Showing posts with label sea spider. Show all posts
Showing posts with label sea spider. Show all posts

Thursday, 25 September 2014

Polzeath and the Pool of dreams

Well first we had the 'Cave of Dreams' (at Fistral), then we had the 'Rock of Dreams' (Looe), and now we have the 'Pool of Dreams' found on our Cornwall Wildlife Trust Shoresearch survey at Polzeath on one of the lowest tides I have ever witnessed on this amazing shore.
As you can see from this photo our transect went down onto rocky kelp covered reefs that would normally be well covered by the w

ater and dangerously close to the surf. However on the day of our survey, 9th September 2014, we were lucky to have bright sunshine, high air pressure holding the water down and absolutely zero surf!! In this seaweed smothered shallow but pebbly pool we found an incredible diversity of marine life! Once again highlighting how fascinating rockpools can be in Cornwall!



As our quadrat landed on the pool we began to move the seaweeds and straight away spotted small tadpole like fish swimming away. This is a species that is only rarely recorded and one that I got extra specially excited about!!  Montagu's sea snail - this was named after Victorian naturalist George Montagu. You can see how it got its name as it can look more like a snail than a fish. When its not swimming it often curls up and using its pelvic fins as a sucker is able to hold tight. After a lot of frustrating fishing I finally caught one specimen from the pool! and here it is..







Also found in the pool of dreams -
One graceful sea spider
one Hairy crab
one large isopod Ideotea baltica
Lots of blue rayed limpets
Squat lobster x1
Hermit crabs x4
Saddle oysters
five bearded rockling x1
Velvet swimming crab x1
Shanny x1
Montagus sea snail x5
Sea scorpion x 1
Sea spider



https://www.youtube.com/watch?v=SGakd0Nt2fY




It was great to see Rosie Ellis again back from her travels and volunteering again with the National Trust. Rosie's eagle eyes allowed her to find a very well camouflaged crustacean. A very rare Gibbs spider crab Pisa armata. This has only been recorded a handful of times in Cornwall with a few recent records found by fishermen off Newquay. You can tell by the knobbly surface of the carapace that it is this and not the similar Eurynome aspersa.
Gibb's spider crab Pisa armata photo by Matt Slater

This guy was covered in colonial seaquirts and bryozoans ! 

 closeup of the Gibb's Spider crab Pisa armata. Photo by Matt Slater



Sadly no stalked jellyfish this time in the usual spot! 

Laura was well chuffed with her find! 

A beautiful decorator crab - Macropodia rostrata

Laura's dog lends a hand with the transect

In Polzeath the star ascidians are all this amazing orange/yellow colour!



Clionia cellata - booring sponge







Monday, 19 May 2014

Stackhouse Cove

Well the weather couldn't have been better for our survey of Stackhouse Cove last Thursday. The sun was out and there wasn't a breath of wind as we walked through the gorse and bluebells from Prussia cove West till Cudden Point (the eastern boundary of the recommended Mounts bay MCZ). Abby and I were joined by a great and enthusiastic group of volunteers, Jake Meyers, Liz Barker, Rob Wells and Rob Seebold (now of Natuaral England), Jonathan Kersley, Margaret Gardener and Kathry Driscoll. We were lucky to be joined later by Angie Gall who shared her fantastic knowledge with all present, me included!

The view from the point taking in Stackhouse cove and its bizarre criss-crossing gullies, down past Perranuthnoe all the way to St Michaels Mount was breathtaking.

What a day! 

We left Abby on the point with her telescope and sun cream to carry out a sea watch for cetaceans and seals while we walked down the narrow path to the cove.

