Perkinsiana littoralis (Hartman, 1967)

Total length 22 to 200 mm. Maximum body width 3 to 5 mm. Thoracic chaetigers, varying from 5 to 20, and abdominal number of chaetigers from 40 to 200. Thoracic chaetigers wider than longer. Abdominal segment shorter and more compressed than thoracic ones. Branchial crown with a thick base, 18 to 30 radioles terminating to very short tips. Radiolar skeleton with large number of cells, and angular in cross section. Collar slightly oblique with low rounded ventral lappets. Dorsal lips with radiolar appendages as long as 3 thoracic chaetigers and each with short pinnular appendage. First 5 thoracic tori with small gap between them and ventral shields. Small specimens with 40 uncini, large specimens up to 80 uncini with handle about twice the distance between crest and breast. Thoracic notochaetae: 10-13 superior and from 20 to 50 inferior narrow paleate with long tip, number of chaetae depending on worm total body length. Abdominal chaetae narrowly hooded. Tube translucent, irregularly spiralled and covered by encrusting organisms. A polymorphism in the colouration of the tentacular crown was noted especially in alive specimens from the Weddel Sea. The colouration pattern ranges from completely red to completely white, with some specimens having up to 7 red or gray bands along radioles. This species reaches the largest size reported for the genus.

in the past confused with Perkinsiana (Potamilla) antarctica

Common name: fan worm