The Daily Bucket is a nature refuge.
We amicably discuss animals, weather, climate, soil, plants, waters and note life’s patterns.
We invite you to note what you are seeing around you in your own part of the world, and to share your observations in the comments below.
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April 2019
Just back from my annual dive trip to the Caribbee, and as I rinse my gear and watch the no-see-um bug bites fade, some memories are still vivid, along with a residual gentle rocking motion of ocean swells, very pleasurable.
One site had a remarkable proliferation of Comb jellies, a type of planktonic marine creature that is mostly invisible, although they glow at night (wasn’t able to see that tho). For folks interested in more information about the group, ADW has a nice page on them animaldiversity.org/....
They are somewhat like jellyfish in overall structure and jellyness, but they don’t sting. They do have rows of cilia — tiny hairs — that beat in concert to give them some movement, and look iridescent when the light is right.
While almost impossible to photograph or film, I did catch some footage of a few. After the fact I discovered they show up best against the blue. I’ll remember that for next year.
The Spot-winged comb jelly against the sand is more visible as a shadow.
Against the cobalt blue of the tropical water, their spots and winged form stand out.
But what’s really amazing is seeing their combs of cilia beating in the backlight of the sun above. Toward the end of this video you may be able to see that.
The Venus girdle is another comb jelly. It undulates sensuously, that movement better visible in the video clip.
Two other species were even trickier to film, the Warty Comb jelly and a yet-unidentified kind with long tentacles. Comb jellies, if they have any, only have two tentacles, unlike jellyfish. In this case what looks like a third shows how the tentacles can branch. The tentacles are covered with sticky cells that snag prey.
(There are some really cool gifs of comb jelly iridescence and other activity but I don’t know how to embed those. Google images has them if you search for “comb jelly gif”.)
Comb jellies (aka ctenophores) come and go. When food is plentiful, as right now during spring breeding season on the reef, their numbers proliferate. That boom and bust lifestyle can be good in controlling other fast-growing marine populations but it can destabilize communities too, as they have in the Black Sea since a comb jelly native to the western Atlantic was introduced in ballast water. There, the fisheries industry crashed after those Comb jellies — the Warty comb jelly — ate up all the tiny crustaceans fish depend on. However, complex healthy ecosystems with high biodiversity tend to dampen population swings like those. One of the many reasons biodiversity is important ecologically.
As diaphanous as Comb jellies are they provide a food source for fish, turtles and other marine creatures. Since a comb jelly is 97% water, it takes a lot of them to make a meal. Usually the resident predators keep their numbers in check.
Comb jellies live mostly in warm tropical seas, although some can be found in northern waters. They are strictly marine, another difference between them and jellyfish.
Comb jellies are predatory creatures, drifting through the sea catching larvae, tiny arthropods and other small creatures. An interesting comparison can be made between them and spiders:
Ctenophores have been compared to spiders in their wide range of techniques from capturing prey – some hang motionless in the water using their tentacles as "webs", some are ambush predators like Salticid jumping spiders, and some dangle a sticky droplet at the end of a fine thread, as bolas spiders do.
en.m.wikipedia.org/...
Segue.…
I did see some spiders down in the Caribbee too, in our bathroom. At first I thought insect — 6 legs — but a closer look, and a sighting of another, says spider. No idea what kind. iNaturalist is stumped too. It’s body is flat in shape, if that helps. Ideas? Happy to have them there anyway, munching on insects and whatnot.
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Partly sunny and cool in the Pacific Northwest islands today. Mid 50s, breezy.
What’s the nature news in your neighborhood?
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