A lot of different creatures live among and on seaweeds. One abundant and species-rich group are the Bryozoans or Moss animals, which are not the easiest of critters to make sense of (then again, which are!?). Here are three species common on seaweeds, identified with the help of David Fenwicks excellent Aphotomarine site. A Sea chervil Alcyonidium diaphanum, Flustrellidra hispida and a close-up of Tubulipora plumosa:
Category Archives: bryozoans
More Scummy Pools
As in Falmouth, the rock pools in Flushing are not looking that great at the moment. Lots of the Corallina has turned white/died (although the clumps in my tank are still their normal purple!). Of course, many species were still thriving, Grape pip weed Mastocarpus stellatus (top), Bunny ears Lomentaria articulata (bottom), new Thong weed Himanthalia elongata ‘buttons’ and a young blade of kelp along with some green Ulva:Among the seaweeds that were thriving was Slimy whip weed Chordaria flagelliformis (I am by no means a seaweed expert and I might be wrong about this, please comment if I am!) and also the beautiful Harpoon weed Asparagospis armata growing as an epiphyte on some darker coloured False eyelash weed. Harpoon weed is invasive and so a good candidate to do well int he aquarium (as most invasive species are quite opportunistic and not too finnicky). It died off in the tank before, but I decided to bring some home to try again now I have a chiller.
Another tangling invasive species: Bonnemaison’s hook weed Bonnemaisonia hamifera (a characteristic curved hook can be seen in the top-middle):Loads more seaweeds to be found but I will save those for another time. All kinds of tunicates pop up in spring, some of them pretty (see for instance here), some of them less so. For instance the invasive species, the Leathery sea squirt Styela clava and an out-of-focus photo of a second, large (>10 cm) species that did not get a lot of response on the NE Atlantic Tunicata FaceBook group. Aplidium nordmanni was offered, see here for a much smaller version of that species. Not a looker either in any case!
I brought my little aquarium net and found many juvenile (<1 cm) fish as well as Mysis shrimp. The fish look like gobies but it is hard to see. They were completely translucent and so you can see what this one just ate. I should take some bits of seaweed home to see what comes crawling and swimming out under a little USB microscope (quite easy to make little videos). It is hard to come up with decent images squatting and squinting on a slippery rock with a salt-encrusted mobile phone!
Last Sunday I ventured to the north coast for a rock pool ramble with Matt Slater of the Cornwall Wildlife Trust (see this great blog) and the local marine conservation group (who also have a nice blog). I actually had never rock pooled at the north coast before (shame on me) and so it was nice to see this exposed habitat, quite different from my main haunts at Castle Beach in Falmouth and Trefusis Point in Flushing:
The rocks were much more bare and the number of animals a lot lower. However, there were quite some seaweeds. I finally saw (the edible) Laver Porphyra spp (probably Black laver Porphyra dioica):
Another edible species, Dulse Palmaria palmata, was incredibly common here:
I won’t add too many seaweed pics in this post, but I liked this shot of Serrated wrack Fucus serratus:
Brown and yellow Flat periwinkles Littorina obtusata (or possibly Littorina mariae, I did not bother to check) where common:
We found a Shore cling fish Lepadogaster lepadogaster and a Five-bearded rockling Ciliata mustela:
I found a couple of pieces of a branched seaweed covered in the bryozoan Electra pilosa:
All in all a good session. I hope to go back soon to take better pictures of the seaweeds!
A close-up of the Sea mat Membranipora membranacea taken with my olloclip macrolens for the iPhone. This Bryozoan forms colonies on flat seaweeds. Each rectangular chamber (cuticle) houses an individual zooid. Each zoid feeds on plankton using a lophophore, a group of ciliated tentacles. Zoids differentiate into specialized types, for feeding, cleaning the colony surface or as brood chambers for embryos.
A close-up of the Hairy sea mat Electra pilosa, a species very common under rocks:
rock pooling from the comfort of my home
It was too cold and windy to spend a lot of time on the beach, so I took a closer look at my seaweed catch back home. I was amazed at the diversity of organisms growing amidst the weeds. A lot of them are easily overlooked when rock pooling as you need some time (and preferably a comfortable seat) to find them. Below Bushy rainbow wrack with epiphytic False eyelash weed and Pink plates Mesophyllum lichenoides (I will not give the Latin names of species described in preceding posts for brevity). Some bright green sea lettuce Ulva, a grey topshell Gibbula cineraria, a snakelocks anemone Anemonia viridis and in the middle a bright orange colony of the tunicate Botrylloides leachi: I found many large Breadcrumb sponges Halichondria panicea but the picture I took did not turn out to be in focus. I do not know what the organism below is, perhaps a bryozoan (please feel free to comment!). I am not sure what this is either! Dog whelk Nucella lapillus eggs (I now also notice a tiny brittle star in the middle): Egg cases of the thick-lipped dog whelk Hinia incrassata: A small snakelocks anemone; interestingly enough all of these were the green variant (with purple tips) and there were none of the pinkish ones. I have read some interesting notes about aggressive behaviors between the two types, something to look into for a future post. A Marbled Crenella Modiolarca tumida, a tiny bivalve typical of seaweed holdfasts: A tiny White tortoiseshell limpet Tectura virginea: I saw something creeping out of the seaweeds on the floor out of the corner of my eye: a small Long-legged spider crab Macropodia rostrata. This species adorns itself with seaweeds for camouflage: