Spaghetti worm

Spaghetti worms are any of the species of marine polychaete worms belonging to the taxonomic Family Terebellidae. Their common name due to their anterior spaghetti-like tentacles (palps) that are used for feeding. They are also commonly known as strawberry worms. Although these small segmented worms have little commercial or economic impact, they contribute to their marine environments by scouring the sea floor for detritus and other organic materials. Spaghetti worms are commonly found in waters near Bermuda, Puerto Rico, New Zealand, Britain, Asia, and the Caribbean.

Body Design
Spaghetti worms are segmented worms characterized by long cylindrical bodies that range anywhere from 5 to 12 inches in length and usually about 1 inch thick. Each individual segment may contain its own set of organs such as the kidney or branches of nerves. Each segment also possesses bristle-like setae used to burrow and move throughout its small enclosure. These generally serve as anchors for the worms as they feed. Spaghetti worms get their name from their many thin tentacles displayed at one end of their body. These palps, which range in color from pale blue to purple depending on species, are mouthparts spread out up to 3 feet across the ocean floor as they probe for food or tough materials to reinforce their home. Generally, the tentacles are not fully retractable, so each palp has hundreds of tiny cilia that move materials along the length of the palp toward the mouth. This process works much like a conveyor belt. However, larger particles are wrapped by the tentacles and essentially dragged to the mouth. These palps will regenerate if eaten by predators. Spaghetti worms have separate sexes. At the mouth, most spaghetti worms possess multiple sets of lips, internal and external, to better meet the diverse food particles captures by their palps. A well developed mucus gland sits near the mouth to lubricate food and the palps. After reaching the mouth, food is digested through an esophagus, fore-stomach, hind-stomach, and intestine with the help of enzymes. For respiration, these worms have three pairs of anterior branched gills. (However, in some species, the gills exists as several simple filaments.) Just like other annelids, spaghetti worms have a closed circulatory system.

Life Cycle
Terebellid larvae are lecithotrophic, meaning they survive by devouring the yolk encased in its egg. The growth of the juvenile worm depends heavily on available food. Terebellids generally do not migrate far from their hatching location. Competition between juvenile worms, if any, is very minimal. After a short time, the worm either digs a burrow on the sea floor or finds a preexisting tube or slender opening (e.g. small man-made objects, another organism's abandoned shell, etc). The organism then begins feeding on detritus with its palps across the sea floor, having optimal growth rate in water temperatures between 50-68°F. As warmer summer months approach, individual sexes begin the production of gametes. The female is known to produce eggs exclusively at night. The males then release sperm, whether a female is present in the vicinity or not. Females are known to do the same, expelling eggs without the guarantee of fertilization. This release of gametes occurs within a two-week period. When a sperm meets with an egg in the water, external fertilization takes place. The larva begins to develop and will later hatch within the same summer months.

Ecology
Spaghetti worms are found in relatively shallow reef areas in waters near Bermuda, the Caribbean, Colombia, Puerto Rico, Florida Keys, New Zealand, and other tropical marine habitats. Although spaghetti worms spend most of their lives apart from other members of their species, many of these Terebellids, such as Eupolymnia crasscornis, are known to share their homes with small burrowing creatures like the tube pea crab. Other species of worms, bivalves, and other crustaceans may also find their homes within a spaghetti worm's burrow. The worm utilizes this symbiotic relationship as a means of protection. Additionally, Eupolymnia nebulosa, a common spaghetti worm, has been observed cleaning detritus from eels as they remain motionless. This symbiotic relationship benefits both the eel and the worm. However, this occurrence is rare and can not yet be determined to be an intended relationship. The spaghetti worm is preyed upon by certain species of fish, notably the blue-stripe butterflyfish which feeds on the exposed palps.

Recent research suggests that a few members of the genus Eupolymnia possess a chemical deterrent. In lab studies, certain species of predatory crab and fish refused pellets of food infused with spaghetti worm extract and tended to avoid water with high levels of the worm's excretions. These results varied widely from the control experiment, when regular pellets of food were aggressively devoured by the predators. Scientists studying these results also suggested that the actual purpose of the chemical is to repel other worm larvae from settling in the area, thus reducing competition. However, the active chemicals (metabolites) were not specifically identified and the exact purpose remains unknown. Additionally, chemical deterrents were not found in other worms in this same Family.

Although making little impact economically, spaghetti worms were once used by ancient Hawaiians for medicinal purposes, although the treated ailment is not clear. Natives called the worm "kauna'oa or kio", and patients regularly drank a soup of the worm's palps for several weeks or directly sucked the live worm's internal fluids from the main body through a bamboo tube. Today, the worms are usually only used by humans as accessories to aquariums, not for medicinal purposes.

Aquarium Life
Spaghetti worms are known among aquarium enthusiasts to be "hitchhikers", as these worms are commonly transported to artificial marine habitats through the sale of sediment and natural rocks and/or coral. Generally, these worms can adjust to environmental changes associated with an aquarium such as pH level and temperature. Upon the discovery of one or more of these worms, some consider them a nuisance. However, many view these Terebellids as a benefit to their artificial habitat, as they clean detritus and unwanted biological waste or even left-over fish food from the tank. Additionally, the worms pose no danger to the intended marine animals of the aquarium.

For these reasons, spaghetti worms are even sold to aquarium keepers as harmless tank cleaners, notably by Hawaiian companies like Indo-Pacific Sea Farms. Because spaghetti worms can produce many offspring under proper conditions, they can be purchased at a relatively low price. Small aquatic enclosures provide conditions to almost guarantee successful reproduction between spaghetti worms, so these worms are promoted as being one-time purchases. Many websites that provide aquarium advice claim spaghetti worms to be near essential.

Video
This spaghetti worm in the genus Amphitrite can be seen moving its palps across the ground as the main body squirms to dig a burrow. zCarFwY-ZME