Magelona papillicornis
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Magelona papillicornis . From A monograph of the British marine annelids, 1915, panel XC. |
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| Scientific name | ||||||||||||
| Magelona papillicornis | ||||||||||||
| Johann Friedrich Theodor Müller , 1858 |
Magelona papillicornis is a grave forming in the sediment of detritus living polychaete (Polychaeta) from the family Magelonidae which at the Atlantic coast of Brazil is widespread.
features
Magelona papillicornis has an elongated body, the first 9 bristle-bearing segments are as long as they are wide and dorsoventrally compressed. From the 10th bristle-bearing segment on, the segments are cylindrical and wider than they are long. Preserved animals are yellowish amber. On the first 9 bristle-bearing segments there are dorsolaterally reddish or dark-colored granular accumulations, which can be seen further back up to the 18th to 20th bristle-bearing segment in the lateral area of the parapodia. No pigmented streaks can be seen in the front part of the body. The prostomium is approximately triangular with no horn-like extensions in front, and the muscles on the sides of the prostomium are clearly visible. On the first 9 bristle-bearing segments, the lamellae of the notopodia correspond in size and mirrored in shape to those on the neuropodia . The lamellae on the notopodia and neuropodia from the 10th segment are stalked ovoid. The bristles on the first 9 bristle-bearing segments have one or two hems and are slightly curved. On the notopodia and neuropodia of the posterior bristle-bearing segments, rows of 8 to 10 double-toothed hooks with hoods sit opposite one another. The hooks next to the side slats are characteristically smaller than the others. On the 9th segment sit special bristles with a subterminal extension.
Distribution, habitat, way of life
Magelona papillicornis is common in the western Atlantic Ocean on the Brazilian coast of Santa Catarina , Paraná , São Paulo and Rio de Janeiro . Like other Magelonidae, it lives in self-dug tunnels in sand and mud and grazes the organic covering of detritus from the sediment surface with the help of its papillary palps.
Development cycle
Magelona papillicornis is segregated, but little is known about its reproductive behavior. Animals ready to mate were observed on the Scottish coast in March and in France in May. The fertilization takes place in the open sea water, and the development proceeds via a freely swimming larva as zooplankton , which sinks after several weeks and metamorphoses into a creeping worm . The species is considered an r-strategist , which develops rapidly, lays many eggs and lives briefly.
History of the systematics and incorrect classification of European animals
Magelona papillicornis was found in 1858 by Johann Friedrich Theodor Müller as the first species of the family off the island of Santa Catarina and was first described at the same time as the genus Magelona . The generic name Magelona refers to the " beautiful Magelone ", a figure from the French fairy tale world, while the specific epithet papillicornis describes the palps ( Latin cornu "horn") with their papillae. Joseph Thomas Cunningham and GA Ramage established their own family Magelonidae in 1888 with the only genus Magelona .
For a long time all Magelona of the North Sea were assigned to the species Magelona papillicornis , to which the European animals, however, do not belong. The European Magelona were later assigned to the species Magelona mirabilis described by Johnston , but it turned out that there were two or even more species and Johnston's description was not clear enough to assign them. Dieter Fiege, Frank Licher and Andrew SY Mackie re-described Magelona mirabilis in 2000 with a neotype and also described a second European species, Magelona johnstoni . The Brazilian species Magelona papillicornis , on the other hand, was newly described by Meredith L. Jones in 1977 .
literature
- Fritz Müller (1858): Some things about the annelid fauna of the island of Santa Catharina on the Brazilian coast. Archive for Natural History, Berlin 24 (1), pp. 211–220, panels VI-VII. (From a letter to Prof. Grube). Here p. 215f., Magelona .
- Joseph Thomas Cunningham, GA Ramage (1888): The Polychaeta Sedentaria of the Firth of Forth. Transactions of the Royal Society of Edinburgh 33 (3), pp. 635-684, here p. 642, Fam. Magelonidæ .
- Germán Armando Bolívar, Paulo da Cunha Lana (1986): Magelonidae (Annelida, Polychaeta) do litoral sudeste do Brasil. Nerítica, Pontal do Sul, PR, 1 (3), pp. 131–147, here 135–137.
- Meredith L. Jones (1977): A redescription of Magelona papillicornis F. Muller. In: DJ Reish, K. Fauchald (Ed.): Essays on Polychaetous Annelids in Memory of Dr. Olga Hartman. Pp. 247-266. Allan Hancock Foundation, University of Southern California, 1977.
- Brigitte Hilbig (1982): Contribution to the ultrastructure of the skin-covered bristles and hooks of polychaetes and their importance for taxonomy and systematics.- Messages from the Hamburg Zoological Museum and Institute , 79, pp. 19-50.
- Dieter Fiege, Frank Licher, Andrew SY Mackie (2000): A partial review of the European Magelonidae (Annelida: Polychaeta): Magelona mirabilis redefined and M. johnstoni n. Sp. distinguished. Journal of the Marine Biological Association of the United Kingdom 80 (2), pp. 215-234.
- Stanley J. Edmonds: Fauna of Australia, Volume 4A. Polychaetes & Allies. The Southern Synthesis 4. Commonwealth of Australia, 2000. Class Polychaeta. Pp. 262-264, Family Magelonidae.
- Gesa Hartmann-Schröder (1996): Annelida, Borstenwürmer, Polychaeta. Tierwelt Deutschlands 58, pp. 1–648, here p. 342, Magelonidae and p. 343–345, Magelona .
