Blog
Nudibranch vs Sea Slug: Every Nudibranch Is a Sea Slug — But Not the Reverse
May 1, 2026
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Every nudibranch is a sea slug — but not every sea slug is a nudibranch. Six species across six lineages, plus the...
What is a Sea Slug? — Nine Orders to Twelve Lineages, 25 Years On
May 1, 2026
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A sea slug is a marine gastropod whose shell has been reduced, internalized, or lost. Tracing how umiushi was...
How a Russian Sea Slug Book Found a Permanent Home in Tokyo: Martynov & Korshunova (2025) and the Quiet Mechanics of Taxonomic Stability
Apr 30, 2026
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Martynov & Korshunova (2025) is a properly issued book on North Pacific sea slug taxonomy, but its small print run...
Japanese Shell Names Decoded — Three Old Names Edo-Period Naturalists Gave to Sea Slugs
Apr 26, 2026
Part 2 of the cross-cultural sea slug naming series. Three very old Japanese shell names — Misugai, Benishibori, and...
Sea Bunny = Jorunna, Blue Dragon = Glaucus: Real Names Behind Viral Sea Slugs
Apr 21, 2026
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Sea bunny, Blue dragon, Pikachu nudibranch — what those viral sea slug nicknames actually refer to, and why the...
How AI Rewrote ~100 Katakana Names in the Sea Slug Field Guide
Mar 15, 2026
A log of how Claude (AI) worked with the site operator to revise the katakana (Japanese phonetic) spellings of ~100...
Thank You to Amakusa Yokayoka Diving for Your Sponsorship
Mar 15, 2026
Yokayoka Diving in Amakusa, Kumamoto — a historically rich area for nudibranch research.
Recap: The 2nd Information Exchange Meeting of the Sea Slug Research Society of Japan
Mar 13, 2026
Held in Kagoshima in March 2026, the 2nd Information Exchange Meeting of the Sea Slug Research Society of Japan...
Behind the Scenes: Building an AI Identification Check
Feb 13, 2026
How we use image-embedding similarity search to help spot misidentifications among 45,000+ sea slug photos...
Contributed to "Umiushi Tsushin": Behind the Scenes of Building and Running SEASLUG.WORLD
Dec 18, 2025
I contributed an article on the construction and operation of Sea Slugs of the World to the magazine "Umiushi...
Announcement: 40,000 Sea Slug Observation Records Published on International Databases
Sep 12, 2025
On the 10th anniversary of Sea Slugs of the World, the 40,000+ observation records contributed by users have been...
Recap: The 1st Information Exchange Meeting of the Sea Slug Research Society of Japan
Mar 6, 2025
An overview of the 1st Information Exchange Meeting of the Sea Slug Research Society of Japan, held in March 2025 at...
Thank You to DIVING SHOP Kazamidori for Your Sponsorship
Oct 28, 2024
Kazamidori — a new dive shop on Hachijojima Island with year-round nudibranch diversity.
Thank You to Sunset Resort Dive Center for Your Sponsorship
Jun 26, 2024
Sunset Resort Dive Center in Ukishima, West Izu — a premier nudibranch diving destination.
What do "sp.", "spp.", "cf." mean in sea slug names? A guide to provisional naming
Feb 29, 2024
A guide to sp., spp., cf., aff. and sp. nov. in sea slug names — how undescribed species are numbered, and how to...
Thank You to Leap Scuba Amami for Your Sponsorship
Dec 28, 2023
Leap Scuba Amami — diving in northern Amami Oshima with expert nudibranch guides.
Thank You to Aqua Star for Your Sponsorship
Dec 28, 2023
Aqua Star in Miyakojima — for those who want to hunt rare nudibranchs in blue waters.