Marine earthworms

More than a dozen species of marine earthworms (Family Lumbrineridae) burrow in the muddy or sandy sediments of the Pacific Northwest. So closely do they resemble terrestrial earthworms (oligochaetes) that the oldest marine earthworm species was actually identified and named as an oligochaete species in 1776! Not unexpectedly, with rather featureless morphology, these marine earthworm species are difficult to identify without detailed examination of the parapodia (appendages), chaetae (bristles) and jaw structures. They likely live for several years. Some species apparently deposit their fertilized eggs in gelatinous egg masses. The marine earthworms may be easily confused with the bighead sludgeworms, p. 126.