Indus River Dolphin
Table of Contents
The Indus river dolphin is a subspecies of the river dolphin which can only be found in the Indus River in Pakistan and India. It is the first cetacean that swims on its side ever discovered.
Until 1998, this dolphin was considered to be the same species with the Ganges River dolphin. Further studies proved that, in fact, these are two subspecies of the freshwater river dolphin. The Indus river dolphin, or Platanista gangetica minor, belongs to the genus Platanista along with its cousin, the subspecies Platanista gangetica. The latter lives in the Ganges river.
This dolphin swims on the side and has adapted to living in freshwaters of large rivers. The main characteristic of this dolphin is its long snout which becomes thicker towards the end. The teeth are visible even when the jaws are closed. The teeth of young individuals are one inch long and very sharp, and they undergo transformation at maturity, becoming square and fat.
Since this species has no crystalline lens in the eyes, individuals are essentially blind, relying entirely on echolocation for hunting and navigation. However, it is believed that the eyes can still distinguish between various intensities of light as well as establish direction. The tail and flippers are large in proportion to the body.
Sexual dimorphism is present, with females being slightly larger than males. Females also grow longer rostrums after reaching 150 cm total length, growing 20 extra centimeters compared to males. Females can measure 2.6 meters and males 2.2 meters.
These dolphins inhabit only the Indus River, which runs mostly through Pakistan. While, in the past, they occupied most of its 3,400 km length, nowadays they only live in small subpopulations occupying a fifth of the river. The preferred habitat is in waters which are deeper than one meter and have more than 700 square meters in sectional area.
The diet of these dolphins mainly consists of fish and crustaceans. Individuals hunt using echolocation only since they cannot rely on their eyesight. The species usually feed on prawns, catfish, carp and a wide range of freshwater crustaceans.
Females have a gestational period of about nine to 10 months, giving birth to calves between January and May. Calves usually do not stay with their mothers for more than a few months. Indus river dolphin individuals can live for more than 20 years, with the oldest known specimen being 28 years old.
The Remarkable Indus River Dolphin: A Dive into Its Natural World
Introduction
The Indus River Dolphin, scientifically known as Platanista gangetica minor, is one of the most unique and rare species of freshwater dolphins in the world. Found primarily in the Indus River of Pakistan, this majestic creature holds a special place in the aquatic ecosystem. Let’s delve into the life, habits, and conservation efforts surrounding the Indus River Dolphin.
Anatomy and Physical Features
Physical Characteristics
The Indus River Dolphin is distinctively characterized by its long beak and a sharp dorsal fin. Unlike most other dolphins, its eyes are tiny and non-functional, an evolutionary adaptation to the murky waters of the Indus River. Their grey-brown skin is smooth and has a slight sheen, allowing them to effortlessly glide through the waters.
Size and Lifespan
Typically, adult Indus River Dolphins measure between 2 to 2.5 meters in length and weigh around 80-90 kilograms. With a lifespan of up to 30 years in the wild, these dolphins showcase a significant maturity period before reaching reproductive age.
Habitat and Distribution
The Majestic Indus River
The Indus River, flowing primarily through Pakistan, provides the primary habitat for the Indus River Dolphin. This river, with its sprawling length and varying depths, offers a diverse habitat for these dolphins, from shallow streams to deeper channels.
Geographic Distribution
The Indus River Dolphin’s range has drastically reduced over the years. Historically, they were found from the foothills of the Himalayas to the Arabian Sea, but now their presence is confined to a 690-mile stretch in the main channel of the Indus River and its two tributaries.
Behavior and Social Structure
Echolocation
Due to their nearly blind nature, Indus River Dolphins heavily rely on echolocation for navigation, hunting, and communication. By emitting high-frequency sounds, they can detect obstacles, prey, and other dolphins, painting a sonic picture of their environment.
Social Habits
Indus River Dolphins are generally solitary, but they can occasionally be seen in small groups. They’re not particularly acrobatic, but their vocal communications through clicks and whistles signify their presence in the waters.
Threats and Conservation
Human-made Challenges
Overfishing, pollution, and habitat fragmentation due to irrigation are significant threats. The construction of dams and barrages has also led to a reduced flow, affecting their natural habitats.
Conservation Initiatives
The Government of Pakistan, in collaboration with various international bodies, has taken several measures for the conservation of the Indus River Dolphin. Protected areas have been established, and frequent surveys monitor their population to ensure their survival.
