Keishu Asada
@cephwarden.bsky.social
A warden of Sand Quentin. Videographer and photographer, mostly of marine wildlife. Marine Fieldwork Specialist at the Okinawa Institute of Science and Technology (OIST), Marine Science Section.
A coral polyp, open alone in its colony, looking like a rose
A polychaete worm like some great spiny four-eyed dragon
Emerging from a sandstorm with a tail held high like a banner. A rare cowtail ray.
In a shallow sunlit channel I came across an area where the rocks were all purple. At first I thought it was just crustose coralline algae, but a closer look revealed that it was all eggs! Apparently a nursery for scissortail sergeant damselfish, who seemed to be the ones tending to them.
Exploring an unfamiliar area and greeted by a large white tip reef shark
A Callistoctopus walks through a plankton storm brought on by our lights, arms up in a suspicious defensive posture.
There were a lot of these in June. Baby octopuses drifting on rafts of sea grass, each off on some grand voyage.
Seen one of these for the first time today, but what is it? Just a common sea snake? No! It's a banded snake eel or harlequin eel. They mimic venomous sea snakes as a defensive strategy. They also have very cute goofy faces but I was sadly unable to get close.
A large uncommon larvacean I refer to as the barrel oik. Most larvaceans live in a spherical mucous 'house' for filtering plankton. This one's house (almost totally invisible here) is barrel-shaped with a clear directionality of movement and even 'intakes' in the front like a biological jet engine.
A young cuttlefish (Ascarosepion latimanus) in just ankle-deep water, right on our marine station's doorstep. Watch it show off some dramatic shifts in body patterns!
Its presence heralded by a dust cloud of its own creation... who could it be!? (A very rare cowtail ray!)
Divers and coral spawn are not the only things looking to have a romantic evening on the night of the full moon... Fireworms coming to surface to spawn.
It's not often I see an upside down jelly actually swimming in the water column.
Been puzzling over this swimming beer hop/artichoke for a few days. The video quality is poor because I was at the surface and without my best lights. I think it's the sea slug Cyerce blackburnae, although the swimming style doesn't fit what it says in the description (from just last year).
An Octopus cyanea moves through the reef, presumably pondering octopus thoughts
A stonefish in magnificent purple and orange... Not blending in at all. You do you.
A manta coming over the crest at a cleaning station on Kume. It's not in the shot, but there were a mating pair of octopuses that crept up to the top and just went out of view. It would have been great to have them all in the same shot!
A nudibranch standing at attention! I think it is waiting for the current to pick it up so it can drift away somewhere farther than its foot can carry it.
The day octopus (Octopus cyanea) camouflaging on the reef
The dreamlike movement of water. At Akame Forty-Eight Falls, Mie Prefecture, from a couple of months ago. We had hoped to get a glimpse of some giant salamanders but no luck.