Acroperus harpae
Acroperus harpae has got its name from the shape of the carapace which resembles a harp. It is a common littoral species, distributed all over Norway, including Svalbard, and occurs both at sea level and in alpine areas.
Key characteristics
Acroperus harpae (female)
Acroperus harpae (male)
Acroperus harpae has got it name from the shape of the carapace which resembles a harp. The body is laterally highly flattened with a high, transparent keel above the eyes. Its eye is placed approximately in the centre of the head shield. The carapace has stripes going diagonally from the upper front corner down to the lower post corner. The post abdomen is long and slender, and is normally protruding out of the carapace. The arrangements of the small bristles on the claw are different from all other species. The carapace is very transparent. Its colour is distinct yellowish.
Female: Length 0.6–1.3 mm
Male: Length 0.5–0.9 mm
Ecology and distribution
A. harpae is a littoral scraper distributed all over Norway including Svalbard and found in about 50 % of all waters. It occurs from sea level and up to 1630 m a.s.l. and the frequency of lakes having the species does not vary with altitude. It occurs in vegetation as well as over stony bottom, and in small ponds as well as in large lakes. pH varies from 3.9 to 8.6 and the species does not seem to be favoured neither by high nor low pH. A. harpae is found both in very dilute waters as well as in brackish water.
| Vitenskapelig navn | < 4,5 | 4,5 - 4,9 | 5,0 - 5,4 | 5,5 - 5,9 | 6,0 - 6,4 | 6,5 - 7,0 | 7,0 - 7,4 | > 7,5 |
|---|---|---|---|---|---|---|---|---|
| 53 | 64,2 | 59,8 | 66,7 | 63,6 | 52,1 | 54,7 | 54 |
| Vitenskapelig navn | < 1,0 | 1,0 - 1,4 | 1,5 - 1,9 | 2,0 - 2,9 | 3,0 - 3,9 | 4,0 - 4,9 | 5,0 - 6,9 | 7,0 - 9,9 | > 10,0 |
|---|---|---|---|---|---|---|---|---|---|
| 55,3 | 57,1 | 56,8 | 61,5 | 62,4 | 50 | 52,4 | 61,1 | 52 |
| Vitenskapelig navn | < 0,01 | 0,01 - 0,09 | 0,1 - 0,9 | 1,0 - 9,9 | 10,0 - 99 | 100 - 999 | > 1000 |
|---|---|---|---|---|---|---|---|
| 44,1 | 34,8 | 48,3 | 58 | 63,9 | 62,7 | 76,1 |
| Vitenskapelig navn | < 100 | 100-299 | 300-499 | 500-699 | 700-999 | >1000 |
|---|---|---|---|---|---|---|
| 51,2 | 62,5 | 60,3 | 61 | 52,4 | 49,3 |
Look-alikes
Acroperus angustatus, Alonopsis elongata and Camptocercus sp
