Why In News?

Researchers identified a new glyptosternine catfish, Exostoma nasibarbatum, in Manipur.

What Is Exostoma Nasibarbatum?

  • Species Type: Exostoma nasibarbatum is a rare glyptosternine catfish, a group of small catfishes adapted to fast mountain streams.

  • Meaning Of The Name: The name “nasibarbatum” refers to its prominent nasal barbel, a sensory whisker near the nostril that extends beyond the rear margin of the eye socket.

  • Features: The new species differs from its close relatives in the Chindwin–Irrawaddy drainage through distinct body features and its adaptation to rocky, torrential waters.

Habitat And Location

  • River System: The fish lives in the Bupal stream, a tributary of the Dujang River, which belongs to the Chindwin river system along the Myanmar border.

  • Habitat Type: It inhabits fast-flowing, turbulent streams with boulders and rocky beds.

  • Local Significance: It is the second fish species described from the Chakpi area of Chandel district.

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How Is Exostoma Nasibarbatum Adapted To Its Environment?

  • Clinging To Rocks: Glyptosternine catfishes have flattened bodies and adhesive pads on their paired fins. These let them grip rocks in strong currents instead of being swept away.

  • Sensory Barbels: Catfish barbels carry chemoreceptors that detect food by touch and chemical signals. This is vital in turbulent, low-visibility water.

  • Scaleless Body: Catfishes lack scales, and their body covering ranges from smooth skin to armour-like plates.

Source: ASSAMTRIBUNE

PRACTICE QUESTION

Q. Consider the following statements about Exostoma nasibarbatum:

  1. It is a newly discovered species of glyptosternine catfish.

  2. It was discovered in a stream of the Chindwin river system in Manipur.

  3. It inhabits slow-moving lowland wetlands.

Which of the statements given above is/are correct?

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 only

(d) 1, 2 and 3

Answer: (a)

Explanation:

Statement 1 is correct: Exostoma nasibarbatum is a newly discovered species of freshwater glyptosternine catfish belonging to the genus Exostoma and family Sisoridae.  

Statement 2 is correct: The species was discovered in the Bupal stream (a tributary of the Dujang River), which forms a part of the Chindwin river system in the Chandel district of Manipur.  

Statement 3 is incorrect: Rather than slow-moving lowland wetlands, this species specifically inhabits fast-flowing, turbulent mountain hill streams. It possesses morphological adaptations like a strongly flattened head/body and adhesive fin structures that allow it to attach to rocky substrates and survive in torrential currents.