Week: 4 Growth and Metabolism Dr. Ir. Happy Nursyam, MS

Growth and Metabolism Im the 1984 Model So, this Is 2007 Length Weight Growth

Growth – Significance Population Estimators Population Estimator Biomass Growth Recruitment Mortality Fishing

Growth (Continued) Descriptors Regression Models and Fit Condition Factor (K) RNA:DNA Ratios Hepato/Somatic Index Weight at Age Bioenergetics Model

Regression Models and Fit Length Weight Length Weight r 2 =.95 r 2 =.75 Transition 1980s to 2000s

Condition Factor K = W · L -3 · 100 K = Condition Factor W = Weight L =Length Used to describe growth as a function of weight length relationships. Is a linear model.

RNA:DNA Ratios Assumption – Growth is protein based, therefore an indirect measure of growth is the ratio of RNA to DNA, the greater the ratio the less the production of protein, hence growth. IE lower RNA indicates a lack of protein production

Hepato-Somatic Index Assumption – Protein biosynthesis is largely mediated through the liver, hence increased demand for protein will be matched with and increase in liver volume. Increased Protein Synthesis Low Protein Synthesis

Weight at Age Age Length Back River MD Chester River MD

Growth Control Linear –G = Growth –a = Constant (growth rate of a 1 gm fish) –W = Fish Weight – b = weight exponent ( ) Asymptotic –The real relationship Age Weight Age Weight G = a x W b

Growth Manipulation TreatmentResponse High Protein DietProtein based growth increases Arginine enrichmentEnhanced juvenile growth Growth hormoneEarly smolt, hypoglycemia, decreased muscle protein IGF-1 (osmotic minipump) Mixed results, hypoglycemia AndrogensReduced condition factor EstrogensMixed results

Growth Manipulation Purpose Aquaculturevs.Restoration Fast GrowthNot Important Except for Juvenile growth Sterility PromotesNo (An obvious) Diversion of Energy From Development of Eggs and Sperm Docility PromotesNo Need Active Fish, Primarily Energy Conservation forForaging Growth

Growth – Issue of Markers Growth – Juvenile Oyster Disease (JOD) Selection resulted in fast growth, allowing for spat to grow beyond the effects of infection, interpreted as increased resistance. Immune Response – Rainbow trout selected for resistance to Enteric Redmouth, result was increased non-specific resistance, but not cell mediated resistance

Metabolism – Storage Sites Glycogen –Liver, Brain Lipid/Fats –Brain, Adipose Tissue, Liver, Red Muscle (Some Species) Proteins –All Cells, Muscle

Metabolism – Products and Exchanges Glucose - Glycogen Products – Glycogen, branched complex carbohydrate, mobilized to blood as glucose a monosaccharide Glycogen – Low storage amounts, short term solution to energy needs, rapidly depleted Dysfunctions – Carbohydrate rich diets (>20%) result in glycogen liver syndrome, excess stimulation of gluconeogenic pathways results in same condition Liver As Glycogen Blood Glucose Distribution to Organs

Metabolism – Products and Exchanges Fats/Lipids Liver – Conversions via Krebs from AAs, Glucose, FAs to FAs Liver – Formation of Lipoproteins Blood – Movement as FAs, Glycerol Adipose – Release as Glycerol and FAs Adipose – Conversion to Mobile FA Form TAG Lipase at Adipose