Alligator gar fish found in Dal lake raises concerns

The discovery of an alligator gar fish in Jammu and Kashmir’s Dal lake has raised concerns as it could pose a threat to the native fish species. The alligator gar is an alien fish species (species which occurs outside of its natural habitat), native to North America.

While the alligator gar’s distribution and its exact impact on the Dal lake biodiversity is not yet established, its potential presence is a cause of concern as the species is primarily carnivorous and can feed on native fish.

The non-native predator fish has an alligator-like head and razor-sharp teeth. “We have examined morphological characters of the fish and it is an alligator gar,” says Farooz Ahmad Bhat, Dean, Faculty of Fisheries, Sher-e- Kashmir University of Agricultural Sciences and Technology (SKUAST), Kashmir. Bhat says that the fish found in Dal lake was around 54 centimetres and weighed around 2.9 kilograms.

The alligator gar (Atractosteus spatula) was sighted on May 11, when Wasim Ahmad Dar, an operator of a weed harvester, was cleaning up the Dal lake. The fish died after it was caught. This is considered to be the first documented instance of an alligator gar in Jammu and Kashmir.

An ancient fish species

Solomon R. David, an aquatic ecologist and assistant professor of biological sciences at the Nicholls State University in Louisiana, USA, confirmed that the fish found in Kashmir is indeed an alligator gar. “The alligator gar is the largest member of the gar family and can grow over 240 centimetres long and weigh over 130 kilograms,” he adds. According to David, alligator gars can live for over 100 years. “They grow very fast and can reach over 50 centimetres in their first year if they’re in suitable conditions. They are harmless to humans, but will eat any prey item that they can swallow whole (they do not have the ability to bite off pieces of flesh, so they must swallow prey whole),” he told Mongabay-India via email.

David, who has studied gar biology and ecology for over 20 years, says that the alligator gar, and gars in general, are among the ultimate survivor fishes. “The family of gars (Lepisosteidae) has been around for over 150 million years (late Jurassic Period), and their appearance has not changed much since the time of the dinosaurs,” he adds.

“If alligator gars were to occur in high enough abundance to successfully reproduce and the young-of-year fish (below a year old) survive, they could disturb the lake ecosystem (where they are not native),” David adds.

Bhat says that the alligator gars pose a threat to biodiversity of the lake for being carnivorous. “It is a threat to our indigenous fishes like Schizothorax, which in turn would affect the livelihood of our fishermen,” he says. According to official figures, around 1,500 licensed fishers are residing in peripheries of the Dal lake.

Neha Quershi, scientist, ICAR-Central Institute of Fisheries Education, Mumbai told Mongabay-India that it is highly likely that there would be more such (alien) fish in the Dal lake, adding that production of Kashmir’s indigenous snow trout fishes (Schizothorax richardsonii), for example, has declined in the lake over the years due to introduction of exotic carp fish. “The presence of alligator gars would create further decline in population of Kashmir’s native fishes,” she adds.

The Jammu and Kashmir Lake Conservation and Management Authority (LCMA) has asked the J&K fisheries department to find out if there are more such species in basins of the lake. The LCMA is a body set-up by the Jammu and Kashmir government with the core goal of conserving and managing the Dal and Nigeen lakes. Over the past two decades, the Central government and Jammu & Kashmir have spent crores of rupees for the conservation of Dal lake.

Experts are yet to establish the reason behind the presence of the alligator gar in Kashmir and say that this particular case could have been of an aquarium release.

“I would say this is very likely an aquarium-release fish,” says David. “The fish captured in Kashmir is larger than the size alligator gars are usually purchased in the pet trade (which is usually around 15 centimetres), and is about the size at which pet owners release the fish when it is growing too large for their home aquarium.”

Over the past few years, there have been several instances of sighting and capturing of alligator gar in India. It has been spotted in West Bengal, Odisha, Maharashtra and Kerala with experts suggesting that they have been found in water bodies of India through ornamental fish trade.

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Banner image: Alligator gar found in Kashmir’s Dal lake. The fish was sighted on May 11, when Wasim Ahmad Dar, an operator of a weed harvester, was cleaning up the Dal lake. Photo by Wasim Ahmad Dar.