Key to Common Families of Sedentary Polychaetes in Hong Kong
The key is for identification of common families of sedentary polychaetes in Hong Kong. Before using the key, please make sure that the polychaete to be identified is Sedentary Polychaete. For more information to define whether it is Errants or Sedentaries, please visit the pages of 'What are Sedentary Polychaetes?', 'The difference between Errants and Sedentaries' and 'Marine Errant Polychaetes in Hong Kong'. |
(a) Most of Errant
Polychaetes have the following characters:
|
|||||||||
(b) Most of Sedentary
Polychaetes have the following characters:
|
|||||||||
(a) Body short and stout. Posterior end covered ventrally by a chitinized shield. | |
Sternaspidae | |
(b) Body elongate. Posterior end not covered by a shield. | |
3 |
(a) Anterior end with specialized setae or protective spines (paleae). | |
4 | |
(b) Anterior end without specialized setae or protective spines (paleae). | |
6 |
(a) Specialized setae long and chambered, forming a protective cage around the retractable anterior end; body with numerous epithelial papillae. | |
Flabelligeridae | |
(b) Specialized anterior setae do not form a protective cage; anterior end not retractable; skin-papillae few and small, or absent. | |
5 |
(a) Specialized anterior setae form 2 fascicles of golden paleae in a transverse row. Tube conical, usually formed of closely fitted sand grains. | |
Pectinariidae | |
(b) 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. | |
Ampharetidae |
(a) 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. | |
Serpulidae | |
(b) Head with soft tentacles for deposit feeding. Tentacles grooved and not retractile into the mouth. Both thoracic and abdominal uncini short-handled. | |
Terebellidae |
(a) With a single mid-dorsal palp on one of the first setigers (usually setiger 3 - 6). | |
Cossuridae | |
(b) With series of long, slender branchial filaments and tentacular and dorsal cirri along the body (often lost, scars remain). | |
Cirratulidae |
(a) Body separated into two regions with different kinds of setae in a thoracic and abdominal region. | |
12 | |
(b) Body not separated into regions; setal distribution and parapodial shapes grade along the body. | |
13 |
(a) Thorax with lateral parapodia; abdomen with both noto- and neuropodia in dorsal positions. | |
Orbiniidae | |
(b) Thorax (and sometimes in the first few abdominal segments) with slender capillary setae; abdomen with retractable filaments if branchiae present. | |
Capitellidae |
(a) Branchiae present on maximally 15-20 segments, starting from one of setigers 4 - 10. | |
Paraonidae | |
(b) Branchiae cirriform, pectinate or absent. All setae simple capillaries. Body fusiform, often grooved ventrally. | |
Opheliidae |
(a) Body divided into two or three distinct parts. | |
Chaetopteridae | |
(b) Body not divided into distinct parts. | |
15 |
(a) Palps present. | |
16 | |
(b) Palps absent. Segments usually elongated and jointed in appearance like a bamboo. | |
Maldanidae |
(a) Prostomium flattened and spade-shaped. A pair of palps papillose. Gills absent. | |
Magelonidae | |
(b) Prostomium not flattened. A pair of palps grooved. Gills often present. | |
17 |
(a) Notopodial cirri flask-shaped in some setigers, plumose setae present. | |
Poecilochaetidae | |
(b) Notopodial cirri cirriform or foliose, plumose setae absent. | |
Spionidae |