The Coelacanth - South African Coastal Information Centre
The Coelacanth - South African Coastal Information Centre
The Coelacanth - South African Coastal Information Centre
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Fishy Facts: <strong>The</strong> <strong>Coelacanth</strong><br />
What is a coelacanth?<br />
<strong>The</strong> <strong>Coelacanth</strong><br />
ICHTHOS<br />
A coelacanth (pronounced "seel-uh-kannth", "selekant" in Afrikaans) is a large marine lobe-finned fish<br />
belonging to the Order <strong>Coelacanth</strong>iformes, a group of primitive bony fishes.<br />
In 1836 Louis Agassiz described a fossil fish in his book Poissons Fossiles and called <strong>Coelacanth</strong>us because the<br />
spines that project from the vertebrae to the caudal fin rays were hollow (coel, Greek for "space" and<br />
acanthus spine). This was the first coelacanth to be described.<br />
Some descriptions of the<br />
coelacanth<br />
"the world’s best known biological<br />
curiosity"<br />
"the most important fish in the world"<br />
"a great, primitive looking fish"<br />
"a great sea lizard " (deck hands on the<br />
Nerine)<br />
"It was so beautiful at first I wanted to<br />
set it free..." (Capt.Goosen)<br />
"the most beautiful fish I had ever seen"<br />
(Majorie Courtenanay-Latiner)<br />
"Look carefully at this fish .It may bring<br />
you good fortune. Note the preculiar<br />
double tail, and the fins." (From the JLB<br />
Smith)<br />
What does the coelacanth look like?<br />
An adult coelacanth can grow at least to 180 cm in length<br />
and weigh 98 kg. It is dark blue, changing after death to<br />
grey/brown. Each fish has a distinctive pattern of pinkish<br />
white blotches that enables scientists to distinguish one<br />
individual from another.<br />
Anatomical features<br />
<strong>The</strong> coelacanth has several very distinctive anatomical<br />
features.<br />
<strong>The</strong> head<br />
<strong>The</strong> skull is in two parts with an intracranial joint which<br />
allows up and down movement between them. A strong pair<br />
of muscles beneath the skull-base lowers the front half of the<br />
skull, giving the coelacanth a powerful bite .<strong>The</strong> coelacanth is<br />
the only living animal with that structure.<br />
<strong>The</strong> eyes and olfactory organs are in the front part of the<br />
skull, and tiny brain and inner ear are in the rear.<br />
In the middle of the snout is a large cavity filled with a jelly-like sac which opens to the outside through three<br />
pores. This sac is called the rostral organ .It may be used to detect weak electric currents and help the<br />
coelacanth to find hidden prey.<br />
<strong>The</strong> fins<br />
<strong>Coelacanth</strong>s belong to a group of bony lobe-finned fishes and have 8 fins (2 dorsals, 2 pectorals, 2 pelvics, 1<br />
anal and 1 caudal). Ray-finned fishes such as bass or perch (in fact most fishes expect sharks and rays)<br />
usually have only one dorsal fin. In ray-finned fishes the fins have a basic structure of bony, flexible fin rays<br />
with a web of skin stretched across them. <strong>The</strong> fin rays can flex slightly so that the fish “fan” or “scull” its fins.<br />
<strong>The</strong> first dorsal fin of the coelacanth is much like that of other fishes and can be folded down or erected. <strong>The</strong><br />
other fins have a well-developed, muscular, limb-like basal lobe projecting from the body wall, and a fringe of<br />
unbranched rays like a fan attached to the outer end of the base. <strong>The</strong> fleshy scale -covered lobe can be bent<br />
or rotated so that each fin can work like a paddle or sculling oar. <strong>The</strong> caudal fin (tail) has three divisions: a<br />
characteristic small projecting middle lobe between the longer upper and lower lobes of the fin.<br />
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<strong>The</strong> skeleton<br />
External anatomy of the coelacanth, Latimeria chalumnae<br />
Internal anatomy of the coelacanth, Latimeria chalumnae<br />
Most of the skeleton is made of cartilage. In place of the vertebral column, a large notochord extends from the<br />
skull to the tip of the caudal fin. <strong>The</strong> notochord is a thick-walled cartilaginous tube filled with oil-like fluid<br />
which is under slight pressure; it is tough and elastic and does the job of a backbone, since no complete<br />
