03 Jan

Fish Diversity

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Content

• Critically Endangered (CR) Fish Species in India
• Important Endangered Species
• Important Vulnerable Fish Species
• Important Food fish species in news
• Invasive Fish Species in News in India
• Recently discovered Fish Species

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1. REPTILES: CRITICALLY ENDANGERED

Indian Swellshark: Small deep-water catshark known from the coast of Kollam, Kerala; A&N; Sri Lanka. Threats: Very limited geographical range and population; accidental catch by deep water trawling.
Scalloped Hammerhead: "Hammerheads" or "hammer shaped head" is the most distinguished characteristic. Distribution: warm, temperate, and tropical coastal waters all around the globe.
Oceanic White Tip Shark: Large shark found in tropical and subtropical oceans throughout the world.
Pondicherry Shark: Extremely rare species found in Indo-Pacific waters from Oman to New Guinea. It has also been seen in Godavari River Estuarine Ecosystem in recent times. In Andhra Pradesh it is locally named as "Pala Sora". Threats: Commercial fishery.
The Ganges Shark (Glyphis gangeticus): Distribution: Found in the Ganges (Padma River) and the Brahmaputra River in India and Bangladesh. It is uniquely adapted (small eyes) fish eating (slender teeth) shark that occur in the turbid waters of Ganga River and the Bay of Bengal. » These are true river sharks which need not to migrate to salt water to reproduce. » Note: Species in the genus Glyphis are true river shark. Threat: Overfishing, pollution, dams, barrages etc.
The Hump Backed Masheer (Tor Ramadevii) The hump backed Mahseer - a large freshwater fish also called the tiger of the water is found only in the Cauvery River basin (including Kerala's Pambar, Kabini, and Bhavani rivers). Inclusion in the red list was possible only after getting the scientific name which it got in June 2018 - Tor Ramadevii.
Other CR Fish: 1. Large Tooth Sawfish (Freshwater sawfish) 2. Green Sawfish or long combed sawfish or narrow snout sawfish

2) IMPORTANT ENDANGERED SPECIES

Whale Shark (Rhincodon Typus)

Whale Shark is the largest known fish species and is the largest non- mammalian vertebrate. It has a lifespan of around 130 years and has a unique pattern of dots on its body. It can grow upto 10 meters in length and weigh around 20 tonnes.

Food: Whale shark are filter feeders and consume plankton, small fish, and squid. They are apex predators and rely on diet of animal- based protein to sustain their large size and energetic demands.

• Filter Feeders: They swim slowly through the water with mouth open, using their large gill rakers to filter out plankton and other small organisms from the water.
• https://youtu.be/jPSgCWl5PrQ?si=QGirwD9wjaRiOMWd

Conservation status

• IUCN: Endangered

Other endangered fish:

Speartooth shark; The knifetooth sawfish; Humphead Wrasse;

Habitat: They inhibit all tropical and warm-temperate seas.

In India, they are found in Saurashtra and Gulf of Kutch coast of Gujarat, Gulf of Mannar and Lakshadweep.

3) IMPORTANT VULNERABLE FISH SPECIES

A)    GREAT SEAHORSE (HIPPOCAMPUS KELLOGI)

• Why in news?
  • The (Hippocampus Kellogi), one of the 12 species of fish with a horse-like head found in the Indo-Pacific region, could be migrating towards coastal Odisha due to fishing pressure. (2023)
• Details about Hippocampus Kellogi

The Great Seahorse (Hippocampus kellogi), also known as Kellog’s seahorse is a species of fish in the family Syngnathidae. It is one of the largest of the 54 species of seahorse.

Distribution: Indo-Pacific region (including sea of Japan, and around north and south Australia). They frequent areas rich in Coral so that they can latch to something.

Seahorses in India’s coastal ecosystem:

Coastal ecosystem of India has 9 species out of 12 species found in indo-Pacific.

The population of the great seahorse, which is among the eight species tagged ‘vulnerable’, is declining due to its overexploitation for traditional Chinese medicines and as ornamental fish, combined with general destructive fishing and fisheries bycatch.

There is a ban on fishing and trading activities on seahorses rom 2002, but illegal, clandestine trade continues. This creates immense pressure one seahorse populations.

Extensive fishing off the coast of Coromandel coast could be forcing the great seahorse to migrate laboriously towards Odisha.

