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The transport of individual sandfish in damp tea- towels for many hours has been practised with varying success.

Avoid

h Sudden temperature shocks and holding for long periods out of water, which can result in evisceration

h Damaging the skin of the animals – handle them gently

h Shocks during road transport

maintaining broodstock in tanks, sea pens and In sea pens

earthen ponds

Broodstock that are not yet mature can be kept in captivity until they ripen. Similarly, following

spawning, broodstock can be maintained near the hatchery for future use. These animals can be held in tanks, sea pens or earthen ponds.

Broodstock held at low density in tanks with continuously flowing seawater, fed powdered dried

algal preparations and ground-up prawn pellets, can often be spawned more than once.

Sea pens for holding broodstock should be located close to the hatchery so they can be monitored easily and regularly. Sea pens should be around 800 m2 and the stocking density of the broodstock should be <200 g/m2. Additional feed is not needed. Survival in sea pens is often very high, but growth rates may be lower than in ponds depending on local environmental conditions.

Earthen ponds, typical of those used for maintaining shrimp broodstock (450 to 1500 m2), have proved suitable for holding sandfish broodstock. Pond sediments should be friable, sandy-mud without large rocks. Water depths of <1 m are best. Ponds should be filled at least 2 weeks before transfer of broodstock to ensure natural plankton development. The stocking density of the broodstock should be <250 g/m². There should be daily water exchange or continuous flow. It should not be necessary to add any feed. Water quality parameters (temperature, dissolved oxygen and salinity) should be measured regularly, and daily if possible.

possible problems: Heavy rain can lead to stratification of water in the pond. Stratification can be detected by the presence of a thin layer of low-salinity water at the surface. The consequences of stratification can include an increase in temperature, fall in dissolved oxygen especially in the bottom layers, and development of anaerobic

areas in the sediment. The combination of these extreme conditions can be dangerous for sandfish, which are benthic and slow moving. It can lead to total loss of broodstock in a few days.

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