vertebrae are developed around it. In most other vertebrates the notochord is replaced by vertebrae in the<br />
embryonic stage of development.<br />
<strong>The</strong> scales<br />
<strong>The</strong> body is covered with hard scales with small toothy-like growths called denticles on the outer surface<br />
which protect the coelacanth from the rocks and predators.<br />
<strong>The</strong> swimbladder<br />
<strong>The</strong> skeleton of Latimeria showing the hollow notochord (indicated by the<br />
arrow)<br />
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Unlike most fishes which have a gas-filled swimbladder, the coelacanth has a large swimbladder that is filled<br />
with fat. Being lighter than the seawater, the fat provides buoyancy.<br />
How the coelacanth swims<br />
<strong>The</strong> lobed fins are extremely mobile and can be rotated through 100 degrees. <strong>The</strong> coelacanth can swim fast<br />
for short periods, but it usually swims around slowly using its paired and median fins as sculls to push itself<br />
through the water. When cruising the fish works the right pectoral fin in tandem with the left pelvic fin and<br />
vice versa. <strong>The</strong> coelacanth likes to hover near the sea bottom with all fins fully extended - a beautiful sight to<br />
see. <strong>The</strong> paired lobed fins are not used to “walk” on the seabed or, as with lungfish, to prop the fish up off the<br />
bottom or push it against it. It seems rather to avoid touching the ground. When started, it darts forward at<br />
speed using the large caudal fin. Sometimes it performs a head stand, keeping its snout to the sea floor and<br />
rotating its rigid body to an upright position. It may then make use of the electro-receptive rostral organ to<br />
find prey on the bottom.<br />
<strong>The</strong> coelacanth, Latimeria chulamnae, as a living fossil<br />
Why is the coelacanth important to science?<br />
Palaeontology is a Greek word for the study of prehistoric plants and animals. Fossils are the remnants or<br />
impressions of plants and animals that lived before the present. <strong>The</strong> original meaning of the word “fossil” is<br />
derived from the Latin verb “fobere”, to dig, as fossils were usually encountered as petrified artifacts<br />
preserved in rock and stone. Charles Darwin coined the term “living fossil” to describe the East Asian ginkgo<br />
tree, but not mean by that a fossil that had somehow come w4s tree, but not mean by that a fossil that had<br />
somehow come back to life. Rather he meant a life that had evolved very little for million of years-a case of<br />
arrested evolution. Examples are cycads, elephant shrew and broad-nosed crocodiles. <strong>The</strong> closest relatives of<br />
“living fossils” have been extinct for a long time.<br />
<strong>The</strong> fossil coelacanth, Whiteia, from the Triassic, which was discovered in<br />
the Orange Free State<br />
<strong>The</strong> scientific discovery of Latimeria chulamnae in 1938 caused a sensation in the scientific world because it is<br />
the only living member of a very old group of fishes, the actinistians (Coelanacanthimorpha). About 120<br />
species of coelacanths are known from fossils. <strong>The</strong>y were predominantly small marine fish (though some lived<br />
in freshwater) which were thought to have died out at the end of the Mesozoic era more than 60 million years<br />
ago. <strong>The</strong>y flourished in the Triassic; a fossil of a coelacanth (Whiteia) was discovered in the Orange Free State<br />
which dates to that time .<strong>The</strong> <strong>Coelacanth</strong>imorpha and lungfishes are separate side-branches of the primitive<br />
fish group that gave rise to the amphibians, reptiles, birds and mammals. Although Latimeria is not a “missing<br />
link” in the story of evolution, it is the sole survivor of a line of development that otherwise became extinct.<br />
From the anatomy, biochemistry, physiology and behaviour scientists can learn much about the processes of<br />
evolution.<br />
<strong>The</strong> story of the coelacanth and the Christmas connection<br />
How the coelacanth became known to science<br />
Marjorie Courtenay-Latimer<br />
Marjorie Courtenay-Latimer was born in East London on 24 th February 1907. From the childhood she was<br />
interested in birds and mammals, and fossil collecting was also a hobby of hers. In 1930 she was appointed<br />
Curator of the newly established East London Museum which had at that time a very small collection of bird<br />
