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Reconstruction of the nervous system in bone-eating Osedax spp. and its evolution across Siboglinidae (Annelida)тезисы доклада
- Авторы: Worsaae K., Rimskaya-Korsakova N., Rouse G.
- Сборник: 12th International Polychaete Conference, Abstracts
- Тезисы
- Год издания: 2016
- Место издания: National Museum Wales
- Первая страница: 49
- Последняя страница: 50
- Аннотация: The annelid nervous system has long been known to encompass a greater variety than many other evolutionary lineages, however, neurophylogenetic studies testing the homology and evolution of these multiple neural traits have never been carried out in the Annelida. The Siboglinidae nervous system is, with a ventrally positioned brain and indistinct segmentation of the anterior body, highly deviant from other annelids and its origin is still questioned. Central for understanding the nervous system of these endosymbiont-housing, generally gutless, tubeworms is the bone-devouring Osedax; the nervous traits of which are here mapped and their evolution traced across Siboglinidae. The four examined female Osedax spp. and the bone-eating O. priapus male all showed a simple nervous system, comprising a ventral brain with several commissures connected with anteriorly directed paired palp and gonoduct nerves, and four main pairs of posteriorly directed longitudinal nerves. A broader comparison across Siboglinidae suggests new homologies of the ambiguous, and much debated, anterior segments - with the trunk of Osedax females (and O. priapus males) suggested to comprise two segments and Osedax dwarf males suggested to have three body segments in total. However, besides from additional lateral and dorsal longitudinal nerves and details of the brain only described for Osedax, this first neural character reconstruction reveals that the intraepidermal nervous system with multiple, widely separated nerve cords, double brain commissures, and double palp nerves of Osedax are all siboglinid plesiomorphies; hereby bridging the evolutionary gap to non-siboglinid annelids and enhancing our understanding of the neural evolution within Siboglinidae.
- Добавил в систему: Римская-Корсакова Надежда Николаевна