Fish Maw
Fish maw is the dried swim bladder of a fish, recovered at processing, cleaned of blood and membrane, and dried into a rigid translucent sheet that keeps for years at ambient temperature. It is a collagen rich delicacy in Chinese and Southeast Asian cooking, soaked and braised into soups and banquet dishes, and it is also a raw material for collagen and isinglass extraction. Croaker, catfish, threadfin, barramundi, cod and totoaba relatives supply most of the trade, and the value of a maw depends heavily on the species it came from, on how thick the bladder wall is, and on how cleanly it was cut and dried.
Listed fish maw markets
Each line is a grade at a delivery point. Open one for its full specification and terms.
Grades
Fish maw is contracted on the species it came from, on the cut and the dressing, on size, and on the thickness and colour that determine how it behaves when it is soaked and braised.
Species identity and product form
6 grades
| Grade | Definition |
|---|---|
| SpeciesDeclared, by scientific name | Croaker and drum species of the Sciaenidae family, catfish of the Pangasiidae family, threadfin, barramundi, cod and hake. Species is the largest single determinant of value and it is verifiable by genetic testing. |
| Wild or farmedDeclared | Wild caught maw and farmed maw trade as different products. Farmed catfish maw is the volume grade and wild croaker maw is the premium. |
| CutDeclared | Whole bladder, split and opened flat, or tube form left uncut. The cut is agreed before processing because it cannot be changed afterwards. |
| DressingDeclared | Blood vessels, the outer membrane and the fatty tissue removed or left on. Fully dressed maw commands the premium and it also loses more weight in processing. |
| FinishDeclared | Sun dried, hot air dried, or dried and then deep fried into a puffed form. Fried maw is a distinct product with its own soaking behaviour. |
| Protected species declarationDeclared, with the permit where applicable | Maw from species listed under the Convention on International Trade in Endangered Species moves only under permit, and several fisheries are closed outright. Species substitution is the fraud risk that customs authorities test for. |
Size and physical grading
7 grades
| Grade | Definition |
|---|---|
| Piece weightGrams per piece | Weighed individually on a drawn sample. Large single pieces carry a disproportionate premium because they present whole on a banquet plate. |
| Piece countCount per kilogram | The commercial size grade, taken on the consignment weight against the drawn sample. |
| Wall thicknessMillimetres | Measured with a gauge at the thickest point on a drawn sample. Thickness governs the soaked texture and it separates a braising grade from a soup grade. |
| Length and widthCentimetres | Measured flat on split maw, and used where the buyer needs a presentation size. |
| ColourDeclared, against an agreed retained sample | Pale gold to amber on well dried maw. Darkening indicates blood left in the tissue or heat damage in drying. |
| Shape and flatnessDeclared | Even, flat and uncurled pieces pack better and soak evenly. Curled and twisted pieces are a lower grade. |
| Holes, cuts and tearsPercentage by count, maximum | Damage from careless removal at the processing line, counted on a drawn sample. |
Composition and laboratory analysis
7 grades
| Grade | Definition |
|---|---|
| MoisturePercentage by mass, maximum | Determined by oven drying. Under dried maw moulds and over dried maw becomes brittle and breaks in transit. |
| Crude proteinPercentage by mass | Determined by the Kjeldahl or Dumas method. Maw is almost entirely collagen and the protein figure is the check on the dressing quality. |
| AshPercentage by mass | Elevated ash points to salt carried in from a brine wash or to sand from a drying floor. |
| Crude fatPercentage by mass | Residual fat from incomplete dressing. It is the cause of the rancid odour that develops in storage. |
| Residual bloodDeclared, against an agreed retained sample | Assessed by inspection under transmitted light. Blood left in the vessels darkens the maw and taints the broth. |
| Soaking and swelling performanceTimes the dry weight, by mass after soaking | Measured by soaking a weighed sample under an agreed protocol. It is the functional test the end user runs and it is written into premium contracts. |
| Peroxide valueMilliequivalents per kilogram | Oxidation on the residual fat, used where the lot has been stored or where a rancid complaint is raised. |
Cleanliness, contamination and food safety
9 grades
| Grade | Definition |
|---|---|
| Foreign matterPercentage by mass, maximum | Sand, shell, stone, plastic, netting and any material that is not the named product, separated by hand from a drawn sample and weighed. |
| Heavy metalsMilligrams per kilogram, maximum, by named element | Mercury, cadmium, lead and inorganic arsenic, determined by atomic absorption or mass spectrometry against the limit in force at the destination. |
| Microbiological criteriaColony forming units per gram, and presence or absence for pathogens | Total plate count, Escherichia coli, Salmonella, Vibrio and Staphylococcus, examined under the Codex and destination criteria on samples prepared to ISO 6887. |
| Additive and preservative residuesMilligrams per kilogram, maximum, by named substance | Sulphite, benzoate, hydrogen peroxide, borax and any bleaching agent, declared and tested. Several destinations prohibit substances that others permit. |
