Purina AquaMax Sport Fish 500 Fish Feed Pellets, 50 lb. Bag

50 may refer to:

• 50 (number)
• one of the following years 50 BC, AD 50, 1950, 2050
• .50 BMG, a heavy machine gun cartridge also used in sniper rifles
• .50 Action Express, a large pistol cartridge commonly used in the Desert Eagle
• .50 GI, a wildcat pistol cartridge
• .50 Beowulf, a powerful rifle cartridge used in the AR-15 platform
• .50 Alaskan, a wildcat rifle cartridge
• 50 Cent, an American rapper
• Labatt 50, a Canadian beer
• Fifty (film), a 2015 film
• "The Fifty", a group of fifty airmen murdered by the Gestapo after The Great Escape in World War II
• 50 (Rick Astley album), 2016
• 50 (Chris de Burgh album), 2024
• Benjamin Yeaten, widely known by his radio call sign "50", a Liberian military and mercenary leader
• "Fifty", a song by Karma to Burn from the album V, 2011
• 50 Virginia, a main-belt asteroid
• Audi 50, a supermini hatchback
• Dodge Ram 50, a compact pickup truck sold in the United States as a rebadged Mitsubishi Triton

A bag (also known regionally as a sack) is a common tool in the form of a non-rigid container, typically made of cloth, leather, bamboo, paper, or plastic. The use of bags predates recorded history, with the earliest bags being lengths of animal skin, cotton, or woven plant fibers, folded up at the edges and secured in that shape with strings of the same material. Bags can be used to carry items such as personal belongings, groceries, and other objects. They comes in various shapes and sizes, often equipped with handles or straps for easier carrying.

Bags have been fundamental for the development of human civilization, as they allow people to easily collect and carry loose materials, such as berries or food grains, also allowing them to carry more items in their hands.

The word probably has its origins in the Norse word baggi, from the reconstructed Proto-Indo-European bʰak, but is also comparable to the Welsh baich (load, bundle), and the Greek Τσιαντουλίτσα (Chandulícha, load).

Cheap disposable paper bags and plastic shopping bags are very common, varying in size and strength in the retail trade as a convenience for shoppers, and are often supplied by the shop for free or for a small fee. Customers may also take their own shopping bag(s) to use in shops.

Although paper had been used for wrapping and padding in Ancient China since the 2nd century BC, the first use of paper bags in China (for preserving the flavor of tea) came during the later Tang dynasty (618–907 AD).

A fish (pl.: fish or fishes) is an aquatic, anamniotic, gill-bearing vertebrate animal with swimming fins and a hard skull, but lacking limbs with digits. Fish can be grouped into the more basal jawless fish and the more common jawed fish, the latter including all living cartilaginous and bony fish, as well as the extinct placoderms and acanthodians. Most fish are cold-blooded, their body temperature varying with the surrounding water, though some large active swimmers like white shark and tuna can hold a higher core temperature. Many fish can communicate acoustically with each other, such as during courtship displays. The study of fish is known as ichthyology.

The earliest fish appeared during the Cambrian as small filter feeders; they continued to evolve through the Paleozoic, diversifying into many forms. The earliest fish with dedicated respiratory gills and paired fins, the ostracoderms, had heavy bony plates that served as protective exoskeletons against invertebrate predators. The first fish with jaws, the placoderms, appeared in the Silurian and greatly diversified during the Devonian, the "Age of Fishes".

Bony fish, distinguished by the presence of swim bladders and later ossified endoskeletons, emerged as the dominant group of fish after the end-Devonian extinction wiped out the apex predators, the placoderms. Bony fish are further divided into the lobe-finned and ray-finned fish. About 96% of all living fish species today are teleosts, a crown group of ray-finned fish that can protrude their jaws. The tetrapods, a mostly terrestrial clade of vertebrates that have dominated the top trophic levels in both aquatic and terrestrial ecosystems since the Late Paleozoic, evolved from lobe-finned fish during the Carboniferous, developing air-breathing lungs homologous to swim bladders. Despite the cladistic lineage, tetrapods are usually not considered to be fish, making "fish" a paraphyletic group.

Fish have been an important natural resource for humans since prehistoric times, especially as food. Commercial and subsistence fishers harvest fish in wild fisheries or farm them in ponds or in breeding cages in the ocean. Fish are caught for recreation, or raised by fishkeepers as ornaments for private and public exhibition in aquaria and garden ponds. Fish have had a role in human culture through the ages, serving as deities, religious symbols, and as the subjects of art, books and movies.

Purina may refer to:

• Ralston Purina, an American pet food company that was acquired in 2001
• Nestlé Purina PetCare, the pet food division of Swiss-based Nestlé S.A., and the acquirer of Ralston Purina Company in 2001 (subsequently merged with Nestlé's Friskies PetCare Company)
• Purina Mills, a farm animal feed company that was spun off from Ralston Purina Company

Sport is a form of physical activity or game. Often competitive and organized, sports use, maintain, or improve physical ability and skills. They also provide enjoyment to participants and, in some cases, entertainment to spectators. Many sports exist, with different participant numbers, some are done by a single person with others being done by hundreds. Most sports take place either in teams or competing as individuals. Some sports allow a "tie" or "draw", in which there is no single winner; others provide tie-breaking methods to ensure one winner. A number of contests may be arranged in a tournament format, producing a champion. Many sports leagues make an annual champion by arranging games in a regular sports season, followed in some cases by playoffs.

Sport is generally recognised as system of activities based in physical athleticism or physical dexterity, with major competitions admitting only sports meeting this definition. Some organisations, such as the Council of Europe, preclude activities without any physical element from classification as sports. However, a number of competitive, but non-physical, activities claim recognition as mind sports. The International Olympic Committee who oversee the Olympic Games recognises both chess and bridge as sports. SportAccord, the international sports federation association, recognises five non-physical sports: chess, bridge, draughts, Go and xiangqi. However, they limit the number of mind games which can be admitted as sports. Sport is usually governed by a set of rules or customs, which serve to ensure fair competition. Winning can be determined by physical events such as scoring goals or crossing a line first. It can also be determined by judges who are scoring elements of the sporting performance, including objective or subjective measures such as technical performance or artistic impression.

Records of performance are often kept, and for popular sports, this information may be widely announced or reported in sport news. Sport is also a major source of entertainment for non-participants, with spectator sport drawing large crowds to sport venues, and reaching wider audiences through broadcasting. Sport betting is in some cases severely regulated, and in others integral to the sport.

According to A.T. Kearney, a consultancy, the global sporting industry is worth up to $620 billion as of 2013. The world's most accessible and practised sport is running, while association football is the most popular spectator sport.