What are the feeds of foli fish (Bronze Feather Back)?

Notopterus notopterus, commonly known as the knife fish or featherback fish or Foli (In Bangla), is a carnivorous freshwater species found in rivers and wetlands across Southeast Asia, including Bangladesh. Like other carnivorous fish, the feeds for Notopterus notopterus need to mimic its natural diet, which primarily consists of smaller fish, aquatic invertebrates, and other animal-based protein sources.

Here are the main types of feeds suitable for Notopterus notopterus:
1. Live Feeds

• Small Fish: Notopterus notopterus is a predatory fish and thrives on live prey such as small fish like guppies, tilapia fingerlings, or other small species. In nature, these fish hunt for small, slow-moving prey.
• Insects: Insects like crickets, grasshoppers, and water insects are part of their natural diet. These can be offered live or, in some cases, freeze-dried.
• Worms: Earthworms and bloodworms are highly nutritious live feeds suitable for juvenile and adult featherback fish. Worms are easy to digest and are often used in aquaculture.
• Larvae: Black soldier fly larvae or mosquito larvae are nutritious and attract Notopterus notopterus due to their movement.

2. Frozen Feeds

• Frozen Fish: For captive Notopterus notopterus, frozen fish (such as small pieces of tilapia, carp, or similar freshwater fish) can be used to mimic the fish’s natural diet. It’s best to thaw frozen fish before offering them to the fish.
• Frozen Shrimp: Frozen shrimp or prawn meat is another excellent source of protein. Shrimp can be offered whole, chopped, or in smaller pieces depending on the size of the fish.
• Frozen or Chilled Mollusks: If available, frozen mollusks (such as snails or clams) can be fed to Notopterus notopterus to add variety to their diet and replicate the natural feeding habits of the fish.

3. Pelleted Feeds (Formulated Diets)

• High-Protein Pellets: While Notopterus notopterus is primarily carnivorous, it can accept specially formulated high-protein pellets designed for carnivorous fish. These pellets are usually made with fishmeal, shrimp meal, or other animal protein sources.
• Sinking Pellets: Since featherback fish typically feed near the bottom or mid-water, sinking pellets are preferred. These provide the essential nutrients for growth and health, particularly in farmed or aquarium settings.

4. Fresh Meats

• Fish Fillets: Freshly filleted fish meat such as tilapia, catfish, or any other locally available freshwater fish can be offered to Notopterus notopterus. Ensure that the fish is free of bones or large chunks that could cause choking.
• Chicken or Beef Heart: Some aquaculture systems feed chicken hearts or beef heart to carnivorous fish. These provide an excellent protein source, although they should be fed in moderation.

5. Supplementary Feeds

• Gel-Based Feed: Gelatinous feeds fortified with essential vitamins and minerals can be used to supplement the diet, especially when natural prey items are not available. These feeds help to ensure a balanced diet.
• Vitamin and Mineral Supplements: For maintaining overall health, vitamin and mineral supplements can be added to the diet, especially in a controlled aquaculture system.

Feeding Frequency:

• Juvenile Notopterus notopterus: Juveniles should be fed small amounts of live or frozen foods 2-3 times a day. The feed size should match their size and developmental stage.
• Adult Notopterus notopterus: Adults can be fed 1-2 times a day with larger portions of live prey, frozen food, or pelleted feed, depending on their size.

Feeding Tips:

• Since Notopterus notopterus is a predatory fish, it is important to feed them prey that moves to stimulate their hunting instincts. Live fish, worms, and insects are excellent options.
• Always ensure that the feed is appropriate in size and texture to avoid choking or difficulty in consumption.
• If using frozen feeds, thaw the food thoroughly before feeding to ensure it’s safe for consumption and to prevent any potential health issues caused by cold or frozen food.
• Featherback fish are known to be picky eaters, so it is best to offer a variety of food types (live, frozen, pellets) to keep them interested and healthy.

By providing a diet rich in protein, primarily from live or frozen animal sources, and offering variety in their food choices, Notopterus notopterus will thrive in captivity or aquaculture settings. These fish are hardy but require a diet that closely resembles what they would naturally consume in the wild.