The Ganges river dolphin is a freshwater dolphin of the rivers of South Asia, with a long, narrow beak, a stocky body, and tiny, nearly blind eyes. Living in murky water, it relies almost entirely on echolocation to find fish and invertebrates and often swims on its side. Endangered by dams, pollution, and bycatch, it is the national aquatic animal of India.

Ganges River dolphins are generally solitary or found in loose aggregations of two to four individuals, with occasional larger groups observed during seasonal migrations. They are most active during the early morning and late afternoon, timing their foraging to coincide with fish movements. Home ranges are fluid, often overlapping with those of neighboring dolphins, and are defined more by the availability of deep channels and prey than by fixed territorial boundaries. Communication relies heavily on a repertoire of clicks, burst‑pulsed sounds, and low‑frequency whistles that convey information about identity, reproductive status, and spatial orientation. Echolocation clicks, which can reach intensities of 180 dB, are used continuously for navigation in the turbid waters where visual cues are limited. Social interactions include gentle rubbing, synchronized swimming, and occasional vocal duets, especially between mother‑calf pairs.

The Ganges River dolphin is a strict carnivore, preying primarily on a diverse assemblage of freshwater fish such as catfish (family Bagridae), carp (Cyprinidae), and gobies, as well as smaller vertebrates like turtles and amphibians. Seasonal shifts in prey composition occur, with a higher reliance on migratory fish species during the monsoon floods. In addition to fish, the dolphin opportunistically consumes crustaceans (e.g., freshwater prawns) and cephalopods when available. Feeding is conducted using rapid, forward‑thrust lunges facilitated by powerful jaw muscles and a flexible neck. The animal’s echolocation system enables detection of prey hidden in turbid water or buried in sediment, allowing it to locate and capture prey with a success rate estimated at 70 % during peak foraging periods. Daily food intake can represent up to 5 % of body mass, equating to roughly 8–10 kg for an adult.

Sexual maturity in Ganges River dolphins is reached at approximately 5–6 years for females and 6–7 years for males, though some individuals may reproduce later in life. Breeding is thought to occur year‑round, with a peak in the pre‑monsoon period (April–June) when river flow increases. The gestation period lasts 10–11 months, after which a single calf is born, measuring about 70 cm and weighing 10–12 kg. Calving intervals are typically 2–3 years, reflecting the species’ low reproductive rate. Newborns are nursed for 12–18 months, during which the mother provides constant protection and guidance. Weaning is gradual, and calves remain with their mothers for up to three years before attaining full independence. The prolonged maternal care and slow reproductive turnover make population recovery especially vulnerable to anthropogenic mortality.

The IUCN classifies the Ganges River dolphin as Endangered, with the global population estimated at 3,000–4,000 mature individuals and a continuing decline of at least 30 % over the past three generations. Primary threats include habitat fragmentation from dam and barrage construction, which disrupts migratory routes and reduces access to critical feeding grounds. Water pollution from industrial effluents, agricultural runoff, and heavy metal accumulation degrades prey availability and impairs dolphin health. By‑catch in gill‑nets and other artisanal fisheries remains the most lethal direct cause of mortality, accounting for an estimated 20–30 % of deaths annually. Additional pressures stem from sand mining, river traffic collisions, and deliberate killing in some regions due to cultural misconceptions. Conservation initiatives involve the establishment of protected river stretches, community‑based monitoring, stricter regulation of fishing gear, and captive rescue programs. International cooperation under the Convention on Migratory Species and national legislation such as India’s Wildlife Protection Act aim to mitigate threats and promote population recovery.

• The Ganges dolphin is effectively blind and relies almost entirely on echolocation for navigation.
• It has a distinctive dorsal ridge instead of a dorsal fin, giving it a smooth back profile.
• Females can give birth to only one calf every 2–3 years, contributing to its slow population growth.
• The species can produce clicks exceeding 200 kHz, some of the highest frequencies recorded among mammals.
• Cultural myths in some regions consider the dolphin a harbinger of bad luck, which hampers conservation efforts.