Polychaeta
Lugworms & relatives
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Fecal cast from a lugworm

Lugworm burrows are common features on mudflats and sandy areas, and are readily identifiable by mounds of ropey feces at the tail-end opening (Fig. 1).  There are two common species of lugworms on our coast, and these are considered here along with a few other representatives of burrowing polychaetes in the families Capitellidae and Maldanidae.

NOTE  the words “lug” from Low German and “log” from Dutch mean “slow, heavy, clumsy” and appear to have been adapted for use in English either as “lug” or “lugg” to refer to several species of common burrowing worms Arenicola in the British Isles.  Later, the name became “lug-worm” and then later “lugworm”

   

ANIMATION of the snail's odyssey © Thomas Carefoot 2023
map used by the snail in A SNAIL'S ODYSSEY

To navigate through the ODYSSEY:

  • Select a TOPIC from the menu at the top of the screen
  • OR: play the animation to the left
  • OR: follow the snail's ODYSSEY by CLICKING on any X-marked invertebrate on the map above

Phylum Annelida (lit. “rings” L.), referring to the segmented nature of the body

Class Polychaeta (lit. “many bristles” G.), including marine segmented worms. Grouped below are mainly burrowing forms or tube-dwelling forms that live in sediments and deposit-feed

Family Arenicolidae (lit. “sand” L. plus “idae” denoting an animal Family), including marine worms living in sand and mud in U-shaped burrows such as Abarenicola pacifica and A. vagabunda

Family Capitellidae (lit. “head” L.), small tube-dwelling forms that deposit-feed, such as  Capitella spp.

Family Maldanidae or bamboo-worms, including several large-sized, burrow-inhabiting deposit-feeders, such as Axiothella rubrocincta

Family Spionidae (lit. “sea nymph” L.), including small tube-dwelling or free-burrowing forms, that deposit-feed using palps, such as Streblospio benedicti and Polydora cornuta

Class Echiura (lit. "viper tail" G.) a small group of shallow-dwelling, suspension-feeding marine annelids that have lost their segmentation. They are included here for convenience because they live in U-shaped burrows

Family Urechidae ("tail" G.), commonly known as spoon worms or fat inkeeper worms

NOTE  as mentioned, polychaetes are very “Family-oriented” and the first task of any aspiring polychaete researcher is to learn to identify the numerous families that comprise our west-coast polychaete fauna.  Contemporary classification of polychaetes seems less attentive to categorising families into larger taxonomic groups but, rather, to grouping them into functional groups of feeding, habitat type, and so on, and this is the approach used here.  Thus, mainly burrowing forms can be found in the LUGWORM part, mainly tube-dwelling species in the TUBEWORM part, and mainly free-living forms in the SANDWORM part of the ODYSSEY.  Because this separation is not finely tuned there will some arbitrary decisions made as to which Family goes where and one or two families appear in more than one section of the ODYSSEY (e.g., Spionidae)