specimens. She worked hard to create a display of natural history of the Eastern Cape. Since fishing was a<br />
major local industry, she decided to concentrate on marine life. She interviewed fishing clubs and managers of<br />
fishing trawlers; specimens were enthusiastically donated and she made mounts of the small fish. She first<br />
met JLB Smith, then a Lecture in Chemistry at Rhodes University College, in December 1933 when he visited<br />
the museum during a camping trip at Igoda. He had been advised by doctors to spend his vacations in the<br />
open air because of ill health, and his love of angling soon turned into scientific interest .He was very<br />
impressed with the work she was doing, and offered to help her with any specimens which might want to<br />
classified, because she had on books on fish at the museum.<br />
In November 1936 she and her parents visited Bird Island where she spent weeks amassing a huge collection<br />
of sponges, seaweeds, sea shells and bird eggs. She also went out to sea in the Irvin & Johnson trawler,<br />
Nerine, and made friends with the Captain, Hendrik Goosen, who took her crates of specimens back to East<br />
London and thereafter saved interesting fishes from the trawl nests for her attention.<br />
On December 22, 1938, Captain Goosen and the Nerine put into East London harbour with the usual catch of<br />
sharks, rays, starfish and rat-tail fish. But there was one unusual fish amongst the catch that had been caught<br />
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in about 70 meters, near the mouth of the<br />
Chalumna River. Once ashore Captain<br />
Goosen left word at the Museum that there<br />
were several specimens at the ship for Miss<br />
Latimer. At first she said that she was too<br />
busy because she was hard at work cleaning<br />
and articulating the fossil reptile bones<br />
collected from Tarkastad. But as it was so<br />
near Christmas time she decided to go and<br />
wish the crew a “Happy Christmas” and took Miss Courtenay-Latimer's sketch of the first coelacanth which she<br />
a taxi to the docks. <strong>The</strong>re, attracted by a<br />
posted to JLB Smith<br />
blue fin amid the pile of sharks, she found a magnificent fish. She and her assistant put it in a bag and<br />
persuaded a reluctant taxi driver to take it to the museum in the boot of the car .It measured 150 cm and<br />
weighed 57.5 kg. From its hard bony scales with sharp, prickly spines and paired fins looking rather like legs,<br />
she knew that it must be some kind of primitive fish. But her greatest problem was to preserve it until it could<br />
be identified. It was extremely hot, the fish was too big to go into a bath and she could not find any<br />
organization willing to store it in a freezer. Although she was told by experts that it was only a type of rock<br />
cod and that she was making a fuss about nothing, she persisted in her attempts to save the fish for science.<br />
At first it was wrapped in cloths soaked in formalin but eventually, on the 26th, Mr. Center, a taxidermist,<br />
skinned it. Unfortunately the internal organs were thrown away. Marjorie went home disappointed and worried<br />
that she had not saved all the soft parts. What she had done, however, was to write immediately to her<br />
friend, JLB Smith, and send him her famous sketch of the strange fish.<br />
James Leonard Brierley Smith<br />
<strong>The</strong> next part of the story concerns JLB Smith, at that time enjoying a working holiday in Knysna. <strong>The</strong> next<br />
fourteen years of his life were to be dominated by this coelacanth and an almost obsessive search for the<br />
second specimen. JLB Smith, born in 1897 at Graff-Reinet, was a self-taught ichthyologist who had published<br />
several papers on the marine fishes of <strong>South</strong> Africa. He knew at once when he opened Marjorie’s letter that.<br />
Though the last coelacanths were supposed to have died out with the dinosaurs, he was looking at a drawing<br />
of a fossil fish:<br />
“One of my most constant and peculiar obsessions had always been a conviction that I was<br />
destined to discover some quite outrageous creature”<br />
He sent to Cape Town for a copy of Arthur Smith Wood-ward’s Catalogue of Fossil Fishes of the British<br />
Museum and, after he had received it, positively identified Marjorie’s unusual fish as a coelacanth. But he did<br />
