To determine if a guppy is pregnant, you can make a comprehensive observation based on the following characteristics:
Abdominal Changes
Swollen Shape: The abdomen will gradually bulge after pregnancy, appearing triangular from the side and possibly approaching a square shape in the later stage.
Fetal Spot Appearance: A fetal spot will appear near the anus. It is light in the early stage (light yellow/orange) and turns black or dark (orange-red for albino varieties) as the pregnancy progresses.
Protruding Genital Opening: The genital pore will obviously protrude before delivery, shaped like a right triangle.
Abnormal Behaviors
Reduced Activity: The guppy often hides in aquatic plants or corners and swims slowly.
Emotional Fluctuations: It may become irritable and attack other fish, or be sensitive and easily frightened.
Rapid Breathing: The breathing frequency speeds up, and the body slightly shakes before delivery.
Appetite and Posture
Loss of Appetite: The guppy may refuse to eat when approaching childbirth.
Curved Back: The back may arch slightly due to fetal pressure.
Signs of Impending Labor
Darkening of Fetal Spots: When the color is darkest, delivery usually occurs within 3-5 days.
Solitary Behavior: The guppy actively seeks hidden corners and rejects other fish from approaching.
It is recommended to judge by combining multiple indicators to avoid confusion with overeating or ascites (overeating recovers the next day, while ascites is cone-shaped and accompanied by illness). If signs of impending labor are found, isolate the female fish in time to prevent the fry from being eaten.