#polychaete worms

dON’t DISTURB THE wORMs

When decorating for the holidays, why not ask the decorator worm to help? These worms are named both for their beautiful irridescent 'plumage' and the tunnels they construct benath the ocean floor, which are often lined with bits of algae, coral, and shells. These tubes can be up to .9 m (3 ft), and are used by the worms to hide from predators.

There’s far more to the world of Annelida than the humble nightcrawlers you find in your yard; many species are found in marine environments, where they take such varied forms as the fearsome bobbit worm or the ethereal tomopteris. Here I’ve rendered a ragworm (family Nerididae); a sort of polychaete (bristle worm) found in benthic marine (and occasionally freshwater) environments the world over.

Some cool facts to win you over:

1. The largest ragworm in the world is the king ragworm (Alitta virens), which ready achieves lengths of 4 ft/120 cm.

2. Ragworms are an important part of the live sea-bait industry. Unfortunately that also means they have been harvested so extensively in some areas that their populations are threatened.

3. Ragworms reproduce through a bizarre process called epitoky, in which the benthic worm either transforms into a free-swimming reproductive morph, or buds off several free swimming sex-clones to party in the world above. Either way, it will be the final act of the animal’s life.

4. Ragworms, like bobbit worms, have large, eversible mandibles in their pharynx that they extrude to give a nasty bite.

Сабеллиды – семейство сидячих многощетинковых червей, распространенных в донных сообществах всех океанов. К сидячему образу жизни сабеллиды приходят не сразу. На стадии личинки червь безмятежно дрейфует в океанических водах. Взрослые особи живут в песке или в илистом грунте мелководной зоны. Сабеллиды - социальные животные, образующие большие колонии в тех местах, где достаточно пищи. На переднем конце тела сабеллид расположена пара перистых, покрытых ресничным эпителием пальп. С помощью этих перьеобразных щупальцев-жабр черви собирают из толщи воды и с поверхности грунта частицы, которые затем используют в пищу или для построения трубки. Кусочки грунта они смешивают со слизью и строят трубки из материала, напоминающего пергамент. Длина трубок в зависимости от вида колеблется от 2 до 10 см. Пальпы одновременно служат и органами дыхания, так как через их поверхность осуществляется интенсивный газообмен. Кроны этих щупальцев выступают из торчащих на дне трубок подобно лепесткам великолепных цветов. Однако при малейшем движении воды «цветы» мгновенно втягиваются, оставляя на поверхности лишь низкие серые «пеньки». Окраска щупальцев-жабр червей разнообразная, но чаще всего это бежевые, желтые, коричневые, черные, темно-красные, лиловые и белые цвета. Зоологи обнаружили более 10 тысяч видов этих животных.

Sabellidae are a family of sessile polychaete worms common in benthic communities of all oceans. Sabellids do not immediately adopt a sedentary lifestyle. At the larval stage, the worm drifts serenely in ocean waters. Adults live in sand or muddy soil in the shallow water zone. Sabellids are social animals, forming large colonies in places where there is enough food. At the anterior end of the sabellid body there is a pair of feathery palps covered with ciliated epithelium. With the help of these feather-like tentacles-gills, the worms collect particles from the water column and from the surface of the soil, which are then used for food or to build a tube.They mix pieces of soil with mucus and build tubes from a material resembling parchment. The length of the tubes, depending on the type, ranges from 2 to 10 cm. The palps also serve as respiratory organs, since intensive gas exchange occurs through their surface. The crowns of these tentacles protrude from tubes protruding from the bottom like the petals of magnificent flowers. However, at the slightest movement of water, the “flowers” ​​are instantly retracted, leaving only low gray “stumps” on the surface. The color of the tentacles-gills of worms is varied, but most often they are beige, yellow, brown, black, dark red, purple and white. Zoologists have discovered more than 10 thousand species of these animals.

14/09/23 - Syllidae sp.

14/09/23 - Annelida sp.

14/09/23 - Unidentified

14/09/23 - Annelida sp.

14/09/23 - Unidentified

14/09/23 - Annelida sp.

Marine worms collected from tidepools

14/09/23

Stop a Moment for the Sand Striker

Also known as the bobbit worm, Eunice aphroditois is a marine bristle worm endemic to both the Atlantic and Pacific oceans, in waters up to 95 m (311 ft) deep. Because they spend most of their time under ground, the sand striker is rarely seen. However, they can be found in both coral reefs and deeper, rocky or sandy ocean floors-- anywhere they can hide and ambush prey.

This species of bristle worm is famous for its hunting methods. Individuals live in burrows deep under ground, with an entrance covered by sand or rocks, and only emerge at night. They keep these burrows stable by secreting a mucus-like substance which coats the sandy walls and keeps them in place. Because their eyes are rudimentary at best, sand strikers use their five antennae to sense passing prey-- usually fish, but also algae or organic debris. When their target is close enough, E. aphroditois ambushes it and drags it back down into the burrow with its large mandibles. This process is extraordinarily fast; bobbit worms have been clocked moving at 6 m (20 ft) per second. The mandibles are also retractible, which helps the bobbit worm swallow its prey.

Though only their heads are usually visible, the sand striker has an impressive body. They can grow to be 1- 3 m (3-10 ft) long, although they’re typically only 25 mm (1 in) wide. Like other bristle worms, their bodies are made up of segments, protected by a hard, irridescent exoskeleton. Most sand strikers are deep purple or black, although individuals in a variety of colors have been documented. In addition to their exoskeleton, bobbit worms also sport sharp, venomous tentacles down the length of their body to deter threats. Adults are typically avoided by other, larger predators, but juveniles can be targeted by fish.

E. aphroditois lacks external reproductive organs, and instead is a broadcast spawner. When they’re ready to mate, female sand strikers produce a pheromone that attracts males and signals them to release their sperm. The females them release their eggs into the water, where they become fertilized and develop into larvae. These larvae swim freely for several months to a year, during which many become food for other animals. The survivors begin to segment and burrow into the sand, where they become sexually mature. In the wild, bobbit worms can live anywhere from 3-5 years, though some biologists believe they may have a longer lifespan of 10-15 years.

Conservation status: E. aphroditois has not been evaluated by the IUCN. However, populations in coral reefs are threatened by habitat decline.

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Photos

Richard Zerpe

Department of Biomedicine, University of Basel