Iruka to Shounen(1975)

Iruka to Shounen

The series presents the adventures of Zoum, a white dolphin and his friends, two children who live with their sailor uncle. The cast includes several animals including a mynah bird (who understands the dolphin language in addition to the language of the other animals and the humans on the island and acts as a translator), a koala, and a sloth.

During their adventures, Zoum meets a beautiful female dolphin, called Za-za-zoom in the English version, with whom he has a baby.

(Source: Wikipedia)