Fish

Fish are water-dwelling animals that breathe through gills and swim using fins. They are important to people for food, culture, and the environment. In Nigeria and many parts of Africa, catfish and tilapia are the two most common types eaten, raised, and sold.

 Scientific Classification

• Kingdom: Animalia

• Phylum: Chordata

• Class: Actinopterygii (ray-finned fishes)

• Order & Family: Varies by type

 Common Names

• Catfish

• Tilapia

• “Point-and-kill” (catfish, in Nigerian restaurants)

• “Water fowl” (local nickname for farmed fish)

Fish have many local names across tribes and are central to meals, business, and culture.

 Geographic Distribution

Catfish and tilapia are found in:

• Rivers, ponds, lakes, and streams

• Man-made fish farms

• Wet markets and restaurants across Africa

• Warm climates across the globe

They are freshwater fish, although some tilapia can survive in slightly salty water

Image showing Freshly harvested catfishes on ice Source: Shutterstock)

 Common species

1. Catfish (Clarias gariepinus)

Image showing a Large catfish with visible whiskers in shallow water (Source: Shutterstock)

 Facts:

• Popular in Nigerian fish farms

• Grows fast and can survive in low oxygen

• Very active and slippery

• Main fish for “pepper soup” and barbecues

2. Tilapia (Oreochromis niloticus)

Image showing Tilapia swimming in a clear fish tank (Source: Shutterstock)

Key Facts:

• Second most farmed fish in Africa

• Easy to raise and hardy

• White flesh with mild taste

• Good for frying, boiling, and stews

What do they eat?

Catfish:

• Insects, small fish, bloodworms

• Floating pellets in farms

• Organic waste in ponds

Tilapia:

• Algae, aquatic plants

• Farm feed pellets

• Small insects and plankton

Both species are omnivores and adapt well to feed provided by fish farmers.

 Fun facts

• Catfish can survive outside water for hours if it’s moist.

• Tilapia are sometimes called “aquatic chickens” because of their fast breeding.

• Catfish use their whiskers to feel for food in the dark.

• Tilapia can change sex depending on environmental needs.

• A female tilapia can carry eggs in her mouth to protect them.

 Importance to Humans

Positives:

• Provide affordable protein for families

• Offer jobs through fish farming and trading

• Important in Nigerian cuisine (e.g., catfish pepper soup, grilled tilapia)

• Easy to raise even in backyard ponds

Negatives:

• Overcrowded ponds can lead to poor water quality

• Escaped farmed fish may disturb natural ecosystems

• Disease can spread quickly in shared ponds

Health & common issues

Fish need clean water and proper feeding to stay healthy.

Common Issues:

• Fungal infections (white patches, cloudy eyes)

• Gill disease from dirty water

• Parasites (worms or lice in the skin or gills)

• Poor growth due to overcrowding or poor feed

Tips for Healthy Fish:

• Change pond water regularly

• Avoid overfeeding

• Quarantine sick fish

• Use approved medications only when needed

 Conservation & sustainability

Catfish and tilapia are not endangered, but wild fish populations are declining due to:

• Overfishing in rivers and lakes

• Pollution from chemicals and plastics

• Habitat loss from human development

Fish farming is encouraged to reduce pressure on wild stocks, but it must be done responsibly.

 Catfish vs Tilapia

Image showing a  farmer holding catfish  and smiling (Source: SCIDev.net)

Do you have a fish farm, sick fish, or want to start aquaculture?, you can visit Doctor Hulk Veterinary Hospital Today or call 08143397614.