WO2008097108A1

WO2008097108A1 - Waterless storage and transport of live aquatic animals

Info

Publication number: WO2008097108A1
Application number: PCT/NZ2008/000014
Authority: WO
Inventors: Peter Cattin
Original assignee: Waterless Live Fish Transport Limited
Priority date: 2007-02-08
Filing date: 2008-02-08
Publication date: 2008-08-14
Also published as: PE20081817A1; WO2008097108A8; AU2008213166A1; TW200833238A; CL2008000414A1

Abstract

A method of storage and transport of live aquatic animals substantially without water, the method including the steps of placing the animal in a sealable receptacle and using the secondary gas effect to extend storage times of the animal. The gas mixture may include oxygen, helium, neon, Heliox28 and nitrous oxide.

Description

WATERLESS STORAGE AND TRANSPORT OF LIVE AQUATIC

ANIMALS

Field of the Invention

This invention relates to the storage of live aquatic animals, particularly crustaceans, fish and/or molluscs. More particularly, but not exclusively, this invention relates to the storage of live crustaceans, molluscs, and/or fish while in transportation.

Background of the Invention

Live crustaceans, fish and molluscs are highly sought after, generally to be sold as food. Live crustaceans, fish, and molluscs, when sold as food, command a premium price because of the guaranteed freshness, quality and flavour in comparison with the chilled and/or frozen counterpart. However, live crustaceans, fish and molluscs may also be desired for other reasons, such as pets.

Despite the significantly better market price possible for live crustaceans, and in particular lobster, crayfish, crabs, prawns, or the like, most crustaceans are not sold alive or, in the case of lobster, they are often sold frozen, and especially as frozen tails.

The problems with live crustacean transport include:

^■ High mortality rates

■ Relatively short survival times

Each of these problems contributes a high cost to industry. These costs must be balanced against the premium price that live crustaceans command.

Pre-shipment containment and conditioning of lobsters is typically as follows. The live lobsters are removed from the cages they are caught in and transferred to a ship where they are held in storage containers. Fresh sea water is continuously pumped through the storage containers. Once the ship docks, the lobsters immediately destined for market are typically transferred by truck to a land based holding system where they are hand graded for size then held in tanks supplied with re-circulated sea water. Each tank has a biofilter to nitrify faecal waste, mechanical filters for the removal of solid material and UV or ozone sterilisers to remove biological contaminants. Each day's catch is kept separate and the lobsters are held this way for several hours to allow the lobsters to purge before they are chilled to slow their metabolism prior to packing. The lobsters may then be packed into holding tanks at a temperature of between about 8⁰C and about 9⁰C, preferably about 8.5⁰C, for about 2-4 hours and then at a temperature of between about 5⁰C and about 6⁰C, preferably about 5.5⁰C, for about 8-10 hours. This procedure varies however, depending on the processor and the species of lobster.

Lobsters are then removed from the storage containers and are typically wrapped in wood wool to reduce the risk of damage; they are then packed in polystyrene shipping boxes with a frozen gel pack added to help maintain a temperature of approximately 5°C-8°C during shipping. Refrigerator trucks transfer the lobsters that have been packed into containers according to the above method to the airport or directly to seafood target markets/outlets.

Many existing target markets are up to 30 hours from the fish/crustacean pack house, with destinations further than 30 hours travel time away not being available due to the lack of ability to reliably deliver lobsters in a live state. It would be desirable to be able to keep crustaceans alive for extended periods of time and to reach markets that can be greater than 30 hours away. It is also highly desirable to make the process one that can achieve this at acceptable or reduced mortality rates. Mortality rates using prior art vary with post harvest handling practices and with distance to market, however prior art mortality rates of up to 12% are commonly accepted. This mortality loss is often compensated by over packing the shipping container, at no additional cost to the purchaser, with the weight of the anticipated mortality loss. Technology capable of reducing mortality rates when transporting crustaceans to existing markets less than 30 hours away would also be an advantage.

Similar issues apply to the provision of live fish, out of water, to target markets with concomitant short survival times and high mortality rates. If fish can be kept alive out of water for extended periods of time to allow access to markets that are currently unavailable to the live fish market, this would also be an advantage. Similarly, reducing the mortality of live fish during transit to existing markets and/or reducing the cost of freight by removing the water supporting the live fish, would also be highly desirable.

For the purposes of this specification, references to live crustaceans, fish and molluscs may be stated as being "live aquatic animals". Obiect of the Invention

It is an object of the invention to provide a method of storage of live aquatic animals that overcomes at least some of the disadvantages of the prior art, or to at least provide the public with a useful choice.

Summary of the Invention

In one aspect, the invention provides the use of the secondary gas effect in a method for the extended storage of live aquatic animals substantially without water.

In another aspect, the invention provides a method for storage of live aquatic animals substantially without water, the method including the steps of placing the animal in a sealable receptacle and introducing a gas mixture into the receptacle that comprises oxygen, helium, or neon in a proportion that differs from the proportion that the aquatic animal is subjected to in its natural habitat.

Preferably the method is capable of providing storage time of live fish for up to at least 10 hours, more preferably 20 hours.

Preferably the method is capable of providing storage time of live crustaceans for up to at least 30 hours, more preferably 40 hours.

Preferably, the use of the secondary gas effect includes providing a gas mixture that includes a gas (or gas mixture proportion) that is not typically in contact with cells or tissues of an animal (e.g., live aquatic animal) under normal environmental conditions (e.g., in resident or typical habitat conditions).

Preferably the method includes the use of a gas mixture including oxygen together with helium or neon. Preferably the gas mixture includes helium in an amount of at least about 0.001% by volume, more preferably at least about 0.01% by volume and more preferably about 0.1% by volume.

Preferably the gas mixture includes neon in an amount of at least about 0.004% by volume, preferably at least about 0.01% by volume, more preferably about 0.1% by volume. - A -

Preferably the gas mixture includes neon and/or helium in an amount of at least 1.0% by volume.

Preferably the gas mixture includes at least about 0.1% oxygen by volume, more preferably at least 1.0% by volume, most preferably at Ieastabout10% by volume.

Preferably the gas mixture is a mixture of helium and oxygen in a ratio of 72:28 (i.e. Heliox²⁸).

Preferably the gas mixture also includes nitrous oxide.

Preferably Nitrous oxide is present in an amount of at least about 0.01% nitrous oxide by volume, more preferably at least about 0.1% by volume, most preferably at least about 1.0% by volume.

In another aspect of the invention there is provided a gas mixture for use in the storage of live aquatic animals, said gas mixture including Heliox²⁸ in combination with nitrous oxide.

