Braken Bat Cave Meshweaver

This blog is about the Cicurina venii. The common name of this spider is the Braken Bat Cave Meshweaver (USFWS). This arachnid is a Eukaryote in the Kingdom Animalia (Zipcode Zoo). It is an arachnid which is an invertebrate. It is an endangered species (USFWS).

The Braken Bat Cave Meshweaver lives only in one cave in the entire world. This cave is on private property in Bexar County in Texas (Zipcode Zoo). Specimens of the spider were collected in 1980 and in 1983. The cave was not described until 1988. It was filled in during construction on the property in 1990 and the effect on the spider’s population is unknown (Dept. of Interior). This cave is called a karst cave. A karst cave is one that is made from water dissolving limestone bedrock. These caves have unusual or rare plant and animal species both on top of them and inside of them (Gander Academy). There may still be food getting into the cave from a small side passage (Dept. of Interior). The spider gets its food from insects that feed off of the decaying matter found in the cave. There were lots of bats in the cave and they may still be there via the side entrance. Their guana on the floor of the cave mixes with leaves and debris that are washed into it and the moisture that seeps in from the ground attract many insects. These are what the Braken Bat Cave Meshweaver traps and eats. The spider may actually benefit from trash and litter being swept into its cave as this would attract more insects. Officials don’t believe that a huge amount of trash would be beneficial to it because of the likelihood of poisoning (Dept. of Interior).

This arachnid may have some venom that it uses on the insects it catches in its web that may be of interest to a bioprospector. Global warming could affect this spider by causing a loss of groundwater which could stop the moisture seeping into the cave. Also if global warming caused a decrease in the bat population of Bexar County that could affect the amount of debris on the floor of the cave to attract insects. It could also affect the insect population which might actually be a bonus to the Braken Bat Cave Meshweaver if there were more. However, an increase in the fire ant population would be detrimental to the cave’s inhabitants as these tend to eat other insects and animals (Dept. of Interior). No pictures were available of this extremely rare spider.

Sources
Department of the Interior: Fish and Wildlife Service. Feceral Register/Vol. 63, No. 250/Wednesday, December 30, 1998. Endangered and Threatened Wildlife and Plants; Proposal to List Nine Bexar County, Texas Invertebrate Species as Endangered. Retrieved 20 February 2007 from http://ecos.fws.gov/speciesProfile/SpeciesReport.do?spcode=J01D.

Gander Academy. Caves Theme Page. Retrieved 20 February 2007 from http://www.stemnet.nf.ca/CITE/cave.htm.

U.S. Fish & Wildlife Service. Species Profile: Braken Bat Cave Meshweaver (Circurina venii). Retrieved 20 February 2007 from http://ecos.fws.gov/speciesProfile/SpeciesReport.do?spcode=J01D.

Zipcode Zoo. Cicurina venii (Veni’s Cave Spider). Retrieved 20 February 2007 from http://zipcodezoo.com/Animals/C/Cicurina_venii.asp.