not commit himself or risk his reputation in the scientific community until, some time later; he traveled to<br />
East London and saw the specimen for himself:<br />
“ Yes, there was not a shallow of doubt, scale by scale, bone by bone, fin by fin, it was a true<br />
coelacanth. It could have been one of those creatures of 200 million years ago and come alive<br />
again.”<br />
He gave the fish its formal scientific name, Latimer chalumnae in honour of Miss Courtenay-Latimer who had<br />
preserved it, and the river near which it was trawled. From January to June 1939 JLB Smith and his young<br />
wife, Margaret, worked furiously on the first scientific paper describing the coelacanth, completing it just four<br />
days before the birth of their son William. All this time the coelacanth, pervasive smell and all, stayed in their<br />
house. It was then returned to be displayed at the East London Museum. Thousands of people visited the<br />
museum to see the famous fish.<br />
How fishes are named<br />
In zoology and botany names are<br />
important. Taxonomy is the science of<br />
the principles of classification. Each<br />
distinct kind or ‘species’ must have its<br />
own name. In 1758 Karl von Linne’<br />
(Linnaeus) from Sweden devised a<br />
system of naming (nomenclature). In<br />
this system generic names must be<br />
unique and species names must not be<br />
used more than once per genus. Each<br />
species has its own (a binomial i.e. in<br />
the two parts) plus the name of the<br />
scientist who first formalized the name<br />
e.g. Homosapiens Linnaeus. JLB Smith<br />
named a fish Pseudocheilinus<br />
margaretae after his wife, Margaret.<br />
Captain Eric Hunt and the second<br />
coelacanth<br />
It was Christmas time 14 years later the next great chapter<br />
in the coelacanth story was written.<br />
Convinced that he East London coelacanth was a stray and<br />
that the home of this fish was to the north in the<br />
Mozambique Channel, Smith distributed posters offering a<br />
reward of one hundred pounds (£100) to anyone finding<br />
another specimen. Meanwhile, in 1949, his Sea Fishes of<br />
<strong>South</strong>ern Africa was published. He and his wife traveled<br />
extensively to Zanzibar, Tanganyika, Mozambique and Kenya<br />
collecting fishes, talking about the coelacanth, and<br />
distributing the reward posters. It is a strange fact that,<br />
although the coelacanth was well known to the local<br />
fishermen of the Comoros (the home of the coelacanth) and<br />
called gombessa by them, nothing more was heard about it<br />
until Christmas 1952.<br />
Whilst in Zanzibar the Smiths had met a young Captain Eric Hunt, who operated a small trading schooner<br />
between the Comoro archipelago (then French territory) and the mainland. He knew fishes well but had never<br />
seen a coelacanth. Wanting to help the Smiths in their search, he took some posters to the Comoros where<br />
they were widely distributed amongst local fishing communities. At his last meeting with the Smiths, he had<br />
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asked Margerat what he should do in case he found a coelacanth, as there were no refrigeration facilities in<br />
the Comoros, and she told him the only thing he could do was to preserve it in salt.<br />
On December 24th 1952 the Dunnottarr Castle, bringing the Smiths back from the expedition, reached<br />
Durban and a telegram from Hunt (which had been sent on from Grahamstown) was urgently delivered to<br />
them. In it was the exciting news which almost drove Smith mad with frustration: Hunt had in his possession<br />
a five foot specimen of the coelacanth, injected with formalin, which had been caught on the 20th off Anjouan<br />
Island. He wanted to know what to do with it! <strong>The</strong> telegram had been sent from Dzaoudzi, at Mayotte.<br />
JLB Smith did not know exactly where Dzaoudzi was, let alone how to retrieve the specimen before the French<br />
did, since it had been landed on French territory. This coelacanth had been caught by a fisherman named<br />
Ahmed Hussein, whilst fishing at night from a dugout canoe in deep water about 200m from shore. A<br />
schoolteacher saw it at a local market where it was being cleaned, and he recognized it as the fish on the<br />
poster. <strong>The</strong> fisherman and his friends were then persuaded to take the huge decomposing fish 40 km overland<br />
on a hot day so that Hunt, a “responsible person”, could take charge of it. He slit the fish and salted it as he<br />