B) OTHER IMPORTANT VULNERABLE FISH SPECIES

• Giant Guitarfish
• Ganges Stringray
• Porcupine Ray
• Giant Grouper

4) IMPORTANT FOOD FISH SPECIES IN NEWS

Hilsa:

Hilsa fish has been ruling the hearts of Bengalis for generations. It is generally referred to as “King of Fish” for its soft texture and pleasant flavor. It is also national fish of BD and state fish of West Bengal and Tripura.

Hilsa catch in West Bengal has decreased over the years. For quite some time, the demand has outstripped the supply. Earlier, Hilsa imported from BD played a key role in fulfilling the gap.

Hilsa’s significance for BD’s economy:

It contributes to 11% of total fish produced in BD and it also contributes to 1% of BD’s GDP.

Nearly 75% of the World’s HILSA production comes from BD.

Hilsa Export has been banned from Bangladesh since 2012. Reason: Decreasing Hilsa population due to over-exploitation, pollution etc.

But, generally during Durga Puja festival in India, Bangladesh allows exports to India.

Hilsa can’t be farmed: This is because of peculiar habitat requirements. The Adult Hilsa swim several kms upstream to fresh water from sea for spawning (laying eggs) and return back to sea. Therefore, the fish is generally found at the mouth of the rivers of Ganga, Brahmaputra, Godavari, Krishna etc.

Sardine:

It is a species of ray-finned fish in the genus Sardinella.

• It is one of the two important commercial fishes in India (with the mackerel).
• It is one of the more regionally limited species of Sardinella and can be found in the northern regions of Indian Ocean.

It was showing declining trend for the past few years but seems to be on revival path on Kerala Coast. This was informed by state-run Central Marine Fisheries Research Institute (CMFRI). Warming of ocean water has been the major reason for decline in the past.

CMFRI has raised concerns over indiscriminate fishing of unmatured sardines.

Trout in Kashmir:

A Scotsman named J.S. Macdonall shipped 1,800 trout eggs into Kashmir in 1900 and introduced Kashmir to fishing culture. These fish which are popular in Europe, found Kashmir suitable as its weather conditions match with that of Europe.

Now, cold-water trout is the most popular fish in the Kashmir plates and growing number of farmers are looking at opportunities to export the fish to Europe.

The last 10 years have seen a tremendous increase in the production of trouts in Kashmir. In 2019-20, J&K had 534 farmers producing 650 tonnes of trouts. In 2022-23, 1114 farmers produced 1,990 tonnes of trout.

Globally, Denmark produces more than 55,000 tonnes of trouts. But Kashmir has much more water and resources and thus can compete with Demark in European market with trout produce.

5) INVASIVE FISH SPECIES IN NEWS IN INDIA

• As of 2018, of 3535 species in India’s freshwater, brackish and marine waters, 14%, or 495, were found to be alien.
• Factors for rise in alien species.
  • Extreme Climate Events may aid the spread of alien species in biodiversity hotspots.
    • E.g., 2018 and 2019 Kerala flood driven release of alien species like alligator gar from illegal aquaculture farms in Kerala to its natural water bodies.
  • Degrading quality of natural water bodies and rivers
  • Ornamental Trade: Most of the alien species that enter India are principally for ornamental trade. These fish are dumped into water bodies causing problems.

Suckermouth Catfish It is native to South America's Amazon River. It is a hardy fish which can survive very hostile conditions. It is an omnivorous feeder and has ability to tolerate hypoxic conditions. They are highly resilient and have armored bodies. It can breed in stagnant water and has thick skin which reduces scope of predation.	They are only fit for aquarium. They don’t have any food value - fisherman don't find buyers for these fish. They are popular in aquarium as they are preferred for cleaning inside walls of aquarium owing to its habit to feed on growing algae.
African Catfish: It's cultivation was banned in 2000 in India but the practice still thrives in many parts of the country. They grow quickly and hence is preferred by fish-farmers. But during floods, they leak into rivers and lakes causing havoc there.
Alligator Gar It is a north American fish which is an invasive species in countries like China and India. It reached India through Aquarium trade. Buyers don't initially that the fish becomes very large. And once, it does, they have to release it in some large water body. These fish are not of much use to humans and are apex predators. Their meat is not palatable, roe is poisonous, skin is like a hide which will cut human hands. The mouth is full of teeth. They kill anything that they can overpower including baby crocodiles.
Thai Magur The fish is also known as African Mangur or Foreign Mangur. Farming of the Thai Magur fish has been banned from 2000 only. But the fish farmers continue to cultivate it. ■ Fish grows to 3 to 5 feet. ■ They can survive in difficult circumstances for e.g. in mud waters between rains. ■ It has an omnivorous diet, burrowing capability and ability to survive of land. MHA fishery department has banned sale of Thai Magur fish in the fish markets, as it is a invasive species in India. ■ A study in Mumbai shows that it is responsible for 70% decline in native fish species of the country. ■ Further, it is cultivated in highly unhygienic conditions, which may lead to people falling sick after consuming it.
Other invasive species in India: red-bellied Pacu, red bellied Piranha, Asian Carp

