Friday 18 September 2015

Exploring the rockpools of Falmouth

Yesterday afternoon saw most of the bioscience students take to the coastal shores of Gylly Beach, on the western side of Pendennis Point. The reason? A rockpooling extravaganza. The low tide early afternoon exposed a large area of the shore, which revealed a rich and diverse intertidal zone, full of different seaweeds, crustaceans, fish, molluscs and much more. It was a fun session, although Rachel, Will and I discovered an even greater amount of shore life on the sheltered side of Pendennis Point, just prior to the rockpooling session. Here, almost every rock harboured a fascinating selection of species, the highlight of which has to go to the 'Cornish Suckers' (!). More about them in a minute...
It was cool to compare the relative abundance and species composition to that of the rich coastline of Bardsey; I haven't managed to take to the sea and do any snorkelling here as yet, but it looks like it would be very productive when I do manage to get around to it!

Here are some of the highlights of the rockpooling. All images are taken with the Lumix FT-5

This curious creature is the Cornish Sucker, or Lepadogaster lepadogaster for short. Apparently, this species is part of the clingfish family, in which the pelvic fins are modified to form a sucker on the underside, which it uses to clamp onto rocks along the intertidal zone. They feed on a variety of invertebrate prey, and are said to live for four years

There were a few anemones to look at along in the rock pools, including the smart Snakelocks Anemone above. The lower image shows one that we saw yesterday, with the very green tentacles and purplish tips, whereas the top image is of a much larger, greyer one that I photographed off Bardsey last week.

We thought this was a strawberry at first! It turns out that Beadlet Anemones (Actina equina) come in a couple of different forms, this being the 'strawberry' form

One of the most common species of seaweed within the rockpools was this purplish Coral Weed (Coralina officinalis). The individual fronds of this seaweed are made up of interlinking rigid sections held together by flexible joints. 

The most common species of crab we encountered was the Common Shore Crab- the one above is perhaps the largest we disovered

This is a small Velvet Swimming Crab, with its unusually-shaped hind legs that are adapted to enable the crustacean to 'swim' through the water at rather quick speeds!

This was our favourite crustacean- the small Hairy Porcelain Crabs, which clung like limpets to the undersides of many of the rocks along the shoreline. 

It was nice to find a single one of these beauties: the Blue-rayed Limpit. I am familiar with these back on Bardsey, encountering many along the kelp fronds exposed at low tide, but I haven't managed to get any images before now. They are very small

 Common Prawns (Palaemon serratus) were very common as the tide began rising, lurking in the lower areas of the pools
 A cute little starfish species we came across, called the Cushion Star (Asterina gibbosa)

A Straight-nosed Pipefish 
A rockpool landscape to finish

Please correct any mis-IDs!

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