THE STEINHART AQUARIUM - Gulf of Guinea Science ...

120 A Docent Field Guide to the Species of the Steinhart Aquarium
Reproduction and Development: When
female produces eggs, male displays intense
colors before fertilization takes place. Eggs are
laid and develop among plants.
Mortality/Longevity: Life span: 5–8 years.
Topsmelt
Atherinops affinis (Atherinidae)
Silversides
Distribution: Southern British Columbia to
Baja California.
Habitat: Usually, these fish are found at about
9 m around piers, rocky reefs, and kelp beds.
In an ocean environment they may be found
at depths up to 26 m. Also found in brackish
bays and estuaries. Juveniles are better able to
tolerate fresh water.
Appearance: Blue-grey to green above, silvery
below with a blue-edged, silver line that runs
the full length of the body. Lateral line lacking.
Their pelvic fins are longer than those of other
smelt in the San Francisco Bay and Delta.
Average length: about 37 cm. Juveniles are
translucent.
Diet: In the ocean, adults eat zooplankton and
small crustaceans. In estuaries, they feed on
plant material. Juveniles feed on algae and
kelp fly larvae. They are diurnal feeders.
Reproduction and Development: Egg clusters
are attached to a macroalgae and eel grass.
Larvae are planktonic.
Mortality/Longevity: Maximum age: 6 to 9
years.
Remarks: They are called topsmelt for their
habit of swimming near the surface where
they form schools, often of thousands of
individuals.
Topsmelt are able to tolerate saline levels 2 to
3 times that of the ocean, and are often found
in salt evaporating ponds in San Francisco Bay.
Jacksmelt
Atherinopsis californiensis (Atherinidae)
Silversides
Distribution: Central Oregon to Gulf of California.
Habitat: Schooling fish that prefers shallow
inshore waters, bays, piers, kelp beds; surface
to 29 m.
Appearance: Length 33–38 cm. Greenish blue
on back, silver shading below. Metallic stripe
with blue border runs the length of the body.
Diet: Small crustaceans.
Reproduction and Development: Mature
at 2 years and/or 15 cm long. Reproductive
females spawn multiple times from October
through March. Peak activity January through
March. Spawning activity probably dependent
on water temperature. Eggs the size of small
BB’s. Adhesive filaments attach large egg mass
to shallow-water seaweeds.
Mortality/Longevity: Nine to 10 years,
maximum: 11 years. Eaten by other fishes,
marine mammals, and seabirds.
Remarks: One of the most common fish caught
by pier anglers.
ORDER CYPRINODONTIFORMES
Redtail Killifish
Nothobranchius guentheri (Aplocheilidae)
Rivulines
Distribution: Africa: endemic to the island of
Zanzibar. eastern Tanzania.
Habitat: Tropical freshwater, especially
seasonal pools and streams.
Appearance: Males: gold face and underside,
pale blue scales on sides outlined in red.
Females: more subdued coloration.
Diet: Carnivorous, especially insect larvae and
small crustaceans.
Reproduction and Development: Lay eggs
in moist mud or sand before seasonal water
evaporates. Adults die; however, eggs and
embryos are able to withstand extended periods
of drought and hatch whenever rains arrive.
Remarks: The lateral line of the killifish is able
to sense ripples made insects struggling at the
water’s surface.
These and other “mosquito” fish have been
studied for introduction to areas needing
mosquito control. Possible adverse effects of
introducing an exotic species are also being
considered.
Patriciae Killifish
Pachypanchax patriciae (Aplocheilidae)
Killifishes
Distribution: Endemic to Madagascar: the
monsoon forests of the northwest and the
deciduous forests of the extreme north.