Description

Dorsal spines (total): 15 - 18; Dorsal soft rays (total): 10 - 13; Anal spines: 3; Anal soft rays: 7 - 12; Vertebrae: 28 - 31. Diagnosis: snout long; forehead with relatively large scales, starting with 2 scales between the eyes followed by 9 scales up to the dorsal fin (Ref. 3058, 3060). Adult males develop a pointed, duckbill-like snout (Ref. 52307) due to enlarged jaws, often causing the upper profile to become concave (Ref. 2, 7248, 12524, 13337, 52307), but upper profile convex in smaller specimens (Ref. 1870, 6460). Pharyngeal teeth very fine, the dentigerous area with narrow lobes, the blade in adults longer than dentigerous area; 28-31 vertebrae; 3 anal spines; 14-20 lower gill-rakers; genital papilla of males simple or with a shallow distal notch; caudal fin not densely scaled; female and non-breeding male silvery with 2-5 mid-lateral blotches and some of a more dorsal series; breeding male black with white lower parts of head and red margins to dorsal and caudal fins (Ref. 2).

Common Names

No common names available.

Taxonomic Hierarchy

Kingdom: Animalia

Phylum: Chordata

Class: Teleostei

Order: Cichliformes

Family: Cichlidae

Genus: Oreochromis

Species: Oreochromis mossambicus (Peters, 1852)

Climate Zone

Location

Biology

Adults thrive in standing waters (Ref. 7248, 12501). Inhabits reservoirs, rivers, creeks, drains, swamps and tidal creeks; commonly over mud bottoms, often in well-vegetated areas (Ref. 44894). Also found in warm weedy pools of sluggish streams, canals, and ponds (Ref. 5723). Most common in blind estuaries and coastal lakes (Ref. 32693), but usually absent from permanently open estuaries and open sea (Ref. 6465) and from fast-flowing waters (Ref. 7248, 12501). Normally not found at high altitudes (Ref. 6465). Able to survive extreme reduction of temporary water bodies (Ref. 2, 27445). Highly euryhaline (Ref. 2, 3, 23, 58, 61, 6465, 12501, 12522, 12524, 13337, 27445, 55352). Grows and reproduces in fresh-, brackish and seawater (Ref. 2, 21, 23, 61, 5214, 27445, 36683, 54362). Can be reared under hyper-saline conditions (Ref. 4537, 44894, 52307). Tolerates low dissolved oxygen levels (Ref. 3, 23, 6465) and can utilise atmospheric oxygen when water oxygen levels drop (Ref. 61, 6465). Mainly diurnal. May form schools (Ref. 3, 4537, 44894). Omnivorous (Ref. 21, 12524), feeds mainly on algae and phytoplankton (Ref. 4537, 7248, 12501, 12522, 12524, 13337, 36683, 44894, 52307) but also takes some zooplankton, small insects and their larvae (Ref. 4537, 7248, 12524, 13337, 44894, 52307), shrimps (Ref. 12524, 13337), earthworms (Ref. 12501) and aquatic macrophytes (Ref. 6465). Juveniles carnivorous/omnivorous, adults tend to be herbivorous or detritus feeders (Ref. 2, 6465, 13517). Large individuals have been reported to prey on small fishes (Ref. 2, 6465, 12501, 12522), and occasionally cannibalise their own young (Ref. 2, 6465). Exhibits considerable plasticity in feeding habits (Ref. 6465, 13544) as well as in reproductive biology (Ref. 13544). Polygamous (Ref. 12524, 13337), maternal mouthbrooder (Ref. 1, 5214, 12524, 13337). Reaches sexual maturity at 15 centimeter length (Ref. 44894), but stunted fish may breed at 6-7 centimeters and at an age of just over 2 months (Ref. 52307). Fecundity high (Ref. 55352). Extended temperature range 8-42 °C, natural temperature range 17-35°C (Ref. 3), with salinity-dependent difference in temperature tolerance (Ref. 2, 23). Somewhat aggressive toward other species (Ref. 36683). Marketed fresh and frozen (Ref. 9987). Excellent palatability (Ref. 6465), with small head and large dress-out weight (Ref. 61), and filets without small bones (Ref. 57960). Used extensively in biological, physiological and behavioural research (Ref. 7248). Translocated and introduced for aquaculture, sport fishing, stocking man-made lakes and biological control of nuisance plants and animals (Ref. 6465). Eurytopic; a most successful and vagile invader (Ref. 6465).

Habitat

brackish