Main Content

The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Ref ID : 6565

G. Melone, Claudia Ricci, and Hendrik Segers; The trophi of Bdelloidea (Rotifera): a comparative study across the class. Can.J.Zool. 76:1755-1765, 1998

Reprint

In File

Notes

The fine morphology of the trophi of bdelloid rotifers was investigated using scanning electron microscopy to provide a detailed description of the structure and to assess its variability within the class. Twelve genera of the four families of Bdelloidea were considered. All trophi studied fit the ramate type typical of bdelloids, and comprise three paired elements: rami, unci (with three groups of teeth: a proximal group of minor teeth, a median group of major teeth with a pore, and a distal group of minor teeth), and manubria. The morphology of the trophi in Adinetida and Philodinida is fairly homogeneous. The trophi of Philodinavida differ in position orientation, and structure: the proximal group of minor uncus teeth is reduced and the ramus apophysis is more developed. In contrast to the trophi of Flosculariacea, small differences in the number of uncus teeth appear to be taxonomically irrelevant in Bdelloidea. The following features of the trophi are recognized as synapomorphies for the Bdelloidea: absence of the fulcurm; formation of major uncus teeth by fusion of elements; and deposition of calcium as a means of stiffening the manubria. The exsistence of these synapomorphies suggests that the ramate type of trophi in Bdelloidea does not represent the primitive type in Rotifera.