(a) Give three reasons for stocking K (TILAPIA) and L (CATFISH) together in a pond. (b) List four fishing gears used for harvesting specimens K and L in a p...

(a) Three reasons for stocking specimen K (tilapia) and specimen L (catfish) together in a pond

• They have different feeding habits and occupy different feeding zones. Tilapia is a herbivorous surface feeder while catfish is a carnivorous bottom feeder, so the food and space in the pond are fully utilised.
• The catfish preys on and controls the population of tilapia, which breeds rapidly and would otherwise overpopulate and become stunted in the pond.
• Stocking the two together increases total fish yield and maximises the farmer's income per unit area of pond.

(b) Four fishing gears used for harvesting specimens K and L

• Hook and line.
• Fish trap/basket.
• Cast net (or seine net, drag net, scoop net).
• Fishing spear/harpoon.

(c) Four products that could be made from specimen M (milk)

• Cheese.
• Yoghurt.
• Butter.
• Ice cream (skimmed/condensed milk, casein, ghee and whey are also obtained).

(d) Four reasons for adding specimen N (lime) to the pond

• It neutralises acidity and corrects the pH of the pond water and mud.
• It reduces turbidity, causing suspended particles to settle so that the water becomes clearer.
• It supplies calcium for the bone development of the fish and destroys leeches and other parasites on the fish.
• It increases the availability of nutrients such as phosphorus and encourages the growth of plankton (natural fish food).