been told to do.<br />
It was a French medical officer on Mayotte who kindly donated hid entire formalin supply to inject the<br />
specimen and save it. <strong>The</strong> fish was then wrapped in cotton and put in a crate, and that is how Smith first saw<br />
it when he arrived in the Comoros on December abroad a SA Air Force Dakota loaned to him on the authority<br />
of the then <strong>South</strong> <strong>African</strong> Prime Minister, DF Malan. He knelt down on the deck to get a closer look at it and,<br />
so moved by emotions, this famous scientist found he was crying. <strong>The</strong> coelacanth was taken back to <strong>South</strong><br />
Africa, and the fisherman duly got his reward.<br />
Aboard Hunt's vessel after the identification of the<br />
second coelacanth. JLB Smith is in the centre of the<br />
photograph and Eric Hunt is on the left<br />
Professor Hans Fricke<br />
Prof. Hans Fricke, a German scientist from the Max.<br />
Planck Institute used a two-man submersible, Geo, to<br />
observe and film Latimeria in its natural habitat. After a<br />
fruitless series of daytime searches he learnt from a<br />
local fisherman that the coelacanth was always taken at<br />
night and was even shown the places where they were<br />
caught. On his first night dive he encountered “this<br />
magnificent beast” and for him a dream had come true.<br />
He filmed it swimming around gracefully and slowly,<br />
seemingly unperturbed by the submersible’s lights. He<br />
was able to show that during the day Latimeria retreats<br />
into caves, but at night it cruises slowly over the sea<br />
bottom, presumably looking for food. He observed the<br />
coelacanth’s most impressive behavior, the headstand:<br />
sometimes these huge animals stand for more than two<br />
minutes vertically in front of the submersible.<br />
Because the specimen lacked the first dorsal fin,<br />
Smith thought that it must be a new genus and<br />
species, and he proposed the name Malania<br />
anjounae (<strong>The</strong> absence of the first dorsal fin was<br />
apparently due to an injury when the fish was<br />
young). But it turned out to be the same species<br />
as Latimeria chalumnae.<br />
<strong>The</strong> reward incentive resulted in the subsequent<br />
capture of over 150 coelacanths in the Comoros.<br />
<strong>The</strong> French kept most of the specimens and for<br />
the next 15 years only French scientists were<br />
allowed to search for the coelacanth in the<br />
Comoros. Several papers and three large<br />
volumes on the anatomy of the coelacanth were<br />
published by a French team under the direction<br />
of Dr Jacques Millot.<br />
<strong>The</strong> German submersible, JAGO, which is used by<br />
scientists to look for coelacanths under the sea<br />
On a subsequent expedition in 1991, using the submersible Jago, Hans Fricke ‘s team (which included Dr.Phil<br />
Heemstra of the JLB Smith Institute) found several individuals together in a cave. <strong>The</strong> scientists also<br />
discovered that coelacanths live at depths far deeper than previously believed, i.e. 150 m to more than 700<br />
m.<br />
<strong>The</strong> Mozambique coelacanth<br />
<strong>The</strong> day before Christmas 1991, a third chapter in the coelacanth story began. Prof Mike Bruton, Director of<br />
the JLB Smith Institute in Grahamstown, received a fax from Reuters informing him that a female coelacanth<br />
had been caught off Mozambique, and that the specimen was lodged in the Natural History Museum of<br />
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Maputo. <strong>The</strong> fish had been captured at depths of 40-44 m over a sandy bottom, about 24 km offshore,<br />
northeast of Quelimane in central Mozambique. Again it was a case of the discerning trawler captain (the<br />
Japanese captain of Vega who recognized the fish immediately as a coelacanth), the informed museum<br />
director (Dr Augusto Cabral, Director of the National Museum of Natural History in Maputo), the anxious<br />
scientists, and the lack of reliable refrigeration, which led to the adult being skinned and the internal organs<br />
discarded. <strong>The</strong> fish had been accidentally catch in the trawler’s nets in August and stored in the onboard<br />
deepfreeze with the caught; but as the ship was out at sea for some months the news only reached<br />
Grahamstown at Christmas time.<br />
Meanwhile Dr Cabral instructed his staff to skin it<br />
