Morphology, feeding and behaviour of British Magelona (Annelida: Magelonidae), with discussions on the form and function of abdominal lateral pouches

Abstract

Observations were made on Magelona johnstoni Fiege, Licher & Mackie, 2000 and Magelona mirabilis (Johnston, 1865) maintained in a laboratory aquarium. Burrowing, feeding, palp regeneration, lateral pouch function, and behaviour were studied. The two morphologically similar (and co-occurring) species exhibited different behaviours and feeding strategies. Individuals of M. johnstoni were seen to undertake lateral sinuous movements of the thorax, both within and outside the burrow. These movements often occurred simultaneously in several animals, and on occasion, semi- emergent pairs also made direct thoracic contact. This behaviour generally took place between April and July and was likely associated with reproduction; published works suggest spawning may take place between May and August. The morphology and function of abdominal lateral pouches was investigated through SEM images, experimental observation, and consideration of literature accounts.