In most biological nomenclature, a scale is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran species, scales are plates on the surface of the insect wing, and provide coloration. Scales are quite common and have evolved multiple times through convergent evolution, with varying structure and function.
The bowfin is a bony fish, native to North America. Common names include mudfish, mud pike, dogfish, grindle, grinnel, swamp trout, and choupique. It is regarded as a relict, being one of only two surviving species of the Halecomorphi, a group of fish that first appeared during the Early Triassic, around 250 million years ago. The bowfin is often considered a "primitive fish" because they have retained some morphological characteristics of their early ancestors. It is one of two species in the genus Amia, along with Amia ocellicauda, the eyespot bowfin. The closest living relatives of bowfins are gars, with the two groups being united in the clade Holostei.
Gars are members of the family Lepisosteidae, which are the only surviving members of the Ginglymodi, an ancient holosteian group of ray-finned fish, which first appeared during the Triassic, over 240 million years ago. Gars comprise seven living species of fish in two genera that inhabit fresh, brackish, and occasionally marine waters of eastern North America, Central America and Cuba in the Caribbean, though extinct members of the family were more widespread. Gars have elongated bodies that are heavily armored with ganoid scales, and fronted by similarly elongated jaws filled with long, sharp teeth. Gars are sometimes referred to as "garpike", but are not closely related to pike, which are in the fish family Esocidae. All of the gars are relatively large fish, but the alligator gar is the largest; the alligator gar often grows to a length over 2 m (6.5 ft) and a weight over 45 kg (100 lb), and specimens of up to 3 m (9.8 ft) in length have been reported. Unusually, their vascularised swim bladders can function as lungs, and most gars surface periodically to take a gulp of air. Gar flesh is edible and the hard skin and scales of gars are used by humans, but gar eggs are highly toxic.
The longnose gar, also known as longnose garpike or billy gar, is a ray-finned fish in the family Lepisosteidae. The genus may have been present in North America for about 100 million years. References are made to gars being a primitive group of bony fish because they have retained some primitive features, such as a spiral valve intestine, but they are not primitive in the sense of not being fully developed.
The pumpkinseed, also referred to as pond perch, common sunfish, punkie, sunfish, sunny, and kivver, is a small/medium-sized North American freshwater fish of the genus Lepomis, from family Centrarchidae in the order Perciformes.
The white crappie is a freshwater fish found in North America, one of the two species of crappies. Alternate common names for the species include goldring, silver perch, white perch and sac-a-lait. USS Goldring is named for the fish. The genus name Pomoxis refers to crappies' sharp operculum, while the species name annularis means 'having rings', i.e., it has vaguely vertical bars on the body.
Polypterus senegalus, the Senegal bichir, gray bichir or Cuvier's bichir, and sometimes called the "dinosaur eel", "dinosaur bichir", or "dragon fish" is in the pet trade due to its lungfish-like appearance, which was described as more primitive and prehistoric than other modern fishes. It is a prototypical species of fish in the genus Polypterus, meaning most of its features are held across the genus. It is commonly kept in captivity by hobbyists. They are native from Africa where they are the most widespread species of the genus.
The alligator gar is an euryhaline ray-finned fish in the clade Ginglymodi of the infraclass Holostei, being most closely related to the bowfins. It is the largest species in the gar family (Lepisosteidae), and is among the largest freshwater fish in North America. The fossil record traces its group's existence back to the Early Cretaceous over 100 million years ago. Gars are often referred to as "primitive fishes" or "living fossils" because they have retained some morphological characteristics of their early ancestors, such as a spiral valve intestine, which is also common to the digestive system of sharks, and the ability to breathe in both air and water. Their common name was derived from their resemblance to the American alligator, particularly their broad snouts and long, sharp teeth. Anecdotal evidence suggests that an alligator gar can grow up to 10 ft (3.0 m) in length.
The Florida gar is a species of gar found in the US from the Savannah River and Ochlockonee River watersheds of Georgia and throughout peninsular Florida. Florida gar can reach a length over 3 ft (91 cm). The young feed on zooplankton and insect larvae, as well as small fish. Adults mainly eat fish, shrimp, and crayfish. Although edible, they are not popular as food. The roe is highly toxic to many animals, including humans and birds.
The spotted gar is a freshwater fish native to North America that has an abundance of dark spots on its head, fins, and dart-like body. Spotted gar have an elongated mouth with many needle-like teeth to catch other fish and crustaceans. It is one of the smallest of the seven species of gar found in North America, growing 2–3 ft in length and weighing 4-6 lb (1.8–2.7 kg) typically. Gars have diamond-shaped, thick, enamel (ganoid) scales. The name Lepisosteus is Greek for "bony scale".