and noticed that it had a very swollen belly. When<br />
it was dissected it was found to contain 26 babies<br />
which were almost ready to be born. <strong>The</strong>y ranged<br />
in length from 308 to 358 mm and weighed<br />
between 410 and 502 g. Dr Cabral had the<br />
babies, or “pups” as they are known, placed in a<br />
freezer at the National History Museum. Because<br />
of an unreliable supply of electricity, Dr Cabral<br />
decided that 10 frozen pups should accompany<br />
Hans Fricke to Germany, 10 should accompany<br />
Prof Bruton to the JLB Smith Institute, and 6<br />
should remain in Maputo to be preserved in<br />
A 348 mm foetus (pup) found inside the female<br />
formalin. <strong>The</strong> curated juveniles will be made Mozambique coelacanth, and almost ready to be born<br />
available to coelacanth researchers worldwide for<br />
study and much will be learnt from this single fortuitous catch.<br />
Where the coelacanth lives<br />
<strong>The</strong> Mozambique coelacanth is, with the 1938 Chalumna specimen, only the second to be recorded from the<br />
shore of the <strong>African</strong> mainland. Until recently all other specimens have been taken at Grand Comoro and<br />
Anjouan Island in the Comoro Islands. <strong>The</strong> East London fish was probably helped on its 2000 km journey by<br />
the strong southwesterly currents of the Mozambique Channel. <strong>The</strong> Mozambique fish is also likely to be stray<br />
from the Comoran population.<br />
133 cm coelacanth caught off Anakaò Madagascar<br />
Photo: courtesy Domique Couttin<br />
On August 5th, 1995 a 32 kg coelacanth was caught in<br />
a net set at a depth of 140-150 m off the village of<br />
Anakao’ about 30 km south of Toliara (Tule’ar) on the<br />
southwest coast of Madagascar. <strong>The</strong> bottom off<br />
Anakao’ is mostly sand and of low relief (the shark<br />
nets are not set in rocky area s, as they would likely<br />
be snagged on the rocks and lost), and the 200 m<br />
depth contour is located about 10 km from shore.<br />
Previously sharks were caught regularly off Anakao’ and St.Augustin Bay with hook and line in depths of<br />
150-250 m. <strong>The</strong> deep-set shark nets, which were introduced some two years ago, proved to be more<br />
productive than hook and line fishing, and most fishermen have switched to this deep -netting method.<br />
Weather permitting, some 50 fishermen (usually working in two-man teams) are engaged every day in the<br />
deep-set shark net fishery off Anakao’. Since none of the local experienced fishermen had previously seen a<br />
coelacanth, it seems unlikely that a resident population of coelacanths occurs off this part of the Madagascar<br />
coast. North of Taliara, the continental shelf broadens and the 200m depth contour is located some 20 or<br />
more kilometers from shore. This increased distance to deep water precludes most local fishermen (without<br />
motorized canoes) from deep-water fishing. For most of the west coast of Madagascar (from Morondava, at<br />
about 20°S, to the north end of Madagascar) the continental shelf extends 50 to 100 km offshore. This broad<br />
expanse of shallow-water habitat would prevent local fishermen from fishing at depths frequented by<br />
coelacanths; consequently, although coelacanths may occur or be resident off the west coast of Madagascar, it<br />
will require a directed exploratory fishing effort or a survey with a research submersible to find them.<br />
In June 1991 Hans Fricke and Mike Bruton used the submersible, Jago, to try to discover whether coelacanths<br />
live off the <strong>South</strong> Africa coast. Since coelacanths need caves for shelter during the day, and the scientists<br />
found no large caves or overhang on the continental slope off the Chalumna River, it appears that the habitat<br />
is not suitable in <strong>South</strong> <strong>African</strong> waters.<br />
<strong>The</strong> biology of Latimeria chalumnae<br />
Feeding habitats<br />
Evidence from the prey found in the stomachs of coelacanths indicates that they are predominantly fish-eaters<br />
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taking lanternfish (Diaphus), cardinal fish (Coranthus) eels (Iiyophis), beardfish (Polymixia), red breams,<br />
skates, sharks and also squid and octopus. <strong>The</strong> vertical head-down position has been found in other<br />
