What is a coelacanth?
A coelacanth (pronounced "seel-uh-kannth", "selekant" in Afrikaans) is a large marine lobe-finned fish belonging to the Order Coelacanthiformes, a group of primitive bony fishes.
In 1836 Louis Agassiz described a fossil fish in his book Poissons Fossiles and called Coelacanthus because the spines that project from the vertebrae to the caudal fin rays were hollow (coel, Greek for "space" and acanthus spine). This was the first coelacanth to be described
What does the coelacanth look like?
An adult coelacanth can grow at least to 180 cm in length and weigh 98 kg. It is dark blue, changing after death to grey/brown. Each fish has a distinctive pattern of pinkish white blotches that enables scientists to distinguish one individual from another.
Anatomical features
The coelacanth has several very distinctive anatomical features.
The head
The skull is in two parts with an intracranial joint which allows up and down movement between them. A strong pair of muscles beneath the skull-base lowers the front half of the skull, giving the coelacanth a powerful bite .The coelacanth is the only living animal with that structure.
The eyes and olfactory organs are in the front part of the skull, and tiny brain and inner ear are in the rear.
In the middle of the snout is a large cavity filled with a jelly-like sac which opens to the outside through three pores. This sac is called the rostral organ .It may be used to detect weak electric currents and help the coelacanth to find hidden prey.
The fins
Coelacanths belong to a group of bony lobe-finned fishes and have 8 fins (2 dorsals, 2 pectorals, 2 pelvics, 1 anal and 1 caudal). Ray-finned fishes such as bass or perch (in fact most fishes expect sharks and rays) usually have only one dorsal fin. In ray-finned fishes the fins have a basic structure of bony, flexible fin rays with a web of skin stretched across them. The fin rays can flex slightly so that the fish fan or scull its fins. The first dorsal fin of the coelacanth is much like that of other fishes and can be folded down or erected. The other fins have a well-developed, muscular, limb-like basal lobe projecting from the body wall, and a fringe of unbranched rays like a fan attached to the outer end of the base. The fleshy scale -covered lobe can be bent or rotated so that each fin can work like a paddle or sculling oar. The caudal fin (tail) has three divisions: a characteristic small projecting middle lobe between the longer upper and lower lobes of the fin.
External anatomy of the coelacanth, Latimeria chalumnae
Internal anatomy of the coelacanth, Latimeria chalumnae
The skeleton
Most of the skeleton is made of cartilage. In place of the vertebral column, a large notochord extends from the skull to the tip of the caudal fin. The notochord is a thick-walled cartilaginous tube filled with oil-like fluid which is under slight pressure; it is tough and elastic and does the job of a backbone, since no complete vertebrae are developed around it. In most other vertebrates the notochord is replaced by vertebrae in the embryonic stage of development.
The scales
The body is covered with hard scales with small toothy-like growths called denticles on the outer surface which protect the coelacanth from the rocks and predators.
The skeleton of Latimeria showing the hollow notochord (indicated by the arrow)
The swimbladder
Unlike most fishes which have a gas-filled swimbladder, the coelacanth has a large swimbladder that is filled with fat. Being lighter than the seawater, the fat provides buoyancy.
How the coelacanth swims
The lobed fins are extremely mobile and can be rotated through 100 degrees. The coelacanth can swim fast for short periods, but it usually swims around slowly using its paired and median fins as sculls to push itself through the water. When cruising the fish works the right pectoral fin in tandem with the left pelvic fin and vice versa. The coelacanth likes to hover near the sea bottom with all fins fully extended - a beautiful sight to see. The paired lobed fins are not used to walk on the seabed or, as with lungfish, to prop the fish up off the bottom or push it against it. It seems rather to avoid touching the ground. When started, it darts forward at speed using the large caudal fin. Sometimes it performs a head stand, keeping its snout to the sea floor and rotating its rigid body to an upright position. It may then make use of the electro-receptive rostral organ to find prey on the bottom.
The coelacanth, Latimeria chulamnae, as a living fossil
Why is the coelacanth important to science?
Palaeontology is a Greek word for the study of prehistoric plants and animals. Fossils are the remnants or impressions of plants and animals that lived before the present. The original meaning of the word fossil is derived from the Latin verb fobere, to dig, as fossils were usually encountered as petrified artifacts preserved in rock and stone. Charles Darwin coined the term living fossil to describe the East Asian ginkgo tree, but not mean by that a fossil that had somehow come w4s tree, but not mean by that a fossil that had somehow come back to life. Rather he meant a life that had evolved very little for million of years-a case of arrested evolution. Examples are cycads, elephant shrew and broad-nosed crocodiles. The closest relatives of living fossils have been extinct for a long time.
The fossil coelacanth, Whiteia, from the Triassic, which was discovered in the Orange Free State
The scientific discovery of Latimeria chulamnae in 1938 caused a sensation in the scientific world because it is the only living member of a very old group of fishes, the actinistians (Coelanacanthimorpha). About 120 species of coelacanths are known from fossils. They were predominantly small marine fish (though some lived in freshwater) which were thought to have died out at the end of the Mesozoic era more than 60 million years ago. They flourished in the Triassic; a fossil of a coelacanth (Whiteia) was discovered in the Orange Free State which dates to that time .The Coelacanthimorpha and lungfishes are separate side-branches of the primitive fish group that gave rise to the amphibians, reptiles, birds and mammals. Although Latimeria is not a missing link in the story of evolution, it is the sole survivor of a line of development that otherwise became extinct. From the anatomy, biochemistry, physiology and behaviour scientists can learn much about the processes of evolution.
The story of the coelacanth and the Christmas connection
How the coelacanth became known to science
Marjorie Courtenay-Latimer
Marjorie Courtenay-Latimer was born in East London on 24th February 1907. From the childhood she was interested in birds and mammals, and fossil collecting was also a hobby of hers. In 1930 she was appointed Curator of the newly established East London Museum which had at that time a very small collection of bird specimens. She worked hard to create a display of natural history of the Eastern Cape. Since fishing was a major local industry, she decided to concentrate on marine life. She interviewed fishing clubs and managers of fishing trawlers; specimens were enthusiastically donated and she made mounts of the small fish. She first met JLB Smith, then a Lecture in Chemistry at Rhodes University College, in December 1933 when he visited the museum during a camping trip at Igoda. He had been advised by doctors to spend his vacations in the open air because of ill health, and his love of angling soon turned into scientific interest .He was very impressed with the work she was doing, and offered to help her with any specimens which might want to classified, because she had on books on fish at the museum.
