Gavialis is charactersied by

Options

A. Prolonged snout
B. Green upper surface
C. Pot-like anterior enlargement of snout in males
D. All the above

Answer

### Step-by-Step Text Solution:

1. **Introduction to Gavialis**: Gavialis, commonly known as gharials, are a type of crocodilian found primarily in freshwater habitats. They are notable for their distinct physical characteristics.

2. **Prolonged Snout**: One of the most prominent features of the gavialis is its long and narrow snout. This adaptation is specialized for catching fish, which is their primary diet.

3. **Green Upper Surface**: The upper surface of the gavialis is typically olive in color, which helps in camouflage within their aquatic environment. This coloration can vary among individuals.

4. **Port-like Anterior Enlargement in Males**: Male gharials exhibit a unique feature where the end of their snout develops a bulbous, pot-like enlargement. This characteristic is more pronounced in adult males and plays a role in mating displays.

5. **Sharp Slender Teeth**: Gavialis have sharp, slender teeth that are interlocked when the mouth is closed, designed for grasping slippery prey like fish.

6. **Conclusion**: Based on these characteristics, it can be concluded that gavialis are characterized by a prolonged snout, a green upper surface, and a port-like anterior enlargement of the snout in males. Therefore, the correct answer to the question is "all of the above."