Preferably the Heliox²⁸ and nitrous oxide are mixed in a ratio of about 9:1.

In another aspect of the invention there is provided a method of storage of at least one crustacean, said method including the steps of:

^■ Placing the at least one crustacean in a sealable receptacle

■ Inserting a gas mixture into the receptacle, wherein the gas mixture is capable of assisting the crustacean(s) to remain alive for at least 30 hours with substantially no water

^■ Sealing the receptacle.

In another aspect of the invention there is provided a method of storage of at least one fish, said method including the steps of:

^■ Placing the at least one fish in a sealable receptacle

^■ Inserting a gas mixture into the receptacle, wherein the gas mixture is capable of assisting the fish to remain alive for at least 10 hours with substantially no water

^■ Sealing the receptacle.

Preferably the gas mixture is a mixture of helium and oxygen. Preferably the gas mixture is Heliox²⁸, a mixture of helium and oxygen in a ratio of 72:28.

Alternatively the gas mixture is a mixture of neon and oxygen.

Alternatively the gas mixture is a mixture of neon, nitrogen and oxygen.

Alternatively the gas mixture is, a mixture of oxygen, helium and nitrogen.

Preferably the gas mixture contains nitrous oxide in combination with one of the gas mixtures described above.

Preferably the gas mixture is a mixture of Heliox²⁸and nitrous oxide.

Preferably the gas mixture is a mixture of Heliox²⁸and nitrous oxide in a ratio of about 9: 1.

Preferably the gas mixture is introduced into the receptacle in a sufficient volume to give a final pressure in the receptacle of about 1 atmosphere.

Preferably a cooling means is placed in the receptacle.

Preferably the cooling means is a frozen gel pack.

Preferably a humidity means is placed in the receptacle.

Preferably, when the gas mixture used is Heliox²⁸ and the Heliox²⁸ is introduced into the receptacle in a sufficient volume to give a final pressure in the receptacle of about 1 atmosphere, the temperature in the receptacle is maintained in the range of about 6⁰C - 1O⁰C.

Preferably, when the gas mixture used is Heliox²⁸ and nitrous oxide in a ratio of about 9:1 and the Heliox²⁸ and nitrous oxide are introduced into the receptacle in a sufficient volume to give a final pressure in the receptacle of about 1 atmosphere, the temperature in the receptacle is maintained in the range of about 5°C - 12°C. Preferably, when the gas mixture used is Heliox²⁸ and nitrous oxide in a ratio of about 9:1 and the Heliox²⁸ and nitrous oxide are introduced into the receptacle in a sufficient volume to give a final pressure in the receptacle of about 1 atmosphere, the temperature in the receptacle is maintained in the range of about 6°C - 10⁰C.

Preferably the crustacean(s) or fish is/are submerged in sea water prior to being placed in a sealable receptacle.

Preferably the sea water is chilled to between about 8⁰C and about 9⁰C.

Preferably the crustacean(s) is/are submerged in seawater for up to about 4 hours while the sea water is chilled to between about 8⁰C and about 9⁰C, preferably about 8.5⁰C.

Preferably, after being held in sea water chilled to between about 8⁰C and about 9⁰C, preferably about 8.5⁰C, for up to about 4 hours, the crustaceans are held in seawater chilled to between about 5⁰C and about 6⁰C, preferably about 5.5⁰C, for up to about 10 hours.

Preferably the crustacean(s) or fish is/are subjected to physical and/or biological sterilisation. Preferably, the physical and/or biological sterilisation is carried out prior to placement in a sealable receptacle. Preferably the physical and biological sterilisation involves re-circulating the chilled seawater with the crustaceaπ(s) or fish therein, with mechanical filters and sterilisers.

Preferably the means of sterilisation is by way of UV irradiation and/or the injection of ozone.

Preferably the receptacle is a plastic bag.

Preferably the crustacean/fish is individually contained in a receptacle.

Preferably the receptacle contains a number of crustaceans/fish.

Preferably the receptacle is a plastic bag capable of assuming the entire or partial internal shape of a typically insulated shipping container.

Preferably the receptacle is dark coloured. Preferably the receptacle includes a gas tight, one-way, valve fitment.

Preferably the receptacle is placed in an insulated shipping container.

Preferably the plastic bag is heat sealed.

In another aspect of the invention there is provided a crustacean or fish that has been stored according to the above method.

In another aspect of the invention there is provided a substantially sealed receptacle containing at least one live crustacean and a gas mixture, wherein said gas mixture is capable of assisting at least one crustacean to remain alive for up to at least about 30 hours with substantially no water.

In another aspect of the invention there is provided a substantially sealed receptacle containing at least one live fish and a gas mixture, wherein said gas mixture is capable of assisting at least one fish to remain alive for at least up to 10 hours with substantially no water.

In another aspect of the invention there is provided a substantially sealed receptacle containing at least one live crustacean or fish and a gas mixture, wherein said gas mixture is either a mixture of helium and oxygen, or Heliox²⁸, which is a mixture of helium and oxygen in a ratio of 72:28, or a mixture of neon and oxygen, or a mixture of neon, nitrogen and oxygen, or trimix, which is a mixture of oxygen, helium and nitrogen.

Preferably the gas mixture contains nitrous oxide in addition to one of the gas mixtures described above.

Preferably the gas mixture is a mixture of Heliox²⁸ and nitrous oxide in a ratio of about 9:1.

Preferably the gas mixture is introduced into the receptacle in a sufficient volume to completely replace the air in the receptacle and to give a final pressure in the receptacle of about 1 atmosphere.

Preferably the receptacle also contains a cooling means. Preferably the cooling means is a frozen gel pack.

Preferably the receptacle contains a humidity means.

Preferably, when the gas mixture used is Heliox²⁸ and the Heliox²⁸ is introduced into the receptacle in a sufficient volume to give a final pressure in the receptacle of about 1 atmosphere, the temperature in the receptacle is maintained in the range of about 6⁰C - 10⁰C.

Preferably, when the gas mixture used is Heliox²⁸ and nitrous oxide in a ratio of about 9:1 and the Heliox²⁸ and nitrous oxide are introduced into the receptacle by such means and in sufficient volume to give a final pressure in the receptacle of about 1 atmosphere, the temperature in the receptacle is maintained in the range of about 5°C - 12°C.

Preferably, when the gas mixture used is Heliox²⁸ and nitrous oxide in a ratio of about 9:1 and the Heliox²⁸ and nitrous oxide are introduced into the receptacle in a sufficient volume to give a final pressure in the receptacle of about 1 atmosphere, the temperature in the receptacle is maintained in the range of about 6°C - 10^βC.

