Myrianida prolifera
| Myrianida prolifera | ||||||||||||
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Autolytus prolifer in schizogamy |
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| Scientific name | ||||||||||||
| Myrianida prolifera | ||||||||||||
| ( OV Müller , 1776) |
Myrianida prolifera ( synonym : Autolytus prolifer ) is a cosmopolitan marine annelid within the polychaete - Family of Syllidae .
features
The body of Myrianida prolifera is up to 2 cm long in adult animals and has up to 70 segments . The rounded prostomium has four lens eyes that do not touch each other. Palps are poorly developed and hardly recognizable from the dorsal side. The center antenna is longer than the two side antennas, which in turn are at least three times as long as the prostomium. The dorsal tentacles - Cirrus clouds are as long as the side antennas ventral but only half as long. Belly cirrus is present as well as 1 to 3 aciculae. The dorsal cirrus on the first bristle-bearing segment are at least as long as the central antenna. All other dorsal cirrus trees change in length, with the longest being at least as long as the segment is wide. The spread of the assembled bristles has two teeth, the one at the end of which is smaller. From the third segment on, the parapodia have an additional needle-shaped bristle sawn on the shaft. The retracted S-shaped pharynx is crowned with a trephine with 10 to 36 teeth of the same type.
The animal is transparent, yellow or slightly reddish with many round, transparent or yellow-orange granules. The tips of the appendages on the anterior segments are often reddish.
distribution and habitat
Myrianida prolifera is widespread as a cosmopolitan in the Arctic and in the northern Atlantic Ocean including the North Sea , Skagerrak , English Channel and Mediterranean Sea , but also on the coasts of South Africa, where it grows between large algae and colony-forming hydrozoans on rocky coasts from the intertidal zone up to about 50 m Sea depth lives.
Life cycle
Myrianida prolifera is separate sexes and initially lives as a sexually immature atoke , which at sexual maturity as a foster animal in the course of a budding process known as schizogamy , produces up to eight stolons lined up in a chain - freely swimming, ready-to-mate, head- and eye- bearing epitokes . These cannot take in food and therefore only live for a short time. The foster animal, on the other hand, can survive for a longer period of time and produce more stolons. To mate, the female and male epitoks, which are filled with eggs or sperm in their foremost segments, swarm out and come together in large numbers on the surface of the water. The sperm are released by the male into the sea water when they mate and are taken up by the female, where they fertilize the egg cells. Until the freely swimming trochophora larvae hatch, the eggs remain in the female's belly sac. The epitoken die after mating or after hatching of the free-swimming larvae, which sink after a pelagic stage and metamorphose into crawling worms .
nutrition
As a carnivore , Myrianida prolifera feeds on the polyps of sessile hydrozoans.
literature
- JD Fish, S. Fish: A Student's Guide to the Seashore. Cambridge University Press, Cambridge 2011. p. 151.
- PJ Hayward, JS Ryland: Handbook of the Marine Fauna of North-West Europe. Oxford University Press, Oxford 1995. pp. 233-235.
Web links
- MJ de Kluijver et al .: Autolytus prolifer (OF Müller, 1776). Macrobenthos of the North Sea - Polychaeta, Marine Species Identification Portal
Individual evidence
- ↑ K.-L. Schiedges (1979): Reproductive biology and ontogenesis in the polychaete genus Autolytus (Annelida: Syllidae): Observations on laboratory-cultured individuals. Marine Biology 54 (3), pp. 239-250.