Newly Discovered Earthworms: Freshwater Species of the Week

As any gardener or farmer should be able to tell you, earthworms can play an important role in ecosystems, by churning up soils, leaving copious amounts of nutrient-rich waste, and serving as food for a wide range of wildlife. Many young students dissect earthworms in biology 101, but there is still a lot we don’t know about this industrious group of Annelids (“everyone’s favorite” phylum according to UC Berkeley).

A study published this week in ZooKeys (an open-access, peer-reviewed journal of biodiversity) identified 10 new species of semi-aquatic, freshwater earthworms. The worms, all in the genus Glyphidrilus, inhabit the fringes of rivers, steams, ponds, and canals in Thailand. Each species seems to inhabit only a single water basin, which is another piece of motivation for protecting a wide array of habitat.

Glyphidrilus earthworms in Thailand, newly described species. Photo: Somsak Panha / 3.0 CC-By

The researchers suggest that Thailand’s monsoonal climate contributed to the proliferation of worm species, since the unevenly shifting weather may have helped drive micro-climate variation, which in turn led to greater adaption and specialization among the related worms.

The worms burrow u-shaped cavities into moist soil. Then they stick their posterior, square-tipped ends out, above the surface. They also have “wings,” flaps of extra skin near the tip. Scientists aren’t sure what the wings are for, but theories include aids in copulation and larger surfaces for oxygen exchange.freshwater species of the week

These Glyphidrilus worms often make their homes in Thai rice paddies, where they help improve farmers’ yield by aerating the soil and depositing nutrients (aka poop). (See “Talking Poop With Author of ‘The Origin of Feces.'”)

Study author Somsak Panha from Bangkok’s Chulalongkorn University said in a statement, “The worms will survive in areas using chemical fertilizers but not those using chemical pesticides. However, the worms did well in areas of organic farming and so are likely to be sensitive to modern agrochemical contamination of the environment. They may play an important role in organic rice farming.”

News of these 10 new species of earthworms is a reminder that there is still a great deal science does not know about freshwater biodiversity. Many of these worms make their homes in rice fields that are regularly tended by people, yet they were long overlooked–even though they may play an important role in soil health.


Brian Clark Howard covers the environment for National Geographic. He previously served as an editor for TheDailyGreen.com and E/The Environmental Magazine, and has written for Popular Science, TheAtlantic.com, FastCompany.com, PopularMechanics.com, Yahoo!, MSN, and elsewhere. He is the co-author of six books, including Geothermal HVACGreen LightingBuild Your Own Small Wind Power System, and Rock Your Ugly Christmas Sweater.

  • Craig Haynes

    Even on land were discovering new species daily,just think what the ocean has & it covers 3/4 of the earth & we have seen only almost 5% underwater & that was just looking and grabbing specimens for about an hour,I hope they get those underwater drones with cameras & other gear running soon all over the ocean.

  • Ima Ryma

    Earth worm – I am humankind’s friend.
    Tickle me in my middle half,
    Listen for sounds – that’s my head end,
    And at humans, I often laugh.
    A great sense of humus have I.
    Tequila bottles – I crawl clear,
    Could be the death of me, tiz why.
    Lots of in-dig-gestion, oh dear!
    Busy fertilizing the ground,
    I get so wrapped up, out and in,
    I catch my other end around.
    Oh where in earth have I not been!

    Earthworms – we’re ever confirming
    All the good of global worming.



About the Blog

Researchers, conservationists, and others share stories, insights and ideas about Our Changing Planet, Wildlife & Wild Spaces, and The Human Journey. More than 50,000 comments have been added to 10,000 posts. Explore the list alongside to dive deeper into some of the most popular categories of the National Geographic Society’s conversation platform Voices.

Opinions are those of the blogger and/or the blogger’s organization, and not necessarily those of the National Geographic Society. Posters of blogs and comments are required to observe National Geographic’s community rules and other terms of service.

Voices director: David Braun (dbraun@ngs.org)

Social Media