Marine worms = worms living in a marine environment

They belong to many different groups, including: Annelida (segmented worms with both tube worms and bristle worms), Platyhelminthes (flatworms), Nematoda (roundworms), Nemertea (ribbon worms), Sipunculid worms (peanut worms), Echiura (Spoon Worms and Innkeeper Worms), Chaetognatha (arrow worms), Hemichordata (acorn worms), and Phoronida (horseshoe worms).

All those marine worms are very different. The only things that they have in common might be: their global shape and the fact that they are called “worms”.

Here, I am gonna focus on my favourite group which is Annelids, segmented worms, and more specifically on Polychaetes.

Polychaetes = worms with lots of bristles

QU'EST-CE QU'UN POLYCHAÈTE?

QU'EST-CE QU'UN POLYCHAÈTE?

Vers marins de l’ordre Polychaeta, qui comprend les formes errantes (en mouvement) et tubicoles (principalement sédentaires). Ils ont sur la plupart des segments une paire d’appendices charnus et semblables à des pattes portant de nombreux poils (chaetae).

Polychètes = ont de nombreux (poly) poils (chaetae)

Biodiversity and habitats

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Polychaeta, Spionidae

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Polychaeta, Phyllodocidae

Polychaeta, Nereididae

Polychaeta, Capitellidae

Polychaeta, Pectinariidae

Polychaeta, Orbiniidae

Important roles in ecosystems

Sabellaria alveolata reefs

The tubes formed by Sabellaria alveolata form large reef-like hummocks, which serve to further stabilize the boulders.

Seashore Lanice conchilega reef

Lanice conchilega have the capacity to affect the stability and sedimentation within the habitat.

Phragmatopoma caudata reef

The worms remain in their tubes and are almost never seen. At low tide, when above the water, they close the entrance to their tubes and when submerged, they extend their tentacles out of the tube to catch food particles.

Polychaetes are interesting

bioindicators…

A bioindicator is any species or group of species whose function, population, or status can reveal the qualitative status of the environment. Bioindicators can tell us about the cumulative effects of different pollutants in the ecosystem and about how long a problem may have been present.

CONCLUSION

Marine worms are amazing because:

  • They have a huge biodiversity

  • They can be found in all oceans around the world

  • They have an important role in sediments through bioturbation

  • They provide food for fish

  • They can be keystone species and ecosystem engineers

  • They are interesting bioindicators to estimate the quality of the environment

I challenge you to take the quiz!

[qwiz style=”border-width: none !important; border-color: #cccccc !important; ” align=”center” repeat_incorrect=”true”]

[q multiple_choice=”true”] What is a polychaete?

[c] a worm that lives in the sediment

[f] Not all polychaetes live in the sediment. Try again! 🙂

[c*] a segmented worm with lots of bristles

[f] Good job!! A polychaete has indeed many (poly) bristles (chaete). Most of them are living in marine environment.

[c] a really cute and amazing little marine worm

[f] True to me 🙂 but maybe not for somone else. Find a definition that would be true to anyone.

[c] I have no idea…

[f] Read the blog post! Go to the introduction and try again 🙂

[q multiple_choice=”true”] Where can you find polychaetes?

[c] In marine sediments

[f] Yes! But also in a lot of other environments! Polychaetes are widespread.

[c*] In all oceans around the world!

[f] Excellent! They are present in all oceans around the world. You can find them under boulders of rocky ocean floors, among algaes, in the mud, in sandy mud, or in sand.

[c] Under rocks or among algea

[f] Yes! But also in a lot of other environments! Polychaetes are widespread.

[c] In fish stomachs

[f] Yes, they are indeed good food for fish but try to think about their habitats. Where do they live?

[c] I have no idea… In my bed???

[f] Read the section on habitats to find the answer 🙂

[q] What is bioturbation?

[c*] Show me the answer  

[f] Bioturbation is defined as the reworking of soils and sediments by plants or animals (such as marine worms). These include burrowing, ingestion, and defecation of sediment grains. Bioturbating activities have a profound effect on the environment. Have a look at the video!!!

[q multiple_choice=”true”] Can fish eat marine worms?

[c*] Yes

[f] Well done! Marine worms can be part of the diet of fish living on or close to the bottom of the sea (benthic fish).

[c] No

[f] Not all fishes eat marine worms but they can be part of their diet.

[q multiple_choice=”true”] Are polychaetes ecosystem engineers?

[c] Yes

[f] Some polychaete species are keystone species and act as ecosystem engineers with bioconstructions but not all polychaetes are.

[c] No

[f] Some polychaete species are keystone species and act as ecosystem engineers with bioconstructions but not all polychaetes are.

[c*] It depends…

[f] Great! Well done! Some polychaete species are indeed keystone species and act as ecosystem engineers with bioconstructions but not all polychaetes are.

[q multiple_choice=”true”] What is a bioindicator?

[c] is the quality of the environment

[f] Try again! Bioindicators allows to estimate the quality of the environment.

[c] is the cumulative effects of different pollutants in the ecosystem

[f] Try again! Bioindicators tell us about the cumulative effects of different pollutants in the ecosystem.

[c*] is any species or group of species whose function, population, or status can reveal the qualitative status of the environment

[f] Well done! A bioindicator is any species or group that gives information on the health of the environment. Polychaetes represent a biological indicator of biodiversity, organic enrichment, heavy metal pollution, and organic contaminants.

[x] [restart]

[/qwiz]