r/nudibranch

PNW cold water diving - Gigantic Tritonia nudibranchs (most 6-8”) and brown and white striped nudibranchs were abundant. What wasn’t expected was the mass of them descending on a sea pen. Also, found a brown and white nudibranch in the middle of laying eggs - looks like a cartoon character sitting up. Wasn’t expecting that as every nudibranch laying eggs I’ve seen have been laying down.

Share your favorite nudibranch and I will use them in a future week!

No strobes? No worries! Constant light can work great for stills of the little guys. Just set ISO to Auto and rock on with your normal settings.

Cyerce nigra, Guam, Nikon Z6iii Z105 Nauticam USA SMC-2 Kraken Sports Abyss 10K, ISO400 (Auto ISO), f29, 1/125

Wanted to share some attempts at pixel stretching some tidepool finds. I really like how it pulls the color palette right out, making nudis even more stunning and colorful.

All photos were taken with my Olympus TG7.

Si quelqu'un peut connaît les espèces je suis preneur :)

Santa Cruz CA, looked to be maybe a couple inches long, looked white but couldn’t get close enough

Share your favorite nudibranch and I will use them in a future week!

Heya everyone,

Over the last few weeks I've been working on a small database of UK nudiranchs and marine molluscs. The idea came from a local ranger who took me nudibranch spotting in exchange for setting up some reptile surveys for them and she mentioned they often take school groups rock pooling, and thought it would be fun to have a really simple, beginner-friendly place to start learning.

The aim isn't to replace the excellent resources already in place (DORIS, WoRMS, iNaturalist, NBN etc.) but to give an accessible starting point.

Taxonomy has been checked against WoRMS, but this absolutely isn't my area of expertise. I've added a report function to each species, so if something is wrong please let me know. I'd genuinely love any feedback and thoughts on how it's coming together. Thank you! 🐌

https://ukseaslugs.co.uk/

It's in free beta right now (TestFlight). Needs a fairly recent iPhone (A17 Pro or newer, iOS 26+).

https://testflight.apple.com/join/n8kSzExR

​