Scottish Fish Farm Production Survey 2023

Glossary

Active: Fish farms in a production growing cycle which may contain stock or be fallow.

Broodstock: Adult fish held until maturation for breeding purposes.

Cleaner fish: Fish species that are used as biological control for parasites in the marine Atlantic salmon farming sector.

Diploid: Fish with the normal two sets of chromosomes.

ERM: Enteric redmouth disease.

Eyed-ova/eggs: Fish egg(s) at the stage of development when the heavily pigmented eyes of the embryo are sufficiently developed to be clearly visible.

Fallow: Fish farm having no stock, but still part of a growing cycle.

Fingerling: A term commonly applied to young stages of salmonid fish.

Fry: The life stage of a young salmon from independence of the yolk sac as the primary source of nutrition to dispersal from the redd.

Grilse: Salmon harvested between 1st January and 31st August after one winter at sea.

Intra-peritoneal: Within the body cavity.

IPN: Infectious pancreatic necrosis.

Larval stage: Recently hatched fish which live off a yolk sac attached to their bodies.

Non-producing: A site which is active, may be stocked with fish, but has not produced any fish for harvest during the specified year.

On-growing: Farm producing fish for the table market.

Ova: Eggs.

0-year fish: Fish in their first year of life.

Parr: Young salmon at stage from dispersal from redd to migration as a smolt.

Photoperiod: Alteration of the daylight regime.

Pre-salmon: Salmon harvested between 1st September and 31st December after one winter at sea.

Raceway: Concrete or brick channels used for farming fish.

SAV: Salmonid alphavirus.

S½: Salmon or sea trout smolting at approximately six months from hatch (usually by photoperiod and/or temperature manipulation).

S1: Salmon or sea trout smolting at approximately one year from hatch.

S1½: Salmon or sea trout smolting at approximately 18 months from hatch.

Smolt: Fully silvered juvenile salmon or sea trout ready to be transferred or to migrate to sea.

Stripped: Collection of ova/milt from broodfish.

Triploid: Triploid fish are sterile fish which have three sets of chromosomes, unlike fertile fish that have two sets of chromosomes (diploid).

Year 2 salmon: Adult salmon harvested during their 2nd year at sea.

Year class: Fish hatched or put to sea in a given year.