In Russian language there are many diminutive and augmentative forms of nouns.
It adds to the richness of the Russian language expression.
In this video the augmentative for fish is used.
Ribischa - Рыбища (Рыбина is the other one)
This is because a golden fish is usually a small size. Actually, in the Russian famous poem-fairy-tale by A.S. Pushkin it is called by a diminutive noun. “ribka“ рыбка (Пушкин “Сказка о золотой рыбке“.
In Spanish language there are both: augmentatives and diminutives, but t