המועדפים של thetidepooler

Undescribed species, 22 mm long. I spotted this specimen on its flat, coiled egg mass (also see 2nd image) on a pebble grabbed with gray mud from 186 m depth off Cape Alava, WA while on a cruise AR-04-04 of the NOAA Ship McArthur II in June 2004. The translucent dorsum was finely scabrous to the touch. The 4th image is an SEM, made by Sandra Millen (UBC), of some of its radular teeth. Sandra confirmed this as an undescribed species and last I heard had been well along in describing it. The first three images were scanned from prints I took shipboard using 35 mm film. The specimen, including two SEM mounts, was deposited by Sandra Millen in the California Academy of Sciences (CASIZ 176807).

Only a few mm long; found on Codium fragile. Unlike Placida dendritica, this undescribed species has simple (not rolled) rhinophores. It appears to be the same species as specimens I found earlier in the same year on Codium fragile at Punta Rosarito, Baja California (http://www.seaslugforum.net/showall/stilsp1). Scanned from prints from 35 mm film.

Eubranchus sp. 2 of Behrens & Hermosillo (2005). Found by Ziggy and the first record of this species outside of La Jolla. Compare to: https://www.inaturalist.org/observations/2958115

In Behrens et al. (2022) this is Eubranchus sp. 1.

6.8 mm long. Found in a shallow, low intertidal pool at South Casa Reef. CASIZ 189422.

This is Eubranchus sp. 2 of Behrens & Hermosillo (2005), which so far is only known from La Jolla, California and remains undescribed. Note: in April 2021 we found one at Tar Pits Reef in Carpinteria, Santa Barbara County: https://www.inaturalist.org/observations/75602522

The white patch on the head, reddish hepatic region, white anal papilla, and rings of papillae on the cerata are distinctive.

The 3rd and 4th images show egg masses, containing early and late-stage embryos, respectively, laid by adult pictured here. The last image shows a newly hatched veliger larva, right lateral view, with a shell 210 microns long.

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!"

missing a tentacle and a little roughed up

undescribed species, first intertidal observation im aware of!
https://www.inaturalist.org/journal/nudibitch/88226-mystery-flatworms-black-midline-black-tentacles

Please leave at genus for now. Preliminary ID by @tgosliner is Catriona group of Tenellia species. Thank you also @jeffgoddard for your ID help.

They were not tiny -- all were between 15-25 mm long.

Non-scientific description:

Body was translucent white with no other markings. No foot corners that I could see.

Ceratal cores were brown with orange tips, with varying degrees of faint opaque white frosting on the leading edge of the cerata, ranging from virtually none on the smaller individuals to obvious on the largest individual.

Rhinophores were smooth with opaque white on the backside of the tips, with a small orange-red patch just below that (barely extended to the front of the rhinophore, so not really a "band").

Oral tentacles were about the same length as the cerata, with a red-orange patch on the leading edge that did not extend to the tip. As with the rhinophores, the oral tentacles had varying degrees of opaque white frosting on the leading edge of the cerata, ranging from virtually none on the smaller individuals to obvious on the largest individual. On only the largest individual, the opaque frosting extended into the head.

Apata cf pricei (Behrens et al 2022)???

“Body is translucent gray-white with a white opaque line running from the tip of the tail part way up the sides of the dorsum. The white tipped cerata have a reddish or brownish red core and may have a greenish cast, and form up to 10 comb shaped rows. Rhinophores are perfoliate and frosted white along most of their length, and oral tentacles have a white line on their dorsal surface”

opaque frosting on the rhinophores appears to be on the top only