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You are here:   animal list > Filograna implexa




Filograna implexa  Berkeley, 1835

Lacy tubeworm or coral worm

Emma Blacklock (2011)

Filograna implexa colony
Photo by Emma Blacklock


Fact Sheet


Brief Summary

Physical Description

Size and Colour

Identification characteristics



Habitat Type

Micro-habitats and Associations




General Anatomy

Internal Anatomy


Respiration and Nutrition

Senses and Circulation

Reproduction and Development


Population status


Names & Taxonomy

Synonyms and Common names


Information Resources



·   Locomotion

Locomotion for the family of Serpulidae is restricted solely to movement in the backwards and forwards direction on withdrawal and emergence from tube (Glasby, 2000).

·     Feeding

F. implexa is a filter feeder using its extensive crown of tentacles to capture food from water column (Glasby, 2000).

Tentacular crown used for filter feeding.
Photo by Emma Blacklock

Social structure 

F. Implexa tends to occur in large intertangled aggregations with both genetically identical individuals from asexual reproduction and brooded larvae (sexual reproduction) which are shown to commonly have a minimal dispersal distance.  Basic factors which affect colony formation in this family are type of reproduction, larvae gregariousness and physical condition of organism (Nishi, 1993).  

Colony of Filograna implexa
Photo by Emma Blacklock

·     Reproduction

Characteristic of many polychaetaes  F.implex exhibits both asexual and sexual reproduction.  Asexual reproduction occurs as budding of the posterior end of worm called paratomy, to produce a genetically identical individua.  However, F. implex also employs sexual reproduction producing genetically diverse through external fertilisation within tube or water column and the brooding of these resultant embryos (Nishi, 1993; Pernet 2001).

Budding adult Filograna implexa
Photo by Bernard Degnan

·    Tube construction

Tube construction is a high energy demanding activity which commenced upon larval settlement and metamorphosis.  In serpulidae the energy requirement for tube formation is double the energy used for generalised somatic growth and gamete production for reproduction.  Firstly a mucopolysacchride framework is laid down which initiates precipitation and secretion of calcium carbonate from the water column.      

In detail, during this early settlement period, larvae secrete an organic “primary tube” attached to desired substrate.  Calcium carbonate is obtained from the surrounding environment and precipitated into crystals suspended in a organic fluid matrix.  This thick fluid mixture is then shaped by organism to the primary tube margin where it hardens into tube wall. 

This primary tube formation is essential and is thought to be only possible during metamorphic juvenile stage.  Therefore, if tube is destroyed or worm is removed from tube, it is unable to secrete another (Glasby, 2000).

During asexual reproduction an “escape hatch” is required to be built consisting of a disc held in place by a thin membrane to allow asexually produced bud to access exterior environment (Pernet, 2001).  For more detail see page " Reproduction and Development".