Preferably the receptacle is a plastic bag.

Preferably the receptacle is a plastic bag capable of assuming the entire or partial internal shape of a typical insulated shipping container.

Preferably the receptacle is dark coloured.

Preferably the receptacle includes a gas tight, one-way, valve fitment.

Preferably the receptacle is contained by an insulated shipping container.

Preferably the plastic bag is heat sealed.

In another aspect of the invention there is provided a method of keeping a crustacean alive for at least about 30 hours substantially without water, said method including the steps of: ■ Placing the at least one crustacean in a sealable receptacle ^■ Inserting a gas mixture into the receptacle, wherein the gas mixture is capable of ^' assisting the crustacean(s) to remain alive for at least about 30 hours, more preferably 40 hours, with substantially no water

^■ Sealing the receptacle.

In another aspect of the invention there is provided a method of keeping a fish alive for at least about 10 hours substantially without water, said method including the steps of:

^■ Placing the at least one fish in a sealable receptacle

^■ Inserting a gas mixture into the receptacle, wherein the gas mixture is capable of assisting the fish to remain alive for at least about 10 hours, more preferably 20 hours, with substantially no water

^■ Sealing the receptacle.

Preferably the gas mixture is a mixture of helium and oxygen.

Preferably the gas mixture is Heliox²⁸, a mixture of helium and oxygen in a ratio of 72:28.

Alternatively the gas mixture is a mixture of neon and oxygen.

Alternatively the gas mixture is a mixture of neon, nitrogen and oxygen.

Alternatively the gas mixture is trimix, a mixture of oxygen, helium and nitrogen.

Preferably the gas mixture contains nitrous oxide in combination with one of the above gas mixtures described above.

Preferably the gas mixture is a mixture of Heliox²⁸ and nitrous oxide.

Preferably a cooling means is placed in the receptacle.

Preferably the cooling means is a frozen gel pack. Preferably, when the gas mixture used is Heliox²⁸ and the Heliox²⁸ is introduced into the receptacle in a sufficient volume to give a final pressure in the receptacle of about 1 atmosphere, the temperature in the receptacle is maintained in the range of about 6⁰C - 10⁰C.

Preferably, when the gas mixture used is Heliox²⁸ and nitrous oxide in a ratio of about 9:1 and the Heliox²⁸ and nitrous oxide are introduced into the receptacle in a sufficient volume to give a final pressure in the receptacle of about 1 atmosphere, the temperature in the receptacle is maintained in the range of about 5^DC - 12°C.

Preferably, when the gas mixture used is Heliox²⁸ and nitrous oxide in a ratio of about 9:1 and the Heliox²⁸ and nitrous oxide are introduced into the receptacle in a sufficient volume to give a final pressure in the receptacle of about 1 atmosphere, the temperature in the receptacle is maintained in the range of about 6°C - 10⁰C.

Preferably the sea water is chilled to a temperature of between about 8⁰C and 9⁰C.

Preferably the crustacean(s) or fish is/are submerged in sea water for up to about 4 hours while the sea water is chilled to between about 8⁰C and 9⁰C, preferably about 8.5⁰C. Preferably, after being held in sea water chilled to between about 8⁰C and about 9⁰C, preferably about 8.5⁰C, for up to 4 hours, the crustaceans are held in sea water chilled to between about 5⁰C and about 6⁰C, preferably about 5.5⁰C, for up to about 10 hours.

Preferably a physical and biological sterilisation is carried out after the crustacean(s) or fish have/has been submerged in chilled water and before the crustacean(s) is/are placed in a sealable receptacle.

Preferably the physical and biological sterilisation involves re-circulating the chilled seawater with the crustaceans or fish therein, with mechanical filters and sterilisers.

Preferably the means of biological sterilisation is by way of UV irradiation and/or injection of ozone. Preferably the receptacle is a plastic bag.

Preferably the plastic bag is capable of assuming the partial or entire internal shape of an insulated shipping container.

Preferably the receptacle is dark coloured.

Preferably the receptacle includes a gas tight, one-way, valve fitment.

Preferably the receptacle is placed in an insulated shipping container.

Preferably the plastic bag is heat sealed.

In another aspect of the invention there is provided a method of storage of at least one aquatic animal, said method including the steps of:

■ Placing the at least one aquatic animal in a sealable receptacle

■ Inserting a gas mixture into the receptacle, wherein the gas mixture is capable of assisting the aquatic animal to remain alive for an extended period of time with substantially no water

■ Sealing the receptacle.

Preferably the method is a method of storage of at least one fish and the storage time is at least 10 hours.

Preferably the method is a method of storage of at least one crustacean and the storage time is at least 30 hours.

It is further preferred that the aquatic animal is either a fresh water or salt water aquatic animal.

In another aspect of the invention there is provided a live aquatic animal that has been stored according to a method according to any one of the above aspects of the invention. Further aspects of the invention, which should be considered in all its novel aspects, will become apparent from the followings description and with reference to the accompanying examples.

Detailed Description

Presently available methods relating to storage of live crustaceans allow for their storage substantially without water for up to a maximum of approximately 30 hours. There are many destinations that can not be reached within this timeframe. A method that allows for storage of live crustaceans for over 30 hours substantially without water is therefore highly desirable.

When using existing methods, it is typical to accept mortalities of up to 12% when transporting lobsters, for example, to current markets. A method that meets or enables a reduction in this mortality rate for live lobsters, and essentially without water, is therefore advantageous.

Similarly for fish, many markets for live fish are essentially unavailable due to the time requirements to reach those markets. It is typically a requirement using prior art, to keep the fish in water, which adds to the cost of the process and particularly to the cost of air freight.

The present invention allows for live aquatic animals, particularly crustaceans and/or fish, to be kept alive without water for extended periods of time. The invention is capable of keeping fish alive for greater than about 10 hours. Of course the invention can be used with fish and/or crustaceans for shorter times as well if desired. Both fresh water and salt water aquatic animals can benefit from this invention.

The method according to the present invention, in a preferred embodiment, allows for the storage of live crustaceans for at least over about 30 hours and in a preferred embodiment over about 40 hours, and in a particularly preferred embodiment over about 48 hours, substantially without water. The method also allows for the storage of live fish for at least over 10 hours, preferably over 20 hours, substantially without water. These preferred embodiments therefore enable the live crustaceans to be transported to almost any destination in the world and extends the transport options for fish substantially. An essential component of the method of this invention is the supply of oxygen to the aquatic animals (e.g. fish/crustaceans/molluscs), and in particular to the cells and tissues of the aquatic animals (as is discussed in more detail below with reference to the "secondary gas effect"). Further, reducing demand of oxygen is also relevant to a preferred method of this invention. The reduction in demand for oxygen is principally achieved by means of reducing the metabolism of the aquatic animals. A combination of techniques, which have been discovered by the inventors, can be used to achieve the desired storage of live aquatic animals.

