Ruhi is a freshwater carp. Its life cycle is completed in several stages. Its steps are:
1. Sexual Maturity: Two-year-old ruhi fish become fertile. Females reach sexual maturity at 51-70 cm and males at 60-65 cm.
2. Breeding Season: In nature, ruhi fish breed once a year. Rainy season or June-July is the best time for their breeding. During this time the water is flowing and cloudy. Turbid water is suitable for the survival of fish. Siddique Publications
3. Spawning: Fecundity is the ability of fish to produce eggs. The process of laying fish eggs is called spawning. Roe fish lives in stagnant water but lays its eggs in flowing water. It is called protamodromous. The suitable environment for egg laying is water temperature 24-280 C. And water contains a lot of oxygen. Cotton fish lays eggs on Amavasya or Purnima. At this time, the male fish secretes steroid hormones into the water and attracts the female fish for reproduction. The female fish lays about 19,00,000 eggs in the turbid water under the obsessive effect of retaxis. Eggs that float in water are called pelagic eggs and eggs that sink are called demersal. Dr. Siddiq Publications
4. Fertilization: The male fish releases sperm on the eggs. The water in the river changes and mixes with the sperm and egg. Fertilization occurs when the sperm and egg meet. As a result of fertilization, the zygote is created. Dr. Siddiq Publications
5. Development : The process by which the zygote divides repeatedly into a full-fledged organism is called fertilization. This is done in three steps.
(i) Embryonic cleavage: Cleavage begins 30-45 minutes after formation of the zygote. The zygote divides by cleavage to form micromere and macromere cells. In the process of blastulation, these cells become blastomeres. Blastomere cells are arranged in a certain layer. During gastrulation, blastomere cells are arranged in three layers. Ectoderm, Mesoderm and Endoderm.
(ii) Hatching of larval stage: Larva emerges from egg within 15-18 hours. The larva is called an egg. Dimpona age of 72 hours is called renupona. In this condition, the embryo takes on a light yellow color. Notochord and nerve cord are formed. Eyes, hearing and chromatophores are formed. Air sacs and digital fins are present.
(iii) Post larval hatching: In this stage the yolk sac is destroyed. Operculum, dorsal fin, caudal fin etc. arise. Air sacs are divided into two parts. The tail is homocircular. The nostrils are fully divided, the eyes are equal and the fleshy mouth is formed.
6. Anguli Pona: If the length of Pona is 7-12 mm then it is called Dhani Pona. When the chick is 9-30 days old, it is called Anguli chick. Fingers, fins, barbel etc. are formed in fingerlings.
7. Brood fish: Morphological and structural changes occur in the fingers. Transforms into a full-fledged fish. attains sexual maturity. When it reaches sexual maturity, it is called brood fish.