The Find-a-Spider Guide

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Garden orb-weaver

Fact Box
Hortophora transmarina
(For name change see below)
Previous species name:
Eriophora transmarina
formerly Argiopidae
Body length:
female: 24 mm
male: 16 mm
In a vertical orb-shaped web between branches of shrubs; the spider usually repairs and sits in its web only in the evenings and waits with its legs extended for prey to blunder into the web. When this happens the spider rapidly wraps it up in silk.
Uncertain; may cause mild illness but this spider is not very aggressive to humans
Hortophora transmarina
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Plain coloured
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Striped example
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Side view
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In web at night
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Egg mass
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Female epigynum
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Spotted female
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Camouflage colours

The female is somewhat larger than the male, which tends to wait on the edge of the web. An unusual feature of the female is the variation in colour and patterning on the upper surface of its shield-shaped abdomen. Some individuals have a white or reddish longitudinal stripe down the centre of the abdomen while others have almost no abdominal patterning. The appearance of the male is so different it looks like it is another species.

A useful identifying feature on a female is the long, needle-like part (called a scape) of its epigynum which points backwards towards the spinnerets. During the day the female hides in a leafy retreat (or under a ledge on a building) near the top of the web with its legs drawn up against its carapace. Egg masses are sometimes seen anchored near the female's retreat and have the appearance of a mass of fluffy webbing that is off-white to grey-green in colour.

Please note that the photos shown on this page are of Eriophora transmarina as described by VT Davies (Queensland Museum) in 1980 but research by Volker Framenau and others showed that some or all of them could instead be Eriophora biapicata which Davies also named. However, in November 2021 the generic name used by Davies was changed to Hortophora by Framenau et al in Evolutionary Systematics, 5(2), pages 275-334 and these authors also described 8 other Australian Hortophora species because it was apparent that there were some 'Eriophora' species that were anatomically distinct from either of the two well known ones.

Nature notes: This kind of spider is never likely to be found inside a house or other building although it might perhaps string its web from a suitable support on an open veranda or porch. Because the entire vertical web can be constructed in a single night the householder may be surprised to find it there one morning. However, the spider itself will probably not be in evidence since the normal practice of Hortophora species is to occupy the web only at night and to hide somewhere near the upper supports of the web during the daylight hours. Until it reaches maturity the male will behave like a female but adult males will cease catching insects and will instead go in search of a web that contains a female. This search is facilitated by the detection of a pheromone secreted by the female. If it is not killed by the female during or after mating the male may search for another female but typically dies soon after reaching maturity even if it has never managed to mate. Even the adult female normally dies when the colder months of the year arrive and the supply of insects to feed on diminishes. This of course means the lifetime of a Hortophora specimen is rarely longer than 12 months but before dying the females usually lay at least one batch of eggs before dying so the species is not at risk of becoming extinct because of its short lifetime.

Known Range: Recorded as being very common in gardens and bush settings in near-coastal parts of Northern Territory, Queensland and NSW, but not in the rest of the Australian mainland or in Tasmania.

Spider(s) with a very similar appearance: Some other araneid species, such as Backobourkia brouni, Hortophora biapicata, and Acroaspis tubiculifera.

The 44-45mm replica watches wide case came in titanium or steel and was made in the 'carbon fiber' era (as I call it). In terms of case size, I am not totally sure, but I think the gold model was a bit larger than the titanium model. The bezel on the top and sides are all inlaid nicely with carbon fiber. This richard mille replica also applied to the chronograph pusher housings on sides of the watch. The chronograph pushers on this model were originally meant to look like gas pedals, but have since been used so much that forget their original theme. I love the woven stitching on the alligator strap. Supposed to look like a racing suit, but (especially on the titanium model) reminds me of a Spiderman web. I believe the crown is meant to look a bit like an F1 car gas cap.

Email Ron Atkinson for more information.    Last updated 3 January 2022.