In the early 20th century, coelacanths were well known from the fossil record, the group having been common and diverse during the Permian and Triassic periods (290-208 million years ago), but they were thought to have gone extinct by 70 million years ago—until a live one was collected off South Africa in December of 1938, causing a splash among biologists around the world. Over the years, subsequent work in the Comoro Islands (located between the African continent and the northern end of Madagascar) turned up a couple of hundred additional L. chalumnae specimens caught with hook and line between 35 and 600 m (the species was known to local fishermen but had no value as a food fish and was not sold in local markets).
In the decades since the remarkable discovery of living coelacanths, submersible-based field work has revealed a great deal about Latimeria. They are lethargic, nocturnal creatures that spend most of the day resting in caves in groups of 2 to 16. Typical habitat appears to be barren rocky slopes providing caves at depths of 100 to 300 m. On nightly forays for food (mainly other fishes), they may travel as much as 8 km before retreating to a cave at the end of the night. Coelacanths reproduce by internal fertilization and the young develop inside the mother. The huge eggs are 9 cm in diameter and over 325 g (the largest known eggs of any fish). Gestation period has been estimated to be around 13 months. The young are born at 35 to 38 cm. (Heemstra and Heemstra 2004)
In the 1990s, additional coelacanths were collected off the southwest coast of Madagascar and off the island of Sulawesi in Indonesia (DNA data have resulted in the recognition of Indonesian specimens as a distinct coelacanth species, L. menadoensis). Subsequently, a coelacanth was collected off the coast of Kenya and a population of coelacanths was discovered in Sodwana Bay off the coast of South Africa. Much remains to be learned about these mysterious fish. (Heemstra and Heemstra 2004) Tetrapods, coelacanths, and lungfishes have long been recognized as closest relatives to each other, but the topology of the relationship among these three groups has been exceptionally difficult to resolve (Takezaki et al. 2004; Modisakeng et al. 2006 and references therein).
Latimeria chalumnae is listed as endangered with extinction (category Appendix I) under the international CITES treaty. IUCN lists Latimeria chalumnae as critically endangered.
The remarkable story of the discovery of these “living fossils” is recounted in the book A Fish Caught in Time: The Search for the Coelacanth (Weinberg 1999).
- Heemstra, P.C. and E. Heemstra. 2004. Coastal Fishes of Southern Africa. South African Institute for Aquatic Biodiversity and National Inquiry Service Centre, Grahamstown, South Africa.
- Modisakeng K.W., Amemiya C.T., Dorrington R.A.,and G.L. Blatch. 2006. Molecular biology studies on the coelacanth:a review . South African Journal of Science 102: 479-485.
- Takezaki, N., Figueroa, F., Zaleska-Rutczynska, Z., Takahata, N., and J. Klein. 2004. The Phylogenetic Relationship of Tetrapod, Coelacanth, and Lungfish Revealed by the Sequences of Forty-Four Nuclear Genes. Molecular Biology and Evolution 21(8): 1512-1524.
- Weinberg, S. 1999. A Fish Caught in Time: The Search for the Coelacanth. 1999. Fouth Estate, London.
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