What is Pinna nobilis?

Pinna nobilis is a large species of Mediterranean clam, a marine bivalve mollusc in the family Pinnidae.

What is Pinna nobilis?
Table of Contents

About Pinna nobilis

  • It is a large species of Mediterranean clam, a marine bivalve mollusc in the family Pinnidae.
  • The clams, whose shells can grow as much as 1.2 m across, play an important ecological role by filtering sea water and allowing other organisms to flourish.
  • It attaches itself to rocks using a strong byssus composed of many silk-like threads which used to be made into cloth.
  • The animal secretes these fibres from its byssus gland; they consist of keratin and other proteins and may be as long as 6 cm (2.4 in). The inside of the shell is lined with brilliant mother-of-pearl.
  • As with other members of its genus, Pinna nobilis hosts symbiotic shrimp which live inside its shell.
  • It is believed that when it sees a threat, the shrimp warns the host, perhaps by retracting its claws or even by pinching. The clam then closes shut.
  • It has been demonstrated that the shrimp has a similar filter-feeding diet to its host and the relationship is likely mutualistic.
  • Distribution: This species is endemic to the Mediterranean Sea. 
  • Threats: It is relatively fragile to pollution and shell damage.
  • The clam, known as the noble pen shell or pinna nobilis, started dying out as a deadly pathogen spread in parts of the Mediterranean around 2016.
  • Conservation status
    • IUCN: Critically endangered

Q1) What are Mollusks?

These are any soft-bodied invertebrate of the phylum Mollusca, usually wholly or partly enclosed in a calcium carbonate shell secreted by a soft mantle covering the body. Along with the insects and vertebrates, it is one of the most diverse groups in the animal kingdom.

Source: Pinna nobilis: Comeback hero

Update Icon
Latest UPSC Exam 2026 Updates

Date IconLast updated on June, 2026

UPSC Prelims Result 2026 is now out.

UPSC IFoS Prelims Result 2026 is now out.

→ Enroll in Vajiram & Ravi’s UPSC Mains Test Series 2026 for structured answer writing practice, expert evaluation, and exam-oriented feedback.

→ Join Vajiram & Ravi’s UPSC Mentorship Program 2026 for personalized guidance, strategy planning, and one-to-one support from experienced mentors.

→ Join Vajiram & Ravi’s UPSC Mentorship Program 2027 for personalized guidance, strategy planning, and one-to-one support from experienced mentors.

UPSC Prelims Provisional Answer Key 2026 out for GS Paper 1 and CSAT.

UPSC Prelims Question Paper 2026 Out, Download GS Paper 1 PDF conducted on 24th May 2026.

UPSC Mains 2026 will be conducted from 21st August 2026 onwards, and UPSC Prelims 2027 will be held on 23rd May 2027.

UPSC Final Result 2025 is now out.

→ UPSC has released UPSC Toppers List 2025 with the Civil Services final result on its official website.

Anuj Agnihotri secured AIR 1 in the UPSC Civil Services Examination 2025.

UPSC Notification 2026 & UPSC IFoS Notification 2026 is now out on the official website at upsconline.nic.in.

UPSC Calendar 2027 has been released.

→ Check out the latest UPSC Syllabus 2026 here.

→ The UPSC Selection Process is of 3 stages-Prelims, Mains and Interview.

Shakti Dubey secures AIR 1 in UPSC CSE Exam 2024.

→ Also check Best UPSC Coaching in India

Vajiram Content Team
Vajiram Content Team
UPSC GS Course 2026
UPSC GS Course 2026
₹1,80,000
Enroll Now
GS Foundation Course 2 Yrs
GS Foundation Course 2 Yrs
₹2,45,000
Enroll Now
UPSC Mentorship Program
UPSC Mentorship Program
₹85000
Enroll Now
UPSC Sureshot Mains Test Series
UPSC Sureshot Mains Test Series
₹19000
Enroll Now
Prelims Powerup Test Series
Prelims Powerup Test Series
₹14000
Enroll Now
Enquire Now