Chemical Changes during Growth and Starvation of Herring Larvae

Herring Clupea harengus larvae were hatched and reared for 66 d in the laboratory to test hypotheses concerning correlations between nucleic acid concentrations and growth rates. A modified absorbance method is introduced which allowed RNA, DNA and protein to be measured on individual larvae. The amounts of RNA, DNA and protein increased per larva but no significant correlation was found between protein growth rates and RNA concentration, RNA:DNA or RNA:protein. After 7 d of starvation there was a significant loss of RNA, DNA and protein only in larvae 65 d old. It is concluded that nucleic acid ratios, except perhaps protein to DNA ratios, are not valuable for estimating growth rates of wild larvae.

Section: Effects Of Food Deprivationmentioning

confidence: 81%

“…It has been shown (Ehrlich 1974a) that starved herring larvae show increased water content and decreased carbohydrate, protein and fat contents. However, the comparison between fed and starved larvae is further complicated by changes in the same parameters with larval age or developmental stage.…”

Section: Effects Of Food Deprivationmentioning

confidence: 99%

RNA, DNA and protein concentrations in fed and starved herring Clupea harengus larvae

Mathers¹,

Houlihan²,

Burren³

1994

“…Herring larvae of 10 to 25 mm length consist of ca 70 O/ O protein, 4 % carbohydrates, and 5 % triglycerides in addition to ash (Erlich 1974). Three to 5 molecules of adenosine triphosphate (ATP) are required to form a peptide bond (e.g.…”

Section: Magnitude and Composition Of Sdamentioning

confidence: 99%

Respiration and growth of larval herring Clupea harengus: relation between specific dynamic action and growth efficiency

Kiørboe¹,

Munk²,

Richardson³

1987

146

Rates of growth and oxygen consumption were measured in larval herring Clupea harengus fed various rations (specific ingestion rate between 0 and 45 % body wt d-l). Initially, growth increased linearily with ingestion. However, it showed a saturating response at highingestion rates, probably caused by a decline in assimilation efficiency. Growth efficiency was expressed as slope of the linear portion of the growth-ingestion (or growth-assimilation) relationship. The efficiency by which ingested (or assimdated) material in excess of maintenance requirements was converted to larval body mass was high, 0.62 (or 0.89), compared to reported estimates in juvenile fish. The oxygen consumption rate (R, ng Oz h-') of anaesthetizedlarvae could beseparated into two components, one proportional to the body mass (W, pg dw) raised to some exponent b and one component proportional to the growth rate (p X W, pg dw d-l): R = 131 WO" + 127 p X W. At starvation, the respiration-mass relationship followed the commonly applied allometric equation and had a weight exponent close to the classical Y3. Growing larvae, however, increased their rate of oxygen uptake above the starvation level by ca 127 ng O2 per pg larval dry weight increment ( = apparent metabolic cost of growth = specific dynamic action (SDA) expressed relative to growth). T h s en~pirical estimate was close to a theoretical minimum estimate of the cost of biosynthesis and transport but was in the lower range of the empirical values reported for juvenile fish. The observed SDA predicted a growth efficiency very close to that actually observed. The magnitude and composition of SDA in larval and juvenile fish is discussed and it is concluded that the cost of growth is minimum and the efficiency of growth maximum in larval compared to juvenile fish. In an ecological context, this difference may be related to the very steep decline in natural mortality with increasing fish body mass and to the extraordinarily high mortality rates experienced by marine pelagic fish larvae in nature.

“…Ehrlich et al, 1976;Theilacker, 1978;Buckley, 1979Buckley, , 1980O'Connell, 1980). Chemical composition -including the relative weights of dry matter, carbon, and nitrogen -change during starvation for larval Atlantic herring (Ehrlich, 1974a). Similarly, the condition factor of larval Atlantic herring decreases during starvation (Hempel and Blaxter, 1963;Ehrlich et al, 1976).…”

Section: Introductionmentioning

confidence: 99%

Relation of growth to ingestion for larvae of Atlantic herring Clupea harengus and other fish

Checkley¹

1984

Larvae of Atlantic herring Clupea harengus were reared on wild plankton and Artemia salina nauplii in the laboratory at 7 to 9OC for 95 d. Between ages of 20 and 38 d, larvae were fed only Artemia nauplii and the specific rates of ingestion and growth were measured and compared. Relations of rate and efficiency of growth to ingestion were similar in terms of carbon and nitrogen. Growth was linearly related to ingestion (r2 = 0.89, n = 9). Starved larvae lost mass at a specific rate of 0.03 d-I (3 % d l ) until death at 14 d. A specific ingestion rate of 0.04 d 1 was required to balance defecation and metabolism. Gross growth efficiency (growth ratehngestion rate) rose from -1.2 at a low ingestion rate (0.015 d l ) to 0.4 at the greatest observed ingestion rate (0.11 d ' ) . Condition factor (dry weight length3) was significantly related to both ingestion rate and length (r2 = 0.69, n = 20). These results, combined with those for other fish larvae, indicate an asymptotic relation between rates of growth and ingestion such that gross growth efficiency is maximal (0.4) at intermediate ingestion rate. Fish larvae surviving in the sea appear to maximize their ingestion rate and thus grow rapidly but with a reduced efficiency.