In November 1936 she and her parents visited Bird Island where she spent weeks amassing a huge collection of sponges, seaweeds, sea shells and bird eggs. She also went out to sea in the Irvin & Johnson trawler, Nerine, and made friends with the Captain, Hendrik Goosen, who took her crates of specimens back to East London and thereafter saved interesting fishes from the trawl nests for her attention.
Miss Courtenay-Latimer's sketch of the first coelacanth which she posted to JLB Smith
On December 22, 1938, Captain Goosen and the Nerine put into East London harbour with the usual catch of sharks, rays, starfish and rat-tail fish. But there was one unusual fish amongst the catch that had been caught in about 70 meters, near the mouth of the Chalumna River. Once ashore Captain Goosen left word at the Museum that there were several specimens at the ship for Miss Latimer. At first she said that she was too busy because she was hard at work cleaning and articulating the fossil reptile bones collected from Tarkastad. But as it was so near Christmas time she decided to go and wish the crew a Happy Christmas and took a taxi to the docks. There, attracted by a blue fin amid the pile of sharks, she found a magnificent fish. She and her assistant put it in a bag and persuaded a reluctant taxi driver to take it to the museum in the boot of the car .It measured 150 cm and weighed 57.5 kg. From its hard bony scales with sharp, prickly spines and paired fins looking rather like legs, she knew that it must be some kind of primitive fish. But her greatest problem was to preserve it until it could be identified. It was extremely hot, the fish was too big to go into a bath and she could not find any organization willing to store it in a freezer. Although she was told by experts that it was only a type of rock cod and that she was making a fuss about nothing, she persisted in her attempts to save the fish for science. At first it was wrapped in cloths soaked in formalin but eventually, on the 26th, Mr. Center, a taxidermist, skinned it. Unfortunately the internal organs were thrown away. Marjorie went home disappointed and worried that she had not saved all the soft parts. What she had done, however, was to write immediately to her friend, JLB Smith, and send him her famous sketch of the strange fish.
James Leonard Brierley Smith
The next part of the story concerns JLB Smith, at that time enjoying a working holiday in Knysna. The next fourteen years of his life were to be dominated by this coelacanth and an almost obsessive search for the second specimen. JLB Smith, born in 1897 at Graff-Reinet, was a self-taught ichthyologist who had published several papers on the marine fishes of South Africa. He knew at once when he opened Marjories letter that. Though the last coelacanths were supposed to have died out with the dinosaurs, he was looking at a drawing of a fossil fish:
One of my most constant and peculiar obsessions had always been a conviction that I was destined to discover some quite outrageous creature
He sent to Cape Town for a copy of Arthur Smith Wood-wards Catalogue of Fossil Fishes of the British Museum and, after he had received it, positively identified Marjories unusual fish as a coelacanth. But he did not commit himself or risk his reputation in the scientific community until, some time later; he traveled to East London and saw the specimen for himself:
Yes, there was not a shallow of doubt, scale by scale, bone by bone, fin by fin, it was a true coelacanth. It could have been one of those creatures of 200 million years ago and come alive again.
He gave the fish its formal scientific name, Latimer chalumnae in honour of Miss Courtenay-Latimer who had preserved it, and the river near which it was trawled. From January to June 1939 JLB Smith and his young wife, Margaret, worked furiously on the first scientific paper describing the coelacanth, completing it just four days before the birth of their son William. All this time the coelacanth, pervasive smell and all, stayed in their house. It was then returned to be displayed at the East London Museum. Thousands of people visited the museum to see the famous fish.
How fishes are named
In zoology and botany names are important. Taxonomy is the science of the principles of classification. Each distinct kind or species must have its own name. In 1758 Karl von Linne (Linnaeus) from Sweden devised a system of naming (nomenclature). In this system generic names must be unique and species names must not be used more than once per genus. Each species has its own (a binomial i.e. in the two parts) plus the name of the scientist who first formalized the name e.g. Homosapiens Linnaeus. JLB Smith named a fish Pseudocheilinus margaretae after his wife, Margaret.
Captain Eric Hunt and the second coelacanth
It was Christmas time 14 years later the next great chapter in the coelacanth story was written.
Convinced that he East London coelacanth was a stray and that the home of this fish was to the north in the Mozambique Channel, Smith distributed posters offering a reward of one hundred pounds (£100) to anyone finding another specimen. Meanwhile, in 1949, his Sea Fishes of Southern Africa was published. He and his wife traveled extensively to Zanzibar, Tanganyika, Mozambique and Kenya collecting fishes, talking about the coelacanth, and distributing the reward posters. It is a strange fact that, although the coelacanth was well known to the local fishermen of the Comoros (the home of the coelacanth) and called gombessa by them, nothing more was heard about it until Christmas 1952.
Whilst in Zanzibar the Smiths had met a young Captain Eric Hunt, who operated a small trading schooner between the Comoro archipelago (then French territory) and the mainland. He knew fishes well but had never seen a coelacanth. Wanting to help the Smiths in their search, he took some posters to the Comoros where they were widely distributed amongst local fishing communities. At his last meeting with the Smiths, he had asked Margerat what he should do in case he found a coelacanth, as there were no refrigeration facilities in the Comoros, and she told him the only thing he could do was to preserve it in salt.
On December 24th 1952 the Dunnottarr Castle, bringing the Smiths back from the expedition, reached Durban and a telegram from Hunt (which had been sent on from Grahamstown) was urgently delivered to them. In it was the exciting news which almost drove Smith mad with frustration: Hunt had in his possession a five foot specimen of the coelacanth, injected with formalin, which had been caught on the 20th off Anjouan Island. He wanted to know what to do with it! The telegram had been sent from Dzaoudzi, at Mayotte.
JLB Smith did not know exactly where Dzaoudzi was, let alone how to retrieve the specimen before the French did, since it had been landed on French territory. This coelacanth had been caught by a fisherman named Ahmed Hussein, whilst fishing at night from a dugout canoe in deep water about 200m from shore. A schoolteacher saw it at a local market where it was being cleaned, and he recognized it as the fish on the poster. The fisherman and his friends were then persuaded to take the huge decomposing fish 40 km overland on a hot day so that Hunt, a responsible person, could take charge of it. He slit the fish and salted it as he been told to do.
It was a French medical officer on Mayotte who kindly donated hid entire formalin supply to inject the specimen and save it. The fish was then wrapped in cotton and put in a crate, and that is how Smith first saw it when he arrived in the Comoros on December abroad a SA Air Force Dakota loaned to him on the authority of the then South African Prime Minister, DF Malan. He knelt down on the deck to get a closer look at it and, so moved by emotions, this famous scientist found he was crying. The coelacanth was taken back to South Africa, and the fisherman duly got his reward.