Stackhouse cove was named after Victorian Naturalist John Stackhouse who was one of the first people to study the reproduction of seaweeds, from his home Acton Castle that overlooks the cove. Although at first sight the shore seemed bare a huge diversity of seaweeds and animals were found near the low water mark. The shore faces south west and is one of the most exposed parts of the MCZ. The terrible battering this coast line experienced this winter may explain the relative lack of seaweeds on all but the lowest shore and the rockpools. On a low shore flat reef Angie pointed out that a huge mass of green gut weed Ulva intestinalis was covering the rock, possibly new successional growth following the winter clear out of seaweeds. Here and there on the smooth slatey rock you would find limpet scars but there were relatively few limpets suggesting these too may have been removed by the force of the sea.
Rob and Mango shore searching

The shore is criss-crossed with spectacular deep gullies which provide their own micro climates. Within one lower shore gully Jake and Rob Seebold found a mass of sponges, hydroids and a group of sea lemons feeding and laying egg masses on this shaded but open rock surface. Prize for the best spot goes to Jake who spotted the legs of a sea spider sticking out from beneath a beadlet anemone. The spider (Nymphon gracilie),  was carrying a mass of eggs below its body. They are predatory animals so I wonder what it was feeding on there? Hydroids or maybe even the anemone!

Sea spider beneath a beadlet anemone - found out of water inside a shady gully









Sea spider - note the egg mass visible beneath the body


In an open area of large flat boulders we found a huge diversity of crustaceans, Montagu's crabs, large velvet swimming crabs, edible crabs, broad clawed porcelain cabs, squat lobsters, plumed bertha sea slugs ,(Bethella plumosa) and even a tiny sea cucumber Pawsonia saxicola.

Female shanny found under a rock 

In cracks facing inshore away from the prevailing swells we found encrusting star ascidians and other colonial sea squirts, being preyed upon by cowries. Beautiful bushy hydroids decorated these gullies and shannies and hairy crabs were hiding in the deepest cracks in the rock.
Male shanny gaurding his eggs in a deep crack in the baked bean seasquirt cave!

Incredible biodiversity beneath a large boulder - Photo taken by Margaret Gardener
Just to summarise how diverse this shore is Margaret sent me a photo she took of a community beneath a large boulder on the lower shore here is what you can see in this photo

1.       Nice colonial ascidian (sea squirt) bright yellow Botryloides leachii,
2.       bright red baked bean sea squirts Dendrodoa grossularia,
3.        Large keel worms Pomatoceros lamarcki,
4.       barnacles,
5.       purple encrusting coralline algae,
6.       black stuff – encrusting brown algae, possibly pterocelis phase of Mastocarpus Stellatus,
7.       Orange encrusting bryozoan Oshurkovia littoralis,
8.       an orange sponge probably Microciona fallax.
9.       Some spirobid worms Spirobis rupestris.
10.   Sea weeds –   Bunny's ears in the bottom left Lomentaria articulata,
11. and a small piece of red seaweed possibly Rhodymenia pseudopalmata

 So total species count from that one photo is  11 but there are probably many more!!  


The highlight of the day was witnessing an overhanging shallow cave where every surface was covered in reddish baked bean sea squirts, sponges and beautiful Actinothoe anemones ( - the fried egg colour variety - a species rarely seen on the shore!)

Angie, Max and the baked bean cave
Baked bean seasquirts  Dendrodoa grossularaia , carpeting the cave

Actinothoe sphyrodeta anemone closed up amongst the Dendrodoa

Actinothoe anemone open 

The diversity of sea weed life is also notable - shallow pools were home to rainbow wrack, tuning fork weed, banded pincer weed and many other notable species and the current scoured gullies were home to species that are used to high levels of water flow such as Alaria esculenta and Laminaria digitata. There were loads of beautiful  tiny new kelp plants growing on the lower shore - most likely Sacchorhiza polyschides, that tasted amazing!
Rainbow wrack  Cystociera tamariskifolia 

Rob Seebold in a seaweed world! 

Desmarets flattened weed - this seaweed is one you shouldn't try eating - contains sulphuric acid! 

Tasty new shoots of juvenile kelps! 


Tiny hermit crab in a grey topshell shell - with a very white smooth and rounded right claw - probably  Anapagurus hyndmanni 
Colonial sea squirt Aplydium proliferum (thanks to Lisa Rennocks for helping with id!)

All agreed that this shore is home to a fantastic diversity of life and one I would like to return to soon!