Correct Option
The Dugong (Dugong dugon) is a marine mammal and the sole surviving species within the family Dugongidae. Often referred to as a "sea cow," it is a herbivore, primarily feeding on seagrasses in shallow coastal waters.
Dugongs are characterized by their slow movement, long lifespan, and low reproductive rate. These biological traits, combined with threats such as habitat degradation, boat strikes, and entanglement in fishing gear, contribute to their vulnerability. Consequently, the species is classified as 'Vulnerable' on the IUCN Red List of Threatened Species.
Incorrect Options
Amphibian: Dugongs are exclusively aquatic animals, spending their entire life cycle in water. They do not possess the characteristic dual life (aquatic and terrestrial phases) typical of amphibians.
Bony fish: Despite inhabiting marine environments, dugongs are classified as mammals, not fish. Their physiological characteristics, such as breathing air with lungs, giving birth to live young, and suckling their offspring, distinguish them from fish.
Shark: Sharks are a type of cartilaginous fish. Dugongs, as explained, are marine mammals, fundamentally different in their biological classification and characteristics from fish, whether bony or cartilaginous.