (when erected) is the reason for the
common name “sailfin.”
Sailfin Catfish aka Sailfin Plecostomus
Pterygoplichthys sp.(Loricariidae)
Armored Catfishes
Distribution: Native to South America: the
Orinoco, Amazon, Parana and other river
systems. Also established in Florida, Hawaii,
Nevada, and Texas.
Habitat: Sluggish streams, floodplain lakes,
swamps and marshes.
Appearance: Members of the genus are distinct
from other members of the family due to their
large dorsal fins with 9 or more long fin rays,
the feature that gives them their common name
“sailfin catfish.” Rows of armor plating cover
the body. Color usually dark brown with spots
or wavy lines.
Diet: Primarily plant matter, may also scavenge.
Often helpful in aquariums as algae eaters.
Reproduction and Development: See entry
above.
Remarks: One of the most successful exotic
species in Florida.
Because of their burrowing habitats, feeding
habits, and fecundity, potential effects
of Pterygoplichthys invasion include bank
alteration and erosion, competition with native
species, and disruption of aquatic food chains.
ORDER GYMNOTIFORMES
(KNIFEFISHES)
Electric Eel
Electrophorus electricus (Electrophoridae)
Electric Eels
Distribution: Amazon Basin: Orinoco, and
related areas in northern South America.
Habitat: Lowland backwaters and muddy
river bottoms, never fast-flowing waters. Dur-
California Academy of Sciences
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ing daylight, retreats to recessed hiding places
shared with conspecifics.
Appearance: Large, long (to 2.5 m), round
body. Very long anal fin. Weight to 20 kg.
Diet: Juveniles eat invertebrates such as shrimp;
adults prey on fish and small mammals.
Reproduction: Males construct foam nests and
guard the growing larvae until mid-January
when the first seasonal rains flood the breeding
area, causing the about 10 cm long young eels to
disperse. Males outnumber females (3:1) and are
considerably larger than females.
Mortality/Longevity: Life span: in captivity males
to 15 years, females to 20+.
Remarks: Active nocturnally.
Unlike “true” eels in the Order Anguilliformes,
they are obligate air breathers, taking up to 80%
of their oxygen directly from the air, an adaptation
for survival in poorly oxygenated water.
The long undulating anal fin allows the electric
eel to move backwards or forwards.
About half the musculature has been converted
into electric organs which produce up to 650 V.
These eels use their electricity to stun the fish
they prey upon, as well as for defense.
Though not an aggressive fish, can produce
enough voltage to severely injure humans.
If an electric eel fires a series of charges, each
successive charge is less powerful. Aquarists
stimulate several discharges before attempting
to handle the animal safely.
These eels also have two other, much smaller
sets of electric organs, used for orientation,
finding prey, and identification of foreign
objects.
ORDER BATRACHOIDIFORMES
Humming Toadfish aka Plainfin Midshipman
Porichthys notatus (Batrachoididae)
Toadfishes
Distribution: Eastern Pacific Ocean along the
West Coast of North America.
Habitat: Ranges from intertidal areas where
they may remain out of water under rocks or
seaweed to deeper water over sand and mud
bottoms. Return to shallow intertidal waters
to reproduce. Seasonally common in San
Francisco, Suisun, and San Pablo Bays.