are deep water fish which take their name from their long slender tails.
Depending on the year, they were also grouped with Lingcod, Spotted Ratfish
, Rex Sole, Pacific Spiny Dogfish, and Pacific Sanddab (Citharichthys sordidus) (Table 2).
However, research has also shown that smaller species like ratfishes
have high bite forces for their size, perhaps due to their need to crush hard shells.
We measured fork length for all species except length of Spotted Ratfish
(Hydrolagus colliei), for which precaudal length (tip of snout to second dorsal fin; Anderson and Quinn, 2012) was measured; all length measurements were made to the nearest millimeter.
Cartilaginous fish, which today include sharks, rays, and ratfish
, diverged from the bony fishes more than 420 million years ago.
Six taxa observed with the ROV had a reaction rate of at least 50%: Pink Seaperch, Pacific Hake (Merluccius productus), Spotted Ratfish
(Hydrolagus colliei), and Yellowtail (S.
But, there are only 1,200 species of cartilaginous fish, including sharks, rays and ratfish
Catch for these 62 species was initially partitioned into seven groups based on taxonomy and depth (in order of decreasing biomass): flatfish (30%), other shallow to mid-depth species (20%), shelf rockfish (15%), sharks, skates, and ratfish
(13%), other deep water species (9%), thornyheads (8%), and slope rockfish (5%), to examine trends over time.
Our results indicate that this fish assemblage is dominated by cartilaginous species (spotted ratfish
[Hydrolagus colliei] and spiny dogfish [Squalus acanthias]) and therefore differs fundamentally from fish assemblages found in shallower estuaries in the northeast Pacific.
helvomaculatus) showed much greater abundance during the day, and spotted ratfish
(Hydrolagus colliei) and widow rockfish (S.
(skates) 6.9 2.8 Unidentified roundfish 3.1 2.1 Anoplopoma fimbria (sablefish) 1.4 1.5 Hippoglossus stenolepis (Pacific halibut) 0.0 nm Microstomus pacificus (Dover sole) 6.1 6.0 Hydrolagus colliei (spotted ratfish
) 7.2 3.0 Sebastes elongatus (greenstriped rockfish) 1.3 0.8 Cottidae (sculpins) 0.0 nm Agonidae (poachers) 23.0 4.1 Unidentified fish 0.0 nm Taxon 1B Mean SE Invertebrates Halipteris spp.
Species in this analysis were limited to oviparous elasmobranchs, which encompassed a diverse group of 13 chondrichthyan fishes: a chimera, the spotted ratfish
(Hydrolagus colliei), two catshark species (Scyliorhinus spp.), and ten species of skates in three genera (Raja, Leucoraja, and Okamejei) (Table 1).