Crab city
VulcanSpirit
Richard & Alison Brunstrom
Fri 2 Aug 2013 11:48
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We're visiting the Mamanuca islands in western
Fiji. There are small islands without much obvious wildlife - in fact by far the
most numerous land animals are the crabs. My favourite are the delightfully
named Sally Lightfoots. This type of crab is found all over the tropical
Pacific, with different coloured species depending on the location. The
Galapagos ones were bright red, while those here in Fiji are beige to bright
green. But they all share the same lifestyle - living around the tideline and
feeding on algae growing on the rocks. They are incredibly fast movers, shooting
across broken rock surfaces at breakneck speed, and able to jump nimbly
considerable distances from rock to rock. Like all shore crabs they have
very good eyesight, with two eyes on moveable stalks, and will run
helter-skelter away from any movement - I guess they get eaten by the local
herons, so have to take care.
 They spend most of their time out of the water, but
still breathe using gills which they need to keep wet, so they mostly hang
around the waterline moving up and down the beach with the tide. This means that
they are constantly getting swamped by waves so have to be able to cling
tenaciously to the rocks - and hence the very flattened body shape that you can
see here.
 And as you can see, they have a very alert posture
- and these guys are built for speed:
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