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Breeding Livebearers
Unlike other fishes, female livebearers are fertilized internally by transferring
milt to females by means of the males modified anal fin, the gonopodium. Breeding
pattern of guppies and other fishes of this group vary and hence have been dealt
separately.
Guppy (Poecilia reticulate)
Male guppy reaches up to 2.5 – 3.5 cm length, while the female is usually
larger when fully grown. They thrive in a large well-planted tank with temperatures
within 20o – 25o C. Gravid females with their abdomen
enlarged are collected and placed in the breeding tank (30 cm x 20 cm x 20 cm) individually
or pairs. Plants like Cabomba can be placed in the aquarium. Once individual
females give birth to 20-200 young ones, the tank is aerated. For mass breeding
of guppy a tank size (100 cm x 100 cm x 60 cm) is ideal, where a perforated cylindrical
basket can be provided in one side of the tank encircled with fibrous plastic flowing
filaments where the female can drop the young ones. Soon after birth, the young
ones escape from their mother and enter into the perforated basket and latter the
young ones are collected from the basket and placed in separate tanks, for further
rearing.
Platy, Swordtail and Molly
The platies, swordtails (Xiphophorus spp.) take 6-8 weeks, while mollies
(Poecilia spp.) 12-16 weeks to mature. Like guppies the male used to insert
its gonopodium with milts into female, fish and eggs are fertilized inside the mother’s
body. After fertilization, the embryo grows to tiny young ones and becomes ready
for free swimming within 4 weeks of gestation period. Platies, swordtails and mollies
are quite hardy fish; they will breed well in most type of water, so long as it
is not too soft or acidic. Addition of little aquarium marine salt or common salt
to water (0.5 –1 g/litre) is beneficial for mollies.
Breeding table of livebearers
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Species
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Sexual dimorphism
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Size
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Optimum water condition for breeding
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Gestation period (days)
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Young ones/ females
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Guppy, Poecilia reticulate
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Male is smaller with more flowing fins and pointed anal fin or gonopodium
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Male 2.5-3.5 cm; female 5-6 cm
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Temp. 20-28o C, water hardness, 50-100 mg CaCO3/litre (moderately
soft water)
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21-35
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20-100
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Platy, Xiphophorus maculates
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Male is smaller and slimmer with gonopodium. General coloration is red, gold, blue,
black, brown etc.
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Male 3-4 cm; female 4-5 cm
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Temp. 23-28o C, water hardness, 50-100 mg CaCO3/litre (moderately
soft water)
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28-42
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10-100
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Sword tail, Xiphophorus helleri
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Male is smaller and slimmer with gonopodium and pronounced sword like projection
on caudal fin
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Male 6-7 cm; female 7-9 cm
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Temp. 23-28o C, water hardness, 50-100 mg CaCO3/litre (moderately
soft water)
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28-42
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20-100
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Black molly, Poecilia sp.
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Male with gono podium, dorsal fin is flowing and bigger. Males are smaller than
females and slimmer also.
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Male 7-8 cm; female 9 cm
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Temp. 23-28o C, Aquarium salt at 0.5-1.0 g/litre
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40-70
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30-70
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(Source: ICAR, 2006)
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