Calculate signed logarithmic specific growth rate from two matched fish-sample means and compare it with an external reference while retaining sample counts.
A quick decision brief for this specific tool
Matched initial/final sample mean weights, elapsed days, whole sample counts and an independently sourced SGR reference using the same conventions
Signed logarithmic SGR, mean-weight change, sample-count context and signed calculated-versus-reference difference
Reconciles two cohort sample records and accepts decline; it does not infer individual growth, survival, feed conversion, health or production performance
Choose your path
Reconcile signed cohort sample growth with an external SGR reference while retaining sample counts and accepting genuine decline records.
Calculate signed SGR from matched sample means and dates without losing sample-count context.
Enter both means, elapsed days, whole counts and a reference using the same conventions.
Sees reproducible signed growth and the reference difference, including a valid negative result.
Keep mortality, grading, feed and water-quality causes outside one mean-weight comparison.
Use the worksheet as one record beside biomass, feed, mortality and repeated environmental observations.
Does not interpret low or negative SGR as a diagnosis or individual-fish result.
Match species, cohort, sample method, interval and formula basis.
Verify the external study and measurement conventions before entering its reference.
Does not transfer a benchmark across incompatible cohorts or conditions.
Outputs and checklists are planning aids. Review the linked current authorities and the records, terms, instructions, and requirements that apply to your exact situation before a consequential decision.
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Enter positive initial and final mean weights from the same defined cohort, the actual interval in days, and the whole number of fish represented by each sample. A smaller final mean is valid and produces a signed negative result.
The worksheet calculates [ln(final mean) minus ln(initial mean)] divided by elapsed days, multiplied by 100. It also retains simple mean-weight change and change per day as separate descriptive records.
The entered reference must use the same species or stock, cohort, weight and time units, sampling convention, production conditions, and logarithmic formula. The signed difference is arithmetic, not a performance grade.
Updated: August 2026
Reconcile two scheduled sample means while keeping the number of weighed fish visible beside the result.
Record a negative SGR rather than rejecting it, then review mortality, grading, feed, disease, handling, temperature, oxygen, and water quality separately.
Compare a cohort record with an independently sourced reference only after matching biological, environmental, and measurement conventions.
The sampled fish may differ between dates, and mortality, removals, grading, and sampling selection affect the mean. Preserve those records and do not infer individual trajectories.
A reference from another species, size class, temperature, feed, husbandry system, interval, or SGR convention is not directly comparable.
This worksheet reconciles signed specific growth from two documented cohort samples with an external comparison value. It preserves counts and accepts decline while leaving health, survival, feed performance, and production decisions to the full farm or study record.
