Breeding of Live-bearers

Breeding of Live-bearers

Live-bearers are fish that give birth to live young. There are two types:

• Ovoviviparous: Eggs develop and hatch inside the female before birth.
• Viviparous: No eggs are formed; young are nourished through an umbilical-like cord or secretions from the female.

Important live-bearers include:

• Guppy
• Molly
• Swordtail
• Platy

Maturity

• Live-bearers typically mature between 4 to 6 months.
• Guppies and platies can mature in as little as 2 months.

 

Conditioning of Parent Fish

Before spawning, parent fish should be conditioned:

• Conditioning: Feeding fish a variety of healthy foods to prepare them for spawning.
• Common foods include:
• Well-balanced flake food
• Live foods (brine shrimp, insect larvae, flying insects)

Parent fish should be separated during conditioning. When reintroduced, they will be ready to spawn.

Breeding of Live-bearers

• In live-bearers, eggs are fertilized in the egg duct.
• Fry remain in the mother's body until they are developed enough to swim freely.
• Ideal temperature for breeding:  27°C

Male and Female Differences

• Males have a pointed anal fin (gonopodium) used for fertilization.
• Females have a normal anal fin and can have multiple broods from one fertilization.

Gestation and Birth

• Gestation period: 3-4 weeks.
• Females show a gravid spot (dark crescent near the vent) when ready to give birth.
• Fry are born fully developed and are similar in size.

Cannibalism Prevention

• Live-bearers may eat their young. To prevent this:
• Provide cover with fine-leaved plants.
• Use a breeding trap to separate the female from the fry.

Breeding Tank Preparation

• Tank size: Not too large, filled to about 20 cm depth with matured water.
• Temperature: Raised to about 25°C
• Stock with fine-leaved plants or nylon knitting wool.

IMPORTANT: Handling live-bearers close to delivery can cause premature births.

Number of Young Ones

The number of young (brood) varies by species and conditions:

• Average: 20-40 young.
• Maximums:
• Guppies: 100
• Platies: 50
• Mollies: 100
• Swordtails: 200

Females can become pregnant again within 2-3 days after giving birth, using stored sperm. This allows for 5-6 releases of young in a year.

Feeding of Fry

Fry can swim and eat immediately after birth. They can be fed:

• Finely crushed dried food
• Brine shrimp nauplii