Where has the Capitellid Thread Worm been recorded?

Heteromastus filiformis occurrence evidence comes from 15,822 records in 16 countries and territories, from 1871 to 2025. Most records come from Netherlands.

• 15,822 records
• 16 places
• 83 years recorded
• Polychaeta class

Observation evidence passport

Compare this animal’s observation pattern

When it is recorded

Peak month: September. Records cluster in the months an animal is present and being looked for, so a summer peak can reflect observer effort as much as the animal.

Records over time

Recording effort has risen steeply almost everywhere since the 1990s, so a rising line usually shows more observers rather than more animals.

Where Capitellid Thread Worm has been recorded

The countries below show where occurrence evidence exists for Capitellid Thread Worm. They do not define a complete habitat range: survey effort differs by place, and historical or one-off records can appear alongside repeated presence.