ISO 6887-3:2017 specifies rules for the preparation of fish and fishery product samples and their suspension for microbiological examination when the samples require a different preparation from the methods described in ISO 6887‑1. ISO 6887‑1 defines the general rules for the preparation of the initial suspension and dilutions for microbiological examination. ISO 6887-3:2017 includes special procedures for sampling raw molluscs, tunicates and echinoderms from primary production areas. NOTE 1 Sampling of raw molluscs, tunicates and echinoderms from primary production areas is included in this document, rather than ISO 13307, which specifies rules for sampling from the terrestrial primary production stage. ISO 6887-3:2017 excludes preparation of samples for both enumeration and detection test methods where preparation details are specified in the relevant International Standards (e.g. ISO/TS 15216‑1 and ISO/TS 15216‑2 for determination of hepatitis A virus and norovirus in food using real-time RT-PCR). ISO 6887-3:2017 is intended to be used in conjunction with ISO 6887‑1. It is applicable to the following raw, processed or frozen fish and shellfish and their products (see Annex A for classification of major taxa): a) Raw fishery products, molluscs, tunicates and echinoderms including: - whole fish or fillets, with or without skin and heads, and gutted; - crustaceans, whole or shelled; - cephalopods; - bivalve molluscs; - gastropods; - tunicates and echinoderms. b) Processed products including: - smoked fish, whole or prepared fillets, with or without skin; - cooked or partially cooked, whole or shelled crustaceans, molluscs, tunicates and echinoderms; - cooked or partially cooked fish and fish-based multi-component products. c) Raw or cooked frozen fish, crustaceans, molluscs and others, in blocks or otherwise, including: - fish, fish fillets and pieces; - whole and shelled crustacean (e.g. flaked crab, prawns), molluscs, tunicates and echinoderms. NOTE 2 The purpose of examinations performed on these samples can be either hygiene testing or quality control. However, the sampling techniques described in this document relate mainly to hygiene testing (on muscle tissues).