Favoritos de luanroberts

La Paz, B.C.S., Mexico
Three of these, found together under a rock with sparse hydroids. Each only about 2-3 mm - quite small. At first, I thought they might be odd Tenellia albocrusta. (B.C.S. is the southern range limit of C. albocrusta according to Gary’s iNat guide: https://www.inaturalist.org/guide_taxa/933633#ref2)

But the thing that gave me pause was how extensive the opaque white speckles are - extensively down the oral tentacles (not seen in any other photo of C. albocrusta on iNat) and the entire length of the rhinophores. All three had the same markings.

In Camacho-Garcia, Gosliner and Valdes, “Guia del Campo de las Babosas Marinas del Pacifico Este Tropical,” 2005, p. 105, a tiny Cuthona Sp 6 looks like a possibility - the photo isn’t reproduced well, but there seems to be white on the oral tentacles (not mentioned in the text, so I may be seeing something incorrectly) and white spots on the rhinophores are mentioned. I haven’t seen more recent information on this Cuthona.

From TGosliner: "This looks like something entirely new to me! It certainly is not Tenellia albocrusta. The head shape and ceratal color are entirely different. Very cool!"

undescribed sp first seen by @imlichentoday

found on kelp (https://www.inaturalist.org/observations/194171357)
but rearing when found, detached quickly

no wind, light to no surge, night, water temp 61 F, -0.8ft tide

found by @nudibitch
2nd record of this species! Found at a -.8ft low tide, at night, no wind, no waves

more pictures of this individual: https://www.inaturalist.org/observations/194171352

More pictures of 1st recorded individual: https://www.inaturalist.org/observations/90419664

HELLO AGAIN.
This is now the second time I've photographed this undescribed nudibranch - the first one was found by Luan Roberts when we were dock fouling in August 2021: https://www.inaturalist.org/observations/91369989

Unfortunately I did not have collecting materials with me, and I couldn't detour via CAS, so it got to go about its nudibranch business after these photos were taken.

This mystery slug does not appear in Behrens et al, Eastern Pacific Nudibranchs, 2021, nor have I found any references to it elsewhere.

Found by @luanroberts. About 7 mm. Orange bands on white-tipped oral tentacles, orange bands on the white-tipped rhinophores, and white specks on the surface of the body.

Obelia and Tubularia (Pink-mouth hydroid) present elsewhere in the marina in small quantities, but didn't see it feeding.

Looks vaguely like the pale one in the left-side photo on Page 124 of Behrens & Hermosillo's Eastern Pacific Nudibranchs, 2005. Same individual as https://www.inaturalist.org/observations/91332884

Update: this hydroid https://www.inaturalist.org/observations/92299348 was the only hydroid on the boat bumper where it was found.