drift-feeding fishes. When the coelacanth is close enough to the prey, the mouth is quickly opened, the prey<br />
grasped very quickly by powerful jaws and then swallowed whole.<br />
Sex and growth rate<br />
<strong>The</strong>re is no obvious external difference between male and female coelacanths. Females re more robust than<br />
males and grow to a greater size. Large reef-dwelling fishes such as snappers and groupers may live to thirty<br />
years, so it is likely that the coelacanth could live longer than that, possibly as long as forty years.<br />
Habitat and population size<br />
Latimeria normally occurs at depths of 150-700 m, with most sightings and catches between 150 and 253 m.<br />
During the day coelacanths retreat to caves where they can rest sheltered from currents and predators<br />
(sharks). <strong>The</strong>re is evidence that coelacanths may return repeatedly to the same caves and that they have a<br />
home range. When in caves they hover in midwater, rarely touching one another. <strong>The</strong>y appear to be social<br />
animals, and aggressive behaviour has not been observed. Where caves are rare, coelacanths are hardly ever<br />
found. Along the western shores of Grand Comoro the scientists found several occupied caves at depths from<br />
180 to 253. Since Hans Fricke’s dives off the Comoros it has become possible to estimate the size of the<br />
coelacanth population. <strong>The</strong> population of adults on the west coast of Grand Comoro was estimated to be about<br />
200. Professor Fricke has never observed juveniles, which probably live in deeper water.<br />
It is known whether birth rate is dependent on population size or what the predation rate on coelacanths is<br />
likely to be. Fricke did observe some large sharks in the habitat of the coelacanths and it is likely that large<br />
sharks may prey on the coelacanths.<br />
Reproduction<br />
<strong>The</strong> reproduction of Latimeria is of a type called ovoviviparous, which means that it has internal fertilization,<br />
and the foetuses are kept are kept inside the mother until they are large enough to look after themselves.<br />
Only one ovary matures (usually the right) and 19-26 enormous eggs about 9cm in diameter and 320g in<br />
weight develop inside it. <strong>The</strong> huge yolk of each egg supplied the nutrients necessary for the foetus to grow.<br />
<strong>The</strong> 26 pups found inside the female Mozambique coelacanth indicate that the fish may breed faster and<br />
produce more young than was previously thought. This female had been carrying around an extra 12 kg<br />
weight.<br />
An inventory of all known specimens of the coelacanth<br />
In 1991 a list complied by Mike Bruton and Sheila Coutouvids was published which included all known<br />
specimens of the coelacanth Latimeria chalumnae based on a survey of the literature (scientific writings) and<br />
museum, aquarium and university holdings. A number was assigned to each specimen and catch and<br />
biological details were given where known. At least 191 coelacanths are known to have been caught since<br />
1938. Many specimens leave the Comoros without being properly documented.<br />
<strong>The</strong> Comoros and conservation of the coelacanth<br />
Map showing the Comoro Islands,<br />
home of the coelacanth<br />
<strong>The</strong> Comoro islands have a hot, wet tropical climate with a cool<br />
season from May to October and monsoon rains from November<br />
to March. <strong>The</strong> youngest island, Grand Comoro, is dominated by a<br />
huge active volcano which has erupted several times in the past<br />
few decades. Deep channels separate the islands from Africa and<br />
Madagascar and from each other. <strong>The</strong>re are about 420 000<br />
people living on the three main islands, the majority being very<br />
poor. <strong>The</strong> Comorans depend on natural resources for food,<br />
medicines, fuel and building materials. Naturally fishing is an<br />
important industry; the problem is that there are too many<br />
people catching too few fish. Nowadays many fishermen use<br />
glassfibre boats powered by outboard motors or diesel engines.<br />
<strong>The</strong> traditional fishing craft for hundreds of years has been the<br />
dugout canoe hollowed from a single log of the mango, kapok, or<br />
other trees and stabilized with one or two outriggers, carrying up<br />
to two men.<br />
Fishermen work in difficult conditions using very simple tackle, basically a long hand line of retwisted cotton or<br />