The method according to the present invention, referred to in relation to crustaceans, involves:

■ Submerging the live crustacean(s) in sea water o Generally the sea water used in this step is chilled to between about 8⁰C and about 9⁰C, preferably about 8.5°C, for about 2-4 hours and then chilled to between about 5⁰C and about 6⁰C, preferably about 5.5⁰C, for about 8-10 hours. The chilling of the sea water to a low temperature is one of the factors that contribute to the reduction of the metabolism of the crustacean(s).

■ Carrying out a physical and biological sterilization o Preferably this step involves re-circulating the sea water with mechanical filters and sterilizers. Mechanical filters typically consist of backwashable mixed-bed sand filters .rotating drum filters or similar, to remove suspended solid material from the re-circulated water. High surface area to volume substrates such as sintered glass beads may be used to provide a surface for the attachment of nitrifying bacteria to convert toxic ammonia wastes to the more benign nitrate. UV irradiation and/or the injection of ozone are generally used as a means of biological sterilization. However, other

: methods of filtration and sterilization may be employed, as one skilled in the art would be aware. These steps allow a small amount of seawater to be used in the process, as it can be re-circulated without causing harm to the crustacean(s). In situations where there is continuous access to good quality sea water such as on a fishing vessel, and a flow-through system is employed, these water treatment steps may be unnecessary.

■ Placing the live crustacean(s) in a sealable receptacle. o One of the most convenient receptacles is a plastic bag, however as one would understand, a great variety of receptacles would be suitable. Further, it is preferable if it is dark in colour so that UV light does not readily penetrate the receptacle. Darkness often serves to calm animals by reducing visually induced stress and this thereby reduces the metabolism. It is also useful if the receptacle includes a gas tight, one-way, valve fitment to allow control of the content or gas make-up as well as the pressure of the gas mixture inside the receptacle. Generally the plastic bag is placed in an insulated shipping container and may entirely or partially fill that container.

The most common material for insulated shipping containers is polystyrene. Clearly, alternative materials may be employed. The shipping containers tend to be approximately 40 litres in volume. Where the receptacle is a plastic bag, it is likely that it will have a packed weight pre-requisite of 10kg, to which it will be filled. A humidity means may also be included. ing a premixed gas mixture into the plastic bag o The premixed gas mixture is preferably introduced in a sufficient volume to give a final pressure in the receptacle of about 1 atmosphere. Where a pressure of about 1 atmosphere is referred to throughout the specification, this is intended to be read as preferably about 1 atmosphere, but can be anything in the range of about 0.5 atmospheres to about 1.5 atmospheres. The inventors have found that by introducing into the receptacle a gas mixture that contains oxygen and exhibits the "secondary gas effect", the desired results can be achieved. The "secondary gas effect" is exhibited where you have a gas mixture containing a gas that is not normally in contact with the cells or tissues of the animal concerned, in combination with oxygen. Due to the concentration gradient of the gas mixture outside the outer surface of the animal and the gas inside the animal, the gas that is not normally in contact with the cells or tissues of the animal will rush into these cells or tissues. As it does so it will drag the oxygen that it is mixed with, with it. When a gas mixture that exhibits this effect is used according to the methods of the present invention, the increase of oxygen in the cells or tissues of crustaceans enables them to survive at least about 30 hours and in a preferred embodiment about 40 hours, and in a particularly preferred embodiment about 48 hours; most preferably storage times up to 100 hours or more may be achieved, whilst substantially without water. Therefore, a further aspect of the invention is the use of the "secondary gas effect" to keep crustaceans alive for up to at least about 30 hours, and preferably about 40 hours, and in a particularly preferred embodiment about 48 hours, substantially without water. The "secondary gas effect" has been used in the underwater diving field but its use in achieving extended storage of live crustaceans is unknown and entirely unexpected.

A gas mixture that exhibits the "secondary gas effect" and is therefore appropriate for use in the present invention is a medical gas known as

Heliox²⁸. Heliox²⁸ is a mixture containing 72% helium and 28% oxygen. This gas is used in the medical profession to treat hypoxia (oxygen lack) in humans. Oxygen lack is generally caused by smoke inhalation and carbon monoxide poisoning. Neon could be used, as an alternative to helium, in combination with oxygen to produce a gas mixture appropriate for use in the method of the present invention. By combining neon with oxygen a gas mixture would be achieved that also exhibited the "secondary gas effect" described above. Trimix is a commercially available breathing gas consisting of various blends of oxygen, helium and nitrogen, and is often used in deep commercial diving and during the deep phase of dives. This gas mixture is appropriate for use in the present invention as the combination of helium and oxygen in this mixture will act in the way described above. While it is not thought that the inclusion of nitrogen provides any extra advantage to the use of this gas mixture, it should not cause any disadvantage when used in the preferred method of the present invention. However, where the method is conducted under hyperbaric pressure and the gas mixture used is trimix, decompression techniques that avoid the crustaceans contracting nitrogen narcosis or decompression sickness ("the bends") would need to be employed.

By way of example, preferred inclusions in the gas mixture will include:

Helium - preferably in an amount of at least about 0.001% by volume, preferably about 0.01 % by volume, more preferably about 0.1% by volume;

Neon - preferably in an amount of at least about 0.004% by volume, preferably at least about 0.01% by volume, more preferably at least about 0.1 % by volume. Oxygen - at least about 0.1% oxygen by volume, more preferably at least about 1.0% by volume, most preferably at least about 10% by volume.

The inclusion of helium and/or neon in an amount of at least about 1.0% is also preferred.

The method of the present invention can be made particularly effective by reducing the metabolism of the crustacean(s) and therefore reducing their demand for oxygen.

Nitrous oxide ("laughing gas") is a stable, colourless gas. Nitrous oxide when administered to an animal acts as an inhalation anaesthetic to assist in reducing the metabolism of the animal. Accordingly, the method of the present invention is particularly effective when the gas mixture contains nitrous oxide. Nitrous oxide has a slightly sweet smell and taste and is preferable to the likes of isoflurane or halothaπe as these interact with membrane stability and not receptors. Unlike ether, it is not irritating to the mucous membranes and unlike chloroform it is relatively safe, especially when mixed with oxygen.