| Veterinary drug and pesticide residuesMicrograms per kilogram, maximum, by named substance | Applies to farmed product. Chloramphenicol, nitrofurans, malachite green and the tetracyclines are the residues most often tested at discharge. |
| Insects, mites and live pestsZero tolerance where specified | Dried marine products are stored goods and they attract pests. Inspected before stuffing, and a live find at discharge is a rejection rather than a discount. |
| Decomposition and taintOrganoleptic examination of a cooked and a raw portion | Assessed by a trained panel under the Codex sensory method. Ammoniacal, rancid or sour notes are defects and they are recorded against the sample. |
| Bleaching agentsDeclared, and prohibited where stated | Hydrogen peroxide and sulphur treatment are used to whiten maw and they are restricted or prohibited in several destinations. |
| Insect damage in storagePercentage by count, maximum | Dried maw is a stored good and beetles bore into it. Inspected before stuffing. |
Delivery, documentation and certification
10 grades
| Grade | Definition |
|---|---|
| PackingDeclared, with the inner and outer format | Carton, sack, drum, vacuum pouch or interleaved block, with the net weight per unit and the marking written into the contract. |
| Weight basisDeclared | Net weight, net of glaze where the product is glazed, and shipped weight or landed weight, with the survey house named. |
| Health certificateCertificate, issued by the competent authority of the exporting country | Required by most destinations for products of animal origin. It names the approved establishment number of the processing plant. |
| Establishment approvalApproval number, issued by the destination authority | European Union approval number, China GACC registration number or United States FDA registration, named on the contract when the destination requires it. |
| Catch or farm documentationCertificate, with the vessel or farm named | Catch certificate under the illegal, unreported and unregulated fishing rules, or the farm registration and movement documents for cultured product. |
| Cold chain or storage conditionDeclared, in degrees Celsius or as ambient dry storage | Carrying temperature, the recorder placed in the container and the tolerance, agreed before loading. |
| CertificationCertificate, with the scheme and the certificate number | Marine Stewardship Council, Aquaculture Stewardship Council, Best Aquaculture Practices, organic or halal, named on the contract when it is contracted. |
| Traceability and lot identityDeclared, with the lot code | Production date, lot number and the vessel, landing site or farm of origin, carried on the carton and on the packing list. |
| Species certificateCertificate or laboratory report | Where the contract or the destination requires it, a genetic species confirmation issued against a drawn sample. |
| PackingDeclared | Carton with interleaving to stop pieces breaking, or vacuum pack for the premium grades, with desiccant where the destination is humid. |
Grades outside this list trade on request. Send us the contract specification you work to and we will price against it.
Locations
| Country | Region | We trade it as |
|---|---|---|
| Bangladesh | Chattogram, Cox s Bazar and the Bay of Bengal coast | Origin and destination |
| India | Tamil Nadu, Kerala, Gujarat and Andhra Pradesh | Origin and destination |
| Vietnam | Khanh Hoa, Kien Giang and the Mekong delta | Origin and destination |
| Indonesia | Sulawesi, Nusa Tenggara, Java and Maluku | Origin and destination |
| Malaysia | Sabah, Sarawak and the Perak coast | Origin and destination |
| Thailand | Samut Sakhon, Songkhla and the Andaman coast | Origin and destination |
| Myanmar | Rakhine and Tanintharyi coasts | Origin and destination |
| Philippines | Visayas, Palawan and Mindanao | Origin and destination |
| China | Shandong, Fujian, Guangdong and Hainan | Origin and destination |
| Hong Kong | Sheung Wan dried seafood trade and re-export into mainland China | Destination and trading hub |
| Taiwan | Kaohsiung and the western coastal processing base | Destination |
| Singapore | Regional trading, finance and re-export | Trading and finance |
| United States | Alaska, the Gulf coast, New England and the Pacific northwest | Origin and destination |
| Mexico | Baja California, Sonora and the Yucatan shelf | Origin and destination |
| Brazil | Northeast coast and the Amazon estuary | Origin and destination |
| Argentina | Patagonian shelf and the Buenos Aires ports | Origin and destination |
| Nigeria | Lagos and the southern consuming market | Destination |
| Mauritania | Nouadhibou and the Banc d Arguin shelf | Origin and destination |
| Senegal | Dakar and the Petite Cote | Origin and destination |
| United Arab Emirates | Dubai re-export and Gulf consumption | Destination |
| Canada | Atlantic provinces and British Columbia | Origin and destination |
| Norway | Nordland, Troms and the Lofoten grounds | Origin and destination |
| Iceland | North Atlantic demersal and pelagic grounds | Origin and destination |
Origins and destinations outside this list trade on request. We are not limited to the locations shown here.
Timing
Harvest is when the catch is landed or the crop is taken at origin. Arrival is when a shipment from that origin typically lands in a consuming market. The gap between them is processing, drying or freezing, inspection, veterinary clearance and the voyage.
