PLATANISTA GANGETICA (GANGES RIVER DOLPHIN)

PLATANISTA GANGETICA (GANGES RIVER DOLPHIN)

Contents hide
1) Introduction
2) Classification of Platanista Gangetica (Ganges River Dolphin)
3) Geographical distribution
4) Habit and habitat
5) Comments on Platanista Gangetica (Ganges River Dolphin)
6) Ecological Importance
7) Conservation Status of Platanista Gangetica (Ganges River Dolphin)
8) Special features
9) Identification
10) Interesting Facts about Ganges River dolphin (Platanista gangetica)

Introduction

The Ganges River dolphin (Platanista gangetica), also referred to as the “Susu” or the “blind dolphin,” is a freshwater dolphin endemic to the Indian subcontinent. It is one of the few species of freshwater dolphins globally and holds immense ecological and cultural importance. These unique mammals have evolved specialized adaptations for their freshwater habitat and are considered flagship species for the conservation of river ecosystems in South Asia. Unfortunately, this remarkable species is under significant threat due to human activities, making it a key focus for conservation efforts.

The Ganges River dolphin (Platanista gangetica) plays an essential role in maintaining the ecological balance of its habitat. It serves as an indicator species, reflecting the health of freshwater ecosystems. However, factors such as habitat degradation, pollution, and accidental entanglement in fishing nets have pushed this species toward the brink of extinction. This article explores the geographical distribution, habitat and habits, ecological importance, conservation status, special features, and other fascinating aspects of the Ganges River dolphin (Platanista gangetica).

Classification of Platanista Gangetica (Ganges River Dolphin)

  • 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 :- Mammalia (Body covered with hairs. Females have mammary glands.)
  • Order :- Artiodactyla (Aquatic mammal. Forelimbs paddle like.)
  • Family : Platanistidae
  • Genus :- Platanista
  • Species :- gangetica
Classification of Platanista Gangetica (Ganges River Dolphin)

Geographical distribution

The Ganges River dolphin (Platanista gangetica) is distributed across the major river systems of South Asia. Its range includes the following regions:

  1. India:
    • Found in the Ganges, Brahmaputra, and Meghna river systems.
    • Rivers such as the Chambal, Yamuna, and Ghaghara are also home to these dolphins.
  2. Nepal:
    • Present in the Karnali and Sapta Koshi rivers.
  3. Bangladesh:
    • Found in the Sundarbans delta and the Brahmaputra and Padma rivers.
  4. Pakistan:
    • The Indus River dolphin (Platanista gangetica minor), a subspecies, inhabits the Indus River system.

These dolphins primarily occupy freshwater rivers but can also be found in estuaries where freshwater meets the sea.

Habit and habitat

The Ganges River dolphin (Platanista gangetica) has evolved to thrive in freshwater ecosystems with slow-moving water and deep pools.

Habitat Preferences

  1. Freshwater Rivers:
    • They prefer rivers with high water flow, deep channels, and sufficient prey availability.
    • Found in areas with meanders, confluences, and sandbars.
  2. Estuarine Zones:
    • Occasionally observed in brackish waters near river mouths.
  3. Environmental Factors:
    • Requires clean water with minimal pollution to sustain itself.
    • High sensitivity to habitat degradation makes it an important indicator species.

Behavior and Habits

  1. Diet:
    • Carnivorous, feeding on a variety of aquatic species such as fish, crustaceans, and mollusks.
    • Known to hunt using echolocation due to their limited vision.
  2. Social Behavior:
    • Typically solitary but can sometimes be seen in small groups.
    • Mothers are highly protective of their calves, showcasing strong maternal instincts.
  3. Breeding:
    • Breeding season varies but generally coincides with the monsoon, when food availability increases.

Females give birth to a single calf after a gestation period of 8–9 months

Comments on Platanista Gangetica (Ganges River Dolphin)

  • Commonly called as Ganges dolphin or Susu.
  • Body divisible into head, neck, back, chest, abdomen and tail.
  • Body dark grey, streamlined, 2 to 3 meters long.
  • Tail fish-like, tapering with 2 fleshy horizontal lobes.
  • Forelimbs are modified into broad paddle-like flippers. Hind limbs absent.
  • Head small. Jaws like large beaks of birds having about 200 homodont teeth in each jaw.
  • Dolphin probes in mud for shell-fishes.
Classification of Platanista Gangetica (Ganges River Dolphin)

Ecological Importance

The Ganges River dolphin is a keystone species, playing a critical role in maintaining the health and balance of river ecosystems.

