Bighead Carp Farming: A Production Guide

How bighead carp (Hypophthalmichthys nobilis) is farmed: zooplankton filter-feeding, role in polyculture with silver carp, pond fertilization, hatchery induced spawning, growth and invasive caution.

Overview

Bighead carp (Hypophthalmichthys nobilis, formerly Aristichthys nobilis) is a large filter-feeding cyprinid native to the large rivers and floodplain lakes of eastern Asia, from southern China to the Amur system. It is a major farmed freshwater food fish; FAO data show production rising from about 15,000 tonnes in 1950 to more than 3 million tonnes by 2013, among the highest of any cultured freshwater fish. It is grown in pond polyculture, especially alongside silver carp.

Biology and feeding

Bighead carp is a filter feeder, recognized by its large, scaleless head and low-set eyes. It feeds on plankton and, compared with silver carp, takes a greater share of the larger zooplankton rather than the finest phytoplankton. It grows to a large size, commonly around 60 cm and exceptionally up to about 146 cm and 40 kg, and it grows quickly where plankton is abundant.

Role in polyculture

In the Chinese polyculture system, bighead carp fills the zooplankton-feeding niche, complementing silver carp, which concentrates on phytoplankton. Stocking the two together lets the pond harvest both major fractions of the plankton, and they are combined with bottom- and plant-feeders such as common carp and grass carp. Because grass carp and other species fertilize the water and promote plankton, adding bighead and silver carp converts that plankton into fish and keeps the pond balanced.

Pond fertilization and growth

As a plankton feeder, bighead carp benefits from fertilized water. FAO integrated-farming guidance describes manuring ponds to raise plankton, for example using cattle manure where bighead is the major species. The fish is usually stocked as a secondary species in polyculture rather than the dominant one, and grows to market size over a growing season or more depending on temperature, stocking and food supply.

Reproduction and seed supply

Like the other Chinese carps, bighead carp is a riverine spawner that does not breed in still ponds, so hatcheries supply fry by induced spawning. FAO records induced spawning of bighead and silver carp in China from 1958, using carp pituitary extract and human chorionic gonadotropin (HCG), with synthetic LRH-A also used; spawning is conducted at an optimum of roughly 22 to 28 °C. Fry are reared through nursery ponds to fingerling size for stocking.

Harvest and main diseases

Bighead carp is harvested by seining or pond draining together with the other polyculture species. As a hardy plankton feeder it is relatively robust, but like other pond carps it is affected by bacterial infections and parasites under crowding or poor water quality, so good water management and biosecurity remain important.