West Indian Ocean coelacanth

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West Indian Ocean coelacanth
Latimeria chalumnae.jpg
Latimeria chalumnae replica.jpg
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Sarcopterygii
Subclass: Actinistia
Order: Coelacanthiformes
Family: Latimeriidae
Genus: Latimeria
Species: L. chalumnae
Binomial name
Latimeria chalumnae
J. L. B. Smith, 1939
Latimeria distribution RUS.png
L. chalumnae range in red
Synonyms

Malania anjouanae

The West Indian Ocean coelacanth[2] (Latimeria chalumnae), sometimes known as the African coelacanth[3] is one of two extant species of coelacanth, a rare order of vertebrates more closely related to lungfish, reptiles and mammals than to the common ray-finned fishes. It has a vivid blue pigment, and is the better known of the two extant species. The species has been assessed as critically endangered on the IUCN Red List.[1]

Biological characteristics[edit]

Latimeria chalumnae embryo with its yolk sac from the Muséum national d'histoire naturelle.

The average weight of Latimeria chalumnae is 80 kg (176 lb), and they can reach up to 2 m (6.5 ft) in length. Adult females are slightly larger than males. L. chalumnae is widely but very sparsely distributed around the rim of the western Indian Ocean, from South Africa northward along the east African coast to Kenya, the Comoros and Madagascar, seemingly occurring in small colonies.

Population and conservation[edit]

L. chalumnae is listed as critically endangered by IUCN.[1] In accordance with the Convention on International Trade of Endangered Species treaty, the coelacanth was added to Appendix I (threatened with extinction) in 1989. The treaty forbids international trade for commercial purposes and regulates all trade, including sending specimens to museums, through a system of permits. In 1998, the total population of the West Indian Ocean coelacanth was estimated to have been 500 or fewer, a number that would threaten the survival of the species.[4]

First find in South Africa[edit]

Preserved specimen of Latimeria chalumnae in the Natural History Museum, Vienna, Austria (length: 170 cm - weight: 60 kg). This specimen was caught on 18 October 1974, next to Salimani/Selimani (Grand Comoro, Comoro Islands) 11°48′40.7″S 43°16′3.3″E / 11.811306°S 43.267583°E / -11.811306; 43.267583.

On December 23, 1938, Hendrik Goosen, the captain of the trawler Nerine, returned to the harbour at East London, South Africa, after a trawl between the Chalumna and Ncera Rivers. As he frequently did, he telephoned his friend, Marjorie Courtenay-Latimer, curator at East London's small museum, to see if she wanted to look over the contents of the catch for anything interesting, and told her of the strange fish he had set aside for her. Correspondence in the archives of the South African Institute for Aquatic Biodiversity (SAIAB, formerly the JLB Smith Institute of Ichthyology) show that Goosen went to great lengths to avoid any damage to this fish and ordered his crew to set it aside for the East London Museum. Goosen later told how the fish was steely blue when first seen but by the time the Nerine entered East London harbour many hours later the fish had become dark grey.

Failing to find a description of the creature in any of her books, she attempted to contact her friend, Professor James Leonard Brierley Smith, but he was away for Christmas. Unable to preserve the fish, she reluctantly sent it to a taxidermist. When Smith returned, he immediately recognized it as a coelacanth, known only from fossils. Smith named the fish Latimeria chalumnae in honor of Marjorie Courtenay-Latimer and the waters in which it was found. The two discoverers received immediate recognition, and the fish became known as a "living fossil". The 1938 coelacanth is still on display in the East London, South Africa, museum.

However, as the specimen had been stuffed, the gills and skeleton were not available for examination, and some doubt therefore remained as to whether it was truly the same species. Smith began a hunt for a second specimen that would take more than a decade.

The second specimen, Malania anjouanae[edit]

A second specimen with a missing dorsal fin and deformed tail fin was captured in 1952 off the coast of Anjouan. At the time it was believed to be a new species and placed in a new genus as well, Malania, named in honour of the Prime Minister of South Africa at the time, Daniel François Malan, without whose help the specimen would not have been preserved with its muscles and internal organs more or less intact.[5]

Genetics[edit]

The genome of Latimeria chalumnae was sequenced in 2013 to provide insight into tetrapod evolution.[6] The full sequence and annotation of the Ensembl entry is available on the Ensembl genome browser.

References[edit]

  1. ^ a b c Musick, J. A. (2000). "Latimeria chalumnae". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 2013-12-23. 
  2. ^ Wägele, H.; Klussmann-Kolb, A.; Kuhlmann, M.; Haszprunar, G.; Lindberg, D.; Koch, A.; Wägele, J. W. (2011). "The taxonomist - an endangered race. A practical proposal for its survival". Frontiers in Zoology 8 (1): 25. doi:10.1186/1742-9994-8-25. PMC 3210083. PMID 22029904.  edit
  3. ^ "The African coelacanth genome provides insights into tetrapod evolution". Nature 496 (7445). 18 April 2013. doi:10.1038/nature12027. PMC 3633110. PMID 23598338. Retrieved 2013-06-19. 
  4. ^ Jewett, Susan L., "On the Trail of the Coelacanth, a Living Fossil", The Washington Post, 1998-11-11, Retrieved on 2007-06-19.
  5. ^ Weinberg, Samantha. 2006. A Fish Caught in Time: the Search for the Coelacanth, pages 63-82. HarperCollins Publishers, New York, NY.
  6. ^ Amemiya CT, Alfoldi J, Lee AP, et al.. "The African coelacanth genome provides insight into tetrapod evolution". Nature 496 (7445): 311–316. doi:10.1038/nature12027. PMC 3633110. PMID 23598338. 

External links[edit]