Topic
Bentheuphausia
About: Bentheuphausia is a research topic. Over the lifetime, 3 publications have been published within this topic receiving 373 citations. The topic is also known as: Bentheuphausia amblyops.
Papers
Book•
1 Jan 1962
TL;DR: A study of the distribution of 59 euphausiid species in the Pacific Ocean, based upon oceanic surveys carried out from 1949 to 1961, finds some species that inhabit a mesopelagic zone between depths of about 500 and 1,500 meters and other species that are characteristically epipelagic, living mainly above 500–700 meters.
Abstract: A study has been made of the distribution of 59 euphausiid species in the Pacific Ocean, based upon oceanic surveys carried out from 1949 to 1961 by the Scripps Institution of Oceanography, California Cooperative Oceanic Fisheries Investigations (CalCOFI), and Pacific Oceanic Fisheries Investigations (POFI). Quantitative aspects of the vertical and horizontal distributions are presented. The species belonging to the genera Bentheuphausia and Thysanopoda are typically deep-living. Bentheuphausia ambloyops, Thysanopoda cornuta, and T. egregia are widely ranging bathypelagic species, the adults of which inhabit depths greater than 1,500 meters. Of the ten genera, six (Thysanopoda, Euphausia, Thysanoessa, Nematoscelis, Nematobrachion, and Stylocheiron)contain some species that inhabit a mesopelagic zone between depths of about 500 and 1,500 meters and other species that are characteristically epipelagic, living mainly above 500–700 meters. The epipelagic species are designated in accord with the analogous water masses inhabited. The Pacific water masses are (1) subarctic, situated to the north of the North Pacific Drift, including only the northern part of the California Current (typical species: Thysanoessa longipes, Tessarabrachion oculatus); (2) transitionzone, including the cooler part of the California Current south of 40°–45° N. and a belt extending westward to Japan in the region of the North Pacific Drift (typical species: Thysanoessa gregaria, Nematoscelis difficilis); (3) central, occupying the oceanic gyrals of mid-latitudes 15°–40° in both hemispheres (typical species: Nematoscelis atlantica, Euphausia brevis); and (4) equatorial, occupying a broad tropical belt in the eastern Pacific and a narrower belt to the west (typical species: Euphausia diomediae, E. distinguenda). Equatorial species occupy equatorial water masses in the Pacific and Indian oceans. A zone occupied by the transition-zone species Thysanoessa gregaria and Nematoscelis megalops (corresponding to N. difficilis of the Northern Hemisphere) occurs near 35°–45° S. Subantarctic and antarctic species are found south of the Subantarctic Convergence. The composite range of a tropical western Pacific group of species (e.g., Euphausia pseudogibba, E. fallax, E. sibogae) extends eastward across the Pacific in a zone 10°–20° S., while an eastern tropical group (e.g., Euphausia distinguenda, E. eximia) extends westward in a tongue having an axis near 10° N. Ekman’s zones of the Pacific littoral fauna each have a counterpart species in the coastal or boundary euphausiid fauna. Seasonal changes in euphausiid distribution are discussed with respect to five regions: (1) the Kuroshio and East China Sea, (2) the North Pacific Drift Current, (3) the California Current, (4) the Peru Current, and (5) the equatorial mid-Pacific.
405 citations
TL;DR: The abundance, biomass, diversity and community structure of euphausiids in the Southern Ocean along the 140°E meridian from latitudes 47°S-65°S were examined by RMT8 from 0 to ca. 1000m during the 2001/2002 austral summer as discussed by the authors.
Abstract: The abundance, biomass, diversity and community structure of euphausiids in the Southern Ocean along the 140°E meridian from latitudes 47°S–65°S were examined by RMT8 from 0 to ca. 1000 m during the 2001/2002 austral summer. Both total abundance and biomass of euphausiids were much higher in the south of the southern branch of the Polar Front (PF-S) located at 60°S–61°S than in the northern part, corresponding with higher chlorophyll a concentrations. Eleven species of euphausiids were collected from the research areas: 2 species of Thysanoessa, 6 of Euphausia, and a single species each of Thysanopoda, Bentheuphausia and Nematoselis. In Euphausia and Thysanoessa, clear horizontal distribution patterns enabled the classification of each species into one of 3 different types: species occurring only at stations north of the PF, species occurring in a broad distribution from south of the PF-S to the south of the Southern Boundary (SB) of the Antarctic Circumpolar Current, and species occurring only south of the SB. The latitudinal zonations occurrence and peak abundance were evident for all species. Hierarchical cluster analysis by species and station resulted in the identification of 2 distinct communities of euphausiids: community I comprised the three stations north of the PF where both euphausiid abundance and biomass were relatively low, and 2 species, Thysanopoda acutifrons and Thysanoessa gregaria dominated, community II comprised the southern five stations where abundance and biomass were high and Euphausia frigida, E. superba and Thysanoessa macrura were numerically dominant. Among the five oceanographic fronts within the research area, the PF (either south or north) appears to be the important biogeographical boundary separating abundance, biomass, and the community structure of euphausiids.
10 citations
1 Jan 2017
TL;DR: All the available, worldwide reports of epibionts and parasites of species of the Order Euphausiacea published between 1885 and 2015 are reviewed, providing a relatively broad and coherent perspective about interespecific interactions inferred in the bases of diversity, prevalence patterns, intensity, parasite–host size ratios, and availability of microhabitats.
Abstract: We review all the available, worldwide reports of epibionts and parasites of species of the Order Euphausiacea published between 1885 and 2015 (126 publications, 346 records) We add our own observations carried out on euphausiids from waters off Oregon (USA), Tasmania (Australia), Concepcion (Chile), and Mexico This information provides us a relatively broad and coherent perspective about interespecific interactions inferred in the bases of diversity, prevalence patterns, intensity, parasite–host size ratios, and availability of microhabitats for parasites on and inside euphausiid bodies, as well as the association of parasitism with the hosts’ reproductive strategies Currently, there are 18 different types of epibionts, pathogens, parasites, and parasitoids infecting krill (107 known taxa reported from 49 of the 86 euphausiid species) Symbionts affect almost all stages of the life cycle of euphausiids (except nauplius-to-metanauplius stages) They increase in diversity, prevalence, and parasitic intensity with euphausiid age Epibionts and ectoparasites generally do not affect the fitness of their hosts, but several pathogens, mesoparasites, and endoparasites can decrease the host fitness to zero by castration or death Currently known parasites do not transmit vertically from parent to offspring and all the endoparasites seem to infect euphausiids by trophic transmission All symbionts interact indistinctly with euphausiid species with broadcast spawning species or sac-spawning reproductive strategies Species of the genera Euphausia, Meganyctiphanes, Nematoscelis, Nyctiphanes, and Thysanoessa possesses the most diverse and better-known parasitic fauna In contrast few parasites are known for krill species of the genus Nematobrachion, Pseudeuphausia, and Stylocheiron No symbionts are known at present from species of Bentheuphausia, Tessarabrachion, or Thysanopoda
1 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2017 | 1 |
| 2010 | 1 |
| 1962 | 1 |