Question

Which of the following is viviparous?
a. Bony fish
b. Shark
c. Lungfish
d. Frog

Answer 1

Hint: A group of elasmobranch fish with a cartilaginous skeleton, 5-7 gill slits on the sides of the head, and non-fused pectoral fins on the head. Although there are a few known exceptions, they are present in all seas and do not live in freshwater.

Complete answer:
> Option A is incorrect. By external fertilisation of their eggs, the majority of bony fish reproduce. During the fish spawning season, hundreds and sometimes thousands of eggs and sperm are released into the water by females and males. In the water, the eggs are fertilised. Other species consume much of the fertilised eggs.

> Option B is correct. Throughout the entire gestation cycle, viviparous sharks bear the embryos and give birth to live shark pups, close to how humans give birth. Embryos have a yolk sac placenta attached to their mother, which is how they obtain their nutrients.

> Option C is incorrect. In a nest in a weedy area of its home, the female African lungfish lays its eggs. The males guard the young for up to two months until the eggs hatch. The larvae have outside gills that are reabsorbed into fully formed lungfish during their metamorphosis.

> Option D is incorrect. Usually, frogs deposit their eggs in water. The eggs hatch into tadpoles called aquatic larvae that have tails and internal gills. On soil, a few species deposit eggs or bypass the stage of the tadpole. In the midst of translucent gel-like globules, the embryos in frogs' eggs look like black spots. By receiving more heat from the light, the black colour makes them hatch faster.

Hence, the correct answer is option (B).

Note: Viviparity is the gestation of young ones which results in live birth without the use of a conventional egg. Viviparity may be placental or aplacental for sharks. Young people are born fully developed and self-reliant. Hammerheads, requiem rays, and smoothhounds are viviparous (such as the bull and the blue rays.