Saturday, 14 August 2021

The Lion lies down with the.......mussel

The westerlies continues. Overcast for most of the day with light showers in the afternoon.

The only records so far are from my check of Heysham skear at low water (MD)
Great Crested Grebe 5 (2 + 3)
Eider 34
Little Egret 15
Grey Heron 1
Oystercatcher c500 on the middle skear - outer skear not checked
Curlew c50
Redshank c150 - including a presumed off passage flock c100 in an area where they do not routinely feed.
Turnstone c50
Juvenile Turnstone 
Ringed Plover 25
Mediterranean gull 1 - This looks like the same bird that I posted yesterday flying to the harbour mouth from the north. I can't recall ever seeing one on the skear before, hopefully the start of a new trend, there appeared to be plenty to eat. This first clip it was on the water on the north side of the skear. It seemed to find something to eat both times that it landed. It then flew to the skear.

It started feeding as soon as it landed on the skear, and certainly found a couple of morsels to eat. 

Today's title refers to Lion's Mane Jellyfish. There were several stranded on the beach, but this small one had dropped lucky and ended up being stranded in a small pool, just large enough for it to retain its form.
Lion's Mane jellyfish stranded in a shallow pool
It was pulsating, you can see the resultant indents in the surrounding mud

I've not had an active but captive Lion's Mane before, so I thought  I'd see how it reacted to a piece of broken mussel. This wasn't easy, mussel in left hand and camera in right, binoculars held between teeth! So I missed the actual encounter. No matter, the interesting thing happened afterwards. As soon as it "realised" that it was in contact with food, the pulsating stopped.

I know very little about jellyfish behaviour, but it makes sense to not swim away from an area that has just provided a meal. Jellyfish can't really dictate where they go, the pulsating will just allow it to rise higher in the water. So stopping pulsating would cause it to drop lower in the water. Or, perhaps, the energy used to pulsate is redirected to the tentacles to retrieve the food. They don't have to move quickly as any prey should be paralysed. Either way it started pulsating again and it definitely took hold of the mussel.

It hadn't long to wait, the incoming tide was only a few minutes away. I would have waited and recorded its release, but the tide would have silted the area up leaving visibility too poor to see anything. Hopefully it will be lucky, but the prevailing west winds will make it difficult. Just another reminder, these do sting, both the short red and long white tentacles have stinging cells. They will not harm you, but the sting isn't pleasant (I have been stung several times whilst  shrimping in the dark).