Meeting Abstract
82.1 Sunday, Jan. 6 Attachment ability of a clamp-bearing fish gill parasite, Diplozoon paradoxum (Monogenea) WONG, W.L.*; MICHELS, J.; GORB, S.N.; Zoological Institute, Christian-Albrechts-Universität zu Kiel, Germany; Zoological Institute, Christian-Albrechts-Universität zu Kiel, Germany; Zoological Institute, Christian-Albrechts-Universität zu Kiel, Germany wlwong@zoologie.uni-kiel.de
An effective attachment system is crucial for the survival of monogeneans, which are mainly fish ectoparasites. Monogeneans use various types of haptoral (posterior) attachment devices to attach themselves onto their hosts. However, there is no study done to assess the efficiency of their attachment devices. The present study aimed to determine (1) the attachment forces of a paired adult Diplozoon paradoxum from the fish gills, (2) the contribution of muscles action to the clamp movements and (3) the distribution of a resilin-like protein in clamp sclerites. An average force of 6.1 ± 2.7 mN (about 246 times of the animals’ weight) is required to dislodge a paired D. paradoxum vertically from the gills of the fish Abramis brama. When the monogeneans were treated in three different solutions, the widths of the clamp openings differ significantly in each treatment. The widest clamp openings were observed in the monogeneans treated in 2.5 % glutaraldehyde (74.52 ± 28.31 µm), followed by the those treated in 20 mM MgCl2 (37.91 ± 7.58 µm), and in filtered lake water (20.16 ± 8.63 µm). Results from the toluidine blue staining and spectral analyses of the blue autofluorescence, exhibited by the clamp sclerites, indicated that the sclerites contain a rubber-like protein similar to resilin of Arthropods. Our results suggest that the closing of the clamps is not due to the continuous contraction action of muscles, but rather due to the elasticity of the clamp material. The presence of the resilin-like protein likely improves the attachment efficiency and the lifespan of the clamp sclerites.
