rekordy: Coelacanth

Evidence: 100 • authority: 72

Coelacanths ( SEE-lə-kanth) are an ancient group of lobe-finned fish (Sarcopterygii) in the class Actinistia. As sarcopterygians, they are more closely related to lungfish and tetrapods (the terrestrial vertebrates including living amphibians, reptiles, birds and mammals) than to ray-finned fish. There is only a single living genus, Latimeria, with two described species. The name coelacanth originates from the Permian genus Coelacanthus, which was the first scientifically named genus of coelacanths (in 1839), becoming the type genus of Coelacanthiformes as other species were discovered and named. Well-represented in freshwater and marine deposits from as early as the Devonian period (more t…

Evidence: 72 • authority: 72

The West Indian Ocean coelacanth (Latimeria chalumnae), sometimes known as the gombessa, African coelacanth, and simply coelacanth, is a crossopterygian, one of two extant species of coelacanth, a rare order of vertebrates more closely related to lungfish and tetrapods than to the common ray-finned fishes. The other extant species is the Indonesian coelacanth (L. menadoensis). The West Indian Ocean coelacanth was historically known by fishermen around the Comoro Islands (where it is known as gombessa), Madagascar, and Mozambique in the western Indian Ocean, but first scientifically recognised from a specimen collected in South Africa in 1938. This coelacanth was once thought to be evolution…

Evidence: 52 • authority: 92

A deep dive into the coelacanth phylogeny.. The discovery in 1938 of a living coelacanth, Latimeria chalumnae, triggered much research and discussion on the evolutionary history and phylogeny of these peculiar sarcopterygian fishes. Indeed, coelacanths were thought to represent the 'missing link' between fishes and tetrapods, a phylogenetic position which is now dismissed. Since the first analyses using a phylogenetic approach were carried out three decades ago, a relatively similar data matrix has been consistently used by researchers for running analyses, with no significant changes aside from the addition of new taxa and characters, and minor corrections to the states' definition and sco…

Evidence: 45 • authority: 72

Latimeria is a rare genus of fish which contains the only two extant species of coelacanth: the West Indian Ocean coelacanth (Latimeria chalumnae) and the Indonesian coelacanth (Latimeria menadoensis). They follow the oldest known living lineage of Sarcopterygii (lobe-finned fish and tetrapods), which means they are more closely related to lungfish and tetrapods (amphibians, reptiles and mammals) than to the common ray-finned fishes and cartilaginous fishes. They are found along the coastlines of the Indian Ocean and Indonesia. Since there are only two known species of coelacanth and both are threatened, it is one of the most endangered genera of animals in the world. The West Indian Ocean…

Evidence: 39 • authority: 92

Allometric growth in the extant coelacanth lung during ontogenetic development.. Coelacanths are lobe-finned fishes known from the Devonian to Recent that were long considered extinct, until the discovery of two living species in deep marine waters of the Mozambique Channel and Sulawesi. Despite extensive studies, the pulmonary system of extant coelacanths has not been fully investigated. Here we confirm the presence of a lung and discuss its allometric growth in Latimeria chalumnae, based on a unique ontogenetic series. Our results demonstrate the presence of a potentially functional, well-developed lung in the earliest known coelacanth embryo, and its arrested growth at later ontogenetic…

Evidence: 39 • authority: 92

Buoyancy and hydrostatic balance in a West Indian Ocean coelacanth Latimeria chalumnae.. Background Buoyancy and balance are important parameters for slow-moving, low-metabolic, aquatic organisms. The extant coelacanths have among the lowest metabolic rates of any living vertebrate and can afford little energy to keep station. Previous observations on living coelacanths support the hypothesis that the coelacanth is neutrally buoyant and in close-to-perfect hydrostatic balance. However, precise measurements of buoyancy and balance at different depths have never been made. RESULTS: Here we show, using non-invasive imaging, that buoyancy of the coelacanth closely matches its depth distribution…

Evidence: 34 • authority: 72

The Chalumna River (Xhosa: Tyolomnqa) is a river in the Eastern Cape, South Africa. It is approximately 78 km long, forming at the confluence of two small rivers, the Qugwala in the West and the Mtyolo in the East. It empties into the Indian Ocean through an estuary near Kayser's Beach. Its catchment area of 441 km2 makes it one of the smallest river basins on South Africa's eastern coast. Its tributaries are Nyatyora, Nxwashu, Quru and Mpintso on the left and Rode, Twecu and Tsaba on the right. Its mouth is located about 45 km south west of the Buffalo Estuary at East London. The African longfin eel (Anguilla mossambica) is common in its waters.

Evidence: 29 • authority: 92

The most detailed anatomical reconstruction of a Mesozoic coelacanth.. Although the split of coelacanths from other sarcopterygians is ancient, around 420 million years ago, the taxic diversity and the morphological disparity of the clade have remained relatively low, with a few exceptions. This supposedly slow evolutionary pace has earned the extant coelacanth Latimeria the nickname "living fossil". This status generated much interest in both extinct and extant coelacanths leading to the production of numerous anatomical studies. However, detailed descriptions of extinct taxa are made difficult due to the quality of the fossil material which generally prevents fine comparisons with the ext…