Segestria florentina

( Segestria florentina [ w] )

Segestria florentina is a True Spiders of the family fishing net spiders. In Europe, it is the largest species of the family. As with all fishing net spinning the six eyes with Segestria florentina are arranged in two mutually -looking pointed triangles at the front.

Appearance

The females reach a body length of up to 22 mm, males up to 15 mm. This type is the darkest kind of this family. While young animals have a greyish abdomen ( opisthosoma ), which has a similar pattern to Segestria senoculata, adult animals are almost uniformly black. A striking and characteristic feature of Segestria florentina is the greenish metallic sheen of the large chelicerae. This color is a structural color, which is generated by a grid of Chitinlamellen.

Distribution and habitat

Original home of the species is the Mediterranean, she comes to the east by Turkey and the Crimea, and the Caucasus. In their original home they inhabited crevices and tree trunks, such as sycamores, where she lives under loose bark, especially common but grossly verfugtes masonry buildings. Further north they live exclusively synanthropic on walls and buildings. Because of their body size, they needed large and deep cracks of the walls as they occur mainly in the masonry of castles, churches and ungrouted stone walls. The species is mainly in the north of their range, linked to areas with maritime climate. They inhabited the Iberian Peninsula and the west of France from Normandy to south. To the east, it is increasingly tied to marine areas close. The eastern boundary of the distribution runs through the province of Zeeland (Netherlands) and seems mainly caused by the winter temperature. In England, she was tied up in the 1980s to some port towns on the south coast, but since a few years back shows a marked tendency to spread to the north. Findings are now north before to Gloucestershire and Essex. From Germany, the spider has been reported only twice .. The way to Switzerland reached in the South ( Ticino) and missing in Austria.

Way of life

The spider builds in wall crevices and cracks a tubular network that opens like a funnel to the outside. From this hopper opening to go outside from long signal threads. At night, the spinning wait near the funnel opening. Touched a prey animal, the signal thread, so it can be quickly located and bitten by the spider. Then the prey is drawn into the tube network.

Bites

Bites from Segestria florentina are painful. It is reported about a case in which not only severe pain and swelling of the bite site and fever, dizziness and headache were the result. Often, the pain subsides after a few hours. The venom contains a neurotoxin that specifically a type of calcium channels ( These are mainly in neurons type N) inhibits the cell membrane.