The fatty acid compositions of the total lipids of three edible deep-sea fishes, Diaphus watasei, Diaphus suborbitalis, and Benthosema pterotum, were compared with those of a highly migratory fish, Katsuwonus pelamis, to clarify their lipid characteristics and nutritional value as seafood. The mean lipid contents in the three myctophids were markedly higher than was that of K. pelamis. All thre...

The myctophids and stomiiforms represent two common groups of luminous fishes, but the source of luminescence in these animals has remained undetermined. In this study, labeled luciferase gene fragments from luminous marine bacteria were used to probe DNA isolated from specific fish tissues. A positive signal was obtained from skin DNA in all luminous fishes examined, whereas muscle DNA gave a ...

Broadband simulated dolphin echolocation signals were used to measure the ex situ backscatter properties of mesopelagic boundary community (MBC) in order to gain a better understanding of the echolocation process of spinner dolphins foraging on the MBC. Subjects were captured by trawling with a 2-m-opening Isaacs-Kidd Midwater Trawl. Backscatter measurements were conducted on the ship in a 2000...

Narrow foraging specialization may increase the vulnerability of marine predators to climate change. The red-legged kittiwake (Rissa brevirostris) is endemic to the Bering Sea and has experienced drastic population fluctuations in recent decades, presumably due to climate-driven changes in food resources. Red-legged kittiwakes are presumed to be a nocturnal surface-foraging seabird that feed al...

Chitinolytic activities, both chitinase (EC 3.2.1.14) and minimum chitobiase (beta-N-acetyl-D-glucosaminidase; EC 3.2.1.30), were measured in stomach and intestinal tissues and their contents, from 13 fish species. Higher activities were found in the tissues than in the gut contents, and higher activities were seen in the stomachs than in the intestines. Demersal species exhibited chitobiase ac...

Myctophids are an ecologically important mesopelagic species in the eastern Pacific Ocean. Due to wide distribution, great diversity and variable biological characteristics of species, there is a lack reliable information regarding their spawning nursery grounds Kuroshio extension region. In this study, we identified total 110 myctophid individuals using DNA barcoding morphological techniques, ...

Declines in marine predator populations have been attributed to anthropogenic activity and environmental change. Southern elephant seals Mirounga leonina are major consumers of biomass in the eastern region of the Southern Ocean and have been declining in numbers since the 1960s. Previous studies have identified evidence for habitat and diet partitioning over a range of spatial and temporal sca...

Micronekton were sampled off the southwest coast of Oahu in October 2004 as part North Pacific Marine Sciences Organization (PICES) Sampling Gear Intercalibration experiment (MIE-1). The initiative employed three different micronekton sampling gears: Cobb Trawl, Isaacs–Kidd midwater trawl (IKMT), and Hokkaido University frame (HUFT). catches from gears used to quantify rates active carbon trans...

Using carbon and nitrogen stable isotope values, we analyzed the trophic position (TP) isotopic niche width of lanternfishes from three different areas in Southern Pacific Ocean. Fishes Perú had slightly higher δ13C values compared with fish Chilean areas. In contrast, δ15N increased latitude (North to South). Myctophids TP differed between study (highest Central Chile, lowest Peru). Peruvian f...