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):
| ¡@ |
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 |
