Argyroneta Surfaces Again
By John Partridge
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The Water Spider, Argyroneta aquatica, has a
fascinating lifestyle, living its life underwater in an
air bubble which is held in a web tent, where the spider
builds its nest, eats, mates and lays eggs, emerging from
the bubble to catch its food underwater, and coming to
the surface from time to time to collect another supply
of air, although this may happen only infrequently, as
carbon dioxide in the bubble can be disposed of, and
oxygen replenished, by diffusion into the surrounding
water. Photo: BAS Slide Set
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It is found throughout Britain, although apparently with a
southern bias, in clean slow moving water. We have a few
Worcestershire records, but I have been looking for it,
unsuccessfully, for the last two years, and quizzing Don Goddard
and Will Watson as to whether they had found it while doing their
aquatic bug-hunting, all without success, until early September,
when Harry Green gave me a few spiders to identify, including two
that had come up with weeds from Lower Bittell Reservoir, where
he had been bug-hunting with Will Watson and John Day (*see NOTE).
Although both specimens were pre-adult, the habitat, and the
hairy abdomen and third and fourth legs confirmed them as A.
aquatica.
Bristowe, in The World of Spiders - Collins New Naturalist
series- says that as a boy he used to watch them swimming below
the water surface, with the air trapped in the body hairs giving
them the appearance of quicksilver. Most people seem to find
them, if at all, by bringing weed to the bank and waiting for the
spider to run out. Roberts says that juveniles can be
distinguished by tossing them onto the water; most spiders will
run rapidly to dry ground, but the water spider young dive down
below the surface.
Are there any fishermen out there who have dragged up water
weeds on their hooks, and found a water spider running out? Are
there any of you with pools who have ever seen the silver
movement below the surface? If so, I should very much like to
hear from you.
Records to date for Worcestershire VC37.