Nitrous oxide can be used in combination with any of the above gas mixtures. A particularly preferred gas mixture is a combination of Heliox²⁸ and nitrous oxide, and in particular in a ratio of about 9:1. Other ratios of Heliox²⁸ and nitrous oxide could also be used as would become apparent to a skilled person once in possession of this invention. By using this mixture, oxygen is being supplied to the cells or tissues by means of the secondary gas effect, and at the same time the demand for oxygen required by the cells or tissues is reduced by means of the nitrous oxide slowing the metabolism. This particularly preferred gas mixture has not previously been known.

Nitrous oxide should be present preferably in an amount of at least about 0.01% nitrous oxide by volume, more preferably at least about 0.1% by volume, most preferably at least about 1.0% by volume. As would be known to one skilled in the art, there are a number of further gas mixtures that would be appropriate to be used in this method.

Once the gas mixture has been introduced into the receptacle, preferably a plastic bag (or bags), it is desirable that the volume and shape of the bag is such that it completely fills the Insulated shipping container. As will be readily apparent, the receptacle should be capable of retaining the gas mixture therein without substantial loss over the period in which the aquatic animal is to be stored. The receptacle should also preferably be capable of holding the gas mixture at the pressures of use in this invention. Such plastic materials or other materials would also be required to retain their physical and chemical properties for at least the duration of the time they are in contact with the contained crustacean and/or fish such that the contained crustacean and/or fish would not be exposed to any chemical elements migrating from the substance includesthe plastic receptacle into the contained space containing the crustacean and/or fish. The types of plastics materials (or other materials) suitable for such use would be well known to a skilled person. Essentially, any plastic material that adequately or completely contains the gases for the duration of the shipment period, is not punctured by the contained aquatic . animal and does not impart anything inappropriate to the contained aquatic animal, would be a suitable material to form the sealable receptacle. Such material should preferably be a dark colour and confer insulation properties to the contained aquatic animal. For example, polyethylene based flexible plastics material meeting desired physical and chemical requirements could be used. Preferably the plastics material could be co-extruded to reduce gas permeability, increase puncture resistance, and/or address thermal issues, would be suitable. Further, rigid materials such as PVC, polycarbonates, or even glass could be used if desired.

^■ Sealing the receptacle. o The means by which this is achieved depends on the receptacle being used.

Where a plastic bag is employed, a convenient method of sealing is heat sealing.

^■ Placing a cooling means on the bag o A cooling means maintains the temperature in the receptacle at the desired level. Keeping the crustaceans cool assists in maintaining a slow metabolism, and therefore a low demand for oxygen. As one skilled in the art would be aware, there are a variety of cooling means that would be appropriate for use in this method. A frozen gel pack is a convenient cooling means for use in this method. Preferably this is a frozen gel pack that weighs approximately 750 grams. Preferably wood wool is used to protect the crustaceans from the frozen gel pack.

It is preferable that after this process has been carried out, the shipping container is lidded and taped.

Surprisingly, it has been found by the inventors that the method that is described in relation to crustaceans above can also be used in the storage of fish substantially without water. They have found that a fish subjected to the above method will survive for at least about 10 hours and preferably for at least about 20 hours. The invention thus also relates to the use of the "secondary gas effect" to keep fish alive for up to at least about 10 hours and more preferably at least about 20 hours, substantially without water. Again, the use of the secondary gas effect to allow extended storage of live fish is entirely unexpected. The inventors believe that storage of molluscs (clams, oysters, mussels, etc) can also benefit from this invention, to the extent at least of currently known options. The use of the secondary gas effect includes providing a gas mixture that includes a gas (or gas mixture proportion) that is not typically in contact with cells or tissues of an animal (e.g., live aquatic animal) under normal environmental conditions (e.g., in resident or typical habitat conditions). Such a gas mixture being capable of providing the secondary gas effect to the aquatic animals).

Thus the invention provides a method for storage of live aquatic animals substantially without water, the method including the steps of placing the animal in a sealable receptacle and using the secondary gas effect to extend storage times of the animal.

The invention should also be seen to reside in a live aquatic animal (as defined above) that has been stored in accordance with any one of the methods of this invention. In addition, the invention includes a sealable (or substantially sealed) receptacle that includes a live aquatic animal together with a gas mixture that includes a gas (or gas mixture proportion) that is not typically in contact with cells or tissues of an animal (e.g., live aquatic animal) under normal environmental conditions (e.g., in resident or typical habitat conditions) and which provides a secondary gas effect. The gas mixture will preferably be a gas mixture including oxygen together with helium or neon and may also include nitrous oxide. The proportions and preferments for the gas mixture have been discussed above.

There are many modifications that may be made to this method. Some of these modifications are discussed below with reference to the experimental Examples.

Experimental Examples

Crustaceans - Example 1

The purpose of the crustacean trials was to hold emerged lobsters in an intact state for at least 30 hours, with an aim to extend survival to 48 hours. Extending survival to 48 hours would enable lobster pack houses to service almost every live market around the world. Various gas mixtures, temperatures and pressures were investigated in an attempt to determine optimal conditions for storage of crustaceans. While these particular crustacean experiments were all conducted on lobsters (Jasus edwardsii), it is expected that the same or similar results would be achieved, and therefore the same conclusions drawn, when the experiments are conducted on other crustaceans, including crayfish, crabs or the like.

Materials and Methods

Example 1

Lobsters (Jasus edwardsii), were purchased from a commercial exporter of live lobsters. The lobsters had been conditioned for export using the method described in the background section. Each lobster weighed 600-800 grams. This weight is typical of the average sized crayfish exported from New Zealand.

The lobsters were transported to the laboratory in a chilled polystyrene container. Once at the laboratory, each lobster was placed in a separate container constructed from a section of commercial water pipe measuring 600 mm long and 160 mm in diameter. Each end of the commercial water pipe was secured with a screw cap. One of the screw caps on each chamber had a pneumatic fitting enabling a connection to be made to a pressurised gas cylinder. So that gas could also be vented from the vessel, a pressure gauge and purge valve were also screwed through this end cap. The containers will be referred to as pressure vessels throughout the remainder of this experimental section. A small microphone was fitted inside each pressure vessel and was used to amplify the "sounds" of the lobsters. This provided a means of determining whether the lobsters were alive.

The volume of the pressure vessels used was 11 litres. In each trial, except Trials 6 and 7, only 1 lobster was placed in each pressure vessel.

A single frozen gel pack was placed at the base of the vessel for the trials run at temperatures of 5⁰C, 6°C, 7⁰C, 8⁰C, and 9°C. The frozen gel packs were separated from the lobsters by wood wool.

Trial 1

The lobsters were each contained in a separate pressure vessel.

