Behavioral and Physiological Characteristics of the Antarctic Krill,<i>Euphausia superba</i>

Quetin, Langdon B.; Ross, Robin M.

doi:10.1093/icb/31.1.49

Cited by 201 publications

(191 citation statements)

References 0 publications

Supporting

Mentioning

175

Contrasting

Unclassified

Order By: Relevance

“…Relative DG length = (DG length (mm) / CL (mm)) × 100. Growth rates were measured following the instantaneous growth rate method for larvae 48 . In situ growth rates were determined by randomly sorting 100-400 freshly caught krill larvae and incubating the animals individually in 150 ml jars with natural seawater at in situ sea surface temperature for three days.…”

Section: Larval Krill Morphometrics Growth and Stomach Content Analymentioning

confidence: 99%

The winter pack-ice zone provides a sheltered but food-poor habitat for larval Antarctic krill

et al. 2017

View full text Add to dashboard Cite

A ntarctic krill Euphausia superba, a key species in Southern Ocean food webs 1 , plays a central role in ecosystem processes and community dynamics of apex predators, and is the target of a commercial fishery 2 . Krill spawn in late spring and their larvae develop during summer, autumn and under the ice in winter to emerge as juveniles in the following spring. The newly spawned eggs sink from the surface to up to 1,000 m depth where they hatch and the developing larvae actively swim upwards to feed in the upper water column 1 . Larval Antarctic krill have low lipid reserves, which are insufficient to support long periods of starvation. Therefore, winter, when primary production is minimal, is assumed to be a critical bottleneck for larval krill development and hence recruitment to the adult population 3,4 . Present hypotheses suggest that high algal biomass in winter sea ice enhances larval krill winter-feeding conditions and growth [5][6][7][8] . This implies that larvae have access to this high algal biomass within the sea ice. However, recent observations 9,10 indicate that the linkage between sea ice and krill recruitment success is not as direct as has been suggested. The timing of ice-edge advance and annual ice-season duration is highly variable, and does not necessarily show a clear link to krill recruitment in the following year ( Supplementary Figs. 1 and 2). Along the Antarctic Peninsula, adult krill have a five to six year population cycle with oscillations in biomass exceeding an order of magnitude 9 . According to bioenergetics models, part of the variability is due to interannual variation in reproductive output 11 as well as autumn blooms that may govern the possible overwinter survival rate of larvae 11,12 . In the Bransfield Strait, three krill winter surveys have shown that krill abundance is an order of magnitude higher than in summer, regardless of concurrent sea-ice conditions 10 A dominant Antarctic ecological paradigm suggests that winter sea ice is generally the main feeding ground for krill larvae. Observations from our winter cruise to the southwest Atlantic sector of the Southern Ocean contradict this view and present the first evidence that the pack-ice zone is a food-poor habitat for larval development. In contrast, the more open marginal ice zone provides a more favourable food environment for high larval krill growth rates. We found that complex under-ice habitats are, however, vital for larval krill when water column productivity is limited by light, by providing structures that offer protection from predators and to collect organic material released from the ice. The larvae feed on this sparse ice-associated food during the day. After sunset, they migrate into the water below the ice (upper 20 m) and drift away from the ice areas where they have previously fed. Model analyses indicate that this behaviour increases both food uptake in a patchy food environment and the likelihood of overwinter transport to areas where feeding conditions are more favourable in spring.

show abstract

Section: Larval Krill Morphometrics Growth and Stomach Content Analymentioning

confidence: 99%

The winter pack-ice zone provides a sheltered but food-poor habitat for larval Antarctic krill

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Observations of adult krill associated with sea ice, either as individuals or in aggregations, are rel atively rare compared to larvae (fable 3). The distinction between life stages made during the cruises is important, since dif· ferences in the physiology of adults and larvae may underlie differences in distribution patterns [Ross and Quetin, 1991]. Larvae were observed on every cruise and during the majority of the dives (52 to 93% of the dives per cruise).…”

Section: 31mentioning

confidence: 99%

Factors affecting distribution and abundance of zooplankton, with an emphasis on Antarctic krill, Euphausia superba

