Image: Arenicola marina (Linnaeus, 1758)
Family Arenicolidae: Arenicola marina (Linnaeus, 1758). (Specimen from the White Sea, photographed alive in the laboratory).
- Alexander Semenov
- © Alexander Semenov
These animals are commonly known as lugworms and live intertidally, burrowing deep in muddy sand sediments and can reach lengths of 6-8 cm. At low tide their coiled faecal casts (masses of excrement) may often be seen piled above their burrows. They are “deposit-feeders”, as they feed by constantly indiscriminately swallowing large amounts of sand to obtain nutrients from the bacteria, algae and decaying organic particles found in these sediments. The bushy gills in the middle of the body are red due to the haemoglobin in the blood which helps the worm to survive periods of low oxygen levels during low tide. Lugworms are commonly used by recreational fishers as bait.