Tokyo Tech OKADA Laboratory -Coelacanth-

Research < Coelacanth

Coelacanth

JSPS AA Science Platform Program

An important step towards the conservation of living fossil

A genetically distinct coelacanth population off the northern Tanzanian coast

Since the sensational discovery of a living coelacanth off the east coast of South Africa, the geographic distribution of viable coelacanth populations has been a subject of debate.
In the past, the coelacanths off the African mainland were thought to be strays from the Comoros because most coelacanths captured were caught in the waters surrounding the Comoros archipelagos.
However, in recent years, a large number of coelacanths were captured off the coast of Tanzania, including nine living specimens observed in a remotely operated vehicles (ROVs) survey.
Thus, it is possible that there is a reproducing population inhabiting waters off the Tanzania coast.
We have sequenced the complete mitochondrial genomes of 23 Tanzanian coelacanths, which were accidentally captured by local fishermen and preserved in the freezer.
Then we analyzed these sequences together with the 38 comoran coelacanths from the literature.
We found that the coelacanth population off the northern Tanzanian coast is genetically differentiated from those of the Comoros and that they diverged at least 200,000 years ago.

These results indicate that the coelacanths off the northern Tanzania coast are not strays but a genetically distinct group.
Our study provides important information for the conservation of this threatened “living fossil”.

* The coelacanths used in the present study were accidentally captured by local fishermen with other fishes and preserved in a freezer of Tanzania Fisheries Research Institute.　
Coelacanths were not captured on purpose.
The samples were transferred to Japan in accordance with international regulations under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).