The shortnose sturgeon is a small and endangered species of North American sturgeon. The earliest remains of the species are from the Late Cretaceous Period, over 70 million years ago. Shortnose sturgeons are long-lived and slow to sexually mature. Most sturgeons are anadromous bottom-feeders, which means they migrate upstream to spawn but spend most of their lives feeding in rivers, deltas and estuaries. The shortnose sturgeon is often mistaken as a juvenile Atlantic sturgeon because of its small size. Prior to 1973, U.S. commercial fishing records did not differentiate between the two species: both were reported as "common sturgeon", although it is believed based on sizes that the bulk of the catch was Atlantic sturgeon. The shortnose is distinguishable from the Atlantic sturgeon due to its shorter and rounder head.
The brook stickleback is a small freshwater fish that is distributed across the US and Canada. It grows to a length of about 2 inches. It occupies the northern part of the eastern United States, as well as the southern half of Canada. Small populations are scattered throughout the Mississippi-Great Lakes basin extending to Colorado, New Mexico, Kentucky, Tennessee, etc., though some of these areas are not native to the species. This small fish inhabits clear, cool streams and lakes. They eat small invertebrates, algae, insect larvae, and occasionally their own eggs. They are also preyed upon by smallmouth bass and northern pike. Feeding time is usually dawn and sunset. The brook stickleback does have active competition mostly from minnows, but feeding times are different, along with diet. Spawning occurs in midsummer. Males secure a territory, build a nest, and mate with females. Males provide protection for the eggs, ward off predators, and usually die later in the season. This is considered an annual species. The nests are built out of aquatic grasses. Though the brook stickleback is not considered a threatened species, deforesting and changing waters are altering ecosystems of the species. Harvesting of trees around riparian environments is having a large effect of the stream ecosystem where the brook stickleback resides.
Coastal fish, also called inshore fish or neritic fish, inhabit the sea between the shoreline and the edge of the continental shelf. Since the continental shelf is usually less than 200 metres (660 ft) deep, it follows that pelagic coastal fish are generally epipelagic fish, inhabiting the sunlit epipelagic zone. Coastal fish can be contrasted with oceanic fish or offshore fish, which inhabit the deep seas beyond the continental shelves.
Eastern blacknose dace is a species of ray-finned fish in the genus Rhinichthys. Its name originates from the Old French word "dars" which is the nominative form of the word "dart" in reference to their swimming pattern. The western blacknose dace formerly was considered conspecific. While morphologically the two species are not significantly different, they are allopatric. The eastern blacknose dace is found across the southeast portion of Canada and down along the United States' east coast. It is dark brown to olive on its dorsal surface and silvery white below, the two shades separated by the darkly pigmented lateral line. In the breeding season, males develop darker pigmentation and an orange lateral line. Blacknose dace live in rocky streams and rivers where they feed upon small invertebrates and microscopic biological matter and provide forage for larger fish.
The tadpole madtom is a species of fish in the family Ictaluridae. It is native to Canada and the United States.
The redfin shiner is a freshwater fish in the family Cyprinidae. The redfin shiner is most commonly found in the Ohio and Mississippi River basins, as well as in drainages of the Great Lakes, all of which are in the United States. The diet of the redfin shiner consists mostly of algae and small insects. This species prefers calm water in low-gradient streams over substrates of gravel or sand with some vegetation.
Percina phoxocephala, the slenderhead darter, is a species of freshwater ray-finned fish, a darter from the subfamily Etheostomatinae, part of the family Percidae, which also contains the perches, ruffes and pikeperches. It is found in North America in the central Ohio and Mississippi River basins, to northeastern South Dakota and the Lake Winnebago system in Wisconsin, and as far south as the Red River in eastern Oklahoma and northeast Texas, typically in small to medium size rivers. It is a colorful species, with an average length of 6 to 9 centimeters. Males take on a deeper hue during the breeding season. It feeds on insect larvae and other small invertebrates, and spawns between April and June. It is a common fish with a very wide range and the International Union for Conservation of Nature has classified its conservation status as being of "least concern".
Mylocheilus caurinus, the peamouth, peamouth chub, redmouth sucker or northwestern dace, is a species of freshwater ray-finned fish from the family Cyprinidae, the carps and minnows, that is found in western North America. It is the only species in its genus.
The Cuban gar, also known as the manjuarí, is a fish in the family Lepisosteidae. It is a tropical, freshwater species, although it also inhabits brackish water. It is found in rivers and lakes of western Cuba and the Isla de la Juventud. The flesh of the fish is edible, but the eggs are poisonous for humans.
Fish go through various life stages between fertilization and adulthood. The life of a fish start as spawned eggs which hatch into immotile larvae. These larval hatchlings are not yet capable of feeding themselves and carry a yolk sac which provides stored nutrition. Before the yolk sac completely disappears, the young fish must mature enough to be able to forage independently. When they have developed to the point where they are capable of feeding by themselves, the fish are called fry. When, in addition, they have developed scales and working fins, the transition to a juvenile fish is complete and it is called a fingerling, so called as they are typically about the size of human fingers. The juvenile stage lasts until the fish is fully grown, sexually mature and interacting with other adult fish.