HarvestArrival
| Origin | J | F | M | A | M | J | J | A | S | O | N | D | Window |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Bangladesh | Harvest and arrival | Harvest and arrival | Arrival | Arrival | Harvest | Harvest | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest Aug to Feb, arrival Oct to AprBay of Bengal croaker season through the post monsoon months, with drying in the cool dry weather. | |||
| India | Harvest and arrival | Harvest and arrival | Harvest and arrival | Arrival | Arrival | Harvest | Harvest | Harvest and arrival | Harvest and arrival | Harvest Sep to Mar, arrival Nov to MayPost monsoon croaker and catfish landings on both coasts. | |||
| Vietnam | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest Jan to Dec, arrival Jan to DecFarmed pangasius maw recovered continuously at the processing plants, so supply is steady rather than seasonal. |
| Indonesia | Harvest | Harvest | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Arrival | Arrival | Harvest Apr to Oct, arrival Jun to DecWild croaker landings through the dry monsoon on the Java and Sumatra coasts. | |||
| Myanmar | Harvest and arrival | Harvest and arrival | Harvest and arrival | Arrival | Arrival | Harvest | Harvest | Harvest and arrival | Harvest Oct to Mar, arrival Dec to MayRakhine and delta croaker season in the dry months. | ||||
| Mexico | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Arrival | Arrival | Harvest | Harvest | Harvest Nov to Apr, arrival Jan to JunGulf and Pacific croaker landings in the cooler half of the year. | ||||
| Brazil | Harvest | Harvest | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Arrival | Arrival | Harvest May to Oct, arrival Jul to DecNortheast coast and estuary landings across the drier months. |
Windows outside this pattern trade on request, including carry, forward positions and stock already sitting in a destination warehouse.
Customs, packing and contract terms
Indicative terms for fish maw. Tariff classification is the importer’s responsibility and limits change, so confirm both against the destination customs authority and the current regulation before you fix a contract.
- HS heading0305.20 Livers, roes and swim bladders of fish, dried, smoked, salted or in brine
- PackingCartons of 10 kg to 20 kg with food grade liner, vacuum packed for high value items. Water activity at pack decides whether the lot ships ambient or chilled.
- Container loading20ft: 10 t to 18 t, generally volume limited. Reefer at minus 18 degrees Celsius for frozen, ambient or chilled for dried depending on water activity.
- Contract and arbitrationSale on sample and specification against a certificate of analysis, with the establishment approval number stated in the contract. Arbitration under ICC rules or at the contract seat.
- Destination limitsEU third country establishment listing and health certification under Regulation 2019/627 with a catch certificate under the IUU Regulation 1005/2008. Heavy metal limits for cadmium, lead, mercury and inorganic arsenic under Regulation 2023/915, histamine controls on scombroid species, CITES Appendix II listing for several sea cucumber species, and novel food authorisation for algae without an EU history of consumption.
Common questions
What grades of fish maw does SIP Global trade?
We quote 39 published grades of fish maw, including Species - Declared, by scientific name, Wild or farmed - Declared, Cut - Declared, Dressing - Declared, Finish - Declared and Protected species declaration - Declared, with the permit where applicable. Every grade is tied to a delivery point and a settlement route. Grades outside the published list are priced on request.
How is fish maw graded?
Fish maw is contracted on the species it came from, on the cut and the dressing, on size, and on the thickness and colour that determine how it behaves when it is soaked and braised. Grading runs on 5 systems: Species identity and product form, Size and physical grading, Composition and laboratory analysis, Cleanliness, contamination and food safety and Delivery, documentation and certification.
Where does SIP Global trade fish maw?
We trade fish maw in Bangladesh, India, Vietnam, Indonesia, Malaysia, Thailand, Myanmar and Philippines and 15 further markets. Origins and destinations outside this list trade on request. We are not limited to the locations shown.
When is fish maw harvested and when does it arrive?
Typical windows are Bangladesh: harvest aug to feb, arrival oct to apr; India: harvest sep to mar, arrival nov to may; Vietnam: harvest jan to dec, arrival jan to dec; Indonesia: harvest apr to oct, arrival jun to dec; Myanmar: harvest oct to mar, arrival dec to may. Harvest is when the lot is taken at origin, arrival is when a shipment from that origin lands in a consuming market. Windows outside this pattern, including carry, trade on request.
What is the HS code for fish maw?
Fish maw is normally classified under HS 0305.20 (livers, roes and swim bladders of fish, dried, smoked, salted or in brine). The heading follows the form the goods are in at the border, and national tariffs extend it beyond six digits, so confirm the full line with the destination customs authority before you fix a contract.
How do I get a price for fish maw?
Send the grade, the origin and the delivery window to the SIP Global desk. That is enough for a trader to come back with a level and a settlement route. 1 listed fish maw market is published on this page, each with its full specification and terms. We take both sides, physical and financial, prompt to long dated.
Standards and data sources
The grading language on this sheet follows published standards. Trade volumes and tariff lines are public record. Verify anything here against the source.
- ISOInternational Organization for Standardization
- Codex AlimentariusFAO and WHO food standards
- UN ComtradeOfficial international trade statistics by HS code
- ITC Trade MapBilateral trade flows and tariff data
- FAOSTATFAO production and trade series for agricultural commodities
Price this with our desk
Grade, origin and window if you have them. If what you are carrying does not fit the sheet above, describe it in your own words and a trader will take it from there.