Do Oscar Fish Carry Young in Their Mouth?

Fish lovers have long been intrigued by the slow-moving freshwater oscar (Astronotus ocellatus) for its size and power. This breed of fish acts like a dog in a tank, actually recognizing and bonding with its owner. They also tend to dig up and move aquarium plants and decorations, making them quite the tricksters.

  1. Characteristics

    • There are several species of oscar. The male and female look basically identical, so finding a pair may prove difficult. In captivity, they generally range between 10 and 14 inches long and weigh up to 2 pounds. After getting to know you, the oscar becomes quite tame and will actually pout if you make him angry. The long lifespan of the oscar -- up to 12 years -- makes him quite popular with fish owners as well.

    Reproduction

    • The female oscar is picky about a mate and will not reproduce with just any old fish. She prefers a male with traits she find appealing. During spawning, the generally docile pair may become aggressive and fight. Often, they will lock lips or kiss, frequently called ̶0;jaw locking.̶1; The female lays white eggs along the bottom of the tank when she is good and ready and the male swims behind her and fertilizes them, at which time they turn tan or brown. The female may lay up to 1,000 eggs.

    Hatching Fry

    • After fertilization, the eggs usually hatch within three days. The fry emerge with a yolk sac still attached; it provides nutrients for up to seven days for the new babies. The adult oscars guard their babies and get aggressive if anyone, even you, tries to mess with them. They generally do not carry them in their mouths for safety, but they do have a tendency to eat their own fry.

    Growth

    • To help the babies grow, feed artemia, crushed flakes or baby brine shrimp as directed by the Tropical Fish Success website. The fry grow quickly and will reach 3 inches long in a couple of weeks. Within a year, the oscar grows to be nearly 10 inches long. Other cichlids, like dempseys and jaguars, make good tank mates, since they can handle the oscar's aggressiveness.