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This is a subject that has undergone a major revision in recent decades. In the 1980's by doing a rough count of the number of possible coelacanth
caves along the west coast of Grand Comoro island - and the
number of fish per cave, plus the birth rate, Hans Fricke and
associates came up with an estimate for the total Comoran coelacanth
population in the low hundreds. However, there was some question
if this estimate took into account the known but unexplored coelacanth
population at the nearby island of Anjouan, the unseen juvenile
population, and the new number of potential embryos in coelacanth births (26 as opposed
to the previous 5) discovered in the 1991 Maputo, Mozambique
trawled specimen.
A total population count was also complicated by another
until recently unresolved issue: Was the Comorian population the only
one? Certainly, the Comoro islands are the only place where regular
annual catches of 6-8 coelacanths occur at Grand Comoro and 4-5
at Anjouan. But from time to time coelacanths turned up elsewhere: the
one trawled off East London, in 1938; the one trawled off Maputo,
Mozambique on August 11, 1991; the four netted off Madagascar in
1995/1997/2001- along with other rumored and newly reported Madagascar catches; and now the Sodwana, South Africa, Kenya/Tanzania/Zanzibar catches.
Are these
fish strays from the Comoros or are they representatives of satellite
colonies? The thinking now is that they are both: strays and colonies established by strays. Certainly, the Sodwana coelacanths of which a couple of dozen have been observed, seem to represent a colony. And is it posssible that the Comorian coelacanths are actually colonies established by drifters from the East African Coast.
Fishing activities differ in the other
catch locales and may not be such as to produce regular coelacanth catches indicating colonies.
And finally, what about other islands in the Indian Ocean such as the
Aldabras and Reunion - which have volcanic drop offs similar to the
Comoros? Do they harbor as yet undiscovered coelacanth colonies?
World coelacanth population became even harder to estimate after the 1998 confirmed identification
by Dr. Mark Erdmann of at least two specimens from North Sulwesi,
Indonesia at 10,000 kilometers from the Comoros with no apparent
water current interactions. This was followed by submersible observation of two more in 1999, and several more after that, plus fresh catches beginning in 2007. The Indonesian population appears to be
distinct by DNA analysis, although the specimens at least superficially resemble the
Comorian coelacanths. Is there an Indonesian colony or are those fish strays from somewhere else?
In 2008, the Comoran population was re estimated at about 500 by the Jago Dive group.
Finally, Jerome Hamlin, dinofish.com author and webmaster has found evidence that coelacanths are being caught in the Solomon Islands of the South Pacific! In 2010, a Fukushima Aquarium expedition confirmed coelacanths as far east as Papua Indonesia.
These additional discoveries likely push the worldwide population well over 1,000. In any event, the coelacanth remains a very
rare creature, probably deserving of its endangered Appendix I status
in the C.I.T.E.S. listings.
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