Family Terebellidae

Terebellidae (Click to enlarge)
Terebellidae (collected from Tai Long Wan).  Lateral view of entire worm. Terebellidae (Click to enlarge)
Terebellidae (Click to enlarge)
Terebellidae (collected from Tai Long Wan).  Lateral view of anterior region. Terebellidae (Click to enlarge)

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Terebellidae (Click to enlarge)
Terebellidae (collected from Victoria Habour).  Ventral view of anterior region. Terebellidae (Click to enlarge)
Terebellidae (Click to enlarge)
Terebellidae (collected from Victoria Habour).  Dorsal view of anterior region. Terebellidae (Click to enlarge)

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Terebellidae (Click to enlarge)
Terebellidae (collected from Victoria Habour).  Ventrolateral view of anterior region. Terebellidae (Click to enlarge)

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Setae of Terebellidae (Click to enlarge)

Setae at anterior region of Terebellidae.

Setae of Terebellidae (Click to enlarge)

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Setae of Terebellidae (Click to enlarge)

Setae at anterior region of Terebellidae.

Setae of Terebellidae (Click to enlarge)

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Order Terebellida
Family Terebellidae

Features
Body: divided into 2 regions; anterior region with biramous parapodia and posterior region with neuropodia only
Prostomium: a simple fold
Branchiae: absent or 1 - 3 pairs on the first segments and associated distinctly with separate segments
Eye: absent
Antennae: absent
Cirri: absent
Palp: absent
Pharynx: absent
Parapodium: biramous or uniramous
Notosetea: smooth or serrated capillaries
Neurosetae: absent or a large main fang and a crest of smaller teeth
Anal cirri: absent
(Fauchald 1977)

Biological Notes
        Terebellids are highly adapted deposit feeders.   They usually live in quiet areas such as lagoons, rock pools or crevices where the organic particles settle.   They all have grooved buccal tentacles which are extensible.   The particles are conveyed along the groove either by ciliary action for small particles or muscular contraction of the whole tentacles for large particles (Day 1967).

        Most terebellids are encased in mucous tubes encrusted with sand, mud, fragments of shell or sponge spicules.   Some larvae build tubes of diatom frustules and float in the plankton.   The tubes of most adults are attached to the side of a rock and extend back into a crevice or down below the sand.   Lanice usually builds a stout tube projecting well above the surface of mud.     The flattened end of the tube is decorated with projecting fingers of sand grains.   Loimia sometimes builds a corkscrew-like tube on open sandy beaches.   Polycirrus and Amaeana do not build tube and creep about naked.   Polycirrus lives among branching organisms such as algae, hydroids and bryozoa and its tentacles pull the body around.   Amaeana burrows through the silt by a papillose proboscis below the mouth (Day 1967).

        Twelve new species of terebellidae were reported from Hong Kong (Hutching 1990).   They were Polycirrus dodeka, P. multus, P. quadratus, Rhinothelepus occabus, Streblosoma duplicata, Thelepus opinus, T. pulvinus, Eupolymnia umbonis, Lanice auricula, Lomia bandera, Longicarpus nodus and Terebella copia.


The difference between ampharetidae and terebellidae
        The terebellids resemble the
ampharetids.   The main features used to separate them are listed below (Fauchald 1977):

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Ampharetidae

Terebellidae

Behavioral withdraw the buccal tentacles completely within their mouth do not withdraw the buccal tentacles completely
No. of Branchiae a few pairs of simple branchiae masses of arborescent branchiae or numerous sessile filaments
Shape of Uncini usually flattened plates always distinctly crested

Genera and Species Reported in Hong Kong

Amaeana trilobata                                            
Amphitrite oculata
Eupolymnia umbonis*
Lanice auricula*                                
Loimia ingens
Lomia bandera*
Longicarpus nodus*
Lysilla Pacifica
Pista typha
Pista violacea
Polycirrus dodeka*
Polycirrus multus*
Polycirrus quadratus*
Rhinothelepus occabus*
Streblosoma duplicata*
Telebella ehrenbergi
Terebella copia*
Thelepus opinus*
Thelepus pulvinus*

* new species