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P Kamptozoa (Entoprocta)





Overview & Classification




Biogeographic Distribution

Physical Characteristics

External Features

Internal Features

Biology & Behaviour

Reproduction & Development

Nutrition, Transport & Excretion

Predation & Disease

Climate Change

Evolution & Systematics

Diversity & Identification



Acknowledgments, References & Additional Notes

Physical Characteristics - External Features

Kamptozoans are small cryptic filter feeders, usually 1mm long but more generally ranging from 0.1mm to 7mm. The specimens found at Heron Island, were invisible the the naked eye and individual zooids were found to be 0.2-0.3mm long.

Although kamptozonan colonies are made from interconnected zooids, either by attachment to a common stolon or by repeatedly branching stems, members of the family Loxosomatidae are solitary, attaching themselves to the substrate by the use of a single muscular foot. In other families, a single foot can provide attachment for multiple zooids. Most solitary epizoic species are able to move about the substrate by creeping with their sucker, or ‘somersaulting’ by rolling onto the substrate and placing the foot further onto the substrate.

The other end of the animal consists of a cup-shaped calyx, with a crown of tentacles encircling the viscera*. These are made from extensions of the body wall and filled by connective tissue.

Between these two we find a stalk, usually filled with longitudinal muscles and fused to the calyx, providing mobility of the latter. It is this ability to bend while feeding which gave Kamptozoa its name (kampte meaning ‘bending’), otherwise known as ‘nodders’. This stalk can be segmented in other families and separated from the calyx by an infolding of the body wall.

The space enclosed by the tentacular crown is called the atrium, and houses both the mouth and the anus of the organism, which in loxosomatids his held above the atrium floor on a tall anal cone. This anatomical arrangement brought about its other name of Entoprocta (ento- meaning ‘inside’ and -procta meaning ‘anus’), and separates it from Bryozoa, or Ectoprocta, which have their anus outside their ring of tentacles (see Phylogeny). These tentacles can be folded over and into the atrium and partially covered by a membrane, as a defensive mechanism, displayed during physical trauma.



Viscera: internal organs in the main cavities in the body.