Sclerotised hard parts of dactylogyrus quadriramus Lim, 1987, D.bitubus Lim, 1987, D.curvicopulatrium Lim, 1987, D.tempuaensis Lim, 1987, D.chelatus Lim, 1987 and D.temperasi lim, 1987 - Lim, S.L.H. (1987)