dejayM's picture

Frosty Sea Mat

Observed: 29th September 2013 By: dejayM
Biological Recording In ScotlandHighland Biological Recording GroupOrkney Biodiversity Records Centre
dejayM’s reputation in InvertebratesdejayM’s reputation in InvertebratesdejayM’s reputation in InvertebratesdejayM’s reputation in Invertebrates
2 bryozans
very close
lacy mat

Whilst browsing the micro-landscape of 'my' Lobed Bryozoan here
I found a sea mat - another bryozoan animal on the same algal frond (probably Egg Wrack)
Alive, but not too well from being away from its home for a day or so, it put on a show for me. Popping in and out of the few living cells (zooids), were little inverted feeding umbrellas (retractable lophophores) which sprang in and out of focus.
The main cell structure here is an elongated, generally oval (rounded), calcified casing with one ajecent post-hole to one end. From each post hole springs a single spine which appears to give an overall hairy appearance to the whole colony and helps the separation of this, the Frosty Sea Mat from the Lacy Crust Sea Mat (Membranipora membranacea).
Picure 1 shows the sponge-like bryozoan and resident within, or upon, its structure Frosty Sea Mat. The white cells have a crown "Between 4 and 12 (often 9) spines surround the frontal membrane"
Picture 2 shows an isolated colony of the animals. A few are still alive but already, after one and a half days away from home, new epiphytic or parasitic (Aufwuchs?) growths are appearing.
The numbers, in picture 3, represent single mms, each segment of the scale is 0.1mm. The cells then are, generally, less than 1mm long and about 0.6mm wide.
For completeness and comparison Picture 4 shows the cell structure of the Lacy Sea Mat.

Species interactions

No interactions present.


JoC's picture

Electra pilosa

Your binoscope photos are good, so as you say, we can see this piece is still alive. Few, if any iSpot photos show it alive, more often moribund at best on washed up pieces of seaweed.