Aboard Hunt's vessel after the identification of the second coelacanth. JLB Smith is in the centre of the photograph and Eric Hunt is on the left
Because the specimen lacked the first dorsal fin, Smith thought that it must be a new genus and species, and he proposed the name Malania anjounae (The absence of the first dorsal fin was apparently due to an injury when the fish was young). But it turned out to be the same species as Latimeria chalumnae.
The reward incentive resulted in the subsequent capture of over 150 coelacanths in the Comoros. The French kept most of the specimens and for the next 15 years only French scientists were allowed to search for the coelacanth in the Comoros. Several papers and three large volumes on the anatomy of the coelacanth were published by a French team under the direction of Dr Jacques Millot.
Professor Hans Fricke
Prof. Hans Fricke, a German scientist from the Max. Planck Institute used a two-man submersible, Geo, to observe and film Latimeria in its natural habitat. After a fruitless series of daytime searches he learnt from a local fisherman that the coelacanth was always taken at night and was even shown the places where they were caught. On his first night dive he encountered this magnificent beast and for him a dream had come true. He filmed it swimming around gracefully and slowly, seemingly unperturbed by the submersibles lights. He was able to show that during the day Latimeria retreats into caves, but at night it cruises slowly over the sea bottom, presumably looking for food. He observed the coelacanths most impressive behavior, the headstand: sometimes these huge animals stand for more than two minutes vertically in front of the submersible.
The German submersible, JAGO, which is used by scientists to look for coelacanths under the sea
On a subsequent expedition in 1991, using the submersible Jago, Hans Fricke s team (which included Dr.Phil Heemstra of the JLB Smith Institute) found several individuals together in a cave. The scientists also discovered that coelacanths live at depths far deeper than previously believed, i.e. 150 m to more than 700 m.
The Mozambique coelacanth
The day before Christmas 1991, a third chapter in the coelacanth story began. Prof Mike Bruton, Director of the JLB Smith Institute in Grahamstown, received a fax from Reuters informing him that a female coelacanth had been caught off Mozambique, and that the specimen was lodged in the Natural History Museum of Maputo. The fish had been captured at depths of 40-44 m over a sandy bottom, about 24 km offshore, northeast of Quelimane in central Mozambique. Again it was a case of the discerning trawler captain (the Japanese captain of Vega who recognized the fish immediately as a coelacanth), the informed museum director (Dr Augusto Cabral, Director of the National Museum of Natural History in Maputo), the anxious scientists, and the lack of reliable refrigeration, which led to the adult being skinned and the internal organs discarded. The fish had been accidentally catch in the trawlers nets in August and stored in the onboard deepfreeze with the caught; but as the ship was out at sea for some months the news only reached Grahamstown at Christmas time.
A 348 mm foetus (pup) found inside the female Mozambique coelacanth, and almost ready to be born
Meanwhile Dr Cabral instructed his staff to skin it and noticed that it had a very swollen belly. When it was dissected it was found to contain 26 babies which were almost ready to be born. They ranged in length from 308 to 358 mm and weighed between 410 and 502 g. Dr Cabral had the babies, or pups as they are known, placed in a freezer at the National History Museum. Because of an unreliable supply of electricity, Dr Cabral decided that 10 frozen pups should accompany Hans Fricke to Germany, 10 should accompany Prof Bruton to the JLB Smith Institute, and 6 should remain in Maputo to be preserved in formalin. The curated juveniles will be made available to coelacanth researchers worldwide for study and much will be learnt from this single fortuitous catch.
Where the coelacanth lives
The Mozambique coelacanth is, with the 1938 Chalumna specimen, only the second to be recorded from the shore of the African mainland. Until recently all other specimens have been taken at Grand Comoro and Anjouan Island in the Comoro Islands. The East London fish was probably helped on its 2000 km journey by the strong southwesterly currents of the Mozambique Channel. The Mozambique fish is also likely to be stray from the Comoran population.
On August 5th, 1995 a 32 kg coelacanth was caught in a net set at a depth of 140-150 m off the village of Anakao about 30 km south of Toliara (Tulear) on the southwest coast of Madagascar. The bottom off Anakao is mostly sand and of low relief (the shark nets are not set in rocky area s, as they would likely be snagged on the rocks and lost), and the 200 m depth contour is located about 10 km from shore.
Previously sharks were caught regularly off Anakao and St.Augustin Bay with hook and line in depths of 150-250 m. The deep-set shark nets, which were introduced some two years ago, proved to be more productive than hook and line fishing, and most fishermen have switched to this deep -netting method. Weather permitting, some 50 fishermen (usually working in two-man teams) are engaged every day in the deep-set shark net fishery off Anakao. Since none of the local experienced fishermen had previously seen a coelacanth, it seems unlikely that a resident population of coelacanths occurs off this part of the Madagascar coast. North of Taliara, the continental shelf broadens and the 200m depth contour is located some 20 or more kilometers from shore. This increased distance to deep water precludes most local fishermen (without motorized canoes) from deep-water fishing. For most of the west coast of Madagascar (from Morondava, at about 20°S, to the north end of Madagascar) the continental shelf extends 50 to 100 km offshore. This broad expanse of shallow-water habitat would prevent local fishermen from fishing at depths frequented by coelacanths; consequently, although coelacanths may occur or be resident off the west coast of Madagascar, it will require a directed exploratory fishing effort or a survey with a research submersible to find them.
In June 1991 Hans Fricke and Mike Bruton used the submersible, Jago, to try to discover whether coelacanths live off the South Africa coast. Since coelacanths need caves for shelter during the day, and the scientists found no large caves or overhang on the continental slope off the Chalumna River, it appears that the habitat is not suitable in South African waters.
The biology of Latimeria chalumnae
Feeding habitats
Evidence from the prey found in the stomachs of coelacanths indicates that they are predominantly fish-eaters taking lanternfish (Diaphus), cardinal fish (Coranthus) eels (Iiyophis), beardfish (Polymixia), red breams, skates, sharks and also squid and octopus. The vertical head-down position has been found in other drift-feeding fishes. When the coelacanth is close enough to the prey, the mouth is quickly opened, the prey grasped very quickly by powerful jaws and then swallowed whole.
Sex and growth rate
There is no obvious external difference between male and female coelacanths. Females re more robust than males and grow to a greater size. Large reef-dwelling fishes such as snappers and groupers may live to thirty years, so it is likely that the coelacanth could live longer than that, possibly as long as forty years.
