The bayad بياض, Bagrus bajad, is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of catfish

Catfish

Catfishes are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the heaviest and longest, the Mekong giant catfish from Southeast Asia and the second longest, the wels catfish of Eurasia, to detritivores...

 (order

Order (biology)

In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...

 Siluriformes) in the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Bagridae

Bagridae

Bagridae are a family of catfish that originate from Africa and Asia from Japan to Borneo. These fish are commonly known as naked catfishes or bagrid catfishes.Large Bagrids are important as food fish. Some species are kept as aquarium fishes....

.

Distribution

The natural habitat of the bayad are lakes and rivers in Africa. These lakes include Lake Chad

Lake Chad

Lake Chad is a historically large, shallow, endorheic lake in Africa, whose size has varied over the centuries. According to the Global Resource Information Database of the United Nations Environment Programme, it shrank as much as 95% from about 1963 to 1998; yet it also states that "the 2007 ...

, Lake Mobutu, and Lake Turkana

Lake Turkana

Lake Turkana , formerly known as Lake Rudolf, is a lake in the Great Rift Valley in Kenya, with its far northern end crossing into Ethiopia. It is the world's largest permanent desert lake and the world's largest alkaline lake...

. Rivers include the Nile

Nile

The Nile is a major north-flowing river in North Africa, generally regarded as the longest river in the world. It is long. It runs through the ten countries of Sudan, South Sudan, Burundi, Rwanda, Democratic Republic of the Congo, Tanzania, Kenya, Ethiopia, Uganda and Egypt.The Nile has two major...

, the Niger

Niger

Niger , officially named the Republic of Niger, is a landlocked country in Western Africa, named after the Niger River. It borders Nigeria and Benin to the south, Burkina Faso and Mali to the west, Algeria and Libya to the north and Chad to the east...

, and the Senegal

Senegal

Senegal , officially the Republic of Senegal , is a country in western Africa. It owes its name to the Sénégal River that borders it to the east and north...

.

Description

The bayad is more or less elongated. The dorsal fin has a smooth spine, and the pectoral fins have spines with serrations on the inside. There are four pairs of barbel anatomy barbels. The maxillary barbels may reach to the ventral fin or pelvic fins. This fish is yellow-greenish or blackish with a white belly. The fins are darker, sometimes reddish purple. Juveniles have little black spots on the sides.

The bayad has a maximum size of about 112 centimetres (44.1 in) FL

Fish measurement

Fish measurement refers to the measuring of the length of individual fish and of various parts of their anatomy. These data are used in many areas of ichthyology, including taxonomy and fisheries biology.-Overall length:...

. It has a maximum published weight of 12.5 kilograms (27.5 lb), but is reputed to reach 100 kg (220 lb). Mean sizes and weight of males are less than those of females from the same age. Males grow up to 7 years old, females 8 years (Ref. 51644).

Ecology

The bayad is found in lakes, swamps and rivers. It avoids salt water

Seawater

Seawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% . This means that every kilogram of seawater has approximately of dissolved salts . The average density of seawater at the ocean surface is 1.025 g/ml...

. This species spends nearly the whole of the daylight hours in crevices of rocks and is therefore seldom seen. It lives and feeds on or near the bottom. Adults are exclusively piscivorous

Piscivore

A piscivore is a carnivorous animal which eats primarily fish. Piscivory was the diet of early tetrapods , insectivory came next, then in time reptiles added herbivory....

; it preys on small fish, particularly Alestes

Alestes

Alestes is a genus in the family Alestidae, known as the "African Characidae" as they are found exclusively on that continent. Alestes is a synonym with Myletes, though this name is not longer used...

species, or Chrysichthys auratus as in Lake Kainji. These fish are also feeds on insect

Insect

Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...

s, crustacean

Crustacean

Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...

s, mollusks, and vegetable matter. The efficiency of catching prey catfish is maximised by face to face attack, avoiding damage by dorsal and pectoral spines of the prey.

There is some indication that the species comes to shallower water to breed. Spawning

Spawn (biology)

Spawn refers to the eggs and sperm released or deposited, usually into water, by aquatic animals. As a verb, spawn refers to the process of releasing the eggs and sperm, also called spawning...

season extends from April to July. The parents build and guard the nest, which is like a flat disc with a central hole where the eggs are dropped; the size of the nest and the central hole depend on the fish size.

Relationship to humans

The bayad is an important food fish. The bayad flesh is good eating and is of economic importance, commonly sold as food.