The trial was run under conditions of normobaric and hyperbaric pressure, wherein the hyperbaric pressure conditions were trialled at both 2 and 3 atmospheres. The pressure was controlled using compressed air, which was the gas mixture injected into the pressure vessel.

The temperature was controlled such that the trial was run at 5⁰C, 6°C, 7°C, 8⁰C, 9⁰C, 10°C and 12°C. These temperatures were achieved by placing the pressure vessel in an insulated container at air temperature, which varied between 10⁰C and 12°C. The pressure vessel was placed in a domestic fridge when a cooler temperature was required or an incubator for temperatures over 12⁰C.

A frozen gel pack was placed in the base of each pressure vessel in the trials that were run at temperatures of 5°C, 6°C, 7⁰C, 8⁰C and 9°C. In these cases, wood wool was also placed in the pressure vessel to prevent the lobster from coming in contact with the gel pack.

When pressure was in excess of normobaric, the vessels were decompressed at a rate of 0.14 atmospheres per 2 minute interval, prior to removing the lobsters from the pressure vessel. Once removed from the chamber, the lobsters were placed into artificial sea water to observe response and recovery.

Trial 2

In this trial the identical conditions to the above were applied, however instead of injecting compressed air into the pressure vessel and using this to control the pressure, compressed air mixed with medical grade oxygen was administered into the pressure vessel. The compressed air was mixed with medical grade oxygen in a ratio of 40:60.

Trial 3

The conditions applied in this trial were the same as those of Trial 2; however, the ratio of compressed air to medical grade oxygen was 5:95

Trial 4

As an alternative to air mixed with pure oxygen, a medical gas mixture known as Heliox²⁸, which consists of 72% helium and 28% oxygen, is sometimes used in the medical profession.

This trial was run under the same conditions as Trial 1 , only using Heliox²⁸ instead of compressed air. The Heliox²⁸ was flushed through the pressure vessel while venting the pressure vessel for approximately 30 seconds until the contents of the pressure vessel (11 litres) was expected to be largely Heliox²⁸.

Trial 5

In this trial a further variation to the gas mixture was applied whilst maintaining the same pressure and temperature conditions described in Trial 1. Heliox²⁸ was used with the addition of gaseous anaesthetic nitrous oxide at a ratio of about 9:1. The nitrous oxide was added to reduce the metabolism of the lobster. Again, Heliox²⁸ was flushed through the vessel while venting the pressure vessel for approximately 30 seconds until the contents of the pressure vessel were expected to be largely Heliox²⁸. According to known methods, shipping containers containing lobsters are vented to the atmosphere. Accordingly, the available air is not necessarily a limiting factor in these methods. In the method of the present invention using the mixture of gases in a sealed receptacle, the volume of support gas available to the lobsters is limited to the internal volume of the pressure vessel less the volume of any solid items in the pressure vessel, and the pressure of the support gas.

The final trial, therefore, was run with the mass of lobsters in each sealed pressure vessel increased to approximate that of a standard shipping container of a similar volume. The typical shipping container for the transport of live lobsters has internal dimensions of 545mm x 370mm x 200mm, and therefore a volume of 40 litres. These typical shipping containers are generally packed with 10kg of lobsters.

Therefore, on a pro rata basis, each of the 11 litre pressure vessels used in this final trial contained approximately 2.8 kg of lobsters, which equates to 4 or 5 lobsters. The lobsters in each pressure vessel were separated from one another using wood wool.

The gas used in this trial was Heliox²⁸ with the addition of gaseous anaesthetic nitrous oxide at a ratio of about 9:1. The pressure vessel was flushed with Heliox²⁸ and the air allowed to purge via the vent, before the nitrous oxide was introduced. A trial was run at each of the temperatures of 7°C, 8⁰C, 9⁰C and 10⁰C. All trials were conducted at normobaric pressure.

Trial 7- Fish

The above methods were also used to conduct trials on the triplefin fish Forsterygion lapillum. One triplefin was placed onto a sheet of cotton wool wetted with sea water inside the pressure vessel. After sealing the pressure vessel, a gas mixture of Heliox²⁸ with the addition of gaseous anaesthetic nitrous oxide in a ratio of about 9:1 , was injected into the pressure vessel at normobaric pressure. Trial 8- Prawn

The above methods were also used to conduct trials on the freshwater king prawn Macrobrachium rosenbergii. One prawn was placed in a pressure vessel and, after sealing the pressure vessel, a gas mixture of Heliox²⁸ with the addition of gaseous anaesthetic nitrous oxide in a ratio of about 9:1 , was injected into the pressure vessel at πormobaric pressure.

Controls

In all trials, the controls used physically identical conditions with the only variable being the use of normobaric atmospheric air replacing the mixture of gaseous Heliox²⁸ and nitrous oxide. Controls were all conducted at a temperature approximating a temperature typically experienced by the aquatic animal being investigated.

Results

Trial 1

This trial, using compressed air produced a surprising result. Both the normobaric and hyperbaric specimens at ambient temperature (10⁰C and 12⁰C) survived greater than 30 hours and longer than the refrigerated specimens. The refrigerated specimens died after less than 30 hours. See Table 1.

Table 1- time (h=hours) lobsters survived in compressed air

Trials 2 and 3

In the trials using compressed air in combination with medical grade oxygen, the survival of the lobsters was reduced. See tables 2 and 3 Table 2- time (h=hours) lobsters survived using compressed air with medical grade oxygen in a ratio of 40:60

A high proportion of the lobsters exposed to high concentrations of oxygen that appeared moribund and that were removed from the pressure vessel before dying, had lost limbs, appeared very sluggish on release and their inter-seg mental spaces were severely distended. When these lobsters were placed in sea water, several lost further limbs. This is a process known as 'autotomy' and is generally used an aid to escaping predators. In most instances, lobsters can regenerate limbs lost in this fashion. However, the lobsters used in these two trials did not recover from the conditions experienced in the pressure vessel.

The lobsters used in these two trials often also haemorrhaged haemolymph which had a blue/grey appearance and appeared to have poured from the period stumps.

Trial 4

In the trials using Heliox²⁸, the lobsters in the normobaric pressure vessels generally survived longer (>30 hours) than the lobsters at 2.0 and 3.0 atmospheres. The lobsters at normobaric pressure in this trial responded immediately following decompression- their antennae were mobile and the typical "threatened" posture was displayed. Tail flapping occurred immediately, suggesting anaerobic reserves were intact.

The lobsters maintained at a pressure of 2 atmospheres across the temperature range of 8°C - 9°C all survived in excess of 30 hours. None of the lobsters held at the higher test pressure of 3 atmospheres survived more than 30 hours. See Table 4.

