המועדפים של passiflora4

12 mm long in 1st image; 20 mm in 2nd; specimen in 3rd image in situ. All were found under the Hwy 101 bridge over Richardson Bay on 14 October. 4th image is of egg mass found on the same date; 5th image is close-up of strand from within the egg mass.

6th image is of newly hatched larvae trapped in surface film of water (shells 370 microns long). 7th image is ventral view of newly hatched larvae crawling on underside of coverslip. Both of these latter images were taken on 27 Oct 2013.

the culprit of the mystery egg sacs!!??? it was in the sea grass burrowed next to several egg masses!!
@jeffgoddard @alanarama3

last photo is not the exact eggs it was next to, just one of many seen that day, but the same type of egg mass

Nudibranchs are a group of sea slugs characterized by having no shell, thus having their gills exposed. The name in latin, nudibranchia means precisely that: nudi (nude, exposed) + branchia (gills).
Instead of the protective shell, the nudibranchs use other intricate defense mechanisms and that's one of the reasons they are such an interesting group to study. Not to mention their exquisite appearance.

More info about this species:
www.seaslugforum.net/find/armimacu
hypselodoris.blogspot.com/2012/02/armina-maculata-rafines...

Thanks to Rui Rosa and Vanessa Madeira Lopes from the Guia Marine Laboratory (lmg.fc.ul.pt/).

Corambe pacifica on its food source, Membranipora membranacea, was located on a fragment of kelp over a sandy substrate at a depth of 40 feet. Empty tests of bryozoans underneath the slug and at the upper right of the image are signs of feeding. Length was 0.5 cm. Water temperature was 52 degrees F.

A large specimen, found on Bugula in the Charleston, OR boat basin. Cropped from the 2nd image, which shows four other species of Bugula-feeding nudibranchs found on the same date. Scanned from a 35 mm slide.