Attached to N.P. spiny dogfish (Squalus suckleyi) caught while longlining.
From what I observed they were only attached to the top side of pectoral fins and only 1 per dogfish. 11 out of 12 observed were on the right pectoral. It was quite hard to tell the ratio as I wasn’t able to check every dogfish throughout the day but once I noticed them on the fin, they appeared to be fairly common.

Habitat small, temporary pool.
Image 1 shows left lateral anterior of male.
Image 2 shows male cercopods with the distinctive distal spines.
Image 3 shows female cercopods.
Image 4 shows male left antenna II. Need to look closely to see the small protrusion between the thumb's main ramus and the spur.
Image 5 shows male frontal appendage to be entire, not cleft.
Image 6 shows ova.

Формально ещё в географических границах моря Лаптевых, но по геоморфологической сути уже в собственно Северном Ледовитом океане. Прилов при подъёме трала с глубины 2350 м. 63 рейс НИС "Академик Мстислав Келдыш", ст. 5225.

Photo CC-BY-NC-SA license and credit and taxonomic work belongs to the Florida Museum of Natural History (FLMNH).

This observation is a part of the long-term monitoring efforts of Gustav Paulay and his team at FLMNH and Friday Harbor Labs.

Although this observation also falls within the boundaries of the MarineGEO iNaturalist umbrella project (which is an ongoing collaborative work between MarineGEO and the Tennenbaum Marine Observatories Network, the Florida Museum of Natural History, the Smithsonian’s National Museum of Natural History Museum, and our network partners), this is not from a MarineGEO specific campaign.

Habitat small, alpine, astatic pool.
This arctic species was reported from this pool in 1968 by R.S. Anderson, probably arriving in Alberta via resting eggs contained in the feces of migrating waterbirds.
Image 1 shows the male, ventral view.
Image 2 shows the female, ventral view.
Image 3 shows the male's 5th pair of legs, posterior view.
Image 4 shows the process on the antepenultimate segment of the male's right first antenna, projecting past the terminal segment.
Image 5 shows a ventral view of the female's genital segment with lateral protrusions, and the ovisac.
Image 6 shows the female's 5th pair of legs.
Image 7 shows specimens swimming near surface. These were preyed upon by the larger Hesperodiaptomus shoshone also inhabiting this pool.

This high magification macro photo is of a female and male pair of the bopyrid parasite (likely) Pseudione galacanthae.

The female is ripe with eggs (the swollen cream colored abdomen), the male lives as a tiny parasite on the female - seen crawling on top of the lower-mid section of the female. Bopyrid parasites are highly modified isopods that infect various crabs and shrimps.

This particular mating pair was found inside the gill chamber of the squat lobster Munida quadrispina.

Flinders Island cave-slater Echinodillo cavaticus. The world has only two known species of the very distinctive Echinodillo cave-slaters. One is found on the Marquesas Islands in the middle of the Pacific Ocean. This other species is known only from a small cave in southern Flinders Island, where its entire global range is measurable in square metres. We found this one during our Bush Blitz on Flinders Island in March 2014.