Habitat and population size
Latimeria normally occurs at depths of 150-700 m, with most sightings and catches between 150 and 253 m. During the day coelacanths retreat to caves where they can rest sheltered from currents and predators (sharks). There is evidence that coelacanths may return repeatedly to the same caves and that they have a home range. When in caves they hover in midwater, rarely touching one another. They appear to be social animals, and aggressive behaviour has not been observed. Where caves are rare, coelacanths are hardly ever found. Along the western shores of Grand Comoro the scientists found several occupied caves at depths from 180 to 253. Since Hans Frickes dives off the Comoros it has become possible to estimate the size of the coelacanth population. The population of adults on the west coast of Grand Comoro was estimated to be about 200. Professor Fricke has never observed juveniles, which probably live in deeper water.
It is known whether birth rate is dependent on population size or what the predation rate on coelacanths is likely to be. Fricke did observe some large sharks in the habitat of the coelacanths and it is likely that large sharks may prey on the coelacanths.
Reproduction
The reproduction of Latimeria is of a type called ovoviviparous, which means that it has internal fertilization, and the foetuses are kept are kept inside the mother until they are large enough to look after themselves. Only one ovary matures (usually the right) and 19-26 enormous eggs about 9cm in diameter and 320g in weight develop inside it. The huge yolk of each egg supplied the nutrients necessary for the foetus to grow. The 26 pups found inside the female Mozambique coelacanth indicate that the fish may breed faster and produce more young than was previously thought. This female had been carrying around an extra 12 kg weight.
An inventory of all known specimens of the coelacanth
In 1991 a list complied by Mike Bruton and Sheila Coutouvids was published which included all known specimens of the coelacanth Latimeria chalumnae based on a survey of the literature (scientific writings) and museum, aquarium and university holdings. A number was assigned to each specimen and catch and biological details were given where known. At least 191 coelacanths are known to have been caught since 1938. Many specimens leave the Comoros without being properly documented.
The Comoros and conservation of the coelacanth
The Comoro islands have a hot, wet tropical climate with a cool season from May to October and monsoon rains from November to March. The youngest island, Grand Comoro, is dominated by a huge active volcano which has erupted several times in the past few decades. Deep channels separate the islands from Africa and Madagascar and from each other. There are about 420 000 people living on the three main islands, the majority being very poor. The Comorans depend on natural resources for food, medicines, fuel and building materials. Naturally fishing is an important industry; the problem is that there are too many people catching too few fish. Nowadays many fishermen use glassfibre boats powered by outboard motors or diesel engines. The traditional fishing craft for hundreds of years has been the dugout canoe hollowed from a single log of the mango, kapok, or other trees and stabilized with one or two outriggers, carrying up to two men.
Fishermen work in difficult conditions using very simple tackle, basically a long hand line of retwisted cotton or nylon with a single large hook baited with a fillet of fish. Near the end of the line is a short piece of string to which is tied a lump of lava rock. When the line reaches the right depth the fisherman gives it a jerk to release the rock and the baited hook then hangs free just above the bottom, waiting for a fish to come along. All coelacanths caught by Comoran fishermen are a by-catch of the nighttime fishery for the oilfish Ruvettus.
It was JLB Smith who warned 25 years ago that the unrestricted catching of coelacanths may threaten their survival, and he proposed that an international society should be formed to protect them. After his death in 1987 the Coelacanth Conservation Council was founded by Prof Mike Bruton and three other ichthyologists, with the headquarters in Moroni, capital of the Comoros, the secretariat at the JLB Smith Institute. The fish is now on Appendix 1 of the Convention on International Trade in Endangered Species (CITES) which prohibits trade in this particular species, and any caught should be released if they are still alive. Now that larger fibreglass outrigger canoes have been introduced into the Comoros by the European Economic Community, and fish aggregating devices are used far from shore, it is hoped that fishermen will concentrate on offshore open water fishing, thus reducing the pressure on nearshore fish populations and potential prey species for the coelacanth. Coelacanths cannot be targeted nor caught on demand no matter what lucrative rewards are offered - the history of the past 43 years confirms this! Threats to its future survival might arise, however, from commercial interests such as public aquariums and a special coelacanth fishery for museums.
A reference guide to the Coelacanth
Bruton M.N. 1989. The living coelacanth fifty years later. Trans. Roy. Soc. S. Africa, 47 (1): 19-28.
Bruton M.N.1990. South African scientists conserve marine resources in the Comoros. Ichthos No.26: 8-9
Bruton M.N. 1992. Archimedes, Special Marine Issue 34
3): 57. (Available from P.O. Box 1758, Pretoria 0001, and from ICHTHOS.)
Bruton M.N. & R.E. Stobbs. 1991. The ecology and conservation of the coelacanth Latimeria chalumnae. Environ. Biol. Fishes 32: 313-339
Forey P.L. 1988. Golden jubilee for the coelacanth Latimeria chalumnae. Nature 336: 727-732
Fricke H. 1988. Coelacanth: the fish that time forgot. National Geographic 173:824-838. (Highly recommended, contains colour photos of the living fish)
Greenwood P.H.1989. Fifty years a living fossil- the coelacanth fish Latimeria chalumnae. Bilogist36 (1): 15-19
Greenwood P.H. 1993. Latimeria chalumnae - The Living Coelananth. J.L.B. Smith Institute of Ichthyology.
Heemstra P.C. 1992. Conservation in the Comoros. Ichthos 34:1-2.
Heemstra P.C. & L.J.V. Compagno. 1989. Uterine cannibalism and placental viviparity in the coelacanth? A skeptical view. S.A. Journal Science 85:485-486.
Heemstra P.C. & P.H. Greenwood. 1992. New observations on the visceral anatomy of the late-term fetuses of the living coelacanth fish and the oophany controversy. Proc. R. Soc. Lond. B. 249: 49-55
Schauer J. 1992. The privacy of a living fossil: the coelacanth off Grande Comore. Underwater 19:31-33. (Obtainable from Ihlane Publications, P.O. Box 35100, Northway 4056. Include beautiful photographs)
Smith M.M. & P.C. Heemstra. 1991. Smiths Sea Fishes. Revised edition. Southern Book Publishers. See pages 151-153.
Smith J.L.B. 1956. Old Fourlegs. The story of the coelacanth. Longman Green & Co.,London, 264pp. ( This book is out of print but obtainable in many libraries )
Thompson K.S. 1991. The story of the coelacanth. WW Norton, New York, 252 pp.
