Opisthoncus quadratarius

Fact Box Species: Opisthoncus quadratarius (but this is a tentative identification: see notes below) Family: Salticidae Body length: female: 13 mm male: 13 mm Habitat: Usually on bark or green leaves of shrubs Toxicity: This is not a dangerous spider but bites may cause local pain

This is one of the many salticid species that can be found anywhere on trees or in green vegetation because of their great mobility. Opisthoncus species are generally quite easy to recognize to genus because of a small 'lump' between the last pair of eyes. However, there are many known Australian Opisthoncus species and for most of them one of the two sexes has not been adequately (if at all) described but is likely to have a very different appearance when compared with the other sex. In addition, several of the more common species are sufficiently similar in appearance and surface markings that they can only be distinguished from each other by a careful examination of their genitalia. The most recent and comprehensive review of the Australian Opisthoncus species can be found in the following paper: Gardzinska J and Zabka M (2013) "Redescription of the genus Opisthoncus L. Koch, 1880 (Araneae: Salticidae)" Zootaxa 3717, 401-447. This paper contains many images of Opisthoncus species but unfortunately these are all of preserved specimens which therefore have changed colour patterns. However, in the 2017 book "A Field Guid to the Spiders of Australia" by Robert Whyte and Greg Anderson there is on page 291 a matching image labelled Opisthoncus quadratarius.

Note that examples of this species are often darker than the one shown above.

Spider(s) with a very similar appearance: Several other Opisthoncus species.