Nutrition and the regulation of egg production in the Calanoid copepod <i>Acartia tonsa</i>

Kleppel, G. S.; Burkart, C. A.; Houchin, Lee

doi:10.4319/lo.1998.43.5.1000

Cited by 137 publications

(84 citation statements)

References 47 publications

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“…Iron deficiency may also contribute to changes in the cellular composition of essential dietary components in algae, such as proteins and essential lipids, some of which have been shown to affect egg production in copepods (Kleppel et al 1998;Hassett 2004). Because Fe limitation may affect the energy available for biosynthesis of these energy-rich compounds and the abundance of Fe-dependent enzymes is important in their synthesis, Fe limitation may affect lipid content and composition of algal food.…”

Section: Discussionmentioning

confidence: 99%

Can copepods be limited by the iron content of their food?

Chen

Baines

Fisher

2011

Limnology & Oceanography

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In laboratory experiments, we show that naupliar survival and egg production by the copepod Acartia tonsa was significantly lower when they were fed iron-depleted algal cells than when they were fed a diet of Fe-replete cells that had two orders of magnitude higher Fe levels. Naupliar survival after 1 week was reduced from 60% for copepods feeding on Fe-replete diatoms (Thalassiosira oceanica) to 0% for those feeding on Fe-depleted cells. The decline of egg production rate was greatest (83%) when T. oceanica was used as prey and smaller (20-30%) when the cryptophyte Rhodomonas salina and the prymnesiophyte Isochrysis galbana were used as food. The assimilation rates of Fe and C from Fe-replete and Fe-depleted algae were determined using radioisotopes. Egg production was hyperbolically dependent on the Fe assimilation rate (r 2 5 0.71). The effect of Fe on copepod reproduction rates could not be explained by changes in ingestion rate and the rate of carbon assimilated, because there was no significant difference of ingestion rate and C assimilation between Fe-replete and Fe-depleted treatments. Iron might limit zooplankton productivity in high-nutrient, low-chlorophyll regions.

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Section: Discussionmentioning

confidence: 99%

Can copepods be limited by the iron content of their food?

Chen

Baines

Fisher

2011

Limnology & Oceanography

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“…Some compounds have been shown to correlate well with rates of fecundity and, hence, may be indicative of their supply controlling natural rates of egg production in copepods. These compounds include amino acids (Kleppel et al 1998) and fatty acids (Pond et al 1996), especially polyunsaturated fatty acids 20 : 5(n-3) and 22 : 6(n-3) (Jónasdóttir et al 1995). The ratio of seston 20 : 5(n-3) to carbon relates closely to daphnid growth rates in fresh waters (Müller-Navarra et al 2000).…”

mentioning

confidence: 99%

Growth of marine planktonic copepods: Global rates and patterns in relation to chlorophyll a, temperature, and body weight

Hirst

Bunker

2003

Limnology & Oceanography

322

265

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We compiled a global data set of copepod in situ weight-specific fecundity and growth rates, together with measurements of their body weights, and the chlorophyll a and temperature of the natural water in which these animals were growing. Juveniles can achieve half-saturation of their growth (K m ) at chlorophyll a concentrations almost an order of magnitude lower than adult females can their weight-specific fecundity. Adult weight-specific fecundity rates in situ are correlated with temperature, but the Q 10 s of 1.59 and 1.43 in broadcast and sac spawners, respectively, are much lower than under food saturated laboratory conditions (Q 10 s of 2.75 and 3.98). By comparing the in situ and laboratory food saturated results we are able to assess food limitation in the environment. The degree of food limitation increases with increasing temperature for adults; in situ rates approximate food saturated rates at low temperatures (0-10ЊC), at 25ЊC they are on average only about one-fifth of those at food saturation. By contrast, in situ juvenile rates are more strongly temperature-dependent than their adults and close to food saturation even at high temperatures. Juveniles grow much more rapidly and closer to food saturation than do adults of a similar size. There are several possible reasons for this. Compounds needed for egg production may simply be more dilute than those used in somatic growth. However, it is also possible that food limitation acts very differently in adults than juveniles. Molting rates in juveniles are strongly temperature dictated, and if sufficient weight is not added between molts, these slower growing juveniles do not survive. Adults, by contrast, can survive for long periods without having sufficient food to produce eggs.Copepods are the dominant mesozooplankton in the marine environment, comprising as much as 80% of its total biomass (Kiørboe 1998). They are important grazers of phytoplankton and microzooplankton (Atkinson 1996) and form a major trophic link to many predatory invertebrates and fish. Copepods also play a fundamental role in the upper ocean-exporting, redistributing, and repackaging carbon and nutrients (Banse 1995).Weight-specific fecundity and growth are key parameters-descriptors of the rates at which copepods process material, these terms also relate to their potential to supply energy and matter to higher tropic levels. Productivity has become a central and extensively studied aspect of marine plankton research over the last few decades (Runge and Roff 2000). Although egg hatch and postembryonic development times show strong temperature dependence in a wide range of animal groups, including zooplankton (Peterson 2001;Gillooly et al. 2002), these rate processes are largely free from food limitation. Postembryonic development times can 1 Corresponding author (aghi@bas.ac.uk).

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“…В свою очередь, речной зообентос является кормом для многих видов рыб (Power and Matthews, 1983;Ronnestad et al, 1999;Conceição et al, 2003). Несбалансиро-ванность АК состава пищи (перифитона) для первичных консументов (макрозообентоса) негативно отражается на многих физиологи-ческих процессах, включая рост, иммунитет и размножение водных беспозвоночных, что, в свою очередь, приводит к ухудшению кормо-вой базы рыб (Kleppel et al, 1998;Conceição et al, 2003;Aragao et al, 2004;Helland et al, 2010).…”

Section: Introductionunclassified