(Meigen, 1804)
Body
Small sized larvae with a length up to 3 mm Nil larvae. The larvae are pale brown without a fringe of swimming hairs (Kownacki and Kownacka, 1968; Wiederholm, 1983).
Head
The head length is 0.35 - 0.45 mm with a cephalic index of 40 - 45% (Kownacki and Kownacka, 1968; Wiederholm, 1983).
Antenna
The antennal segments are all yellow and the antennal ratio is 2.3 - 3.2. The ring organ is situated at 0.6 - 0.7 of the height of the first segment. The second segment is normal and lacks a tuning fork (Wiederholm, 1983).
Mentum
Dorsomentum without teeth (Wiederholm, 1983).
Ligula and paraligula
Ligula with 5 brown teeth in a convex row. The inner teeth are shorter than the middle and outer teeth Nil ligula (Kownacki and Kownacka, 1968; Wiederholm, 1983)
Mandible
The mandible has a large basal and accessory tooth (Kownacki and Kownacka, 1968; Wiederholm, 1983).
Maxilla
The maxilla is short and the basal segment is undivided (Wiederholm, 1983).
Anal tubules
4 anal tubules are very long and about the same length as the posterior parapods.
Posterior parapods
Posterior parapods very elongate. All claws on the posterior parapods are yellow Nil post. parapods. One claw with a comb of small teeth. The long seta on the parapods is longer than the anal tubules (Kownacki and Kownacka, 1968; Wiederholm, 1983).
Differential characteristics
The convex row of dorsomental teeth Nil ligula is a character shared with Labrundinia. Nilotanypus lacks the lateral toothed humps on the head and inhabits fast flowing streams and rivers, while Labrundinia lives in acidic lakes and bogs.