A coelacanth (pronounced "seel-uh-kannth", "selekant" in Afrikaans) is a large marine lobe-finned fish belonging to the Order Coelacanthiformes, a group of primitive bony fishes.
In 1836 Louis Agassiz described a fossil fish in his book Poissons Fossiles and called Coelacanthus because the spines that project from the vertebrae to the caudal fin rays were hollow (coel, Greek for "space" and acanthus spine). This was the first coelacanth to be described
What does the coelacanth look like?
An adult coelacanth can grow at least to 180 cm in length and weigh 98 kg. It is dark blue, changing after death to grey/brown. Each fish has a distinctive pattern of pinkish white blotches that enables scientists to distinguish one individual from another.
Anatomical features
The coelacanth has several very distinctive anatomical features.
The head
The skull is in two parts with an intracranial joint which allows up and down movement between them. A strong pair of muscles beneath the skull-base lowers the front half of the skull, giving the coelacanth a powerful bite .The coelacanth is the only living animal with that structure.
The eyes and olfactory organs are in the front part of the skull, and tiny brain and inner ear are in the rear.
In the middle of the snout is a large cavity filled with a jelly-like sac which opens to the outside through three pores. This sac is called the rostral organ .It may be used to detect weak electric currents and help the coelacanth to find hidden prey.
The fins
Coelacanths belong to a group of bony lobe-finned fishes and have 8 fins (2 dorsals, 2 pectorals, 2 pelvics, 1 anal and 1 caudal). Ray-finned fishes such as bass or perch (in fact most fishes expect sharks and rays) usually have only one dorsal fin. In ray-finned fishes the fins have a basic structure of bony, flexible fin rays with a web of skin stretched across them. The fin rays can flex slightly so that the fish fan or scull its fins. The first dorsal fin of the coelacanth is much like that of other fishes and can be folded down or erected. The other fins have a well-developed, muscular, limb-like basal lobe projecting from the body wall, and a fringe of unbranched rays like a fan attached to the outer end of the base. The fleshy scale -covered lobe can be bent or rotated so that each fin can work like a paddle or sculling oar. The caudal fin (tail) has three divisions: a characteristic small projecting middle lobe between the longer upper and lower lobes of the fin.
External anatomy of the coelacanth, Latimeria chalumnae
Internal anatomy of the coelacanth, Latimeria chalumnae
The skeleton
Most of the skeleton is made of cartilage. In place of the vertebral column, a large notochord extends from the skull to the tip of the caudal fin. The notochord is a thick-walled cartilaginous tube filled with oil-like fluid which is under slight pressure; it is tough and elastic and does the job of a backbone, since no complete vertebrae are developed around it. In most other vertebrates the notochord is replaced by vertebrae in the embryonic stage of development.
The scales
The body is covered with hard scales with small toothy-like growths called denticles on the outer surface which protect the coelacanth from the rocks and predators.
The skeleton of Latimeria showing the hollow notochord (indicated by the arrow)
The swimbladder
Unlike most fishes which have a gas-filled swimbladder, the coelacanth has a large swimbladder that is filled with fat. Being lighter than the seawater, the fat provides buoyancy.
How the coelacanth swims
The lobed fins are extremely mobile and can be rotated through 100 degrees. The coelacanth can swim fast for short periods, but it usually swims around slowly using its paired and median fins as sculls to push itself through the water. When cruising the fish works the right pectoral fin in tandem with the left pelvic fin and vice versa. The coelacanth likes to hover near the sea bottom with all fins fully extended - a beautiful sight to see. The paired lobed fins are not used to walk on the seabed or, as with lungfish, to prop the fish up off the bottom or push it against it. It seems rather to avoid touching the ground. When started, it darts forward at speed using the large caudal fin. Sometimes it performs a head stand, keeping its snout to the sea floor and rotating its rigid body to an upright position. It may then make use of the electro-receptive rostral organ to find prey on the bottom.
The coelacanth, Latimeria chulamnae, as a living fossil
Why is the coelacanth important to science?
Palaeontology is a Greek word for the study of prehistoric plants and animals. Fossils are the remnants or impressions of plants and animals that lived before the present. The original meaning of the word fossil is derived from the Latin verb fobere, to dig, as fossils were usually encountered as petrified artifacts preserved in rock and stone. Charles Darwin coined the term living fossil to describe the East Asian ginkgo tree, but not mean by that a fossil that had somehow come w4s tree, but not mean by that a fossil that had somehow come back to life. Rather he meant a life that had evolved very little for million of years-a case of arrested evolution. Examples are cycads, elephant shrew and broad-nosed crocodiles. The closest relatives of living fossils have been extinct for a long time.
The fossil coelacanth, Whiteia, from the Triassic, which was discovered in the Orange Free State
The scientific discovery of Latimeria chulamnae in 1938 caused a sensation in the scientific world because it is the only living member of a very old group of fishes, the actinistians (Coelanacanthimorpha). About 120 species of coelacanths are known from fossils. They were predominantly small marine fish (though some lived in freshwater) which were thought to have died out at the end of the Mesozoic era more than 60 million years ago. They flourished in the Triassic; a fossil of a coelacanth (Whiteia) was discovered in the Orange Free State which dates to that time .The Coelacanthimorpha and lungfishes are separate side-branches of the primitive fish group that gave rise to the amphibians, reptiles, birds and mammals. Although Latimeria is not a missing link in the story of evolution, it is the sole survivor of a line of development that otherwise became extinct. From the anatomy, biochemistry, physiology and behaviour scientists can learn much about the processes of evolution.
The story of the coelacanth and the Christmas connection
How the coelacanth became known to science
Marjorie Courtenay-Latimer
Marjorie Courtenay-Latimer was born in East London on 24th February 1907. From the childhood she was interested in birds and mammals, and fossil collecting was also a hobby of hers. In 1930 she was appointed Curator of the newly established East London Museum which had at that time a very small collection of bird specimens. She worked hard to create a display of natural history of the Eastern Cape. Since fishing was a major local industry, she decided to concentrate on marine life. She interviewed fishing clubs and managers of fishing trawlers; specimens were enthusiastically donated and she made mounts of the small fish. She first met JLB Smith, then a Lecture in Chemistry at Rhodes University College, in December 1933 when he visited the museum during a camping trip at Igoda. He had been advised by doctors to spend his vacations in the open air because of ill health, and his love of angling soon turned into scientific interest .He was very impressed with the work she was doing, and offered to help her with any specimens which might want to classified, because she had on books on fish at the museum.
