Smallmouth Yellowfish

The Orange-Vaal river system, also translocated to Gouritz, Great Fish and Kei river systems as well as the Limpopo river and Kyle dam in Zimbabwe.

The smallmouth yellowfish is a hardy and adaptable species that is widespread across its natural distribution range. It has the ability to inhabit smaller streams owing to its smaller size. Attaining a mass of around 9 kg it is an opportunistic feeder, eating a variety of food types ranging from plant material to aquatic insects, crabs, shrimps and small fish. The smallmouth yellowfish is a slow-growing species with a low egg-to-mass ratio (fecundity), only becoming sexually active at a fork length of 30 cm when it is almost seven years old. During the spawning season the skin of the male fish is covered in sensory papillae, giving it a rough feel to the touch. This is also found in females but to a lesser extent, therefore always wet your hands before handling fish as dry hands can remove this critical mucous layer that protects the skin and scales. When water temperatures exceed 19 °C in Spring, small shoals of fish migrate to shallow rocky areas to spawn and may do so intermittently from October to February. The long spawning season is an adaptation to the food-driven river and ensures that yellowfish will be able to lay eggs whenever favourable conditions occur. …