C) MOSQUITOFISH BECOMING INVASIVE (NOV 2023)

What is Mosquito Fish?

Mosquitofish is a small fish of genus Gambusia. They are small in comparison to many freshwater fish, with females reaching a max length of 7 cm and males 4 cm.

• It is called “mosquitofish” because the fish eats mosquito larvae and has been used more than any other fish for mosquito control.

The two most important species are G. affinis and G. holbrooki. These fish originated in North America but are now a global inhabitant.

• Gambusia in India:
  • Gambusia was first introduced in India during British rule. Later, government organizations like ICMR, local bodies etc took over in an effort to combat malaria.
  • In 2023, several government and NGOs in Andhra, Odisha, and Punjab have released mosquitofish into local water bodies to deal with mosquito menace.
• Invasive:
  • Mosquitofish are among the hundred most deterimental invasive alien species. They have emerged as some of the most widespread freshwater fish.
    • They are resilient to fluctuating environmental conditions and have voracious feeding habits.
    • These fishes are notorious for their detrimental ecological impact, including displacing and preying on native fauna, leading to extinction of native fish, amphibians, and various other freshwater communities.
    • For these reasons, in 1982, WHO stopped recommending Gambusia as a mosquito control agent.
    • In 2018, the National Biodiversity Authority of Government of India, also designated G. affinis and G. holbrooki as invasive alien species.
  • A study has revealed that two species of mosquitoe fish have invaded various ecosystems across India.
    • Gambusia affinis and G. holbrooki are widely distributed specially in northeast India.
  • How can mosquitofish be controlled?
    • Stringent restriction on introduction of these fish in freshwater ecosystem; manage consequence of past introduction.
    • NCVBDC (of MoH&FW) on its website recommends use of these mosquitoes. This needs to be removed on priority.
    • R&D to identify alternative local fish species for mosquito control.

D) GOLDFISH: A CUTE PET IN BOWL, GIANT THREAT WHEN FREE IN A LAKE (NOV 2023)

The goldfish is a freshwater fish. It is commonly kept as pet in indoor aquariums and is one of the most popular aquarium fish. It is native to China and relatively small member of carp family.

Goldfish released in wild can grow to very large size and have become invasive pest in North America. They eat pretty much everything, roots up plants and reproduce and grow so quickly that almost no predator can stop it.

Nov 2023: A goldfish weighing more than 30 kg was caught from Bluewater Lakes in Champagne, France.

6) RECENTLY DISCOVERED FISH SPECIES

A) BADIS LIMAAKUMI (OCT 2023: SOURCE-DTE)

Scientists have recently discovered a new fish species from Milak River, Nagaland. It has been named Badis limaakumi, after Limaakun, assistant professor and head of the zoology department at Fazl Ali College, nagaland.

It belongs to family Badidae, a small freshwater fish found in streams with slow or moderate water flow. These are edible fish and are also found in ponds and stagnant water. The new species differs from other members of the genus due to its larger size and other physical characteristics.

Fish from the Badis family are also known as chameleon fish for their ability to change color. This helps them blend with the surrounding when under stress.

B) PTERYGOTRIGLA INTERMEDICA (SEP 2023)

The scientists of Zoological Survey of India (ZSI) have discovered this new fish species. It is the fourth species of Pterygotrigla genus reported in India so far.

It is commonly known as gurnards or sea-robins and belong to the family Trigidae.

Discovered where: It’s a marine water fish discovered from Digha Mohana in WB.