Channa striata, the striped snakehead, is a species of snakehead fish. It is also known as the common snakehead, chevron snakehead, or snakehead murrel and generally referred simply as mudfish. It is native to South and Southeast Asia, and has been introduced to some Pacific Islands.

GEOGRAPHIC RANGE

• It is a bony fish with endoskeleton ribcage, grows up to a meter in length, though because of fishing, this size is rarely found in the wild.

• It has a widespread range covering southern China, Pakistan, most of India, southern Nepal, Bangladesh, Sri Lanka, and most of Southeast Asia.

•  It has more recently been introduced to the outermost parts of Indonesia, the Philippines, and Mauritius.

• PHYSICAL DESCRIPTION

• The striped snakehead has a long body characterized with dark black-brown on the upper section of its body, and bands of a white on its belly. The striped snakehead can reach lengths up to 90cm and up to 3 kg - growth studies report they reach an average body mass is reported as 60g by 12 weeks past the fingerling stage. The female striped snakehead is larger than the male. As juveniles, the striped snakehead has a tan coloring with dark brown stripes. Striped snakeheads have a long dorsal fin, a pectoral fin, a pelvic fin that is almost directly under the pectoral fin, and a long anal fin. They also have large mouths with sharp visible teeth with 4-7 canines, located on the bottom row of their mouths. Species in the family Channidae have relatively wide heads with large scales that have been compared to that of snakes, which is why they were given their name "snakeheads."

HABITAT

• Channa striata occurs mainly in shallow freshwater habitats, typically at depths of 1-2 m, rarely below 10 meters.

• This species can be found in most types of slow-moving freshwater habitat, including rivers, lakes, ponds, canals, creeks, flooded rice paddies, irrigation reservoirs, and swamps.

• Compared to most freshwater fish it is quite tolerant of turbid conditions and low oxygen levels.

• In regions with rainy and dry seasons, these fish may migrate out from permanent lakes and streams into flooded areas during the rainy season, and then return to permanent waters as the flooded areas dry.

REPRODUCTION

• The striped snakehead is mainly a solitary fish except during spawning season. In its native habitat, spawning occurs June through August (southwest monsoon) and October through December (northeast monsoon).

• The striped snakehead is a monogamous fish, because it keeps the same mate throughout the year.

• It was also found in the study that the males are very involved in the courtship of the females. They exhibit this activity by hitting the snout and the vent of the female frequently, while gametes are being released.

• The striped snakehead reproduces up to two times per year, during the periods of the southwest and the northeast monsoon in flooded rivers and ponds.

• During their spawning period, the striped snakehead can produce up to 4,000 eggs. Once the eggs have been produced, if vegetation is present, parents will use this to build a nest for the fertilized eggs.

• Parental investment is an important part of spawning and reproduction in the striped snakehead. From the point of fertilization until the time the young reach the fingerling stage (15-20cm), the striped snakehead behaves aggressively to protect their young.

• Both parents participate in caring for their young, but there is always one parent who guards the eggs at all times. It is unknown which parent guards the eggs more often.

• Although the striped snakehead invests a great amount of care for their young when food becomes scarce the parents will eat their young in order to survive.

BEHAVIOR

• Channa striata is a solitary, territorial fish. Some populations migrate between permanent waters and flooded areas created by seasonal rains.

• These fish are capable of limited movement overland by the use of a wriggling motion, which they use to disperse to new bodies of water on rainy nights.

• When the striped snakehead is unable to relocate from drying habitats during dry season, they can survive by burrowing in the bottom of mud lakes, canals, and swamps to keep their skin and breathing apparatus moist.

• The striped snakehead can breath air from the surface of the water, and so is able to survive in waters that have low levels of oxygen.

FOOD HABITS

• Channa striata is a predacious, ambush feeding fish that has a carnivorous - specifically piscivorous - diet.

• It is a generalist species that preys on any available source of food that is attainable.

• As young fish, also known as a fry, the striped snakehead hunts in groups with their main source of food being zooplankton and small insects.

• Once the young fry become adults, they begin to hunt on their own, feeding on other adult fish, and the progeny of those fish.

• They can also feed on frogs, snakes, insects, earthworms, tadpoles, birds, small mammals, and crustaceans. When food sources become limited, adult snakeheads may feed on young of their own species.

PREDATION

• It is likely that any large fish-eating predator in their habitats might prey on them, such as larger fish, birds, crocodilians, turtles, otters, etc. Channa eggs and fry are small enough to be attacked by aquatic invertebrate predators too, such as dragonfly nymphs (Odonata) or predaceous diving bugs (Belostomatidae), if not protected by their parent.

• The coloration pattern of these fish is probably cryptic, but this has not been shown experimentally

ECOSYSTEM ROLES

• Channa striata is host to a number of parasite species. One of special concern is the nematode Gnathostoma spinigerum. This roundworm uses the striped snakehead as a intermediate host. Larvae of G. spinigerum infect copepods that are an important food source for juvenile snakeheads. The larval nematodes survive consumption by the fish, and encyst in fish tissues, particularly muscles. If uncooked snakeheads are consumed by humans, the larvae will also survive and migrate through tissues. The definitive host for these worms are canines and felines. Only in the stomach of one of these mammal species can the worm mature and reproduce.

ECONOMIC IMPORTANCE FOR HUMANS: POSITIVE

• The striped snakehead is cultivated to be an important food source for India, southeastern Asia, China, and parts of Africa.

• Due to its availability and affordability, the striped snakehead is a suitable food source of all economic classes. In some communities striped snakehead is also used for traditional medicinal purposes. It is believed that consumption of the striped snakehead provides healing powers, because of its ability to live out of water for several days as long as their skin stays moist.

• Some cultures use snakehead muscle tissue and oils to heal wounds, prevent scarring, and administer it to those recovering from surgery or sickness. Additionally, the striped snakehead is used as an aquarium fish and to control densities of Nile tilapia Oreochromis niloticus.

ECONOMIC IMPORTANCE FOR HUMANS: NEGATIVE

• Despite the economic importance of the striped snakehead as a source of food consuming the fish can be risky. The striped snakehead is a host for a parasitic nematode, Gnathostoma spinigerum, which can be contracted if meat is not properly prepared.

• In humans, it can cause gnathostomiasis, a disease that can be lethal if untreated. An additional negative effect that could caused by the presence of exotic striped snakehead introduced outside their native range is ecological damage to native fisheries.