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What is a Rohu?

Angie Bates
Angie Bates

The rohu is a type of carp that is native to the rivers of India and other Asian regions, and has also been introduced with relative success into rivers and lakes in Japan, the Philippines, and some African countries. This fish is extremely important to the commercial fishing industry in India. The scientific name for the rohu is Labeo rohita.

Also called a rui, the rohu can reach a maximum length of 78.7 inches (200 cm) and weight as much as 99 pounds (45 kg). These fish have blue or black scales on their backs and lighter, silvery scales on their bellies. They have a single dorsal fin, as well as two pectoral and anal fins, and a forked caudal fin, or tail. Their mouths are small and their heads have no scales.

The rohu fish is extremely important to the commercial fishing industry in India.
The rohu fish is extremely important to the commercial fishing industry in India.

A solitary species, the rohu lives and feeds alone. Primarily active in daylight, these fish are largely column feeders, eating mostly algae and other aquatic vegetation. They are eurythermal, meaning they can tolerate changes in water temperature, but need water warmer than 57.2°F (14°C) to survive.

During monsoon season from April to September, the rohu spawns. Moving to shallow parts of flooded rivers, females lay 266,000 to 2,794,000 eggs, depending on the individual female's size. Temperatures ideal for spawning, 71.6–87.8°F (22–31°C), are significantly higher than the minimum temperature that these fish can normally tolerate.

Juvenile fish eat primarily zooplankton and may swim in schools while feeding until reaching adulthood. Rohu are fast growing, attaining 13.7–17.7 inches (35–45 cm) in length and 24.6–28.2 ounces (700–800 g) within their first year. These fish do not live longer than ten years.

The Rohu is the most important species of carp in the commercial fishing industry in India because of its low maintenance cost and high market value. Though most eggs, or seeds, are produced artificially in the fisheries themselves, seeds are also collected from rivers to use in the hatcheries. Fish are usually sold fresh in local markets, but many are put on ice and shipped by truck to places as far as 1,243–1,864 miles (2,000–3,000 km) away. The iced fish, however, have a lower market value than then fresh.

Ideally fish are grown in ponds with organic methods and materials, so in theory, these hatcheries are environmentally friendly. Unfortunately, poor practices, such as overstocking ponds to produce more fish, lead to disease and the increased use of environmentally unfriendly pesticides in some hatcheries. In these non-ideal hatcheries particularly, rohu are susceptible to many types of bacterial, fungi, and parasitic diseases.

Frequently Asked Questions

What is a Rohu fish?

Rohu, scientifically known as Labeo rohita, is a freshwater fish that is a member of the carp family. It is native to rivers in South Asia, particularly in the Indus, Ganges, and Brahmaputra river basins. Rohu is highly valued for its tender meat and is a staple in aquaculture in the region, contributing significantly to local diets and economies.

Where can Rohu fish be found?

Rohu is predominantly found in the freshwater rivers and lakes of South Asia. It thrives in the waters of India, Nepal, Bangladesh, Pakistan, and Myanmar. The species prefers a tropical climate and is well-suited to the warm waters of this region, often inhabiting the middle layer of water bodies, avoiding both the surface and the bottom.

What does Rohu fish eat?

Rohu is an omnivorous fish with a diet that primarily consists of plankton, aquatic vegetation, and small invertebrates. Its feeding habits contribute to the ecosystem by controlling the growth of algae and other small organisms, thus maintaining a balanced aquatic environment. This diet also influences the quality and taste of its flesh, making it a preferred species for consumption.

How is Rohu fish used in cuisine?

Rohu is a culinary favorite in South Asian cuisine, known for its delicate flavor and smooth texture. It is commonly prepared in a variety of ways, including being fried, grilled, or used in curries. The fish is rich in protein and omega-3 fatty acids, making it not only tasty but also a nutritious addition to meals.

What is the size and lifespan of a Rohu fish?

A Rohu fish can grow to a significant size, typically reaching up to 1 meter in length and weighing up to 45 kilograms. Its lifespan can extend up to 15 years under optimal conditions. These characteristics make Rohu a valuable species for long-term aquaculture projects and a sustainable food source for growing populations.

How important is Rohu in aquaculture?

Rohu is one of the most important aquaculture species in South Asia, particularly in India and Bangladesh. According to the Food and Agriculture Organization, it is extensively cultured due to its fast growth rate, adaptability to various types of water conditions, and high consumer demand. Its cultivation supports the livelihoods of millions and contributes significantly to regional food security.

Discussion Comments

anon162799

Quote: Females lay 266,000 to 2,794,000 eggs, depending on the individual female's size. The eggs variation is huge. Is it possible to know how much eggs per kg of females can lay? Thanks. --Hendry

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    • The rohu fish is extremely important to the commercial fishing industry in India.
      By: polesnoy
      The rohu fish is extremely important to the commercial fishing industry in India.