Tag Archives: Arachnids

On to solid foods.

The harvestman (Opiliones) is an small arachnid (eight, joint legged invertebrate) like spiders and scorpions. Their bodies are typically no longer than 7mm in length and some species are as small as 1mm.

There are over 6,500 identified species.

Harvestman and scorpions differ from spiders in, amongst other things, the fact that they can eat solid food.

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Harvestman (Opiliones)

(#76 of 100)

Better off than dead I’ll say.

Autotomy (from the Greek auto- “self-” and tome “severing”) or self amputation is the observed behaviour where an animal discards one or more of its own appendages.

This is usually done as a self-defense mechanism. The lost body part may be regenerated later. The best known example is most probably the gecko’s tail.

Under natural conditions, orb-weaving spiders undergo autotomy if they are stung in a leg by wasps or bees.

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(#70 of 100)

Gone Fishing

Fishing spiders (genus Dolomedes) do not spin webs to catch pray. Instead they hunt by anchoring themselves to shore with their hind legs and extending their front legs onto the water surface to detect movement much like other spiders use webs. When they detect the ripples from prey, they run across the surface to subdue it using their foremost legs, which are tipped with small claws.

They are able to travel on water because they are covered all over in short, velvety hairs which are unwettable (hydrophobic).

They are also more than capable of going underwater. The hairs on the abdomen trap air, allowing it to carry its own air supply when it submerges.

The nursery web spider (Dolomedes minor) do not restrict themselves to stay close to open water but are capable fisherman none the less.

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New Zealand Nursery Web spider (Dolomeded minor)

(#54 of 100)

Motherly ‘Love’

The New Zealand nursery web spider ( Dolomedes minor) is a spider endemic to New Zealand.

The female of the species carries her eggs with her until they are ready to hatch, she then spins a “nursery” in which the young spiderlings can develop.

She guards the nursery by sitting on it at night and hiding close by during the day.

Have a closer look; you will notice the little spiderlings in the nursery (where her posterior middle leg touches the web).

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New Zealand nursery web spider ( Dolomedes minor) on nursery web with spiderlings.

(#26 of 100)