Cerbalus aravaensis

Cerbalus aravaensis

Cerbalus aravaensis is the name of a spider that was discovered in 2003 in the sand dunes in the Arava in the south of Israel and Jordan. The spider is included legs (range ) about 14 cm tall, making it the largest giant crab spider of the Middle East.

Features

The females are up to approximately 3 cm long, the males remain quite small. The carapace is sandy, light gray to yellowish, and densely covered with fine bristles. A dark brown band extends posteriorly beyond the middle of the carapace and ends at the front of the tips of the chelicerae. The abdomen is uniformly cream-colored and without special drawing. The striking heavily built legs can be used for digging in the sand. They have the same basic color as the carapace are, but black at the joints and at the tips. The anterior median eyes are the largest, the smallest rear. The clypeus, between the front pair of eyes and the edge of the carapace, is very narrow.

Cerbalus aravaensis resembles also in Israel, in the Negev desert to Elusa, nature -based Cerbalus Psammodes. The males, however, differ from this species by a short, pointed extension with thread-like swellings on the bottom of both pedipalps. A similar extension is on the rails of the pedipalps. The females differ from those of the type Cerbalus Psammodes by the internal shape of the spermathecae.

Dissemination

The Arava Valley in the southern border area of Israel and Jordan belongs geologically to the Great African grave breach. It forms an enclave, bounded by mountains and the Dead and the Red Sea. Due to the seclusion Cerbalus aravaensis could develop independently in this valley, it came to crossing barriers with the closely related species Cerbalus negebensis and Cerbalus Psammodes. The occurrence of the species is limited according to the current state of knowledge on the dunes and the more stable sand concretions on the edge of the salt marsh, the spider is endemic in the Arava Valley.

Way of life

Cerbalus aravaensis lives in a hot, arid climate. However, the spiders are active mainly in the summer. During the hottest in their area of ​​distribution months of the year, in July and August, especially the males go wandering. The spiders are nocturnal and live the day in underground caves, which are closed with a kind of trap-door with spin silk zusammengeklebtem sand. This operculum not only provides a good cover of the input, but also protection against sandstorms.

Endangering

The sand dunes of Samar in the southern Arava, where most of the population of Cerbalus aravaensis is located, are the only ones remaining in this area. They covered previously an area of ​​about 7 square kilometers, but are now shrunk to 2.6 square kilometers. A disappearance of the sand dunes, which are threatened by expansion of agricultural land and the resumption of sand mining would have the extinction of the species result.

Taxonomy

The species was first described by the Israeli biologists and arachnologists Gershom Levy 2007. The Artepithet aravaensis refers to the habitat of the spider, the Arava Valley. It is often wrong in popular scientific articles as aravensis or arvensis reproduced.