I just came across this mind-blowingly beautiful time lapse work of some slow organisms. Take a look (on a big screen at full size and resolution):
On the same hike with the escaping amphipods, I also saw a tidal flat (is that the right word?) covered in dead things. I’m unsure what the cause of the death was. We were just at the end of a neap tide cycle (with smaller tide fluctuations), and the weather had been really nice (~20C, http://climate.weather.gc.ca/). Perhaps it was just too hot, and this spot was fairly high up on the shore. Perhaps a combination of no really high tides with many hot days was too much. This is unsurprising, and certainly happens all the time. There are many occaisions where you can see swathes of dead barnacles and sea weed after a scorching summer day with a mid-day low tide. This was the first time I saw a diversity of organisms. Beyond fish and chitons (pictured) There were many empty limpet shells and crabs.
By Nicole Webster
This was an interesting little incident encountered in a tidal pool. We saw an amphipod get caught by an anemone, then escape!
This was in a reasonably large tidepool on Nudibranch point.
We saw this happen several time in just a few minutes, so it must happen constantly. The anemone did react, pulling the amphipod in, but to no avail.
I can imagine that the anemones do catch and eat one every now and then, but there was no thrashing or panic evident on the part of the amphipod, it simply, carefully, kinda crawled out. It would not be a very viable strategy to swim seemingly randomly around the tide pool without being able to escape small anemones. I think it would be a different story escaping from the larger Anthopleura xanthogrammica.
These anemones also don’t appear typical, they are missing their green colouration, and are strangely elongate. The white colouration is probably bleaching, a loss of the symbiotic zooxanthellae, just like you hear about for coral. There could be several causes, but I think that this loss is due to chemical or temperature stress. The tide pool was fairly high up, and may have been low salinity (based on the algae?)
EDIT: Almost instantly after posting, I got my answer. This is clearly the bioluminescent dinoflagellate Noctiluca scintillans, and thank you to everyone who sent this to me via comments and Facebook. I’m not that familiar with protists, and will strive to learn more.
The original post:
Looking through some PubEd plankton samples this week, one of the students found something unidentifiable:
They are clear, round, and floating. They are mostly empty save for a thickening down one edge, and some reddish blobs, usually two. Each one had a ‘tail’, that waved slowly (not like a flagella‘s frantic beating). Long observation showed the tails do not all move at the same time or in the same direction,suggesting its not water flow that is causing them to drift. They are not all consistent (see 3rd figure).
So what do I think they are? Well the first guess is eggs/embryos. They are all collected in a bunch, and rather round. But: They are transparent, and not yolky or double-layered.
My second thought was something dead, but the wagging ‘tail’ makes me question that.
My third thought was total confusion.
My fourth thought was salp. Salps are a group planktonic tunicates, a group of filter feeding vertebrate relatives. Salps have very little visible morphology, and often have red spots. But the balls aren’t all chained together into a colony, and there’s no sign of a branchial basket structure.
Back to confusion.
I’m at a loss. Do you have any ideas?
So a week ago I took these photos of the larvae. Anatomically they don’t seem much different from last time. There’s a few noticeable developments though. The chromatophores appear more active, the tissue seems a bit less transparent, and the larvae are much more active, swimming around in their eggs. They are not much larger though, which surprised me. They are around 4mm in this photo.
Over the weekend many of the little rascals hatched, and have since been returned to the wild.
By Nicole Webster
Last week I showed you a larval squid of unknown age *n*, here’s n+7!
They are much more active, with clearly visible heart beats, functional chromatophores, and active swimming. As a result it wouldn’t stay still long enough to get a good depth photo, so I resorted to a series: