Fish jaw in the context of "Salmonids"

Angling (from Old English angol, meaning "hook") is a fishing technique that uses a fish hook attached to a fishing line to tether individual fish in the mouth. The fishing line is usually manipulated with a fishing rod, although rodless techniques such as handlining also exist. Modern angling rods are usually fitted with a fishing reel that functions as a cranking device for storing, retrieving and releasing out the line, although Tenkara fishing and traditional cane pole fishing are two rod-angling methods that do not use any reel. The fish hook itself can be additionally weighted with a denser tackle called a sinker, and is typically dressed with an appetizing bait (i.e. hookbait) to attract and entice the fish into swallowing the hook, but sometimes an inedible fake/imitation bait with multiple attached hooks (known as a lure) is used instead of a single hook with edible bait. Some type of bite indicator, such as a float, a bell or a quiver tip, is often used to relay underwater status of the hook to the surface and alert the angler of a fish's presence.

When angling, the fisherman (known as the angler) will first throw the hook (i.e. "cast") to a chosen area of water (i.e. fishing ground), and then patiently wait for fish to approach and devour the hookbait. It is also not uncommon for the angler to scatter some loose bait (groundbait) around the target area before even casting the hook, to better attract distant fish with scents. If a fish has succumbed to its own feeding instinct and swallowed the baited hook (i.e. "bite" or "strike"), the hook point will likely pierce into and anchor itself inside the fish jaw, gullet or gill, and the fish in turn becomes firmly tethered by the fishing line. Once the fish is hooked (often colloquially called "fish-on"), any struggles and attempts to escape will pull along the line, causing the bite indicator to signal the angler, who jerks the fishing rod back to further deepen the hook anchorage (i.e. "setting the hook") and then tries to retrieve the line back, pulling the fish closer in the process. During the line retrieval, the angler will carefully monitor the line and rod tension to avoid equipment breaking. With stronger and feistier fish, the angler might need to temporarily halt or even reverse the line retrieval to prolong the struggle time and tire out the fish (i.e. "walking" the fish), before dragging it near enough to eventually lift it out of the water (known as "landing") for a successful catch. Sometimes a hand net (or "landing net") or a long-handled hook is used to make fetching the fish easier.

Placoderms (from Ancient Greek πλάξ [plax, plakos] 'plate' and δέρμα [derma] 'skin') are vertebrate animals of the class Placodermi, an extinct group of prehistoric fish known from Paleozoic fossils during the Silurian and the Devonian periods. While their endoskeletons are mainly cartilaginous, their head and thorax were covered by articulated armoured plates (hence the name), and the rest of the body was scaled or naked depending on the species.

Placoderms were among the first jawed fish (their jaws likely evolved from the first pair of gill arches), as well as the first vertebrates to have true teeth. They were also the first fish clade to develop pelvic fins, the second set of paired fins and the homologous precursor to hindlimbs in tetrapods. 380-million-year-old fossils of three other genera, Incisoscutum, Materpiscis and Austroptyctodus, represent the oldest known examples of live birth.

A fish hook or fishhook, formerly also called an angle (from Old English angol and Proto-Germanic *angulaz), is a hook used to catch fish either by piercing and embedding onto the inside of the fish mouth (angling) or, more rarely, by impaling and snagging the external fish body. Fish hooks are normally attached to a line, which tethers the target fish to the angler for retrieval, and are typically dressed with some form of bait or lure that entices the fish to swallow the hook out of its own natural instinct to forage or hunt.

Fish hooks have been employed for millennia by fishermen to catch freshwater and saltwater fish. There is an enormous variety of fish hooks in the world of fishing. Sizes, designs, shapes, and materials are all variable depending on the intended purpose of the hook. Fish hooks are manufactured for a range of purposes from general fishing to extremely limited and specialized applications. Fish hooks are designed to hold various types of artificial, processed, dead or live baits (bait fishing); to act as the foundation for artificial representations of invertebrate prey (e.g. fly fishing); or to be attached to or integrated into other devices that mimic prey (lure fishing). In 2005, the fish hook was chosen by Forbes as one of the Top 20 tools in human history.

Salmonidae (/sælˈmɒnɪdiː/, lit. 'salmon-like') is a family of ray-finned fish, the only extant member of the suborder Salmonoidei, consisting of 11 extant genera and over 200 species collectively known as "salmonids" or "salmonoids". The family includes salmon (both Atlantic and Pacific species), trout (both ocean-going and landlocked), char, graylings, freshwater whitefishes, taimens and lenoks, all coldwater mid-level predatory fish that inhabit the subarctic and cool temperate waters of the Northern Hemisphere. The Atlantic salmon (Salmo salar), whose Latin name became that of its genus Salmo, is also the eponym of the family and order names.

Salmonids have a relatively primitive appearance among teleost fish, with the pelvic fins being placed far back, and an adipose fin towards the rear of the back. They have slender bodies with rounded scales and forked tail fins, and their mouths contain a single row of sharp teeth. Although the smallest salmonid species is just 13 cm (5.1 in) long for adults, most salmonids are much larger, with the largest reaching 2 m (6 ft 7 in).

In recreational fishing terminology, the hookset or setting the hook is when an angler makes a sudden lifting motion to a fishing rod in order to pull the line and anchor the fish hook firmly into the mouth of a fish once it has gulped in the hook along with the bait/lure.

In order to securely tether the fish with the line, sufficient force is needed to drive the hook point through the epithelium into the connective tissue and muscle of the fish's mouth, preferably under and around a jaw bone. If this were not achieved, while it is still possible for the hook to anchor itself in to the fish's oral tissue, the likelihood of successfully landing the fish is reduced since, without the hook piercing to enough depth, the fish can shake the hook loose during struggle, spit it out and then escape. A deep enough hookset also catches more tissue (thus making it less likely to tear through the flesh), and transfers most of the deformational stress longitudinally along the shank portion of the hook (where it also has the greatest tensile strength), instead of onto the bend (the curved portion of the hook) where the hook is more vulnerable to deflection and slippage when pulled by the line.

In fishing, a gaff is a handheld pole with a sharp hook or sideway spike on the distal end, which is used to pull large fish from the water. Fishing activities that are solely done with gaffs are known as gaffing.

Gaffs are used when the size and weight of the target fish exceeds the breaking strength of the fishing line or the fishing rod, and thus typical angling retrieval would be problematic. Like spearfishing, gaffs cannot be used if it is intended to release the fish unharmed after capture, unless the fish is skillfully gaffed right in a non-vital part such as the lip, jaw or lower gill using a thin hook (though very difficult to perform and thus unlikely).