(J. P. Gosse, 1963)
Pterophyllum leopoldi, also referred to as the teardrop angelfish, Leopold's angelfish  dwarf angelfish, or roman-nosed angelfish,  is an angelfish species native to the Amazon River (between Manacapuru and Santarém), Essequibo River and Rupununi River. 
It is distinguished from other members of the genus Pterophyllum by the absence of a pre-dorsal notch, and by the presence of a black blotch at the dorsal insertion on the 4th vertical bar. 
The species is frequently misidentified as P. dumerilii when it is imported in the aquarium trade.  P. leopoldi is the smallest of the angelfish species, reaching a length of 5 centimetres (2.0 in) SL,  and the most aggressive.[ citation needed ]
The specific name honours King Leopold III of Belgium, who sponsored the expedition to the Amazon that collected the type of this species. 
Pterophyllum is a small genus of freshwater fish from the family Cichlidae known to most aquarists as angelfish. All Pterophyllum species originate from the Amazon Basin, Orinoco Basin and various rivers in the Guiana Shield in tropical South America. The three species of Pterophyllum are unusually shaped for cichlids being greatly laterally compressed, with round bodies and elongated triangular dorsal and anal fins. This body shape allows them to hide among roots and plants, often on a vertical surface. Naturally occurring angelfish are frequently striped transversely, colouration which provides additional camouflage. Angelfish are ambush predators and prey on small fish and macroinvertebrates. All Pterophyllum species form monogamous pairs. Eggs are generally laid on a submerged log or a flattened leaf. As is the case for other cichlids, brood care is highly developed.
Heterotilapia buttikoferi, also known as the zebra tilapia, is a West African species of cichlid.
Maylandia lombardoi, is a 13 centimetres (5.1 in) long freshwater fish from the family Cichlidae. This species is popular in the aquarium hobby where it is sold under a variety of common names including: lombardoi mbuna, kenyi mbuna or kennyi mbuna or kenyi cichlid. This species is sometimes seen in the genus Metriaclima owing to a dispute in which a minority of cichlid researchers do not consider Maylandia valid (see Maylandia for discussion. The specific name honours the exotic fish dealer John Lombardo.
The threadfin acara, also known as Heckel's thread-finned acara, is a South American species of cichlid fish. It is the only member of the genus Acarichthys and is native to rivers in the Amazon and Essequibo basins in tropical South America, and has become established in southeastern Asia. It is sometimes found in the aquarium trade.
Nimbochromis livingstonii, Livingston's cichlid or (locally) kalingono, is a freshwater mouthbrooding cichlid native to Lake Malawi, an African Rift Lake. It is also found in the upper Shire River and Lake Malombe. They are found in inshore areas of the lake over sandy substrates.
Paratilapia polleni is a medium-sized cichlid endemic to Madagascar. It is also a popular fish for display at public aquaria.
The sulfurhead aulonocara or sulfurhead peacock is a species of haplochromine cichlid which is endemic to Lake Malawi in the country of Malawi and has only been observed on West Reef and Eccles Reef. It is threatened by collection for the aquarium trade and this has caused a 70% reduction in numbers. In this mouthbrooding species, the eggs are cared for by the females only, and it is found over mixed sand and rocky areas where they hunt small invertebrates in the sand. It closely resembles the blue orchid aulonocara though it develops a yellow blaze across its dorsal In the past these two taxa have been considered to be subspecies. The specific name honours Hans-Joachim Mayland, an author on cichlids and a fishkeeper, brought the species to the attention of Ethelwynn Trewavas.
The resplendent pygmy angelfish is a species of marine ray-finned fish, a marine angelfish, belonging to the family Pomacanthidae. It is endemic to Ascension Island in the South Atlantic Ocean.
Iodotropheus stuartgranti is a species of cichlid endemic to Lake Malawi. It can also be found in the aquarium trade. This species can reach a length of 10 centimetres (3.9 in) TL. The specific name honours Stuart M. Grant (1937-2007), an exporter of cichlids from lake Malawi for the aquarium trade. This species feeds maonly on aufwuchs. The males are territorial and the female will lay anywhere within a male's territory.
The convict julie is a cichlid species in the subfamily Pseudocrenilabrinae family endemic to Lake Tanganyika. Hence it is found in Burundi, the Democratic Republic of the Congo, Tanzania, and Zambia. The fish is named after Charles Tate Regan.
Limnotilapia dardennii, the latticed cichlid, is a species of cichlid endemic to Lake Tanganyika, where it prefers rocky areas near the coast. It may also be found in the aquarium trade. This species is currently the only known member of its genus.
The threadfin cichlid is a species of cichlid endemic to Lake Tanganyika found in areas with rocky substrates on which it can graze on algae. This species can reach a length of 18 cm (7.1 in). It can be found in the aquarium trade. The specific name of this cichlid honours the British ichthyologist Ethelwynn Trewavas (1900-1993).
Protomelas kirkii is a species of cichlid endemic to Lake Malawi where it is most commonly found in areas vegetated with Vallisneria. This species can reach a length of 18 centimetres (7.1 in) TL. This species can also be found in the aquarium trade.
The banded angelfish, also known as the bandit angelfish and three spine angelfish, is a distinctive species ray-finned fish belonging to the family Pomacanthidae. It is endemic to deeper reefs in Hawaii and the Johnston Atoll.
Apolemichthys griffisi, or Griffis angelfish, is a species of ray-finned fish, a marine angelfish belonging to the family Pomacanthidae. It is found in the Pacific Ocean. It is a rarity for the species to enter the aquarium trade.
Centropyge heraldi, the yellow angelfish or Herald's angelfish is a species of marine ray-finned fish, a marine angelfish belonging to the family Pomacanthidae. It comes from the Pacific Ocean that sometimes makes its way into the aquarium trade.
Centropyge venusta, the purplemask angelfish is a species of marine ray-finned fish, a marine angelfish belonging to the family Pomacanthidae, It is found in the Western Pacific and is occasionally found the aquarium trade.
Apistogramma agassizii is the scientific name for the Agassiz's dwarf cichlid, a fish that occurs in many Southern tributaries of the Amazon river. Its specific name honours the Swiss-American zoologist and geologist Louis Agassiz (1807-1873).
The peppermint angelfish is a relatively small species of marine ray-finned fish, a marine angelfish belonging to the family Pomacanthidae. It occurs in the Central Pacific Ocean.
Australoheros facetus, the chameleon cichlid or chanchito, is a species of cichlid from the subfamily Cichlasomatinae which is native to northern Argentina, Paraguay, Uruguay and southern Brazil.