Page 158 - Encyclopedia of Aquarium and Pond Fish, 3rd Edition

156 FRESHWATER FISH DIRECTORY

LIVEBEARERS

These popular fish are characterized by their breeding
habits. The eggs are fertilized internally; in most
species, sperm are transferred to the female
via the male’s gonopodium—a tubelike
projection of the anal fin—and the eggs
subsequently develop in the relative safety
of the female’s body. Some livebearers,
including limias, have a restricted
distribution in the wild and are not
widely kept. Others, including guppies,
platies, and swordtails, are popular
worldwide. The ease with which they
can be bred has led to the Sexing livebearers is not difficult. The
development of these fish into upper fish in this pair of Red-Tailed
Goodeids (Xenotoca eiseni) is male, as
a host of exhibition varieties. evidenced by the hump on his head.

Anableps anableps Gambusia sexradiata Gambusia affinis
Four-Eyes Tropical Mosquitofish Mosquitofish

ORIGINS Ranges from southern Mexico southward into ORIGINS Central America, occurring in parts of Mexico, ORIGINS North America, occurring in the San Antonio
northern parts of South America. northern Guatemala, and northern Belize. River and the Rio Medina in Texas.
SIZE 10 ⁄2 in (27 cm). SIZE 2 ⁄2 in (6.5 cm). SIZE 2 ⁄2 in (6.5 cm).
1
1
1
DIET Live foods preferred. DIET Flake and small live foods. DIET Prepared foods and small live foods.
WATER Temperature 72–86°F (22–30°C); hard WATER Temperature 61–77°F (16–25°C); hard WATER Temperature 61–77°F (16–25°C); hard
(100–150 mg/l) and alkaline (pH 7.5). (100–150 mg/l) and alkaline (pH 7.5). (100–150 mg/l) and neutral (pH 7.0).
TEMPERAMENT Alert by nature. TEMPERAMENT Social and nonaggressive. TEMPERAMENT Peaceful and social.
Although dullish brown in color, these livebearers Both sexes are brownish with silvery underparts,
are fascinating to keep, particularly because they but females are significantly larger than males. In
breed so readily. Males are much smaller than the wild, these fish feed on mosquito larvae, and
females and rarely exceed 6 in (15 cm) in length. they have been widely introduced in tropical areas
The female can produce a batch of 6–13 offspring, to control mosquito numbers. Up to 60 young are
each measuring up to 1 ⁄2 in (4 cm) long, twice a born after a gestation of 24 days. The tank should
1
year. An aquarium for Four-Eyes should not be be well planted to provide hiding places for the
filled to the top and must be covered to prevent fry, or they will be eaten. The fry will take small
them from leaping out. This species sometimes live foods and are best reared in their own tank.
prefers brackish water.
Swollen belly indicates Dorsal fin set
Silver and blue feature strongly on the body of this a gravid female well back
fish, while the fins are marked with red and blue.
Unlike other mosquitofish, this species does
not tolerate brackish water. Include floating
plants in its tank. Females are twice as large
as males and have broader bodies. Some 10 –35
young are born about a month after mating, and
further broods follow at one-month intervals.

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