Home - ARACHNE.ORG.AU

Phoroncidia sp. Phoroncidia silver-sided 'fatback'

The silver-sided 'fatback' is common on Enoggera Creek. Body length of the male about 1.8mm, female about 2.5mm. The female's abdomen tends to be somewhat peaked. They are marked with silvery scales on the sides of the abdomen, and often have yellow areas on the underneath of the abdomen near the spinnerets.

Phoroncidia 'fatback' facing

After a while it becomes easy to recognize this little Phoroncidia in the field. It is a small spider with strong white markings on the sides and sometimes upper surface of the shiny, hard abdomen. Usually between 1 and 3mm in body length. Underneath there is usually a yellow patch before stubby converging spinerettes. The caput (top of cephalothorax) and face (eye area) is more or less turreted. The modified pedipalps of the male (genitals) are lare and globular. If it falls onto a hard surface it sometimes makes a bright click on impact, because of its sclerotized (hardened) abdomen. The abdomen always more or less peaked, not spherical like Phoroncidia rotunda or extremely highly peaked like some other species. It is often recognizable as a small, relatively slowly moving spider with its shiny abdomen sparkling to the naked eye.

Phoroncidia sp
Photo: Robert Whyte

Phoroncidia 'fatback' from side, underneath


Araneid spider
Photo: Robert Whyte

Phoroncidia 'fatback' facing, on stick

Araneid spider
Photo: Robert Whyte

Phoroncidia 'fatback' from side, above


Araneid spider
Photo: Robert Whyte

Phoroncidia 'fatback'. Another specimen, oblique view


Theridiid spider
Photo: Robert Whyte

Phoroncidia 'fatback'. Another specimen, from behind


Theridiid spider
Photo: Robert Whyte

Phoroncidia 'fatback'. Another specimen, in alcohol


Phoroncidia sp
Photo: Robert Whyte

Phoroncidia 'fatback', male from above, facing


This male has a central white mark on the front of the abdomen, a yellow underneath and a distinct squat, not very peaked shape. Collected on the creek near the SOWN shed, Paten Park in early July 2009. Body length about 1.5mm. The cephalothorax is somewhat broad in this specimen, slightly turreted.

Unknown Araneid
Photo: Robert Whyte

Phoroncidia 'fatback', male facing, showing turret


This views a quite pronounced turret with the eyes on the front. Some very small spiders like this may hatch out more or less sexually mature. Ther may moult one or two times if they have a chance to feed and grow, but some may be able to mate virtually from birth.

Unknown Araneid
Photo: Robert Whyte

Phoroncidia 'fatback', male from underneath, showing yellow patch and spinerettes


Unknown Araneid
Photo: Robert Whyte

Phoroncidia 'fatback', male pedipalps alongside face


The pedipalps make the head look broad, especially as the 'knees' reflect like eyes, but the cephalothorax is narrowed into a turret.

Unknown Araneid
Photo: Robert Whyte

Phoroncidia 'fatback', male 070610 from above


Phoroncidia sp fatback silver side
Photo: Robert Whyte

Phoroncidia 'fatback', male 070610 facing


Phoroncidia sp fatback silver side
Photo: Robert Whyte

Phoroncidia 'fatback', male 070610 from underneath


Phoroncidia sp fatback silver side
Phoroncidia 'fatback', male 070610 from above

Phoroncidia 'fatback', male 070610 palp


Phoroncidia sp fatback silver side
Photo: Robert Whyte

Phoroncidia 'fatback', male 070610 palp


Phoroncidia sp fatback silver side
Photo: Robert Whyte

Female 18710 in alcohol from side


Phoroncidia sp fatback silver side
Photo: Robert Whyte

 

View My Stats