Freshwater fish are species that primarily inhabit freshwater environments, such as rivers and lakes, with salinity levels of less than 0.05%. These habitats differ greatly from marine environments, mainly due to the salinity of the water. To survive in freshwater environments, fish species must have physiological adaptations.
Approximately 41.24% of all fish species are found in freshwater. This is mainly due to the diversification that disperses their habitats. When managing lakes and ponds, similar basic models can be used for differentiation when studying biogeography in islands.
Vietnam is also home to a wide variety of rich and diverse freshwater fish species. Below are some common freshwater fish in Vietnam; let’s see how many species you know:
Exploring Freshwater Fish Species in Vietnam
What are freshwater fish?
Freshwater fish are those that live almost their entire lives in freshwater environments (such as lakes and rivers) with salinity levels below 0.05%.
It is estimated that about 41.24% of all fish species are found in freshwater. This indicates that diversification has dispersed the habitats of fish species, similar to the management of ponds and lakes along with the use of different aquaculture models.
Freshwater fish need specific physiological characteristics to adapt to their habitats. For example, the gills of these fish can diffuse dissolved gases while retaining sodium levels in their body fluids.
Moreover, their scales function to reduce water diffusion through the skin, making freshwater fish very vulnerable to death if they lose many scales. Additionally, the kidneys of freshwater fish are often well-developed to absorb salts from body fluids before excretion.
Types of Freshwater Fish in Vietnam
Here are some types of freshwater fish in Vietnam that you should know and may choose to include in your daily meals:
Mackerel
Mackerel, scientifically known as Sardinella, belongs to the Clupeidae family. The shape of mackerel resembles that of a sardine but is larger, with a long body, small bones, a slightly green skin layer, and equal jaws. Mackerel have small teeth, and their round, thin scales tend to fall off easily, especially on the belly where they have serrated edges.
Mackerel typically inhabit the surface layer of water, swimming quite fast due to their strong tails. According to records, mackerel are part of the small-bodied bony fish group that survived the mass extinction event at the end of the Cretaceous period, so they continue to exist today.
In Vietnam, locals refer to mackerel by specific names according to their captured forms. Specifically, ‘thin mackerel’ often has a slim body, many white-green scales, especially its flesh which is white, fatty, and fragrant but has many bones. In contrast, ’round mackerel’ has a round body, fewer scales, and its flesh is red, more abundant but not as tasty as thin mackerel.
Additionally, coastal residents living in the Central region often call small mackerel ‘de fish’ and larger ones ‘Mắt Tráo’ (Eye Fish).
Carp
Carp, scientifically known as Cyprinus carpio, belongs to the Cyprinidae family and is related to goldfish. Carp can grow up to 1.2 meters in length and weigh up to 37.3 kg, with a lifespan of up to 47 years.
There are also many varieties of carp with different characteristics, such as: mirror carp (often scaleless but with a row of scales along the body), scaled carp (a type of omnivorous fish), and leather carp (only has scales near the dorsal fin).
Butterfly Fish
Butterfly fish, scientifically known as Notopterus notopterus, belongs to the Notopteridae family. They have a long body (about 400mm), flattened, with a small tail and small scales covering the entire body. They have a relatively large mouth and a short snout. On average, they weigh around 200 grams, sometimes up to 500 grams.
We often see butterfly fish with gray on their back and silver-white on their belly, while yellow appears under the edge of their gill cover.
In Vietnam, this fish has a good growth rate, resulting in high yield, primarily distributed in the Đồng Nai River, the Mekong Delta, the Central provinces, and the Central Highlands.
Loach
Loach belongs to the Actinopterygii class. Its shape is quite similar to that of an eel, with a long body and many filaments and fleshy whiskers developed around the mouth area. Loaches are commonly found in the northwestern regions of Africa, Asia, and Europe.
Catfish
Catfish belong to the Siluriformes order and typically live in natural environments such as ponds, lakes, rivers, and lakes in Vietnam. Additionally, the catfish family has about 100 species living in freshwater environments in Eastern Europe and most parts of Asia, except for the Arabian Peninsula and Siberia.
Catfish have smooth skin, no scales, but have small dorsal fins and long anal fins. Their heads are slightly flattened, with a wide mouth and two long whiskers on the upper jaw, while the lower jaw has four short whiskers. Catfish can range from 8 cm to 3 m in length, depending on the species.
Walking Catfish
Walking catfish or the catfish family in general, scientifically known as Clariidae, includes about 114 species that all live in freshwater environments. Most walking catfish are found in Southeast Asia, but the most diverse species are in Africa.
Each species of walking catfish has different physical characteristics. For instance, the black catfish (also known as Hong Kong catfish) has a long black body and smooth skin; the head is flat, while the body and tail tend to be laterally flattened; they have a wide mouth, sharp teeth, and four pairs of long whiskers; their eyes are small and the nostrils are spaced apart.
Alternatively, the gray catfish has a flat head, a long cylindrical body that tapers towards the tail, smooth skin, and black fins with dark spots; their eyes are small, with a wide distance between the two eyes, a large mouth, and four pairs of long whiskers.
Giant Gourami
The giant gourami, scientifically known as Plotosus canius, belongs to the Plotosidae family. The giant gourami can live in both freshwater and brackish water, with the main breeding season occurring from June to August each year.
The shape of the giant gourami is quite similar to that of the walking catfish but is larger and has more whiskers, and does not have fatty fins. Its elongated tail resembles that of an eel, either pointed or rounded. Some giant gourami species may have venom from their spines, so they must be carefully processed before consumption, especially the two sharp spines near the gills.
Pangasius
Pangasius, belonging to the Siluriformes order, can live in freshwater and brackish water, distributed throughout southern Asia. The body of pangasius is robust, scaleless, resembling the walking catfish but without spines. The dorsal fin is located near the head, triangular in shape with about 5-7 fin rays and 1-2 spines.
In Vietnam, pangasius are primarily distributed in the Mekong River basin and the basins of the major rivers in the southernmost regions. They have a flattened body, smooth skin, and short whiskers.
Bagrid Catfish
Bagrid catfish belong to the catfish family, with about 245 species, capable of living in both freshwater and brackish water, usually found at the bottom of rivers or in muddy areas with slow currents.
They are relatively large, reaching lengths of up to 1.5 meters and weighing between 10-30 kg. Bagrid catfish have an elongated body, scaleless, with a spine in the front part of the dorsal fin, serrated pectoral fins, and fat fins surrounding their bodies. Their heads are slightly flattened with four pairs of long whiskers.
Indian Mackerel
The Barramundi (Lates calcarifer) belongs to the Perciformes order, which includes around 270 species. In Vietnam, the most common species is the silver barramundi.
The barramundi has an elongated, oval-shaped body that is slightly flattened on the sides, with a large head and small teeth. Its dorsal fin is divided into two sections: the front section consists of hard spines, while the rear section is soft. The flesh of the barramundi is thick, with few bones, rich in fat, especially in the rear part of the body. It has a mild sweetness and leaves a rich aftertaste when eaten.
Rosy Barb
The rosy barb, scientifically known as Helostoma temminckii, is also called the “mùi fish” and belongs to the Helostomatidae family. They primarily inhabit freshwater environments, even in harsh and polluted conditions due to their accessory respiratory organs. In Vietnam, rosy barbs are widely distributed in the Mekong Delta.
Rosy barbs are small in size and have a slightly bony texture. Their flesh is white, rarely has a fishy smell, tender, and very delicious.
Anabas
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