Cristatella mucedo

Cristatella mucedo is a freshwater invertebrate sometimes known as a ‘moss animal’.

Individuals called zooids possess tentacle crowns for feeding and collectively form long gelatinous colonies with a soft, transparent body wall.

To the naked eye undisturbed colonies are ‘fuzzy’ and caterpillar-like in appearance.

Colonies are loosely attached to a substrate that might be a root, rock or manmade structure, via their muscular ‘foot’.

They can ‘glide’ slowly and divide by fission.

Species detail

Allman figure

© Allman 1956


According to the eminent Victorian naturalist George Allman ‘a more interesting and beautiful animal than….Cristatella mucedo can scarcely be imagined’ (Allman 1856).

Allman’s iconic image of a Cristatella mucedo colony draped over a stem appears in many textbooks.

  • Statblast

    Cristatella mucedo is the only known member of the genus Cristatella. Find out what analysis of the organism's DNA tells us about this species.

  • allman
    Distribution and habitat

    Cristatella mucedo is found mainly in slow moving waters in the northern hemisphere. It attaches to a variety of substrates from plants to plastics. Find out more about its habitat.

  • Degenerate C. mucedo colonies filled with statoblasts.

    Cristatella mucedo colonies form by zooidal budding. Find out how this fascinating animal reproduces.

  • Sacs of myxozoan parasite within Cristatella mucedo colony

    Cristatella mucedo colonies provide a home for numerous other species, but not all of them are welcome. Find out what happens when leeches, snails and midge larvae move in.

  • Cristatella mucedo figure, George Allman

    Find out the conservation status of this species.

  • Cristatella mucedo colony

    Get reference material for Cristatella mucedo.


Scanning electron micrograph of statoblast (approximately 1mm in diameter).

Scanning electron micrograph of statoblast (approximately 1mm in diameter). 

© P. Taylor & B. Okamura.
Degenerate Cristatella mucedo colonies filled with statoblasts.

Degenerate Cristatella mucedo colonies filled with statoblasts.

© B. Okamura
Sacs of myxozoan parasite within Cristatella mucedo colony

Cristatella mucedo colony.

© B Okamura
Cristatella mucedo

Plate showing colonies and statoblasts of Cristatella mucedo from: Allman, G.J. 1856. A monograph of the Fresh-water Polyzoa, including all the known species, both British and foreign. The Ray Society 28: 1-119.

© Allman
Statoblasts ensnared in feather.

Statoblasts ensnared in feather. 

© P Taylor & B Okamura
Sacs of myxozoan parasite within Cristatella mucedo colony.

Sacs of myxozoan parasite within Cristatella mucedo colony. 

© B Okamura
About the author
Professor Beth Okamura
Prof Beth Okamura

Merit Researcher in the Bryozoa Group, focusing on the ecology and evolution of bryozoans and their myxozoan parasites.

A word from the author

'My PhD training was in marine ecology, but moving to the University of Oxford meant the ocean was not close to hand. I soon discovered that there are many lakes and ponds in the vicinity that are inhabited by Cristatella mucedo. I became fascinated by the consequences of a life history that allows clonal lineages to persist for an indefinite period of time and the role of waterfowl in dispersal. Although I now work on several freshwater bryozoans, C. mucedo remains my favourite, largely because it is such a beautiful organism.'

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Aufwuchs  are communities of small animals and plants intimately associated with inanimate and living substrata in aquatic environments.

are asexually produced encapsulated buds of a freshwater bryozoan. Statoblasts are released as the colony disintegrates and develop into new organisms in spring.

Metapopulation are a group of spatially separated populations of the same species which interact at some level.

Oligotrophic environments are low in nutrients.

Eutrophic environments are rich in mineral and organic nutrients.