GAVIALIS (GHARIYAL)

GAVIALIS (GHARIYAL)

Contents hide
1) Introduction
2) Classification of Gavialis (Gharial)
3) Geographical distribution
4) Habit and habitat
5) General Characteristics of Gharial
6) Ecological Importance
7) Conservation Status of Gharial
8) Special features
9) Identification

Introduction

The genus Gavialis represents one of the most distinctive groups of crocodilians, commonly known as gharials. These ancient reptiles are renowned for their elongated, narrow snouts, perfectly adapted for catching fish, their primary prey. Gavialis gangeticus, the gharial, is the sole extant species of this genus and is a vital indicator of the health of freshwater river systems. Fossil records trace the lineage of Gavialis back millions of years, making them one of the oldest crocodilian species.

Gharials are endemic to the Indian subcontinent, inhabiting the clear, fast-flowing rivers of northern India, Nepal, and Bangladesh. They are critically endangered, facing threats from habitat loss, pollution, and riverine changes caused by human activities. Their ecological role as apex predators and scavengers makes them vital for maintaining aquatic ecosystem health.

Classification of Gavialis (Gharial)

  • Phylum :- Chordata (Dorsal tubular nerve cord, notochord and gill-slits present.)
  • Group :- Craniata (Definite head, Cranium with brain present.)
  • Sub phylum :- Vertebrata (Vertebral column present.)
  • Division :- Gnathostomata (Jaws and paired appendages present.)
  • Super Class :- Tetrapoda (Paired limbs, lungs, cornified skin and bony skeleton.)
  • Class :- Reptilia (Scaly vertebrates. Right and left aortic arches present. Single condyle. Pulmonary respiration. Embryo with amnion and allantois.)
  • Sub Class :- Diapsida (Skull with two temporal openings separated by post-orbital and squamosal.)
  • Order :- Crocodilia (Body and head large. Jaws powerful. Skin thick and leathery. Tongue non protrusible Heart 4-chambered.)
  • Family :-  Gavialidae (Snout not distinct from the rest of the skull.)
  • Genus :- Gavialis
Classification of Gavialis (Gharial)

Geographical distribution

  1. Historically ranged across the rivers of the Indian subcontinent, including Pakistan, Bhutan, and Myanmar.
  2. Currently restricted to fragmented populations in:
    • India: Chambal, Ganges, and Mahanadi River systems.
    • Nepal: Narayani and Rapti Rivers

Habit and habitat

  1. Habit:
    • Primarily aquatic and seldom venture far from water.
    • Bask on sandbanks for thermoregulation.
  2. Habitat:
    • Prefer clean, freshwater rivers with deep pools, sandbanks, and shallow stretches.
    • Juveniles often inhabit quieter, backwater zones

General Characteristics of Gharial

  • Commonly known as Gharial.
  • It is the largest of all crocodilians but not dangerous to mankind. Body divisible into head, neck, trunk and tail. Body measures 5 meters.
  • Head contains eyes and elongated snout with nostrils at the tip.
  • Body is covered with an exoskeleton of bony and epidermal horny scales. The upper part of the body dark olive green with dark markings.
  • Head large and produced into a long and narrow snout which is sharply distinct from rest of the skull. Jaws powerful, rimmed with various conical teeth. Teeth sub-equal and internal nares within the pterygoids. Upper jaw contains 28 and lower jaw 25 teeth on either side.
  • Mandibular symphysis is so long that it comprises a great portion of the splenial bones and extends backwards almost to the level of the last teeth. The first and fourth lower teeth fIt into grooves in the upper jaw.
  • Forelimbs and hind limbs short pentadactyle ‘and ending in clawed toes with webs between. Vertebrae procoelus.
  • Tongue is not protrusible. Heart 4-chambered with separate ventricles. Bladder absent.
  • Tail is strong and powerful and laterally compressed, containing vertical scutes.
  • A flap of skin covers the ears. In male the nose is very much swollen which is inflated like a beak when nostrils are closed.
Classification of Gavialis (Gharial)
Image Source : IStock

Ecological Importance

  1. Apex Predator Role: Regulates fish populations, ensuring a balanced aquatic ecosystem.
  2. Scavenger Role: Consumes carrion, contributing to the natural cleaning of river systems.
  3. Indicator Species: Their presence signifies the health and purity of freshwater ecosystems

Conservation Status of Gharial

  1. Status: Critically Endangered (IUCN).
  2. Population: Fewer than 1,000 mature individuals in the wild.
  3. Threats:
    • Habitat destruction from sand mining, agriculture, and dam construction.
    • Water pollution and reduced fish availability.
    • Poaching and accidental entanglement in fishing nets.
  4. Conservation Efforts:
    • Protected under the Indian Wildlife Protection Act (1972).
    • Breeding and reintroduction programs in India and Nepal.
    • Community-based conservation initiatives to safeguard habitats
Classification of Gavialis (Gharial)
Image source IStock

Special features

  • Elongated Snout:
    • Gharial Adapted for catching fish with minimal water resistance.
    • Male gharials develop a bulbous growth called a “ghara” at the snout tip, used for vocalization and attracting mates.
  • Aquatic Adaptations: Streamlined bodies and webbed feet enable efficient swimming.
  • Unique Dentition: Interlocking teeth are perfect for gripping slippery fish.
  • Reproductive Behavior: Females lay eggs on sandbanks, and hatchlings are highly dependent on warm temperatures for survival.
  • Long Lifespan: Gharials can live up to 50–60 years in the wild.

Identification

  • Since the animal contains long and narrow snout and all above features, hence it is Gavialis.

References

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