Dolloff cave spider (Meta dolloff)

KingdomAnimalia
PhylumArthropoda
ClassArachnida
OrderAraneae
FamilyAraneidae
GenusMeta (1)
SizeLength: 10 - 15 mm (2)

The Dolloff cave spider is classified as Vulnerable (VU) on the IUCN Red List (1).

The Dolloff cave spider (Meta dolloff) is the largest web-building spider to occur within the Santa Cruz Caves in the United States (2). The body of this species is mostly brown, with indistinct barring on its legs. There are two dark patches on the top of the abdomen, with two light triangular markings between them, and the back of the abdomen is marked with dark, horizontal bars. The sides of the body are streaked. The measurement of the length and height of the abdomen of Meta species is roughly equal, and is narrower towards the head and widest at the centre. In this genus the first pair of legs is the longest and the third pair is the shortest. The underside of the abdomen of the Dolloff cave spider is grey and has two parallel white lines made up of tiny spots (3).

The head region of the Dolloff cave spider is narrow and has very strong mouthparts and closely-spaced eyes, which are present in all members of this genus (3). 

The female Dolloff cave spider is slightly larger than the male. Males of the genus Meta generally have more curved mouthparts than the female (3).

The Dolloff cave spider is found in California in the United States, where it is occurs in the Santa Cruz cave system (1) (2).

As its name suggests, the Dolloff cave spider inhabits caves, where it creates large vertical webs (2). The webs are usually located on the roof of the cave, close to the entrance (2) (4), as well as in the ‘twilight zone’ where there is a small amount of natural light (2).

Almost nothing is known of the biology about the Dolloff cave spider. However, although its diet is likely to mainly consist of cave moths such as Triphosa haesitata and harvestmen such as Leiobunum exilipes (4).

The main threat to the Dolloff cave spider is humans accessing the cave system it inhabits and causing pollution and poisoning by lighting bonfires and vandalising the area with graffiti. A nearby university has no storm drains to remove excess water from its campus, meaning that large amounts of water can enter the cave system, reducing available food supplies and affecting all species within. The water in the caves is also known to be polluted, posing another potential threat to the Dolloff cave spider and its prey (4). 

To protect the Dolloff cave spider, the expansion of the university campus must be halted until the water runoff problems have been resolved. Tougher law enforcement must also be implemented to prevent behaviour which is detrimental to the Dolloff cave spider, and vandals should be prevented from accessing the site. A gate was previously installed to prevent access to the cave, although this was broken into shortly after (4).

No other specific conservation measures are currently known to be in place for this poorly-known spider.

More information on the Dolloff cave spider:

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

  1. IUCN Red List (April, 2012)
    http://www.iucnredlist.org/
  2. Ubick, D. (2001) Cavernicolous Invertebrates of Cave Gulch, Santa Cruz County, California. California Academy of Sciences, San Francisco. Available at:
    http://www.parks.ca.gov/pages/734/files/cavebio.pdf
  3. Levi, H.W. (1980) The orb-weaver genus Mecynogea, the subfamily Metinae and the genera Pachygnatha, Glenognatha and Azilia of the subfamily Tetragnathinae north of Mexico (Araneae: Araneidae). Bulletin of the Museum of Comparitive Zoology, 149: 1-74.
  4. Endangered Species and Habitats of Santa Cruz County - Dolloff Cave Spider (April, 2012)
    http://www.oatney.com/endangered_species/