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Daily News Analysis

Sea Robins or Triglidae

30th September, 2024 Environment

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Context: 

Researchers have uncovered new insights into evolutionary adaptations by examining the unusual "walking" abilities of sea robins.

Sea Robins/Triglidae

About

Triglidae, commonly known as gurnards or sea robins, are a family of bottom-feeding scorpaeniform ray-finned fish

Species

There are many species of Sea Robins but two species poses special features:

Prionotus carolinus possesses shovel-shaped legs covered in papillae, similar to taste buds, allowing them to dig for buried prey.

P. evolans has rod-shaped legs without papillae, used primarily for locomotion and probing.

Distribution

The gurnards are distributed in temperate and tropical seas worldwide.

Size

Most species are around 30 to 40 cm (12 to 16 in) in length with the females typically being larger than the males.

Features

It is bottom-dwelling fish that use leg-like appendages to navigate the ocean floor.

These appendages function as bona fide sensory organs, capable of detecting both mechanical and chemical stimuli.

The sea robin "legs" are actually modified pectoral fins, with three on each side of the body. 

Triglidae gurnards have mouths which are either terminal or positioned slightly below the snout, which has its tip normally having paired rostral projections, frequently armed with spines, and these create the impression of a 2 lobed snout when seen from above.

Another distinctive feature is the presence of a "drumming muscle" that makes sounds by beating against the swim bladder.

Feeding habit

Classified as carnivores, gurnards mainly feed on crustaceans. Most species are opportunistic predators and will feed on prey such as teleost and mollusks as well.

Conservation status

According to the IUCN Red List, the northern sea robin (Prionotus carolinus) is listed as Least Concern (LC)

Sources:

https://www.indiatoday.in/science/story/mysterious-fish-living-on-the-ocean-floor-has-legs-to-walk-2607344-2024-09-27

https://en.wikipedia.org/wiki/Triglidae

PRACTICE QUESTION

Q.Consider the following statements about the “Sea Robins” recently seen in the news: 

  1. They are bottom feeding carnivore fishes.
  2. They are found only in temperate waters.
  3. The sea robin "legs" are actually modified pectoral fins, with three on each side of the body. 

How many of the above statements is/are correct?

A.Only one

B.Only two

C. All Three

D.None

Answer: B

Explanation:

Statement 1 is correct: 

Triglidae, commonly known as gurnards or sea robins, are a family of bottom-feeding scorpaeniform ray-finned fish. 

Classified as carnivores, gurnards mainly feed on crustaceans. Most species are opportunistic predators and will feed on prey such as teleost and mollusks as well.

Statement 2 is incorrect: 

The gurnards are distributed in temperate and tropical seas worldwide.

Statement 3 is correct: 

It is bottom-dwelling fish that use leg-like appendages to navigate the ocean floor.

These appendages function as bona fide sensory organs, capable of detecting both mechanical and chemical stimuli.

The sea robin "legs" are actually modified pectoral fins, with three on each side of the body. 

Triglidae gurnards have mouths which are either terminal or positioned slightly below the snout, which has its tip normally having paired rostral projections, frequently armed with spines, and these create the impression of a 2 lobed snout when seen from above.

Another distinctive feature is the presence of a "drumming muscle" that makes sounds by beating against the swim bladder.