Fittkau, 1962
Body
Medium sized larvae with a length up to 8 mm. Living larvae are white or yellowish. Fringe of swimming hairs absent.
Head
The head length is 0,66 - 0,80 mm with a cephalic index of 50 - 65%. (Moller Pillot, 1984a).
Antenna
The antennal segments are all yellow and the antennal ratio is 3.5 - 5. The ring organ is situated at 0.65 - 0.75 of the height of the first segment. The second segment is normal and lacks a tuning fork (Wiederholm, 1983; Moller Pillot, 1984a).
Mentum
Dorsomentum without teeth.
Ligula and paraligula
Ligula with 5 brown teeth in a concave row. Paraligula with a long outer and a smaller inner tooth Rhe ligula paraligula.
Mandible
The mandible has a very small basal tooth Rhe mandible.
Maxilla
The maxilla is short with an undivided besal segment. The b-seta has 3 segments Rhe maxilla9.
Anal tubules
4 anal tubules which are longer than wide.
Posterior parapods
One claw on posterior parapods is brown Rhe post. parapod. No teeth on the inner margin of these claws.
Differential characteristics
Rheopelopia is closely related to Arctopelopia, Conchapelopia and Thienemannimyia. Their common characters are:
dorsomental teeth absent
concave ligula Rhe ligula paraligula
small basal tooth of mandible Rhe mandible
Rheopelopia differs from the other genera by:
the brown claw on the posterior parapod (all genera) Rhe post. parapod.
confined to rivers while the other genera live in streams or lakes, except Conchapelopia which is very rare in rivers.
Rheopelopia has a lower cephalic index (50-65 vs 65-75) and ring organ higher on the first antennal segment than Arctopelopia. The antennal ratio is lower (3 - 4) than in Arctopelopia and Thienemannimyia (4 - 6).
Diversity
European species: 3
Treated species: 0