(a) ldentify specimens N, O, and P.
Specimen N; Specimen O; Specimen P;
(b) State the relationship between specimens O and P.
(c) List five economic importance of specimen N in an aquatic ecosystem,
(d) Give three benefits of stocking both specimens O and P together in the same pond.
Explanation
(a) identification of Specimens:
- N - Water lettuce
- O - Cat Fish,
- P - Tilapia spp.
(b) Relationship between Catfish and Tilapia Spp: Catfish feeds on the fries/fingerlings of tilapia spp. OR Specimen O (Catfish) helps to control the population of specimen. Predator-prey relationship.
(c) Economic Importance of Specimen N in an aquatic ecosystem:
- Hinders free movement of aquatic organisms.
- Limits the penetration of light into ponds.
- Hinders proper aeration.
- Takes nutrients from the pond that could have been used by the planktons.
- Hides fishes from being sighted by predators.
- Some herbivorous fish feed on it. Interferes with fish harvesting.
- Competes with fish for dissolved oxygen for root respiration.
- Provides breeding ground for some fish species.
- Increases cost of production of fish.
- Makes navigation difficult.
(d) Ways of Controlling Specimen N:
- Physical removal by hand (manual).
- Remove it consistently/mechanically.
- Stock an adequate number of herbivorous fishes.
- Lime the pond properly before stocking.