Q1. Give the common names and scientific names of two Indian major carps and one Chinese carp which are cultured in fresh water. If you were given two carps, how will you know which one is male and which one is female by observing (i) the genital aperture/vent, and (ii) the pectoral fins?State the specific features which distinguish a mature female carp from a spawning female carp and a spent female carp.What is meant by 'induced breeding by hypophysation under pond conditions'? Describe the technique.
- (a)) Give the common names and scientific names of two Indian major carps and one Chinese carp which are cultured in fresh water. If you were given two carps, how will you know which one is male and which one is female by observing (i) the genital aperture/vent, and (ii) the pectoral fins? (350 words)
- (b)) State the specific features which distinguish a mature female carp from a spawning female carp and a spent female carp. (250 words)
- (c)) What is meant by 'induced breeding by hypophysation under pond conditions'? Describe the technique. (400 words)
Key Points:
- Indian Major Carps: Rohu (Labeo rohita), Catla (Catla catla); Chinese Carp: Grass Carp (Ctenopharyngodon idella).
- Male carp vent is slit-like and pale; female vent is rounded, swollen, and reddish.
- Male carp pectoral fins are rough with nuptial tubercles; female pectoral fins are smooth.
- Mature female has a full, soft belly; spawning female actively expels eggs; spent female has a flaccid, sunken belly.
Answer: Freshwater aquaculture in India heavily relies on indigenous Indian major carps and introduced Chinese carps. Understanding their identification, particularly sex differentiation, and mastering breeding techniques like hypophysation, are fundamental for successful seed production and sustainable aquaculture practices. Distinguishing between different reproductive stages in female carps is also critical for effective broodstock management. The process of induced breeding by hypophysation, especia...