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Eated the pond bottom prior to filling up with water and
Eated the pond bottom prior to filling up with water and stocking. Immediately after harvest, ponds had been drained and totally exposed to prevailing sunlight for a period ranging from to days, normally within the months of December to PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/9549335 January. During this fallow period, generally, on the list of following four solutions of sediment treatment was adoptedremove sludge, dry in sunlight with addition of quicklime (CaO) ( of farms); dry in sunlight with addition of quicklime ( of farms); dry in sunlight and tilling with quicklime ( of farms); only drying in sunlight ( of farms). Following the above pond preparation, submerged macrophytes utilized for preserving water high-quality and giving refuge during the mitten crab growth cycle, were transplanted back into ponds. By far the most commonly transplanted species integrated Elodea canadensis Michx. (EC) ( of farms), Vallisneria natans Hara (VN) (. of farms), Ceratophyllum demersum Lin (CD) ( of farms), Hydrilla verticillata (Linn. F.) Royle var. rosburghii Casp. (HV) ( of farms), and Myriophyllum spicatum L. (MS) ( of farm). Most farms adopted a mixture from the above species, but in varying combinations and proportions of species. Availability was also a key issue that constrained macrophyte species selections. 5 to seven days just before cultivation of macrophytes culture ponds have been filled with water to a depth of cm. Commonly crab culture ponds had been drained to a depth of cm prior to transplanting macrophytes. As an example, for species such as E. Canadensis, C. demersum and H. verticillata, the stem was cut into a couple of pieces of cm. Each and every bunch of macrophytes with 5 to ten pieces of stem was planted evenly at an interval of .Fig. Frequency distribution of a size, b water surface location, and c pond size on the mitten crab farms surveyedRoyal Swedish Academy of Sciences www.kva.seenAmbio , :. m on the entire bottom from the ponds. Thereafter, the water depth was regulated determined by the development of macrophyte just before stocking mitten crab. Prior to stocking, farmers adopted a varying quantity of approaches to eradicate all undesirable fish, crayfish andor other aquatic animals. The most widespread approaches applied had been application of quicklime ( of farms), Calcium hypochlorite (Ca (ClO)) , povidoneiodine ((CHNO)n I) ( of farms), teaseed cake ( of farms) and remaining of farms utilized other procedures. The amounts and also the number of instances applied varied in between farms and didn’t strictly adhere to any recommendations. Stocking The main stocking period was among February and April along with the stocking size of mitten crab ranged from . to . g person, and averaged . (. g person. Of your surveyed farms . stocked mitten crab of g individual. Stocking densities applied in growout mitten crab farming ranged from to people ha , and primarily depended on the size and also the availability of coinsized crabs as well as the projected market place cost. Of the surveyed farms stocked individuals ha mitten crab. Amongst each of the surveyed farms, stocked only when in a calendar year and the rest stocked instances, frequently when driven by low survival rates of stocked c
oinsized crab at the initial stocking. Higher early mortalities resulted mainly from, for example, longdistance transportation, extreme climate (e.g. water shortage), incomplete PHCCC biological activity disinfection or water pollution. All farms treated coinsized crab prior to stocking, as well as the big therapies integrated application of salt (NaCl) ( of farms) and potassium permanganate (KMnO) ( of farms). The amounts of those chemical substances applied varied involving far.

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Author: Gardos- Channel