Table 4- time h=hours lobsters survived usin 100% Heliox²⁸

Trial 5

In this trial nitrous oxide was introduced in conjunction with Heliox²⁸ in a ratio of Heliox²⁸ to nitrous oxide of about 9:1. Nitrous oxide is an inhalation anaesthetic and was introduced to slow the metabolism of the lobster. The trials using Heliox²⁸ and nitrous oxide showed a marked improvement in survival, particularly over the mid temperature range and at normobaric pressure. See Table 5.

Table 5- time (h=hours) lobsters survived using Heliox²⁸ with nitrous oxide in ratio of about 9:1

Using normobaric Heliox²⁸ and nitrous oxide in the ratio of about 9:1 with the pressure vessel held at temperatures of 6°C - 1O⁰C consistently allowed the lobsters to survive out of the water in excess of 48 hours. The lobsters resumed normal behaviour within seconds of being re-submerged in seawater.

Trial 6

This trial demonstrated that the volume of gas in these test vessels would be sufficient to support 10kg of live lobsters for more than 48 hours in a typical shipping container when held at 7°C - 9°C. See Table 6.

Table 6- time (h=hours) lobsters survived using Heliox²⁸ with nitrous oxide in ratio of about 9:1 total lobster mass ~2.8k

In this trial, all lobsters except those held at 10⁰C completely recovered when re-submerged in seawater.

Trial 7 The common triple fin showed remarkable survival albeit at the higher temperature range tested, using the same gas mixture and pressure as that successfully trialled with the lobsters. See Table 7. Table 7- time (h=hours) triplefins survived using Heliox²⁸ with nitrous oxide in ratio of about 9:1

Trial 8

The king prawn showed remarkable survival albeit at the higher temperature range tested," using the same gas mixture and pressure as that successfully trialled with lobsters. See Table 8.

Table 8- time (honours) the king prawn survived using Heliox²⁸ with nitrous oxide in ratio of about 9:1

Controls

During the course of these trials, the control lobster survived for 21 hours at 2O⁰C, the control triplefin survived for less than 3 hours at 2O⁰C while the king prawn survived for less than 1 hour at 28⁰C. All four species of fishes used to demonstrate the phylogenetic diversity of this technology, survived for less than 1 hour. The two cold water species - the mountain minnow and the goldfish, were each tested at 16⁰C while the two tropical species were tested at 26⁰C.

Conclusion

The results of the trial using air at a normobaric pressure and temperatures at 10°C - 12⁰C were surprising in that the lobsters survived in excess of 30 hours. However, the inventors also did not expect these results to be able to be achieved consistently. The results of this trial show that Heliox²⁸ is the gas of choice for extending transport times for live lobster out.of water. The inventors believe that Heliox²⁸ provides a "secondary gas effect". Helium is a rare, inert gas and does not normally exist in animal tissues. When an animal is exposed to gaseous helium, the helium rushes into the tissues and drags oxygen with it. The mechanism of this "secondary gas effect" has not been truly elucidated. However, Heliox²⁸ is used for patients suffering carbon monoxide poisoning, asphyxia and hypoxia, specifically to exploit this phenomenon. The application of this secondary gas effect to the storage of live crustaceans, fish and molluscs (aquatic animals) in a substantially waterless environment is, however, very surprising. Use of other gas mixes as discussed herein are also expected to achieve this effect and consequent advantages as they will also act in a manner similar to Heliox²⁸. In all tests, the results of the trials consistently exceeded the results of the controls by at least one order of magnitude. Typically, trials were halted once a reasonable period had passed and before the specimen succumbed. A reasonable period was considered to be a period at least twice that of the control as the principle underlying this technology had clearly been proven once this period had passed. The trials conducted on the lobster were typically halted once the lobster had survived for more than twice the 24 hour period cited by the local lobster industry as being the usual period lobsters survived. Local lobster processors would prefer lobsters to survive for a period much closer to two days in order to reduce mortalities during shipping and to allow more remote and more lucrative markets to be exploited. The technology of the present invention in fact enabled survival of the local lobster for a period in excess of 110 hours at which time the lobster finally succumbed. In all trials referred herein, the trials were optimised only to the point where the specimen in the experimental trial using this technology, survived for at least twice as long as the experimental control. Thus the relativity of at least 1 :2 (control: experimental) was always used as the arbitrary benchmark to demonstrate proof of principle of this technology. Longer survival times were clearly able to be attained.

The supply of oxygen to the crustaceans, in this case lobsters, is only one aspect of the success of this process. Consideration of factors reducing demand for oxygen is also important widens the storage options.

Gaseous anaesthetics such as nitrous oxide administered at very low doses help to reduce the metabolic rate. As the gaseous anaesthetics discussed in this specification achieve this by interacting with membrane stability and not receptors, the inventors believe that they will function equally well across a range of organisms including crayfish, finfish and shellfish such as molluscs (i.e. "live aquatic animals"). The gaseous anaesthetics dissipate rapidly from tissue and the inventors therefore believe they will be safe with regards to the Food and Drug Administration (FDA).

A normobaric atmosphere appears to provide the best results relative to hyperbaric pressure.

All trials using hyperbaric pressure or elevated concentrations of oxygen were relatively unsuccessful at supporting the lobsters' extended exposure to air. The specimens maintained in hyperoxic conditions most likely died from oxygen toxicity. Example 2

To further demonstrate the potential for commercial applicability of this technology, four small fish species were chosen to represent cold water and tropical fish, and obligatory gill breathing versus facultative air breathing fish and saltwater fish. These species were selected to be representative of gas transfer strategies exhibited by the fin fish across the phylogenetic spectrum, both fresh water and saltwater.

Most fish taken out of water soon succumb to suffocation and die because the gills collapse and drastically reduce the surface area for gas exchange. Activity and desiccation exacerbate the problem. However, it is not necessary for all the gas transfer to take place across the gills: alternative sites for gas exchange are the general cutaneous surface, the buccal cavity, and accessory breathing organs such as the swim bladder or other modifications of the oesophagus. Indeed, numerous fish species survive well for considerable periods out of water and are able to obtain oxygen directly from the atmosphere. Representatives from some 49 families of fish have air-breathing capabilities

(JB Graham, 1997. Air-Breathing Fishes, Academic Press) that imply considerable scope for adaptation to low oxygen levels in the aquatic environment.

Many highly valued ornamental species occur naturally in hypoxic habitats. Accordingly, the final part of this study anticipates exploitation of the core physiological plasticity underpinning basic fish design in order to improve the efficiency of live fish transport. Each of these trials was conducted at normobaric pressure. The gas mixture was Heliox²⁸ and nitrous oxide at a ratio of about 9: 1.

