The LARVAL NURSERY Table

After hatching, yolk-sac fry need to be transferred to a new environment for on-growing.

The field Nursery system gives a broad classification of the appropriate culture systems for the selected species. The field Details gives additional information on the rearing facilties, such as handling of larvae, shape and technical design of rearing facilities, and details about water supply and exchange.

The Number of larvae field indicates the typical number of larvae in a rearing tank, whereas the Stocking density field gives a relative number per unit for optimal stocking of larvae.

The field Main water source indicates the most common water source used for water supply; an alternate source is mentioned in the field Supplemental water source.

The fields Temperature, Salinity, pH, Oxygen and Hardness and Illumination indicate optimal abiotic values for larval rearing.

The Time to fry field gives information on the time needed for larvae to reach the fry stage in day-degrees and in days. Because this period depends to a great extent on the water temperature, the values presented here relate to the indicated Temperature.

Larval morality

The Mortality field states the range of relative larval mortality encountered during the period from hatching to fry stage, in percent.

The First feed field gives in day-degrees or days the time after hatching when commencement of first feeding is necessary for good survival rates.

The Production/cycle field indicates the number of larvae produced per cycle and unit (e.g., number/m3). The field Production/year indicates the total production per year and unit (e.g., number of larvae/m2). Notes about growth performance may be shown in the free text field Growth rate, where larval growth can be noted in relation to environmental conditions and feeding regime.

The next section Nutrient inputs in the Larval Nursery System table refers to the larval feed. The Main food field generally indicates the feed needed throughout the larval period until metamorphosis. Description of nutrient input is a free text field and describes details such as the diet sequence, food quality (e.g., the need for certain fatty acid profiles for normal development) and density of food organisms. The free text field Comments may be used for further relevant notes about specific requirements of the species, such as sorting, grading and transportation, critical periods, quality control measures, treatment against infection and parasites, and more.