ChrisMcA's picture

AstGibGower169

Observed: 26th April 2009 By: ChrisMcAChrisMcA is knowledgeable about InvertebratesChrisMcA’s earned reputation in InvertebratesChrisMcA’s earned reputation in InvertebratesChrisMcA’s earned reputation in InvertebratesChrisMcA’s earned reputation in Invertebrates
AstGibGower169
Description:

Asterina gibbosa isn't listed in the New Naturalist's 'Gower' book's species list & it's the only 1 I've ever seen on the Gower

Identifications
Species interactions

No interactions present.

Comments

nightfly's picture

Hi Chris, I dont recall ever

Hi Chris, I dont recall ever seeing a cushion star to date. Just had a look at MarLINs page on the species, are the above species easily seperated from Asterina phylactica? Just out of curiosity can the differences be appreciated in the above pic? Cheers.

Cathal.

ChrisMcA's picture

1st difference is size;

1st difference is size; A.phylactica up to 15mm (ie about the size of the shell in the pic if it's a small Gibbula sp's) & A.gibbosa to 5cm diameter; & 2ndly A.phylactera has a RED star mark on it's back (almost invariably).I emphasize red as the only examples with a dark star mark I know are in Collins' guide & the habitas page http://www.habitas.org.uk/marinelife/species.asp?item=ZB1140 .(there's also 1 DORIS-FFESM photo,with a note that such a colouration's rarely found [my translation]).
A.phylactica was only discovered in1978 at West Angle pembrokeshire after an oilspill (& so for a while thought to be very rare), by Crump & Emson, & they wrote a 1983 paper http://www.field-studies-council.org/fieldstudies/documents/vol5.5_160.pdf (16 pages). It describes both species (but nowhere uses the word red), eg phylactica (p.867) is dark green with a chocolate brown substar.[One of their study sites was Lough Ine,Cork].It's habitat description's useful, gibbosa often at LT under boulders & phylactica often in high shore tidepools. Also gibbosa's found abundantly in suitable W. coast sites (eg Pembroke, & Cornwall etc).
My 2 examples, show the contrast between A. gibbosa's found in high tidepools (as here), & the more orange at low shore, as at http://www.ispot.org.uk/node/204276. N.B. Habitas mentions Strangford Lough as a site for A.phylactica, so maybe there's some there with dark substars

nightfly's picture

Thanks for all this Chris, I

Thanks for all this Chris, I will be keeping my eyes peeled for them locally. Planning a bit of shore walking tomorrow, the last time the sea here was as rough a lot of dead marine life was washed up and I'm hoping to make a find or 2 tomorrow, will post anything of note.

Cathal.