The following species of small ornamental fishes were tested:

• -hardy, cold-temperate gill breather and member of the carp family - known to tolerate low oxygen conditions, Goldfish Carassius auratus var. comet

• -cold-temperate gill breather found in well-oxygenated habitats, Mountain minnow Tanichthys albonubes • -tropical air-breathing species, possesses a labyrinthine air-breathing organ in addition to gills, Gourami Trichogaster trichopterus var. opaline

• -tropical gill-breathing species, Neon tetra Paracheirdon innesi

The supply of oxygen to fish is only one side of the equation however, and consideration of factors reducing demand is equally important. Both sides of this equation have been considered in our experiments, and in suggestions for taking the next step to commercialisation of the concept. It is noted that tropical fish species will have substantially greater metabolic rates than their cold water counterparts.

Although the invention has been described by way of example, it should be appreciated that variations and modifications may be made without departing from the scope of the invention as defined in the attached claims. Furthermore, where known equivalents exist to specific features, such equivalents are incorporated as if specifically referred in this specification.

Claims

CLAIMS:

1. A method for storage of live aquatic animals substantially without water, the method including the steps of placing the animal in a sealable receptacle and using the secondary gas effect to extend storage times of the animal.

2. The method according to claim 1 for storage of live aquatic animals substantially without water, the method including the steps of placing the animal in a sealable receptacle and introducing a gas mixture into the receptacle that includes oxygen, helium, or neon in a proportion that differs from the proportion that the aquatic animal is subjected to in its natural habitat.

3. The method according to claim 1 or claim 2 wherein the aquatic animal is a fish and the storage time is for up to at least 10 hours.

4. The method according to claim 3 wherein the aquatic animal is a fish and the storage time is for up to at least 20 hours.

5. The method according to claim 1 or claim 2 wherein the aquatic animal is a crustacean and the storage time is for up to at least 30 hours.

6. The method according to claim 5 wherein the aquatic animal is a crustacean and the storage time is for up to at least 40 hours.

7. The method according to any one of claims 1 to 7 wherein the secondary gas effect is achieved using a gas mixture including, by volume, at least about 0.001% helium, and/or at least about 0.004% neon, and/or at least about 0.1% oxygen, and/or at least about 0.01% nitrous oxide.

8. The method according to any one of the previous claims wherein the method includes the use of a gas mixture including oxygen together with helium or neon.

9. The method according to claim 7 or claim 8 wherein the method includes the use of a gas mixture including a mixture of helium and oxygen in a ratio of 72:28 (i.e. Heliox²⁸).

10. The method according to any one of claims 2 to 9 wherein the gas mixture includes nitrous oxide.

11. A gas mixture for use in the storage of live aquatic animals, said gas mixture including Heliox²⁸ in combination with nitrous oxide.

12. The method according to claim 11 wherein the Heliox²⁸ and nitrous oxide are mixed in a ratio of about 9: 1.

13. A method of storage of at least one live aquatic animal, said method including the steps of:

^■ Placing the at least one aquatic animal in a sealable receptacle

^■ Inserting a gas mixture into the receptacle, wherein the gas mixture is capable of assisting the aquatic animal to remain alive for an extended period of time with substantially no water

■ Sealing the receptacle.

14. The method according to claim 13 wherein the aquatic animal is a fish and the fish remains alive for up to at least 10 hours or up to at least 20 hours.

15. The method according to claim 13 wherein the aquatic animal is a crustacean and the crustacean remains alive for up to at least 30 hours or up to at least 40 hours.

16. The method according to any one of claims 13 to 15 wherein the secondary gas effect is achieved using a gas mixture including, by volume, at least about 0.001% helium, and/or at least about 0.004% neon, and/or at least about 0.1% oxygen, and/or at least about 0.01% nitrous oxide.

17. The method according to any one of claims 13 to 16 wherein the method includes the use of a gas mixture including oxygen together with helium or neon.

18. The method according to claim 16 or 17 wherein the gas mixture contains nitrous oxide.

19. The method according to any one of claims 13 to 18 wherein the gas mixture is a mixture of Heliox²⁸and nitrous oxide.

20. The method according to claim 13 wherein the gas mixture used is Heliox²⁸, and wherein the Heliox²⁸ is introduced into the receptacle in a sufficient volume to give a final pressure in the receptacle of about 1 atmosphere, and the temperature in the receptacle is maintained in the range of about 6°C - 10⁰C.

21. The method according to claim 13 wherein the gas mixture used is Heliox²⁸ and nitrous oxide in a ratio of about 9:1 and wherein the Heliox²⁸ and nitrous oxide are introduced into the receptacle in a sufficient volume to give a final pressure in the receptacle of about 1 atmosphere, and the temperature in the receptacle is maintained in the range of about 5°C - 12⁰C.

22. The method according to any one of claims 13 to 21 wherein the aquatic animal is a salt water aquatic animal and the aquatic animal is submerged in sea water prior to being placed in a sealable receptacle.

23. A live aquatic animal that has been stored according to the method of claim 1 , 2 or 13.

24. A substantially sealed receptacle containing at least one live crustacean and a gas mixture, wherein said gas mixture is capable of assisting the at least one crustacean to remain alive for up to at least about 30 hours with substantially no water.

25. A substantially sealed receptacle containing at least one live fish and a gas mixture, wherein said gas mixture is capable of assisting at least one fish to remain alive for at least up to 10 hours with substantially no water.

26. A substantially sealed receptacle that includes a live aquatic animal together with a gas mixture that includes a gas (or gas mixture proportion) that is not typically in contact with cells or tissues of an animal (e.g., live aquatic animal) under normal environmental conditions (e.g., in resident or typical habitat conditions) and which provides a secondary gas effect.

27. A substantially sealed receptacle containing at least one live aquatic animal and a gas mixture, wherein said gas mixture is either a mixture of helium and oxygen, or Heliox²⁸, which is a mixture of helium and oxygen in a ratio of 72:28, or a mixture of neon and oxygen, or a mixture of neon, nitrogen and oxygen, or trimix, which is a mixture of oxygen, helium and nitrogen.

28. The receptacle according to claim 27 wherein the gas mixture also contains nitrous oxide.

29. The receptacle according to claim 26, 27 or 28 wherein the gas mixture substantially completely replaces the air in the receptacle and gives a final pressure in the receptacle of about 1 atmosphere.

30. A method for storage of live aquatic animals substantially without water, the method being substantially as described with particular reference to any one of the Examples and

Trials, excluding controls.

31. A live aquatic animal that has been stored according to the method of claim 30.