המועדפים של clauden

10-15 mm
Found with Onchidoris bilamellata (coincidence?) under rocks at low tide. Quite common.

According to https://repository.library.noaa.gov/view/noaa/14990 there are 7 species of free swimming flatworms recorded from Alaska. Of these Nexilis epichitonius and Nesion arcticum do not reach this size and can be ruled out, as can Kaburakia excelsa which should be considerably larger. Acerotisa arctica seems to be known from only one species collected at Utquiagvik at the Arctic Ocean. I was not able to find any information about Notocomplana sanjuania or Notoplana longastyletta even under any of their synonyms.

Pleioplana atomata (also known as Notoplana atomata) seems like the most likely candidate. It is 9-28mm; found under stones and weeds in intertidal zone and matches iNat photos well.

I am told that this is a "megalopa larva of the family Caiuli" but cannot find a crab family with that name. Can anyone translate the Japanese in the second picture, the caption from a reference that identifies this?

From my first "blackwater dive", night diving in the open ocean over a thousand feet of water looking for interesting plankton and pelagics.

A calcareous sponge forming slender tubes up to 10 cm long. Collected as NM #362 and identified by Dr. Bruce Ott as a species of Sycon. Specimen in the Royal BC Museum collections. Very abundant at this site on steep rocky wall.