In November 1936 she and her parents visited Bird Island where she spent weeks amassing a huge collection of sponges, seaweeds, sea shells and bird eggs. She also went out to sea in the Irvin & Johnson trawler, Nerine, and made friends with the Captain, Hendrik Goosen, who took her crates of specimens back to East London and thereafter saved interesting fishes from the trawl nests for her attention.
Miss Courtenay-Latimer's sketch of the first coelacanth which she posted to JLB Smith
On December 22, 1938, Captain Goosen and the Nerine put into East London harbour with the usual catch of sharks, rays, starfish and rat-tail fish. But there was one unusual fish amongst the catch that had been caught in about 70 meters, near the mouth of the Chalumna River. Once ashore Captain Goosen left word at the Museum that there were several specimens at the ship for Miss Latimer. At first she said that she was too busy because she was hard at work cleaning and articulating the fossil reptile bones collected from Tarkastad. But as it was so near Christmas time she decided to go and wish the crew a Happy Christmas and took a taxi to the docks. There, attracted by a blue fin amid the pile of sharks, she found a magnificent fish. She and her assistant put it in a bag and persuaded a reluctant taxi driver to take it to the museum in the boot of the car .It measured 150 cm and weighed 57.5 kg. From its hard bony scales with sharp, prickly spines and paired fins looking rather like legs, she knew that it must be some kind of primitive fish. But her greatest problem was to preserve it until it could be identified. It was extremely hot, the fish was too big to go into a bath and she could not find any organization willing to store it in a freezer. Although she was told by experts that it was only a type of rock cod and that she was making a fuss about nothing, she persisted in her attempts to save the fish for science. At first it was wrapped in cloths soaked in formalin but eventually, on the 26th, Mr. Center, a taxidermist, skinned it. Unfortunately the internal organs were thrown away. Marjorie went home disappointed and worried that she had not saved all the soft parts. What she had done, however, was to write immediately to her friend, JLB Smith, and send him her famous sketch of the strange fish.
James Leonard Brierley Smith
The next part of the story concerns JLB Smith, at that time enjoying a working holiday in Knysna. The next fourteen years of his life were to be dominated by this coelacanth and an almost obsessive search for the second specimen. JLB Smith, born in 1897 at Graff-Reinet, was a self-taught ichthyologist who had published several papers on the marine fishes of South Africa. He knew at once when he opened Marjories letter that. Though the last coelacanths were supposed to have died out with the dinosaurs, he was looking at a drawing of a fossil fish:
One of my most constant and peculiar obsessions had always been a conviction that I was destined to discover some quite outrageous creature
He sent to Cape Town for a copy of Arthur Smith Wood-wards Catalogue of Fossil Fishes of the British Museum and, after he had received it, positively identified Marjories unusual fish as a coelacanth. But he did not commit himself or risk his reputation in the scientific community until, some time later; he traveled to East London and saw the specimen for himself:
Yes, there was not a shallow of doubt, scale by scale, bone by bone, fin by fin, it was a true coelacanth. It could have been one of those creatures of 200 million years ago and come alive again.
He gave the fish its formal scientific name, Latimer chalumnae in honour of Miss Courtenay-Latimer who had preserved it, and the river near which it was trawled. From January to June 1939 JLB Smith and his young wife, Margaret, worked furiously on the first scientific paper describing the coelacanth, completing it just four days before the birth of their son William. All this time the coelacanth, pervasive smell and all, stayed in their house. It was then returned to be displayed at the East London Museum. Thousands of people visited the museum to see the famous fish.
How fishes are named
In zoology and botany names are important. Taxonomy is the science of the principles of classification. Each distinct kind or species must have its own name. In 1758 Karl von Linne (Linnaeus) from Sweden devised a system of naming (nomenclature). In this system generic names must be unique and species names must not be used more than once per genus. Each species has its own (a binomial i.e. in the two parts) plus the name of the scientist who first formalized the name e.g. Homosapiens Linnaeus. JLB Smith named a fish Pseudocheilinus margaretae after his wife, Margaret.
Captain Eric Hunt and the second coelacanth
It was Christmas time 14 years later the next great chapter in the coelacanth story was written.
Convinced that he East London coelacanth was a stray and that the home of this fish was to the north in the Mozambique Channel, Smith distributed posters offering a reward of one hundred pounds (£100) to anyone finding another specimen. Meanwhile, in 1949, his Sea Fishes of Southern Africa was published. He and his wife traveled extensively to Zanzibar, Tanganyika, Mozambique and Kenya collecting fishes, talking about the coelacanth, and distributing the reward posters. It is a strange fact that, although the coelacanth was well known to the local fishermen of the Comoros (the home of the coelacanth) and called gombessa by them, nothing more was heard about it until Christmas 1952.
Whilst in Zanzibar the Smiths had met a young Captain Eric Hunt, who operated a small trading schooner between the Comoro archipelago (then French territory) and the mainland. He knew fishes well but had never seen a coelacanth. Wanting to help the Smiths in their search, he took some posters to the Comoros where they were widely distributed amongst local fishing communities. At his last meeting with the Smiths, he had asked Margerat what he should do in case he found a coelacanth, as there were no refrigeration facilities in the Comoros, and she told him the only thing he could do was to preserve it in salt.
On December 24th 1952 the Dunnottarr Castle, bringing the Smiths back from the expedition, reached Durban and a telegram from Hunt (which had been sent on from Grahamstown) was urgently delivered to them. In it was the exciting news which almost drove Smith mad with frustration: Hunt had in his possession a five foot specimen of the coelacanth, injected with formalin, which had been caught on the 20th off Anjouan Island. He wanted to know what to do with it! The telegram had been sent from Dzaoudzi, at Mayotte.
JLB Smith did not know exactly where Dzaoudzi was, let alone how to retrieve the specimen before the French did, since it had been landed on French territory. This coelacanth had been caught by a fisherman named Ahmed Hussein, whilst fishing at night from a dugout canoe in deep water about 200m from shore. A schoolteacher saw it at a local market where it was being cleaned, and he recognized it as the fish on the poster. The fisherman and his friends were then persuaded to take the huge decomposing fish 40 km overland on a hot day so that Hunt, a responsible person, could take charge of it. He slit the fish and salted it as he been told to do.
It was a French medical officer on Mayotte who kindly donated hid entire formalin supply to inject the specimen and save it. The fish was then wrapped in cotton and put in a crate, and that is how Smith first saw it when he arrived in the Comoros on December abroad a SA Air Force Dakota loaned to him on the authority of the then South African Prime Minister, DF Malan. He knelt down on the deck to get a closer look at it and, so moved by emotions, this famous scientist found he was crying. The coelacanth was taken back to South Africa, and the fisherman duly got his reward.