  1. Indicator of Ecosystem Health:
    • The presence of Platanista gangetica signals a healthy river system, as it requires clean water and abundant prey.
  2. Top Predator:
    • As an apex predator, the dolphin regulates fish populations, preventing overpopulation of certain species and ensuring a balanced aquatic ecosystem.
  3. Nutrient Cycling:
    • By consuming prey and excreting waste, the dolphin contributes to the transfer of nutrients within the ecosystem.
  4. Cultural and Economic Significance:
    • Revered in local folklore and traditions, the dolphin holds cultural importance for communities living along riverbanks.

Conservation Status of Platanista Gangetica (Ganges River Dolphin)

The Ganges River dolphin is classified as Endangered by the International Union for Conservation of Nature (IUCN).

Threats

  1. Habitat Loss:
    • Large-scale dam construction and water diversion projects disrupt the river’s natural flow and fragment dolphin habitats.
  2. Pollution:
    • Industrial waste, agricultural runoff, and plastic pollution degrade water quality, affecting both dolphins and their prey.
  3. Accidental Bycatch:
    • Frequently entangled in fishing nets, leading to injury or death.
  4. Climate Change:
    • Rising temperatures and changing rainfall patterns impact river flow and food availability.

Conservation Efforts

  1. Protected Areas:
    • Designation of dolphin sanctuaries, such as the Vikramshila Gangetic Dolphin Sanctuary in India.
  2. Community Involvement:
    • Awareness campaigns and local participation in conservation programs.
  3. Legislation:
    • Legal protection under India’s Wildlife Protection Act of 1972.
    • International collaboration under conventions like CITES.
  4. Research and Monitoring: Scientific studies to understand dolphin behavior, population dynamics, and habitat requirements
Classification of Platanista Gangetica (Ganges River Dolphin)

Special features

The Ganges River dolphin possesses several unique adaptations that enable its survival in freshwater habitats:

  1. Echolocation:
    • Due to their limited vision, these dolphins rely on echolocation to navigate and hunt in murky river waters.
  2. Flexibility:
    • Their long, flexible bodies allow them to maneuver efficiently in narrow river channels.
  3. Paddle-Like Flippers:
    • Used for steering and stability while swimming.
  4. Teeth Adaptations:
    • Sharp, interlocking teeth help them grasp slippery prey.
  5. Survival in Low Oxygen:
    • Can adapt to low-oxygen environments by slowing their metabolism.

Evolution

Freshwater dolphins like the Ganges River dolphin are believed to have evolved from ancient marine dolphins. Geological evidence suggests that around 20–25 million years ago, some marine dolphins migrated into rivers, adapting to freshwater environments. Over time, they developed distinct physical traits such as reduced eyesight and enhanced echolocation capabilities to survive in murky river waters.

The genus Platanista diverged from other dolphins roughly 10 million years ago. Fossil records show their ancestors once inhabited vast river systems, but modern species are now confined to a few specific regions due to habitat loss and environmental changes.

Identification

  • Since the animal has elongated jaws and above features, hence it is Ganges Dolphin

The Ganges River dolphin (Platanista gangetica) is a marvel of evolution and a cornerstone of freshwater ecosystems. Its survival depends on immediate and sustained conservation efforts. Protecting this endangered species is not just about saving a single animal but about preserving the health and diversity of entire river systems. By addressing threats such as pollution, habitat destruction, and climate change, we can ensure that future generations continue to marvel at the elegance of the Ganges River dolphin.

Interesting Facts about Ganges River dolphin (Platanista gangetica)

  1. Blind but Brilliant: Despite being nearly blind, these dolphins navigate their environment with incredible precision using echolocation.
  2. National Aquatic Animal: Declared the National Aquatic Animal of India in 2009 to emphasize its conservation.
  3. Solitary Swimmers: Unlike marine dolphins, Ganges dolphins are solitary by nature and rarely form large pods.
  4. Ancient History: Known to locals for centuries, they feature prominently in Indian folklore and mythology.
  5. Long Lifespan: Can live up to 30 years in the wild under optimal conditions.
  6. Breathing Behavior: Need to surface every 30–120 seconds to breathe, making them vulnerable to surface threats.
  7. Slow Reproduction: Long gestation periods and limited offspring per birth hinder population recovery.
  8. Dolphin Clicks: Their echolocation clicks are so precise that they can detect objects smaller than a fish egg.
  9. Endemic Status: Only found in South Asia, making them one of the rarest dolphin species in the world.
  10. Critically Endangered Subspecies: The Indus River dolphin (Platanista gangetica minor) is listed as Critically Endangered.

References

This Post Has One Comment

Leave a Reply