Photos and Main Morphological Features (Quick Identification)

          The photographs and main morphological features of each common families of sedentary polychaetes in Hong Kong are listed in the following.   Quick identification can be done by browsing the photos and main morphological of each families.

Quick Identification

Which of the following features match with your specimen of unknown sedentary polychaetes?

1.     Body short and stout.

2.     Anterior end with specialized setae or protective spices (paleae).

3.     Anterior region with numerous tentacles.

4.     Prostomium conical.

5.     None of the above.


1.     Body short and stout

Sternaspidae

Go to Family Sternaspidae
Sternaspis scutata (collected from off Waglan Island).  Ventral view of entire worm.

Posterior end covered ventrally by a chitinized shield.

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2.     Anterior end with specialized setae or protective spices (paleae).

Ampharetidae

Go to Family Ampharetidae

Ampharetidae (collected from Tai Long Wan).  Lateral view of entire worm.

Specialized anterior setae form a fan-shaped group of paleae on either side of the anterior end.  Anterior end with two to four pairs of branchiae.  Buccal tentacles retractable.

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Flabelligeridae

Go to Family Flabelligeridae

Flabelligeridae (collected from Tathong Channel).  Dorsal view of anterior region.

Specialized setae long and chambered, forming a protective cage around the retractable anterior end; body with numerous epithelial papillae.

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Pectinariidae

Go to Family Pectinariidae
Pectinariidae (collected from Tathong Channel).  Dorsal view of anterior region; other part inside a sandy tube.

Specialized anterior setae form 2 fascicles of golden paleae in a transverse row.  Tube conical, usually formed of closely fitted sand grains.

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3.     Anterior region with numerous tentacles.

Serpulidae

Go to Family Serpulidae
Serpulidae (collected from Tathong Channel).  Ventral view of entire worm.

Head with a crown of bipimmate radioles for suspension feeding.  Body symmetrical; more than four thoracic setigers.  Tube calcareous and irregular twisted or straight, sometimes coiled near base.

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Terebellidae

Go to Family Terebellidae
Terebellidae (collected from Tai Long Wan).   Lateral view of entire worm.

Head with soft tentacles for deposit feeding.  Tentacles grooved and not retractile into the mouth.   Both thoracic and abdominal uncini short-handled.

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4.    Prostomium conical.

Capitellidae

Go to Family Capitellidae
Capitella capitata (collected from Victoria Habour).  Lateral view of anterior region.

Body cylindrical.  Thorax (and sometimes in the first few abdominal segments) with slender capillary setae.  Abdomen with retractable filaments if branchiae present.

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Cirratulidae

Go to Family Cirratulidae

Cirratulidae (collected from Tathong Channel).  Ventral view of entire worm.

With series of long, slender branchial filaments and tentacular and dorsal cirri along the body (often lost, scars remain).

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Cossuridae

Go to Family Cossuridae
Cossuridae (collected from Tathong Channel).  Lateral view of anterior region.

With a single mid-dorsal palp on one of the first setigers (usually setiger 3-6).

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Opheliidae

Go to Family Opheliidae

Opheliidae (collected from Tathong Channel).  Ventrolateral view of entire worm.

Branchiae cirriform, pectinate or absent.  All setae simple capillaries.  Body fusiform, often grooved ventrally.

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Orbiniidae

Go to Family Orbiniidae

Orbiniidae (collected from Victoria Habour).  Entire worm.

Threadlike worm.   Body with 2 regions: thorax with lateral parapodia; abdomen with both noto- and neuropodia in dorsal positions.

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Paraonidae

Paraonidae (Click to enlarge)
Paraonidae (collected from off Waglan Island).  Dorsal view of entire worm.

Branchiae present on maximally 15-20 segments, starting from one of setigers 4-10.

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5.    None of the above

Chaetopteridae

Go to Family Chaetopteridae
Spiochaetopterus sp. (collected from Tathong Channel).  From left to right: Lateral, ventral and dorsal view of anterior region.

Body divided into two or three distinct parts.  Setiger 4 with one or a few thick spines; some median parapodia strongly modified, usually fan-shaped.  Tube parchment-like or distinctly annulated if horny.

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Magelonidae

Go to Family Magelonidae
Magelona sp. (collected from Tai Long Wan).   Dorsal view of anterior region.

Prostomium flattened and spade-shaped with a pair of papillated palps.

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Maldanidae

Go to Family Maldanidae
Maldanidae (collected from Tathong Channel).   Lateral view of entire worm.

Segments usually elongated and jointed in appearance like a bamboo.

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Poecilochaetidae

Go to Family Poecilochaetidae

Poecilochaetidae (Tathong Channel).   Dorsal view of anterior region.

Fragile worms with 1 anterior antenna, 3-lobed nuchal organ, 4 cirri and a pair of grooved palps. Notopodial cirri flask-shaped in some setigers, plumose setae present.

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Spionidae

Go to Family Spionidae
Minuspio cirrifera (collected from Victoria Habour).  Lateral view of anterior region.

A pair of grooved palps.  Setigers 1-8 with capillary setae; setiger 9 with capillary or spatulate setae; remaining setigers with hooded hooks.

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