Spawn (biology)Spawn is the eggs and sperm released or deposited into water by aquatic animals. As a verb, to spawn refers to the process of releasing the eggs and sperm, and the act of both sexes is called spawning. Most aquatic animals, except for aquatic mammals and reptiles, reproduce through the process of spawning. Spawn consists of the reproductive cells (gametes) of many aquatic animals, some of which will become fertilized and produce offspring.
Forage fishForage fish, also called prey fish or bait fish, are small pelagic fish which are preyed on by larger predators for food. Predators include other larger fish, seabirds and marine mammals. Typical ocean forage fish feed near the base of the food chain on plankton, often by filter feeding. They include particularly fishes of the order Clupeiformes (herrings, sardines, shad, hilsa, menhaden, anchovies, and sprats), but also other small fish, including halfbeaks, silversides, smelt such as capelin and goldband fusiliers.
Swarm behaviourSwarm behaviour, or swarming, is a collective behaviour exhibited by entities, particularly animals, of similar size which aggregate together, perhaps milling about the same spot or perhaps moving en masse or migrating in some direction. It is a highly interdisciplinary topic. As a term, swarming is applied particularly to insects, but can also be applied to any other entity or animal that exhibits swarm behaviour.
Bait ballA bait ball, or baitball, occurs when small fish swarm in a tightly packed spherical formation about a common centre. It is a last-ditch defensive measure adopted by small schooling fish when they are threatened by predators. Small schooling fish are eaten by many types of predators, and for this reason they are called bait fish or forage fish. For example, sardines group together when they are threatened. This instinctual behaviour is a defence mechanism, as lone individuals are more likely to be eaten than an individual in a large group.
BluegillThe bluegill (Lepomis macrochirus), sometimes referred to as "bream," "brim," "sunny," or "copper nose" as is common in Texas, is a species of North American freshwater fish, native to and commonly found in streams, rivers, lakes, ponds and wetlands east of the Rocky Mountains. It is the type species of the genus Lepomis (true sunfish), from the family Centrarchidae (sunfishes, crappies and black basses) in the order Perciformes (perch-like fish). Bluegills can grow up to long and about .
Bluefin trevallyThe bluefin trevally (Caranx melampygus), also known as the bluefin jack, bluefin kingfish, bluefinned crevalle, blue ulua, omilu, and spotted trevally), is a species of large, widely distributed marine fish classified in the jack family, Carangidae. The bluefin trevally is distributed throughout the tropical waters of the Indian and Pacific Oceans, ranging from Eastern Africa in the west to Central America in the east, including Japan in the north and Australia in the south.
Southern OceanThe Southern Ocean, also known as the Antarctic Ocean, comprises the southernmost waters of the world ocean, generally taken to be south of 60° S latitude and encircling Antarctica. With a size of , it is regarded as the second-smallest of the five principal oceanic divisions: smaller than the Pacific, Atlantic, and Indian oceans but larger than the Arctic Ocean. Since the 1980s, the Southern Ocean has been subject to rapid climate change, which has led to changes in the marine ecosystem.
HerringHerring are forage fish, mostly belonging to the family of Clupeidae. Herring often move in large schools around fishing banks and near the coast, found particularly in shallow, temperate waters of the North Pacific and North Atlantic Oceans, including the Baltic Sea, as well as off the west coast of South America. Three species of Clupea (the type genus of the herring family Clupeidae) are recognised, and comprise about 90% of all herrings captured in fisheries.
Fishing vesselA fishing vessel is a boat or ship used to catch fish in the sea, or on a lake or river. Many different kinds of vessels are used in commercial, artisanal and recreational fishing. It is difficult to estimate the number of recreational fishing boats. They range in size from small dinghies to large charter cruisers, and unlike commercial fishing vessels, are often not dedicated just to fishing. Prior to the 1950s there was little standardisation of fishing boats. Designs could vary between ports and boatyards.
BarracudaA barracuda is a large, predatory, ray-finned fish known for its fearsome appearance and ferocious behaviour. The barracuda is a saltwater fish of the genus Sphyraena, the only genus in the family Sphyraenidae, which was named by Constantine Samuel Rafinesque in 1815. It is found in tropical and subtropical oceans worldwide ranging from the eastern border of the Atlantic Ocean to the Red Sea, on its western border the Caribbean Sea, and in tropical areas of the Pacific Ocean.