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Live sample collection for transportationFish should be packed in secured containers such as double plastic bags or polystyrene box. Polystyrene box issuitable to pack the spiny fish species which requires a durable container and when the destination is not far.Double plastic bags are more popular for long distance transportation including by airways. Water can be filled toone third of the container capacity with the remaining 2/3 volume inflated with oxygen. The bags should be tightlysealed with rubber bands and packed inside a polystyrene box or cardboard box lined with styrofoam. Ice packsmay be required for a long transportation. The volume of water to fish volume is particularly important for live fishbeing shipped for ectoparasite examination, so advance checking with the diagnostic laboratory is recommended.To shorten the time between removal of fish from water and transportation, samples should be collected as closeas to the shipping time and early inform the diagnostic laboratory.Tissue sample collectionPrior to fixation, fish should be humanly killed. Small fish can be done by decapitation, while the larger fish isdone with a overdose of anaesthetics. Very small fish can be wholly immersed into the fixative agent in a minimumof 10:1 (fixative: fish) volume ratio. For large fish, the body cavity should be split open and displaced the visceraorgans to allow maximum penetration of the fixative. The organs can be possibly removed and fixed separatelywith the 10:1 (fixative: sample) volume ratio. Most tissues require a minimum of 24-48 h fixation time. Howeverfor some specific diagnostic techniques, the length of fixation may be varied. For instance, the samples collectedfor DNA-based technique analysis, the fixation time should not exceed 24 h as it may cause difficulty to recoverthe DNA from sample. So, it is highly recommended to get some advice for the diagnostic laboratory before theprocedure.The most suitable fixative for preservation of finfish for histopathological study is phosphate buffered formalinwhich can be prepared as following:37-40% Formaldehyde 100mlTap water 900 mlNaH 2 PO 4 .H 2 O 4.0 gNa 2 HPO 4 6.5 gGeneral diagnosisExternal examinationPlace the specimens on the clean flat board and keep them moist during examination. Examine external bodysurface, body form, abdominal form, skin coloration, eye appearance, and record any abnormality. The entiresurface should be examined including opercular and oral cavities, gills and fins.Scrape along the body trunk of specimen with coverslip and place on a slide with a drop of water. Examine thesample under a light microscope. Gill samples are also taken and examine in the same method.Internal examinationWithdraw blood samples from a caudal peduncle, where the fish is too small to do so, the caudal peduncle can bechopped off to collect the blood sample. Place a small drop of blood and smear on the slide and observe underthe light microscope for any parasite infection.Open up the abdominal cavity. Observe any lesion and abnormality of the visceral organs such as discoloration,enlargement, ascites, oedema, lesion and nodules. The organ can be aseptically collected for bacteriogical andvirological examination.50