Exploring unknown life stages of Arctic Tanytarsini (Diptera: Chironomidae) with DNA barcoding
Author
Stur, Elisabeth
Author
Ekrem, Torbjørn
text
Zootaxa
2011
2743
27
39
journal article
10.5281/zenodo.205429
813e2d0c-4310-4c4a-a74c-80a579563230
1175-5326
205429
Micropsectra insignilobus
Kieffer, 1924
Material examined:
7 larvae
,
Norway
,
Svalbard
, Nordenskioldland, Kapp Linné, Søndre Borgdam,
N78.07055°
E13.79345°
,
35m
,
08.viii.2008
, K. Hårsaker, G. Velle & T. Ekrem.
Diagnostic characters.
Micropsectra insignilobus
can be separated from other described
Micropsectra
larvae by having a moderately long antennal pedestal (c. 120 µm) including a minute spur (8 µm); antennal segment 2 about 1/3 length of segment 1; labral seta SII simple; posterior parapod with about 90–100 claws in 2–3 rows.
FIGURES 17–26.
Larvae. 17–21:
Micropsectra insignilobus
. 17: spur of antennal pedestal, 18: antenna, 19: pecten epipharyngis, 20: mentum, 21: mandible. 22–26:
Micropsectra radialis
. 22: antennal pedestal, 23–24: premandible, 25: mentum, 26: mandible.
Description (n = 7).
Head capsule (
Fig. 10
) light yellowish-brown with dark brown posterior margins and mandibular teeth; mentum brown. Live individuals light red. Total length c.
9 mm
.
Head capsule length c. 400 µm, width c. 360 µm; AR 2.0–2.2, 2.1; AHR 0.27–0.36, 0.31; AAR 0.52–0.72, 0.62; antennal pedestal 108–143, 127 µm long with 8 µm long triangular spur (
Fig. 17
); antenna with segments 1– 2 well sclerotized, segments 3–5 pigmented, antennal seta placed at about 2/3 length of antennal segment 1 (
Fig. 18
); lengths of antennal segments (in µm): 190–211, 203; 70–75, 73; 8–10, 9; 8; 6; Lauterborn organs small, on 125–135, 130 µm long pedicels; LOR 5.0–6.0, 5.6; SII simple; chaetae plumose, pectinate; chaetulae simple; S3 simple. Pecten epipharyngis consisting of three scales with tapered, sharp teeth (
Fig. 19
); premandible with 2 robust teeth, inner tooth broader, brush well developed. Mentum (
Fig. 20
) about 135 µm wide, median tooth with obvious notches laterally, about equally strong in colour as lateral teeth; ventromental plates 145 µm wide, evenly curved, with obvious striation along whole length; MVR c. 0.93. Mandible (
Fig. 21
) with 3 inner teeth, one apical tooth, one dorsal tooth; pecten mandibularis slightly convex; postoccipital arch narrow making the well developed, hyaline plate almost triangular in shape (
Fig. 10
).
Body. Anterior parapods with long, simple spines; posterior parapods with 70–100 simple hooks in two–three rows (
Fig. 15
); Second lateral seta of abdominal segments 2–7 fan-shaped with c. 20 branches; anal segment with 4 anal tubules, c. 175 µm long; procercus with one short and one long dorsal seta, with 4–5 short (c. 600 µm) and 3 long (c. 1000 µm) anal setae.