Limnic and other micro-organisms from Germany: Aspidiphorus silvaticus Varga 1963, Chaetonotidae, Gastrotricha

Aspidiophorus silvaticus Varga 1963

Aspidiophorus silvaticus, dorsoventral view. Around the mouth there is one pair of stiff setolae on each side (arrows); at the sides of the head there are another 2 pairs each (arrowheads). At the posterior part of the trunk another pair of setolae (yellow arrows). The adhesive tubules at the posterior end of the toes are unusually long

Aspidiophorus silvaticus, dorsoventral view. The base of the toes are connate (arrow). Because of this untypical habitus and their fast hectic movement this species might be confused with the rotifer Bryceella (perpusilla), which -interesting enough- was also found in the same sample.

Aspidiophorus silvaticus, dorsoventral view. In contrast to the drawings in SCHWANK 1990 the posterior setola are inserted at the base of the toes (arrows)

Aspidiophorus silvaticus, head with everted mouth tube (arrow).

Aspidiophorus silvaticus, lateral view. SCHWANK 1990 reports A. silvaticus to be found only in Poland and Hungary at that time. Maybe this is the first discovery in Germany.

Aspidiophorus silvaticus, dorsal view. Focal plane on the scales of the head.

Aspidiophorus silvaticus, focus plane on the ventral cilia. A strange behavior could be observed at several specimens: from time to time A. silvaticus contracts in the middle of the body giving the impression of having two eggs.

Aspidiophorus silvaticus, specimen from Norway. (2)

Aspidiophorus silvaticus, three aspects of the head. Upper left: dorsal view, crop of the above image. Focus plane is on the dorsal spines which seem to be hollow. Upper right: optical median section of the head showing two minute light-refracting structures (arrowheads). Lower left: View on the ventral cilia which seem to be arranged in groups.(2)