Summary details for Diplocephalus connatus Bertkau, 1889

Species Details

Species name
Diplocephalus connatus Bertkau, 1889
Synonyms
Diplocephalus connatus subsp. jacksoni O.P.-Cambridge, 1903, Diplocephalus adjacens O.P.-Cambridge, 1903, Diplocephalus jacksoni O.P.-Cambridge, 1903, Diplocephalus connatus form jacksoni O.P.-Cambridge, 1903, Diplocephalus connatus var. jacksoni O.P.-Cambridge, 1903
Taxonomy
Animalia :: Araneae :: Linyphiidae
habitat
running water

Distribution

In Britain, the species has only been recorded from two areas in South Northumberland: from the north bank of the River South Tyne near Hexham (1902 and subsequently), and from the confluence of the Rivers West and East Allen (1965). Further survey work is needed to establish the limits of its range. It is also known from France, Germany, Switzerland, the Balkans and Poland.

Habitat and ecology

Riverine shingle banks. D. connatus was originally found among waterborne debris on the river bank, but all subsequent records have been from under stones and boulders on sandy shingle banks at the side of rivers. Adults of both sexes have been found in June, September and October.

Status

Area of occupancy limited to four hectads. The spider was numerous at both its British sites, but the last known record was in 1965, an apparent decline of 100%.

Threats

No immediate threats are known, but the habitat is vulnerable to river engineering work. Survey work to establish its continued presence is urgently required.

Management and conservation

Ensure engineering works on rivers in N.E. England do not destroy the riverine shingle banks on which it is found. Text based on Dawson, I.K., Harvey, P.R., Merrett, P. & Russell-Smith, A.R. (in prep.).

Stats

First recorded
1902
Last recorded
1969
Total records
15
Total visits
15

Conservation status

Diplocephalus connatus
SourceReporting categoryDesignationDate designatedComments
A Review of the scarce and threatened spiders (Araneae) of Great Britain: Species Status No. 22 (Sep 2017)Rare and scarce speciesNationally Rare. Includes Red Listed taxa01/09/2017
A Review of the scarce and threatened spiders (Araneae) of Great Britain: Species Status No. 22 (Sep 2017)Red listing based on 2001 IUCN guidelinesCritically Endangered01/09/2017Recorded only from two areas of riverine shingle banks in northern England. Although numerous at both sites, the last known record was in 1969. The habitat is vulnerable to river engineering work but only one of the hectads with previous records has been surveyed in recent times; it may still persist in the other locations. Threats: No immediate threats are known, but the habitat would be vulnerable to river engineering work. Survey work to clarify its continued presence is urgently required.

Photos and media

Spatial distribution - hectad map

Click on one of the date ranges in the key to highlight that particular range. Click anywhere else on the map to go back to all three date ranges.
Thresholds:
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Rejected records are excluded from this map. Unverified records are included.

Temporal distribution - records by year

Records that span more than one year are not included in this chart.

Temporal distribution - records by week