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<br />
which is tied a lump of lava rock. When the line reaches the right depth the fisherman gives it a jerk to<br />
release the rock and the baited hook then hangs free just above the bottom, waiting for a fish to come along.<br />
All coelacanths caught by Comoran fishermen are a by-catch of the nighttime fishery for the oilfish Ruvettus.<br />
It was JLB Smith who warned 25 years ago that the unrestricted catching of coelacanths may threaten their<br />
survival, and he proposed that an international society should be formed to protect them. After his death in<br />
1987 the <strong>Coelacanth</strong> Conservation Council was founded by Prof Mike Bruton and three other ichthyologists,<br />
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Fishy Facts: <strong>The</strong> <strong>Coelacanth</strong><br />
with the headquarters in Moroni, capital of the<br />
Comoros, the secretariat at the JLB Smith Institute.<br />
<strong>The</strong> fish is now on Appendix 1 of the Convention on<br />
International Trade in Endangered Species (CITES)<br />
which prohibits trade in this particular species, and<br />
any caught should be released if they are still alive.<br />
Now that larger fibreglass outrigger canoes have<br />
been introduced into the Comoros by the European<br />
Economic Community, and fish aggregating devices<br />
are used far from shore, it is hoped that fishermen<br />
will concentrate on offshore open water fishing, thus<br />
reducing the pressure on nearshore fish populations<br />
and potential prey species for the coelacanth.<br />
<strong>Coelacanth</strong>s cannot be targeted nor caught on<br />
demand no matter what lucrative rewards are<br />
offered - the history of the past 43 years confirms<br />
this! Threats to its future survival might arise,<br />
however, from commercial interests such as public<br />
aquariums and a special coelacanth fishery for<br />
museums.<br />
A reference guide to the<br />
<strong>Coelacanth</strong><br />
Map showing the areas where the coelacanth has been<br />
caught: 1) mouth of the Chalumna River; 2) off the<br />
Mozambique coast; 3) Grand Comoro; 4) Anjouan; 5)<br />
Madagascar<br />
Bruton M.N. 1989. <strong>The</strong> living coelacanth fifty years later. Trans. Roy. Soc. S. Africa, 47 (1): 19-28.<br />
Bruton M.N.1990. <strong>South</strong> <strong>African</strong> scientists conserve marine resources in the Comoros. Ichthos No.26: 8-9<br />
Bruton M.N. 1992. Archimedes, Special Marine Issue 34:(3): 57. (Available from P.O. Box 1758, Pretoria<br />
0001, and from ICHTHOS.)<br />
Bruton M.N. & R.E. Stobbs. 1991. <strong>The</strong> ecology and conservation of the coelacanth Latimeria chalumnae.<br />
Environ. Biol. Fishes 32: 313-339<br />
Forey P.L. 1988. Golden jubilee for the coelacanth Latimeria chalumnae. Nature 336: 727-732<br />
Fricke H. 1988. <strong>Coelacanth</strong>: the fish that time forgot. National Geographic 173:824-838. (Highly<br />
recommended, contains colour photos of the living fish)<br />
Greenwood P.H.1989. Fifty years a “living fossil”- the coelacanth fish Latimeria chalumnae. Bilogist36 (1):<br />
15-19<br />
Greenwood P.H. 1993. Latimeria chalumnae - <strong>The</strong> Living Coelananth. J.L.B. Smith Institute of Ichthyology.<br />
Heemstra P.C. 1992. Conservation in the Comoros. Ichthos 34:1-2.<br />
Heemstra P.C. & L.J.V. Compagno. 1989. Uterine cannibalism and placental viviparity in the coelacanth? A<br />
skeptical view. S.A. Journal Science 85:485-486.<br />
Heemstra P.C. & P.H. Greenwood. 1992. New observations on the visceral anatomy of the late-term fetuses of<br />
the living coelacanth fish and the oophany controversy. Proc. R. Soc. Lond. B. 249: 49-55<br />
Schauer J. 1992. <strong>The</strong> privacy of a living fossil: the coelacanth off Grande Comore. Underwater 19:31-33.<br />
(Obtainable from Ihlane Publications, P.O. Box 35100, Northway 4056. Include beautiful photographs)<br />
Smith M.M. & P.C. Heemstra. 1991. Smith’s Sea Fishes. Revised edition. <strong>South</strong>ern Book Publishers. See pages<br />
151-153.<br />
Smith J.L.B. 1956. Old Fourlegs. <strong>The</strong> story of the coelacanth. Longman Green & Co.,London, 264pp. ( This<br />
book is out of print but obtainable in many libraries )<br />
Thompson K.S. 1991. <strong>The</strong> story of the coelacanth. WW Norton, New York, 252 pp.<br />
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