Tanytarsus aberrans

Author: Lindeberg, 1970

Diagnosis (Material in coll. B. Lindeberg)
Exuviae 4.8-5.1mm long (m=5.0, n=7).
Cephalothorax: Cephalic tubercles narrow conical, 30µm high; frontal setae 75-85µm long (n=6). Antennal sheaths with a small conical papilla at base. Thoracic horn 435-585µm long (n=4), minutely toothed; ThR 16.3-28.8 (n=3). Posterior thoracic mound bulbous. Wing sheaths rounded apically, pearl row absent.
Abdomen: Length hook row II 0.27, 0.32x width tergite (n=2); hooks 70-90 (n=6). Tergites III-VI with the armament arranged in longitudinal bands, III and IV with spines; ArR III-VI 1.08-1.28 : 1.0 : 0.33-0.47 : 0.28-0.39 (m=1.18 : 1.0 : 0.46 : 0.33, n=7). Longest spine IV : III 1.0 : 1.0 (n=1). Comb of segment VIII 60-75µm wide; with 9-10 marginal teeth (n=7). Lateral taeniae of segments VII, VIII (0,1)2,5. Ventral taeniate setae of segment VIII short, not reaching the posterior edge of the segment (146e.jpg).
Anal segment: Anal lobe ratio 1.24-1.34 (n=7). Fringe of anal lobe with 39-50 taeniae (m=43, n=14), forming a complete series.

Note: Only distinguishable from Tanytarsus gregarius and Tanytarsus inaequalis by the length of the taeniate setae of segment VIII, and the somewhat longer cephalic tubercles the validity of which remain to be confirmed with further associated material.

Species keys out at Page 483: Tanytarsini 124 Tanytarsus of the Text Key.

NW+C Europe.
(For more information see module IdentifyIt – file: Chironominae).

Ecological notes
Far northern lakes and tarns.