Quetin

Ross

Frazer

et al. 1996

Antarctic Research Series

Self Cite

View full text Add to dashboard Cite

Variation in the abundance and distribution ci zooplankton is an inherent characteristic ci pelagic marine ecosystems. In this chapter, we discuss how patterns of abundance and distribution &JC affected by the life cycle characteristics c:I some rl the predominant macrowoplankton west c::l the Antarctic Peninsula.Because ci the importance of Antarctic krill, EuphausitJ Sllptrba. within this region, some aspects ci its ecoiolY ~ given special .uentian. Of particular relevance to rum:nt hypotheses is the association of krill and sea icc , and new evidence is presented for winter habilal Icgreg_tion between adult and larval Slages. Subsequent discussion focuses 00 strategies for winter survival, and variation in recruilmenl. Finally, we discuss the effects of abiotic facton such as frontal shifts, and biotic factors such as food composition, as they ~late to abundance and distribution ci zooplankton .

show abstract

“…The role of lipids in Antarctic krill has been the concern of several papers in relation to reproduction (Clark 1980, Kolokowska 1991, Pond et al 1995, Virtue et al 1996, energy storage for overwintering (Quetin & Ross 1991. Hagen et al 1996 and trophlc interactions (Bottino 1974, Reinhardt & Van Vleet 1986, Virtue et al 1993a.…”

Section: Introductionmentioning

confidence: 99%

“…In krill the 2 major energy utilizing events are summer reproduction and winter survival under low phytoplankton conditions. Knll store significant amounts of lipids (Clarke 1984, Hagen et al 1996, although most studies have concluded that the concentrations are not sufficient to meet the energy requirements during the winter, when food supply is low (Quetin & Ross 1991, Quetin et al 1994. However, the contribution of lipids to the overall survival strategy of 0 Inter-Research 1998 Resale of full article not permitted krill appears quite s~gnificant (Hagen et al 1996) and, during the summer period, is channeled mainly into reproductive output.…”

Section: Introductionmentioning

confidence: 99%

“…Krill reproduction takes place over several spawning phases (Cuzln-Roudy 1987, Quetin & Ross 1991; hence, their reproductive output seems directly related to the richness of the food supply (Ross & Quetin 1986). Yolk accumulation is characterized by high concentrations of neutral lipids and high levels of triacylglycerols in ovaries of mature females (Clarke 1980, Hagen 1988, Pond et al 1995.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Changes in lipid composition of the Antarctic krill Euphausia superba in the Indian sector of the Antarctic Ocean:influence of geographical location, sexual maturity stage and distribution among organs

Mayzaud¹,

Albessard²,

Cuzin-Roudy³

1998

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

ABSTRACT-Lipid content and lipid class composition of Euphausia superba were studied at different levels for populations and individuals sampled in the Indian sector of the Antarctic Ocean. Strong siteto-site var~ability was recorded whlch could only partially be related to sex or development stage differences. Three groups of stations could be d~fferentiated. Northern stations were characterized by 'high lipid-high triglyceride' content, western and eastern locations by 'high lipid-high phosphatidyl choline' content and southern areas by 'low lipid-high phosphatidyl ethanolamine/glycolipid' content. Such variability was likely related to advected populations h a v~n g spent variable lengths of time in the area studled. Lipid content and class among organs were studied in 5 body fractions: abdomen, stomach, digestive gland, gonad and fat body. In absolute terms, the hi.ghest concentrations were observed in the ovaries of mature females and the abdomens of the other stages. In relative terms ("'0 dry weight), the digestive gland displayed the highest level, except in mature females. Distribution varied with stages, with low triglyceride levels in abdomen tissues of most stages and in the fat body and stomach fractions of subadults. H~g h triglyceride levels were recorded In the other fractions for post spawning females and males, as well as in the fat body fraction for mature females and in subadult gonads. A reverse pattern was observed for the relative content of phosphatidyl choline. Phosphatidyl ethanolamine showed maximum values in the abdomen and the gonad. Glycolipid percentages were maximum in the abdomen, suggesting a structural role. The roles of the different lipid classes are discussed w~t h respect to the function of the organ.

show abstract

Behavioral and Physiological Characteristics of the Antarctic Krill,Euphausia superba

Cited by 201 publications

References 0 publications

The winter pack-ice zone provides a sheltered but food-poor habitat for larval Antarctic krill

The winter pack-ice zone provides a sheltered but food-poor habitat for larval Antarctic krill

Factors affecting distribution and abundance of zooplankton, with an emphasis on Antarctic krill, Euphausia superba

Changes in lipid composition of the Antarctic krill Euphausia superba in the Indian sector of the Antarctic Ocean:influence of geographical location, sexual maturity stage and distribution among organs

Contact Info

Product

Resources

About