Natural Habitats: Aquatic and Terrestrial

A habitat is the specific environment in which an organism lives and thrives. In the JAMB syllabus, habitats are categorized primarily into Aquatic (water-based) and Terrestrial/Arboreal (land and tree-based).

1. Aquatic Habitats

Aquatic habitats are divided based on salinity and water movement.

• Freshwater Habitats (Lentic and Lotic): These include ponds, streams, and lakes. Freshwater has very low salt content. Lentic habitats are standing waters (ponds, lakes), while lotic habitats are running waters (streams, rivers).
• Seashores (Marine): Characterized by high salinity, tidal movements, and wave action. Organisms here face the danger of desiccation (drying out) and being washed away.
• Mangrove Swamps (Estuarine): These occur where freshwater meets saltwater. They have high organic matter, low oxygen (anaerobic) mud, and fluctuating salinity.

Adaptations in Aquatic Habitats

• Water Lily: Has long petioles and stomata on the upper surface of floating leaves for gas exchange.
• Tilapia Fish: Has a streamlined body to reduce friction and gills for dissolved oxygen absorption.
• Mangrove Trees: Possess pneumatophores (breathing roots) to obtain oxygen from the air and stilt roots for stability in soft mud.
• Crabs: Have hard exoskeletons and the ability to burrow to survive tidal changes.

2. Terrestrial and Arboreal Habitats

Terrestrial habitats refer to life on land, while arboreal specifically refers to life in trees.

• Tree-tops (Arboreal): Typical of rainforests and oil palm plantations. Factors include high light intensity and exposure to wind.
• Savanna (Grasslands): Characterized by tall grasses, scattered trees, and distinct wet and dry seasons. Frequent fires occur here.
• Burrows and Holes: Underground habitats where temperature is relatively stable, but oxygen may be limited.
• Abandoned Farmland: Sites of secondary succession dominated by weeds, insects, and rodents.

Adaptations in Terrestrial Habitats

• Monkeys: Possess prehensile tails and opposable thumbs for grasping tree branches.
• Chameleons: Use camouflage and a long sticky tongue to catch insects in trees.
• Xerophytes (Savanna plants): Have thick bark to survive fires and needle-like leaves to reduce transpiration.
• Earthworms: Have cylindrical bodies and secrete mucus to ease movement through soil burrows.