Aboard Hunt's vessel after the identification of the second coelacanth. JLB Smith is in the centre of the photograph and Eric Hunt is on the left
Because the specimen lacked the first dorsal fin, Smith thought that it must be a new genus and species, and he proposed the name Malania anjounae (The absence of the first dorsal fin was apparently due to an injury when the fish was young). But it turned out to be the same species as Latimeria chalumnae.
The reward incentive resulted in the subsequent capture of over 150 coelacanths in the Comoros. The French kept most of the specimens and for the next 15 years only French scientists were allowed to search for the coelacanth in the Comoros. Several papers and three large volumes on the anatomy of the coelacanth were published by a French team under the direction of Dr Jacques Millot.
Professor Hans Fricke
Prof. Hans Fricke, a German scientist from the Max. Planck Institute used a two-man submersible, Geo, to observe and film Latimeria in its natural habitat. After a fruitless series of daytime searches he learnt from a local fisherman that the coelacanth was always taken at night and was even shown the places where they were caught. On his first night dive he encountered this magnificent beast and for him a dream had come true. He filmed it swimming around gracefully and slowly, seemingly unperturbed by the submersibles lights. He was able to show that during the day Latimeria retreats into caves, but at night it cruises slowly over the sea bottom, presumably looking for food. He observed the coelacanths most impressive behavior, the headstand: sometimes these huge animals stand for more than two minutes vertically in front of the submersible.
The German submersible, JAGO, which is used by scientists to look for coelacanths under the sea
On a subsequent expedition in 1991, using the submersible Jago, Hans Fricke s team (which included Dr.Phil Heemstra of the JLB Smith Institute) found several individuals together in a cave. The scientists also discovered that coelacanths live at depths far deeper than previously believed, i.e. 150 m to more than 700 m.
The Mozambique coelacanth
The day before Christmas 1991, a third chapter in the coelacanth story began. Prof Mike Bruton, Director of the JLB Smith Institute in Grahamstown, received a fax from Reuters informing him that a female coelacanth had been caught off Mozambique, and that the specimen was lodged in the Natural History Museum of Maputo. The fish had been captured at depths of 40-44 m over a sandy bottom, about 24 km offshore, northeast of Quelimane in central Mozambique. Again it was a case of the discerning trawler captain (the Japanese captain of Vega who recognized the fish immediately as a coelacanth), the informed museum director (Dr Augusto Cabral, Director of the National Museum of Natural History in Maputo), the anxious scientists, and the lack of reliable refrigeration, which led to the adult being skinned and the internal organs discarded. The fish had been accidentally catch in the trawlers nets in August and stored in the onboard deepfreeze with the caught; but as the ship was out at sea for some months the news only reached Grahamstown at Christmas time.
A 348 mm foetus (pup) found inside the female Mozambique coelacanth, and almost ready to be born
Meanwhile Dr Cabral instructed his staff to skin it and noticed that it had a very swollen belly. When it was dissected it was found to contain 26 babies which were almost ready to be born. They ranged in length from 308 to 358 mm and weighed between 410 and 502 g. Dr Cabral had the babies, or pups as they are known, placed in a freezer at the National History Museum. Because of an unreliable supply of electricity, Dr Cabral decided that 10 frozen pups should accompany Hans Fricke to Germany, 10 should accompany Prof Bruton to the JLB Smith Institute, and 6 should remain in Maputo to be preserved in formalin. The curated juveniles will be made available to coelacanth researchers worldwide for study and much will be learnt from this single fortuitous catch.
Where the coelacanth lives
The Mozambique coelacanth is, with the 1938 Chalumna specimen, only the second to be recorded from the shore of the African mainland. Until recently all other specimens have been taken at Grand Comoro and Anjouan Island in the Comoro Islands. The East London fish was probably helped on its 2000 km journey by the strong southwesterly currents of the Mozambique Channel. The Mozambique fish is also likely to be stray from the Comoran population.
On August 5th, 1995 a 32 kg coelacanth was caught in a net set at a depth of 140-150 m off the village of Anakao about 30 km south of Toliara (Tulear) on the southwest coast of Madagascar. The bottom off Anakao is mostly sand and of low relief (the shark nets are not set in rocky area s, as they would likely be snagged on the rocks and lost), and the 200 m depth contour is located about 10 km from shore.
Previously sharks were caught regularly off Anakao and St.Augustin Bay with hook and line in depths of 150-250 m. The deep-set shark nets, which were introduced some two years ago, proved to be more productive than hook and line fishing, and most fishermen have switched to this deep -netting method. Weather permitting, some 50 fishermen (usually working in two-man teams) are engaged every day in the deep-set shark net fishery off Anakao. Since none of the local experienced fishermen had previously seen a coelacanth, it seems unlikely that a resident population of coelacanths occurs off this part of the Madagascar coast. North of Taliara, the continental shelf broadens and the 200m depth contour is located some 20 or more kilometers from shore. This increased distance to deep water precludes most local fishermen (without motorized canoes) from deep-water fishing. For most of the west coast of Madagascar (from Morondava, at about 20°S, to the north end of Madagascar) the continental shelf extends 50 to 100 km offshore. This broad expanse of shallow-water habitat would prevent local fishermen from fishing at depths frequented by coelacanths; consequently, although coelacanths may occur or be resident off the west coast of Madagascar, it will require a directed exploratory fishing effort or a survey with a research submersible to find them.
In June 1991 Hans Fricke and Mike Bruton used the submersible, Jago, to try to discover whether coelacanths live off the South Africa coast. Since coelacanths need caves for shelter during the day, and the scientists found no large caves or overhang on the continental slope off the Chalumna River, it appears that the habitat is not suitable in South African waters.
The biology of Latimeria chalumnae
Feeding habitats
Evidence from the prey found in the stomachs of coelacanths indicates that they are predominantly fish-eaters taking lanternfish (Diaphus), cardinal fish (Coranthus) eels (Iiyophis), beardfish (Polymixia), red breams, skates, sharks and also squid and octopus. The vertical head-down position has been found in other drift-feeding fishes. When the coelacanth is close enough to the prey, the mouth is quickly opened, the prey grasped very quickly by powerful jaws and then swallowed whole.
Sex and growth rate
There is no obvious external difference between male and female coelacanths. Females re more robust than males and grow to a greater size. Large reef-dwelling fishes such as snappers and groupers may live to thirty years, so it is likely that the coelacanth could live longer than that, possibly as long as forty years.
