Latimeria

From Safaripedia
Jump to: navigation, search
Coelancanth

Latimeria, named for Marjorie Courtenay-Latimer, the curator of East London's Museum, is a living representative of the lobe-finned fish order known as Coelacanths. It is often called a living fossil. Coelacanth (‬Hollow spine)‬ belongs to the oldest lineage of fish currently known to science. The oldest found Coelacanth fossils imply that the Coelacanth fish species developed during the Devonian period. Coelacanthiform lobe-finned fish were a large group comprising about 90 valid species that were distributed worldwide in both marine and freshwaters. Fossil finds declined steadily until the Late Cretaceous extinction when Coelacanths disappear from the fossil record and were assumed extinct.


Content List

1. Genera & species

2. Characteristics

a. Size

b. Behavior

3. History of Discovery

4. Paleoenvironment

5. References


Genera and Species

Classification: Sarcopterygii, ‬Actinistia, ‬Coelacanthimorpha, ‬Coelacanthiformes, Latimeridae, Latimeria.

Species: L. chalumnae, L. menadoensis

Common Name: West Indian Ocean Coelacanth, African Coelacanth, Gombressa (L. chalumnae), Indonesian Coelacanth (L. menadoensis)


Characteristics

Latimeria had proportionately small fins and a tail fin that was split into three parts called ‘‬lobes’ with two dorsal fins on the back. It had thick scales for armor, not found in modern fish. It had a blue color with a pattern of white spots that was different for each individual.


Size

LENGTH: 200cm.

WEIGHT: 80 kg.


Behavior

Coelacanths give birth to live young. They prey on smaller fish and sharks.


History of Discovery

The first present day coelacanth was caught in late 1938 by a fishing captain named Hendrik Goosen in South Africa. He kept the fish and told his friend Marjorie Courtenay-Latimer, a museum curator, about the odd catch. She contacted her friend, professor by J. L. B. Smith, who recognized the fish from fossils. The genera of Latimeria is named for Marjorie.


In 1997, a second living species, the Indonesian coelacanth, was discovered in a fish market. Unlike the West Indian Ocean coelacanth, which is blue, the Indonesian variety is brown.


Paleoenvironment

Latimeria is found living off the coast of East Africa and Indonesia in the depths at the base of islands and in caves during the day. Fossil Coelacanths are known worldwide in a range of fresh and marine environments. Lobe-finned fish are considered close to origins of land vertebrates. The classic theory of Alfred Romer theorized that the lobe-finned fish first used the fleshy rays of their fins to walk on the bottom of lakes and over time the lobes became legs. It now seems that amphibians developed the lung fish line of lobe-finned fish, not Coelacanths, and legs did not develop from the rays of lobed fins.


Present Status

The West Indian Ocean Coelacanth is listed as critically endangered, and the Indonesian Coelacanth is considered "vulnerable" by the IUCN.


References

1. Coelacanths and their living examples the Latimeria. (n.d.). Retrieved May 22, 2014, from http://www.prehistoric-wildlife.com/articles/coelacanths-and-latimeria.html.

2. Knol, R. (2007, August 25). Paleozoic Seas in the Devonian. Retrieved May 22, 2014, from http://www.dinosaurcollectorsitea.com/devonian.htm.