In photogenic surroundings , the spiny starfish is an impressive animal
where the bedrock or other hard material under the sediment is relatively shallow so the clams can ’ t move themselves any deeper and are ‘ trapped ’?
Despite their tough , well-armoured appearance , spiny starfish are apparently quite fragile if handled , something I have never put to the test . They are however , experts at regeneration , as is typical with starfish . Individuals in the process of regrowing the odd arm or two are quite a common sight , but what I find more striking are the ones where what I assume is overenthusiastic regeneration has resulted in them having six , seven or even eight arms rather than the usual five . One I saw recently with eight good-sized arms looked like a bright blue sunstar !
If you are equipped for macro photography , try inspecting what look like little cushions surrounding the big spines that give this species its name . You will see they are bunches of tiny pincers and there are also larger but still miniature pincers in between the ‘ cushions ’. They are different types of pedicellariae , special structures found on starfish and sea urchins that kill and remove any spores or larvae that land on them to keep their surfaces immaculately free of unwanted encrusting growths . �
Close-up of an arm , showing different types of pedicellariae
Paul ’ s photos and video clips capturing UK marine life stories are on Instagram @ paulnaylormarinephoto
An unusual spiny starfish with eight arms
Regrowing a lost arm …
‘ I can do soft sediment too ’ – spiny starfish on muddy sand among seagrass
A large spiny starfish leaves a star-shaped crater and empty clam shells in its wake
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