Bagrus bajad (Forsskål 1775)

Procamallanus Infection 14. Parasitic infestations (protozoa, worms, etc.)

Post-larval B. bajad feed on copepods (Ref. 27490). Small fish (immature) take a mixed food of organic detritus, crustaceans and fish (Ref. 51638). Adults feed on insects, fish and plants (Ref. 6160), crustaceans and molluscs (Ref. 28714), or are exclusively piscivorous (Ref. 31256). In small specimens the percentage of insects declines with increasing body size, while that of shrimps increases; for individuals larger than 24cm the trends reverse (Ref. 33614). Lives and feeds on or near the bottom (Ref. 3034, Ref. 33614). Avoids salt water (Ref. 31439).

Dorsal spines (total): 1; Dorsal soft rays (total): 8 - 12; Analspines: 0; Analsoft rays: 13 - 15; Vertebrae: 48 - 53

Potamodromous. Migrating within streams, migratory in rivers, e.g. Saliminus, Moxostoma, Labeo. Migrations should be cyclical and predictable and cover more than 100 km.

Reproduction takes place during high water (Ref. 2756). There is some indication that the species comes to shallower water to breed (Ref. 43507). From 4 breeding fish taken, 3 were from inshore waters and 1 from 40m depth in the open water (Ref. 49805). The nest is a relatively large depression with the shape of a flat dish and proportions relative to the size of the fish (Ref. 51638). A single well formed hole of about 10-15cm in diameter and 10-15cm depth is present nearly in the middle (Ref. 51638). Eggs are laid inside this hole (Ref. 51638). Eggs are white, having a diameter of little more than 1 millimeter (Ref. 45962). Larvae stay in the hole a couple of days after hatching (Ref. 51638). They swim above the nest when disturbed and return to hole after disturbance has stopped (Ref. 51638).

Phyllodistomum Infestation 7. Parasitic infestations (protozoa, worms, etc.)

Eustrongylides Disease (larvae). Parasitic infestations (protozoa, worms, etc.)

Ergasilus Disease 6. Parasitic infestations (protozoa, worms, etc.)

Fish Louse Infestation 7. Parasitic infestations (protozoa, worms, etc.)

Fish Louse Infestation 6. Parasitic infestations (protozoa, worms, etc.)

Thwaitia Infestation. Parasitic infestations (protozoa, worms, etc.)

Acanthostomum Infestation 2. Parasitic infestations (protozoa, worms, etc.)

Quadriacanthus Infestation. Parasitic infestations (protozoa, worms, etc.)

Astiotrema Infestation. Parasitic infestations (protozoa, worms, etc.)

Acanthostomum Infestation. Parasitic infestations (protozoa, worms, etc.)

Lernaeid Infestation (larval Lernaeid). Parasitic infestations (protozoa, worms, etc.)

Diagnosis: head much depressed, often ridged (Ref. 4903), roundly pointed when viewed from above (Ref. 28714). Head width 1.6-2.2 times in head length (Ref. 28714, 57125) or 47.5-63% HL (Ref. 81641). Body rather elongate, 5-6 times longer than deep (Ref. 7324, 57125). Premaxillary tooth plate 6-7 times as long as broad, a little shorter than the vomerine tooth plate (Ref. 43434). Occipital process 4-6 times longer than broad (Ref. 57125). 9-11 branched dorsal-fin rays (Ref. 57125), the first prolonged into short filaments (Ref. 13851, 31256, 57125). Longest filament comprised 3-4 times in standard length (Ref. 7324, 57125). Predorsal length 2.4-2.6 times in standard length (Ref. 57125). Adipose fin long, its origin well in front of the anal fin (Ref. 28714), narrowly separated from dorsal fin (Ref. 43434). Width of premaxillary tooth plate 2.5-2.8 times in head length (Ref. 57125). Lobes of caudal fin often with short filaments (Ref. 7324, 13851, 57125). Upper caudal-fin lobe comprised 2-3 times in standard length (Ref. 57125).Description: supralateral eyes with a free orbital margin (Ref. 367, 11410). Posterior and anterior nostrils remote from each other, the posterior being provided with a barbel (Ref. 11410). Nasal barbel 0.3-0.6 times the head length (Ref. 367). Maxillary barbel reaching ventral or anal fin (Ref. 43434). External mandibular barbel 0.7-1.1 times head length; internal mandibular barbel 1.7-2.1 times head length (Ref. 367). Occipital processus in contact with the first interneural (Ref. 42499, Ref. 2756). Dorsal fin with smooth spine (Ref. 367). Last ray of dorsal fin behind inner ray of ventral fin (Ref. 4912). Adipose fin height 2.5 times in length of its base (Ref. 3036) and its length twice as long as rayed dorsal fin, narrowly separated one from another (Ref. 43434). Pectoral spine as long as dorsal spine and with serrations at the inside (Ref. 367, 2756). No pectoral filaments (Ref. 2756, 3036). Pelvic fins inserted under 5th or 6th branched ray of dorsal fin (Ref. 3036, 13851). Lateral line system consists of a straight line of tubular elevations, from the scapulare to the middle of the caudal fin (Ref. 562). Coloration: life specimens yellow-greenish or blackish with white belly (Ref. 7324, 13851, 57125). Fins darker, sometimes reddish purple; juveniles with little black spots on the sides (Ref. 7324, 57125).

Found in lakes, swamps and rivers (Ref. 31256). Avoids salt water (Ref. 31439). Spends nearly the whole of the daylight hours in crevices of rocks and is therefor seldom seen (Ref. 51850). Lives and feeds on or near the bottom (Ref. 3034). Adults exclusively piscivorous (Ref. 31256). Preys on small fish, particularly Alestes spp. (Ref. 13851), or Chrysichthys auratus as in Lake Kainji (Ref. 3034), but also feeds on insects, crustaceans and molluscs (some debris and vegetable matter may also be ingested) (Ref. 28714). Efficiency of catching prey catfish is maximised by face to face attack, avoiding damage by dorsal and pectoral spines of the prey (Ref. 33614). There is some indication that the species comes to shallower water to breed (Ref. 43507). Spawning season extends from April to July (Ref. 51850). Parents build and guard the nest, which is like a flat disc with a central hole where the eggs are dropped; size of the nest and the central hole depend on the fish size (Ref. 51638). Males become up to 7 years old, females 8 years (Ref. 51644). Mean sizes and weight of males are less than those of females from the same age (Ref. 51644, 51645). An important food fish. Flesh is good eating and of economic importance (Ref. 36900), commonly sold as food (Ref. 43521). Reputed to reach 100,000 g.

fisheries: commercial; gamefish: yes