Preparation of the culture system

Initially, the system should be cleaned and flushed with filtered freshwater. Valenti et al. (1998) also recommended that tanks, filters and every piece of equipment should remain immersed in running water for a few weeks prior to first-time use. This process eliminates toxic substances from the material.

Tanks and biofilters should be filled with brackishwater or freshwater and artificial salts. Water prepared using a commercially manufactured artificial salt mixture should be thoroughly filtered after addition of the salts, because most oftheseproducts use a protein-based carrier molecule that leaves a film or colour. As described in section 5.3.3, caution should be used in selecting artificial salt mixtures and experimentation with new salts is recommended.

Water temperature and salinity need to be adjusted to optimal larval culture conditions and allowed to stabilise prior to stocking. Systems may require adequate heating, and it is desirable to provide a controlled water temperature regardless of air temperature. It should be maintained between 28 and 32°C. Salinity should be kept within 12 to 16p.p.t. (Sandifer et al. 1977; Valenti 1996) and abrupt changes should be avoided. Cooper & Heinen (1991) reported that the best salinity for stage II M. rosenbergii larvae is 13 p.p.t. However, tolerance to salinity and to other environment factors is population-specific and, therefore, may vary according to the origin of broodstock. The initial salinity can be made lower (5-7p.p.t.) than the standard salinity used for rearing; this allows larvae to be stocked directly from the hatching tank, without acclimation. The salinity in the culture tank can then be increased by introducing the salt mixture through the sand filter. Addition of either salts or freshwater to adjust salinity during the larval culture phase should not be performed via the biofilter tank once the biofilter substrate has been added. Bacteria in the biofilter are sensitive to sudden changes in temperature and salinity. New water should be disinfected and filtered prior to introduction into the system. If properly handled and processed, the same brackishwater can be used for at least two consecutive cycles in M. rosenbergii hatcheries without affecting production (Mallasen & Valenti 1998a).

How To Have A Perfect Boating Experience

How To Have A Perfect Boating Experience

Lets start by identifying what exactly certain boats are. Sometimes the terminology can get lost on beginners, so well look at some of the most common boats and what theyre called. These boats are exactly what the name implies. They are meant to be used for fishing. Most fishing boats are powered by outboard motors, and many also have a trolling motor mounted on the bow. Bass boats can be made of aluminium or fibreglass.

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