How does it look like?
It is a wandering polychaete worm that can reach 20 centimeters in length and 8 cm in width. It has a pair of eyes and an odd number of frontal tentacles. Its body is segmented and, while the ventral part is flattened, the dorsal part is convex and oval. The dorsal surface is covered by 15 pairs of elytra, a special type of rigid scales that give it a hairy appearance. However, these scales are not normally visible, as the dorsal surface is usually covered with sandy sediments, giving it a brownish coloration. In addition, on the sides of the body there are a series of fine black quetae, very characteristic of this species. These quetae are arranged in bundles, so that they glow when the animal moves, forming a halo reminiscent of the colors of the rainbow.
Where does it live?
Its distribution area is quite wide, from the seas of Scandinavia to the French coast, including the North Sea, the English Channel, and, in less abundance, the Mediterranean. It is usually found from shallow waters to depths of more than 2.000 meters, especially in muddy and sandy bottoms, buried and hidden, as it is a burrowing worm. It is also possible to see it on the seashore after a storm or very strong swells.
How does it feed?
They are active predators and basically feed on other worms, both sedentary and free-living. It seems that Pectinaria and Lumbriconereis, as well as nemerteans and small hermit crabs, are part of their diet. They are capable of swallowing whole prey, up to 3 times their size, usually starting with the head and ending with the tail; for this reason digestion is usually slow. The order of ingestion is reflected in their stool. It is preyed upon by cod and other fish.
How does it reproduce?
These organisms have separate sexes. According to Fordham (1925), "sperm and eggs are released into the water through the nephridia and nephridiopores on the dorsal surface". From the fertilization of these cells, few-segmented larvae are formed, which have a very short pelagic life. The reproductive season takes place in winter and spring.
Is a confusion possible?
Although similar in appearance to Aphrodita alta and Aphrodita perermata, Aphrodita aculeata is easily distinguishable by the presence of iridescent quetae in the lateral zones. It also resembles Hermione hystrix, but this one has a more conical shape and more visible antennae.
· Its stubby shape does not cause any problems when moving, since it has a very effective locomotion mechanism by which the movement of each of its parapodia pushes the animal forward, unlike the typical undulatory movement characteristic of other polychaete worms.
· It is common to find commensal organisms on the dorsal part, under the chetas and scat, as the entoprocts Loxosmella claviformis, Loxosmella fauveli and Loxosmella obesi. Rarely parasitic forms are observed.
· It is able to pump water into its respiratory cavity, which is located between the dorsal area and the elytra, in order to provide oxygen.
· Its introduction to aquarium life is easy and does not usually cause problems.
· Very recent studies indicate that the iridescence of its quetae serves to scare off potential predators, making them believe that they are poisonous when, in fact, they are soft and harmless. At the same time, it has been discovered that quetas contain photonic crystals that are very efficient at trapping light, so researchers in optical engineering are trying to copy their molecular structure for future applications and thus revolutionize the world of fiber optic telecommunications.
· According to Christopher Lehmann-Haupt referring to the writer Ms. Hubbell in the New York Times of July 8, 1999, the scientific name Aphrodita is not due to the beauty of its iridescence, as is widely believed. It seems that due to the ironic humor of Linnaeus, he named it for the resemblance of the worm with female genitalia. In the northern European slang of the time, the term mouse was used to designate the sexual parts of the female.
Phylum: Annelida, Class: Polychaeta, Order: Phyllodocida, Suborder: Aphroditoidea, Superfamily: Aphroditacea, Family: Aphroditidae, Genus: Aphrodita