| Polypterus polli | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Polypteriformes |
| Family: | Polypteridae |
| Genus: | Polypterus |
| Species: | P. polli |
| Binomial name | |
| Polypterus polli J. P. Gosse, 1988 [2] | |
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Polypterus polli, Poll's bichir, is a species of bichir from the Malebo Pool and the lower and central basins of the Congo River. It was named in honor of Belgian ichthyologist Max Poll. [2]
P. polli is an “upper-jaw” bichir, meaning its maxilla protrudes further out than its mandible. It has a maximum recorded length of 12.6 inches (32.1 cm). [2] It can be distinguished from other bichirs by its dull gold body color, greenish-yellow fins, and reticulated body pattern with light-colored “polka-dots” toward the base of the tail. It is oftentimes mistaken for P. palmas in the aquarium trade because they were once considered conspecific and have a similar color pattern, but P. polli lacks the dark transverse barring and speckled look characteristic of both P. palmas morphs. It can also be distinguished by its count of 5-7 dorsal finlets. [3]
Bichirs are stabilomorphic fishes that diverged from other ray-finned fishes possibly as early as the Devonian period. As such, P. palmas can be considered a living fossil, and exhibits many "primitive" traits when compared to other extant fishes. This species has true lungs in addition to gills, and uses a blowhole-like organ called a spiracle to take breaths of atmospheric oxygen (a trait it shares with stem-tetrapods). This allows P. palmas to survive poorly oxygenated water conditions—such as in dried-out seasonal pools—or even entirely on land indefinitely provided that their spiracles and gills remain damp. Juvenile bichirs have underdeveloped lungs, so they exhibit external gills—much like a larval salamander or lungfish—with a branching, featherlike architecture to maximize surface area for oxygen exchange until their lungs mature.
Like most bichirs, P. polli's vision is somewhat lackluster, so it instead hunts using its lateral line and sense of smell. One of its notable stabilomorphic traits is its accessory olfactory organ—an internal structure that has become vestigial or nonexistent in most extant fishes. Due to its retention of this organ and elongate, nostril-like structures called nares, P. polli has a very precise sense of smell. [4]
P. polli was once considered one of three subspecies of P. palmas. [5] The other two subspecies, P. palmas palmas and P. palmas buettikoferi, are no longer considered valid subspecies and are now simply considered morphs of the monosubspecific P. palmas, while P. polli was elevated to species status in 1988. [2]
Despite historically being taxonomically associated with P. palmas, recent molecular studies have placed P. polli as a sister taxon to P. delhezi. [3]
P. polli is occasionally seen in the aquarium trade. Wholesalers and local fish stores often mistake this species for other bichirs such as P. palmas and P. retropinnis , so one must be careful and well-versed in bichir identification to ensure the correct fish is purchased. Captive breeding has not been observed in this species, so P. palmas in the aquarium trade are wild-caught. Because it reaches lengths of over a foot, a tank of at least 75 gallons is required for keeping this species in captivity. They prefer soft, slightly acidic water, but are very hardy fishes tolerant of a wide range of water chemistries in the aquarium. As nocturnal fish that hail from densely vegetated waters, they appreciate a lot of shade and places to hide. They can be sustained on a diet of frozen or live foods, such as bloodworms or earthworms. [6]
Its captive behavior is typical of smaller bichirs. It is not particularly aggressive and territorial disputes only tend to happen with other bichirs, and they tend to be over very quickly once a bichir pecking order has been established. However, as an opportunistic predator, P. palmas is liable to eat small tankmates. The ideal tankmates for P. palmas are large, tall-bodied fishes that tend to stay higher in the water column so as not to compete for territory (such as large cichlids), or other similarly-sized bichirs (such as P. senegalus , P. retropinnis , P. palmas , and P. mokelembembe ).
Bichirs and the reedfish comprise Polypteridae, a family of archaic ray-finned fishes and the only family in the order Polypteriformes.
The reedfish, ropefish, or snakefish, Erpetoichthys calabaricus, is a species of fish in the family Polypteridae alongside the bichirs. It is the only member of the genus Erpetoichthys. It is native to fresh and brackish waters in West and Central Africa. The reedfish possesses a pair of lungs in addition to gills, allowing it to survive in very oxygen-poor water. It is threatened by habitat loss through palm oil plantations, other agriculture, deforestation, and urban development.
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.
Polypterus is a genus of freshwater fish in the bichir family (Polypteridae) of order Polypteriformes. The type species is the Nile bichir. Fish in this genus live in various areas in Africa. Polypterus is the only known vertebrate to have lungs, but no trachea.
Amphibious fish are fish that are able to leave water for extended periods of time. About 11 distantly related genera of fish are considered amphibious. This suggests that many fish genera independently evolved amphibious traits, a process known as convergent evolution. These fish use a range of terrestrial locomotory modes, such as lateral undulation, tripod-like walking, and jumping. Many of these locomotory modes incorporate multiple combinations of pectoral-, pelvic-, and tail-fin movement.
Hans Christian Bjerring is a Danish-Swedish vertebrate paleontologist and comparative anatomist. He has spent his career at the Swedish Museum of Natural History in Stockholm, Sweden, as curator at the Department of Palaeozoology.
Polypterus bichir lapradei is a subspecies of freshwater fish in the family Polypteridae. P. bichir lapradei are demersal, primitive, and popular with experienced aquarists.
Polypterus ornatipinnis, the ornate bichir, is a bony fish found in Lake Tanganyika and the Congo River basin in Central and East Africa.
The barred bichir, armoured bichir, bandback bichir, or banded bichir is an elongated fish found in the Congo River, specifically in the upper and middle portions. This species is one of the more commonly available in commercial pet stores.
Max Fernand Leon Poll was a Belgian ichthyologist who specialised in the Cichlidae. In the years 1946 and 1947 he organised an expedition to Lake Tanganyika.
Cladistia is a clade of bony fishes whose only living members are the bichirs of tropical Africa. Their major synapomorphies are a heterocercal tail in which the dorsal fin has independent rays, and a posteriorly elongated parasphenoid.
The saddled bichir, Polypterus endlicheri endlicheri, is a prototypical subspecies of the Polypterus genus, meaning most of its features are held across the genus.
Polypterus endlicheri, the saddled bichir, is one of the largest species of the Polypterus genus of freshwater fish.
Polypterus palmas, also called the shortfin or marbled bichir, is a fish in the family Polypteridae found in freshwater environments throughout West Africa.
The West African bichir or retropinnis bichir, is a freshwater fish in the family Polypteridae, is found in the central Congo River basin and Ogooué River in Africa. It is a long, slender fish that grows to a maximum length of about 34 cm (13 in).
Polypterus teugelsi is a species of carnivorous, nocturnal bichir that lives in the Cross River drainage basin in the country of Cameroon. P. teugelsi was described in 2004 by Ralf Britz.
Polypterus mokelembembe is a species of the fish genus Polypterus, found in the central basin of the Congo River. It was once considered a morph of the closely related Polypterus retropinnis, but was given species status in 2006 with a description that reclassified both fishes. Because of the recency of the species' description and the fact that P. mokelembembe is the paralectotype of P. retropinnis, they are often mistaken for one another in the aquarium trade.
Spiracles are openings on the surface of some animals, which usually lead to respiratory systems.
The Bichir Handbook is a book written by science communicator and graphic designer Joshua Pickett from Salisbury, England, about living fossil fishes known as Polypteriformes (bichirs), found throughout west and central Africa, and formerly South America. In the book, Pickett describes all extant Polypteridae, and details extinct species with illustrated reconstructions. The book was designed by the author and illustrated by paleoartist Dorian Noël.
