This glossary of ichthyology is a list of definitions of terms and concepts used in ichthyology, the study of fishes.
The channel 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 native to North America where it typically occurs in the sandy or gravelly shallows of lakes and in small and medium-sized rivers in riffles over sand, gravel or rock bottoms. It is a small fish ranging from 34 to 72 mm in length, olive brown with darker speckles and sometimes with a dark spot below the eye and dark blotches along the flank. It feeds mostly on insect larvae and other small invertebrates and breeds in small streams. This species is listed as threatened by the Canadian Species at Risk Act (SARA) but overall it has a wide range and numerous sub-populations and the International Union for Conservation of Nature has rated it as a "least concern species".
The johnny 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 native to shallow waters throughout North America east of the Rocky Mountains.
The blenny 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 a poorly known species which occurs in Alabama and Tennessee where it inhabits swift riffles.
The greenside 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 inhabits swift riffles in the eastern United States and southern Ontario.
Etheostoma exile, the Iowa 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, along with about 17 other species of darters, is native to the lakes and streams of Iowa.
The bluntnose 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 eastern North America where it is found in slower moving and still waters.
The Coosa 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 endemic to the eastern United States.
The swamp 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 endemic to the Eastern United States.
The least 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 generally found in lakes and streams in northeastern part of the United States and along the Mississippi River systems.
The speckled 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 endemic to the central and southeastern United States. It occurs in the Mississippi River basin and through the Gulf Coast drainages. It is also found in the Clinch River and the Powell River. This species inhabits rocky or sandy pools in flowing waters up to the size of medium rivers with fast currents. It can reach a length of 6.1 centimetres (2.4 in) TL though most only reach about 4 centimetres (1.6 in).
Stegastes pictus, the yellowtip damselfish, is a species of damselfish found near the sea bed on shallow rocky reefs off the coast of Brazil, where it is endemic. It is a small, laterally-compressed, dark brown fish with yellow pectoral and caudal fins. It feeds on algae and detritus and is often found in the vicinity of the fire coral Millepora alcicornis. It is a territorial fish and forms a pair bond in the breeding season. The eggs are laid in a shallow scoop on the seabed and the male tends them to keep them well-aerated.
Chaetodon hoefleri, the four-banded butterflyfish, is a species of marine ray-finned fish, a butterflyfish from the family Chaetodontidae. It is native to the tropical eastern Atlantic and has been recorded in the Mediterranean.
Halichoeres zulu, the Kwa-Zulu Natal wrasse, is a species of ray-finned fish from the family Labridae, the wrasses. It is native to the south western Indian Ocean. It was first described in 2010.
Polydactylus sextarius, the blackspot threadfin, is a species of marine ray-finned fish, a threadfin from the family Polynemidae which is native to the western Pacific and eastern Indian Oceans.
The Christmas darter i is a species of ray-finned fish, a darter from the subfamily Etheostomatinae, part of the family Percidae which includes the perches, ruffes and pike-perches. It is found in the Savannah, Ogeechee and Altamaha catchment areas in South Carolina and Georgia. It is a small but colorful fish, typically less than 5 cm (2 in) in total length, with blackish, red and green streaks on its flanks. Green and red are associated with Christmas, hence the common name Christmas darter. Like other darters, it lives on or close to the stream-bed, in riffles and vegetation-laden stretches of small rivers, creeks and spring-fed streams. It feeds on aquatic insects and probably breeds in the spring, but its biology and behavior are poorly known.
The redfin 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 native to the south-central United States, where it occurs in Missouri, Arkansas, Kansas, and eastern Oklahoma.
The Savannah 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 endemic to the eastern United States, where it occurs in the Edisto, Combahee, Broad and Savannah River drainages in South Carolina and Georgia. It inhabits gravel riffles, gravel and sand runs of creeks and small rivers. This species can reach a length of 7.4 cm (2.9 in).
Chromis hangganan, the dark margin chromis, is a species of marine fish of the damselfishes in the family Pomacentridae belonging to the genus Chromis. This species was first described in 2019, along with Chromis bowesi and Chromis gunting, discovered and known only from Lubang Island, in the Philippines. It is characterized by 10–12 dorsal fin rays, 11–12 anal fin rays, 18 pectoral fin rays, 3 caudal fin rays that are procurrent, 16 lateral line scales that are tubed, 23–26 gill rakers, and a body depth of 1.9–2.0 in standard length(5.78 cm in length) as differed from other congeners. The adult fish's color when fresh is yellowish having dark black margins on the dorsal and anal fins.
Placidochromis boops is a species of deep-water African cichlid endemic to the southern portion of Lake Malawi. This species can reach a length of up to 11.2 centimetres (4.4 in) SL.
