Fresh water habitat

Characteristics of Freshwater Habitat

The freshwater habitat includes the lakes, ponds, streams, springs, and rivers. These water bodies are known for low salt content or low salinity. The animals and plants in freshwater habitat vary from the ones in the estuarine habitat. This is due to the salinity factor.

Some characteristics of freshwater habitat include:

1. It has low salt content.
2. Relatively small body of water.
3. The water is shallow.
4. Its temperature varies with depth and season.
5. Low density water.
6. Turbidity depends on season.
7. There is available oxygen in all parts of water but more at the surface.
8. Freshwater habitat accommodates bony fishes like tilapia.

Types of Freshwater

Freshwater is divided into two broad types:

1. Stagnant water (lentic):Pools, pond, puddles, and lakes.
2. Running water (lotic): Springs, streams, and rivers.

EVALUATION (POST THE QUESTION TITLE AND YOUR ANSWER IN THE QUESTION BOX BELOW FOR EVALUATION AND DISCUSSION)

1. Mention five water bodies that can be categorise as freshwater habitat.
2. List two major types of freshwater habitat with three examples each.

Zones in Fresh Water Habitat

In freshwater habitat, four major zones are considered:

1. The edge of the water.
2. Water surface.
3. Body of water.
4. Bottom of water.

Fresh Water Organisms

Some organisms in freshwater habitat include: 

Fresh Water Plants

Grasses, raffia palm, algae, bamboos, sedges, water lettuce, duckweed, microscopic plankton, water hyacinth, submerged plants such as phytoplankton (algae), ceratophylum, bacteria, water lilies, spirogyra, hornwort and bladderwort.

Fresh Water Animals

Crabs, water snails, dragon flies, water snakes, toads, frogs, mosquito larvae/pupae, water scorpion, tadpoles, water bugs, diving beetles, fishes such as tilapia, flatworms, insect larvae, molluscs, worms, copepods, water skaters, water beetles, mud fish and cat fish, planarian, and dragonfly nymph.

Adaptation of Organisms to Fresh Water

Those features of organisms which structurally, physiologically, and behaviorally fit them for life in their particular habitats and improve their chances of survival are known as adaptations. They are adapted to the environment in the following ways:

1. Some animals attach to stationary objects by adhesive structures like suckers (leech), foot (water snail) and hooked claws (mayfly nymph).
2. Most submerged water plants have extensive parenchyma with large air spaces which enable oxygen to diffuse to all parts of the plants during photosynthesis.
3. Crustaceans use antennal gland as osmo-regulatory organ.
4. The lung fishes (protopterus) use gills for respiration but when the water dries up, they dig into the mud and breathe with lungs until the rains.
5. The presence of chloroplasts even in the epidermal cells of leaves and stems of submerged plants for photosynthesis.
6. A streamlined body is typical of many animals from insect larvae to fish for swimming
7. Roots are shorter and less branched, while rootless are devoid of root hairs for support.

Submerged plants absorb water and nutrients directly due to lack of cuticle.

EVALUATION (POST THE QUESTION TITLE AND YOUR ANSWER IN THE QUESTION BOX BELOW FOR EVALUATION AND DISCUSSION)

1. Outline four zones or areas of freshwater habitat.
2. List ten plants and animals of freshwater habitat.
3. Enumerate five adaptive measures of plants and animals.
4. (a) Outline four characteristics of freshwater habitat. (b) When is the freshwater turbidity likely to be high?
5. Mention two plants and two animals that live in freshwater and how they adapt to the habitat.
6. List all the characteristics of the four zones or areas of the freshwater habitat.