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.
Videographer and photographer, mostly of marine wildlife. Marine Fieldwork Specialist at the Okinawa Institute of Science and Technology (OIST), Marine Science Section.
A squid beneath the waves. From my last dive of 2025.
December 21, 2025 at 5:12 AM
A squid beneath the waves. From my last dive of 2025.
Scorpionfish hiding
December 17, 2025 at 10:32 PM
Scorpionfish hiding
A old spent bullet casing. Not sure if it dates back to the Battle of Okinawa but it's fairly unlikely for one to end up here otherwise.
December 16, 2025 at 10:41 PM
A old spent bullet casing. Not sure if it dates back to the Battle of Okinawa but it's fairly unlikely for one to end up here otherwise.
Squid in sunshine
December 10, 2025 at 10:47 PM
Squid in sunshine
A pteropod in the sunlight. Maybe like a dream where your ice cream cone is flapping away
December 10, 2025 at 10:53 AM
A pteropod in the sunlight. Maybe like a dream where your ice cream cone is flapping away
A broadclub cuttlefish (Ascarosepion latimanus) showing what I call the 'angry bull' signal to another cuttlefish. It flicks its arms from side to side as a wave of dark color flashes over them, and it releases a small puff of ink. Sadly with its back mostly turned to me. 1/2
December 9, 2025 at 10:09 AM
A broadclub cuttlefish (Ascarosepion latimanus) showing what I call the 'angry bull' signal to another cuttlefish. It flicks its arms from side to side as a wave of dark color flashes over them, and it releases a small puff of ink. Sadly with its back mostly turned to me. 1/2
Sunbeams and sealife
December 8, 2025 at 10:58 PM
Sunbeams and sealife
The quiet storm of fish under the pier
December 8, 2025 at 11:08 AM
The quiet storm of fish under the pier
Since Duolingo decided to basically brick its app with the new 'energy' system that won't let you get through three lessons in a day, does anyone know any decent Duolingo alternatives?
October 14, 2025 at 1:35 PM
Since Duolingo decided to basically brick its app with the new 'energy' system that won't let you get through three lessons in a day, does anyone know any decent Duolingo alternatives?
Okinawa had its hottest September at 1.6C above the average. I filmed this mass coral bleaching last year, but didn't have the heart to share. Total annihilation of the first few meters of depth. This stuff happens before our eyes, and yet people who think it isn't real keep gaining power.
October 2, 2025 at 10:24 AM
Okinawa had its hottest September at 1.6C above the average. I filmed this mass coral bleaching last year, but didn't have the heart to share. Total annihilation of the first few meters of depth. This stuff happens before our eyes, and yet people who think it isn't real keep gaining power.
Yajaagama cave: Turning back at the clearing and heading out.
October 1, 2025 at 11:24 PM
Yajaagama cave: Turning back at the clearing and heading out.
Yajaagama cave: Human bones. The cave is a historical burial ground with many broken urns. The remains are placed in several places, like the clearing at the end. Apparently the locals are fine with leaving them be.
October 1, 2025 at 11:19 PM
Yajaagama cave: Human bones. The cave is a historical burial ground with many broken urns. The remains are placed in several places, like the clearing at the end. Apparently the locals are fine with leaving them be.
The exit of Yajaagama. You're supposed to turn around at this clearing, although the cave actually continues just beyond it. You can see that this clearing was once part of the cave that has collapsed.
October 1, 2025 at 11:17 PM
The exit of Yajaagama. You're supposed to turn around at this clearing, although the cave actually continues just beyond it. You can see that this clearing was once part of the cave that has collapsed.
Parts of the cave look like it's melting. The dark specs here are inse.. cts.A species or subspecies of cave cricket (クメカマドウマ). These are one of the most common things in the cave, although I couldn't find much information on them.
October 1, 2025 at 11:10 PM
Parts of the cave look like it's melting. The dark specs here are inse.. cts.A species or subspecies of cave cricket (クメカマドウマ). These are one of the most common things in the cave, although I couldn't find much information on them.
Yajaagama cave: Close to the exit, there were this endemic subspecies of ground gecko, Goniurosaurus kuroiwae yamashinae. Beautiful stripes.
October 1, 2025 at 11:07 PM
Yajaagama cave: Close to the exit, there were this endemic subspecies of ground gecko, Goniurosaurus kuroiwae yamashinae. Beautiful stripes.
Yajaagama cave: Parts of the cave have glittering minerals. Sometimes they form beautiful little terraced pools.
October 1, 2025 at 11:06 PM
Yajaagama cave: Parts of the cave have glittering minerals. Sometimes they form beautiful little terraced pools.
Yajaagama cave: In many places it looked like there were veins of gold or some such mineral, but up close they turn out to be growths of lichen, covered in little droplets of water so they glitter.
October 1, 2025 at 10:51 AM
Yajaagama cave: In many places it looked like there were veins of gold or some such mineral, but up close they turn out to be growths of lichen, covered in little droplets of water so they glitter.
Yajaagama cave: The ceilings were the domain of the oogeji (Thereuopoda clunifera), a type of centipede. They are about 10cm long I think. Never seen ones this huge, or so many. It's not one of the endemic species however.
October 1, 2025 at 10:45 AM
Yajaagama cave: The ceilings were the domain of the oogeji (Thereuopoda clunifera), a type of centipede. They are about 10cm long I think. Never seen ones this huge, or so many. It's not one of the endemic species however.
Yagaajima cave: This is a species of land-dwelling isopod endemic to Kume, with distinct yellow spots. It has a Japanese common name but is a scientifically undescribed species (Ligia sp.). Here in the cave it is 800m away from the closest seashore, where isopods of this genus are usually found.
October 1, 2025 at 10:40 AM
Yagaajima cave: This is a species of land-dwelling isopod endemic to Kume, with distinct yellow spots. It has a Japanese common name but is a scientifically undescribed species (Ligia sp.). Here in the cave it is 800m away from the closest seashore, where isopods of this genus are usually found.
Yajaagama, a cave on Kume Island. Supposed to be 800m long and closed off at various points, some areas for bat conservation, some because they are unsafe. Filled with endemic wildlife, darkness, and human bones.
October 1, 2025 at 10:37 AM
Yajaagama, a cave on Kume Island. Supposed to be 800m long and closed off at various points, some areas for bat conservation, some because they are unsafe. Filled with endemic wildlife, darkness, and human bones.
The footage quality is poor, but this is a rare Rhina ancylostoma, bowmouth guitarfish, seen in Oura Bay (Okinawa), where they are building a new US marine corps base. It's a type of ray. I've never seen one in the wild before!
September 8, 2025 at 10:52 PM
The footage quality is poor, but this is a rare Rhina ancylostoma, bowmouth guitarfish, seen in Oura Bay (Okinawa), where they are building a new US marine corps base. It's a type of ray. I've never seen one in the wild before!
Rain and rainbow
September 4, 2025 at 10:54 PM
Rain and rainbow