Habitat and population size
Latimeria normally occurs at depths of 150-700 m, with most sightings and catches between 150 and 253 m. During the day coelacanths retreat to caves where they can rest sheltered from currents and predators (sharks). There is evidence that coelacanths may return repeatedly to the same caves and that they have a home range. When in caves they hover in midwater, rarely touching one another. They appear to be social animals, and aggressive behaviour has not been observed. Where caves are rare, coelacanths are hardly ever found. Along the western shores of Grand Comoro the scientists found several occupied caves at depths from 180 to 253. Since Hans Frickes dives off the Comoros it has become possible to estimate the size of the coelacanth population. The population of adults on the west coast of Grand Comoro was estimated to be about 200. Professor Fricke has never observed juveniles, which probably live in deeper water.
It is known whether birth rate is dependent on population size or what the predation rate on coelacanths is likely to be. Fricke did observe some large sharks in the habitat of the coelacanths and it is likely that large sharks may prey on the coelacanths.
Reproduction
The reproduction of Latimeria is of a type called ovoviviparous, which means that it has internal fertilization, and the foetuses are kept are kept inside the mother until they are large enough to look after themselves. Only one ovary matures (usually the right) and 19-26 enormous eggs about 9cm in diameter and 320g in weight develop inside it. The huge yolk of each egg supplied the nutrients necessary for the foetus to grow. The 26 pups found inside the female Mozambique coelacanth indicate that the fish may breed faster and produce more young than was previously thought. This female had been carrying around an extra 12 kg weight.
An inventory of all known specimens of the coelacanth
In 1991 a list complied by Mike Bruton and Sheila Coutouvids was published which included all known specimens of the coelacanth Latimeria chalumnae based on a survey of the literature (scientific writings) and museum, aquarium and university holdings. A number was assigned to each specimen and catch and biological details were given where known. At least 191 coelacanths are known to have been caught since 1938. Many specimens leave the Comoros without being properly documented.
The Comoros and conservation of the coelacanth
The Comoro islands have a hot, wet tropical climate with a cool season from May to October and monsoon rains from November to March. The youngest island, Grand Comoro, is dominated by a huge active volcano which has erupted several times in the past few decades. Deep channels separate the islands from Africa and Madagascar and from each other. There are about 420 000 people living on the three main islands, the majority being very poor. The Comorans depend on natural resources for food, medicines, fuel and building materials. Naturally fishing is an important industry; the problem is that there are too many people catching too few fish. Nowadays many fishermen use glassfibre boats powered by outboard motors or diesel engines. The traditional fishing craft for hundreds of years has been the dugout canoe hollowed from a single log of the mango, kapok, or other trees and stabilized with one or two outriggers, carrying up to two men.
Fishermen work in difficult conditions using very simple tackle, basically a long hand line of retwisted cotton or nylon with a single large hook baited with a fillet of fish. Near the end of the line is a short piece of string to which is tied a lump of lava rock. When the line reaches the right depth the fisherman gives it a jerk to release the rock and the baited hook then hangs free just above the bottom, waiting for a fish to come along. All coelacanths caught by Comoran fishermen are a by-catch of the nighttime fishery for the oilfish Ruvettus.
It was JLB Smith who warned 25 years ago that the unrestricted catching of coelacanths may threaten their survival, and he proposed that an international society should be formed to protect them. After his death in 1987 the Coelacanth Conservation Council was founded by Prof Mike Bruton and three other ichthyologists, with the headquarters in Moroni, capital of the Comoros, the secretariat at the JLB Smith Institute. The fish is now on Appendix 1 of the Convention on International Trade in Endangered Species (CITES) which prohibits trade in this particular species, and any caught should be released if they are still alive. Now that larger fibreglass outrigger canoes have been introduced into the Comoros by the European Economic Community, and fish aggregating devices are used far from shore, it is hoped that fishermen will concentrate on offshore open water fishing, thus reducing the pressure on nearshore fish populations and potential prey species for the coelacanth. Coelacanths cannot be targeted nor caught on demand no matter what lucrative rewards are offered - the history of the past 43 years confirms this! Threats to its future survival might arise, however, from commercial interests such as public aquariums and a special coelacanth fishery for museums.
A reference guide to the Coelacanth
Bruton M.N. 1989. The living coelacanth fifty years later. Trans. Roy. Soc. S. Africa, 47 (1): 19-28.
Bruton M.N.1990. South African scientists conserve marine resources in the Comoros. Ichthos No.26: 8-9
Bruton M.N. 1992. Archimedes, Special Marine Issue 34
3): 57. (Available from P.O. Box 1758, Pretoria 0001, and from ICHTHOS.)Bruton M.N. & R.E. Stobbs. 1991. The ecology and conservation of the coelacanth Latimeria chalumnae. Environ. Biol. Fishes 32: 313-339
Forey P.L. 1988. Golden jubilee for the coelacanth Latimeria chalumnae. Nature 336: 727-732
Fricke H. 1988. Coelacanth: the fish that time forgot. National Geographic 173:824-838. (Highly recommended, contains colour photos of the living fish)
Greenwood P.H.1989. Fifty years a living fossil- the coelacanth fish Latimeria chalumnae. Bilogist36 (1): 15-19
Greenwood P.H. 1993. Latimeria chalumnae - The Living Coelananth. J.L.B. Smith Institute of Ichthyology.
Heemstra P.C. 1992. Conservation in the Comoros. Ichthos 34:1-2.
Heemstra P.C. & L.J.V. Compagno. 1989. Uterine cannibalism and placental viviparity in the coelacanth? A skeptical view. S.A. Journal Science 85:485-486.
Heemstra P.C. & P.H. Greenwood. 1992. New observations on the visceral anatomy of the late-term fetuses of the living coelacanth fish and the oophany controversy. Proc. R. Soc. Lond. B. 249: 49-55
Schauer J. 1992. The privacy of a living fossil: the coelacanth off Grande Comore. Underwater 19:31-33. (Obtainable from Ihlane Publications, P.O. Box 35100, Northway 4056. Include beautiful photographs)
Smith M.M. & P.C. Heemstra. 1991. Smiths Sea Fishes. Revised edition. Southern Book Publishers. See pages 151-153.
Smith J.L.B. 1956. Old Fourlegs. The story of the coelacanth. Longman Green & Co.,London, 264pp. ( This book is out of print but obtainable in many libraries )
Thompson K.S. 1991. The story of the coelacanth. WW Norton, New York, 252 pp.
