Gazelle : The Palestinian Biological Bulletin (ISSN 0178 – 6288) . Number 112, April 2014, pp. 1-10. | Page 5

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the intracranial joint, which allows it to open its mouth extremely wide.
Coelacanths also retain a notochord, a hollow, pressurized tube which is
replaced by the vertebral column early in embryonic development in most other
vertebrates. The heart of the coelacanth is shaped differently from that of most
modern fish; the heart's chambers are arranged in a straight tube. The coelacanth
braincase is 98.5% filled with fat; only 1.5% of the braincase contains brain tissue.
The cheeks of the coelacanths are unique because the opercular bone is very
small and holds a large soft-tissue opercular flap. The coelacanth also possesses a
unique rostral organ within the ethmoid region of the braincase. Also unique to
extant coelacanths is the presence of a "fatty lung" or a fat-filled single-lobed
vestigial lung (Wikipedia).

Prof. Dr. Sc. Norman Ali Bassam Khalaf-von Jaffa standing beside the Coelacanth
(Latimeria chalumnae) at the Educational Science Museum, Kuwait City, State of
Kuwait. 22.09.2013. Photo by: Nora Norman Ali Khalaf.
http://www.flickr.com/photos/50022881@N00/10382072074/
Latimeria chalumnae and Latimeria menadoensis are the only two known living
coelacanth species. The word coelacanth is derived from the Greek for “hollow
spine”, because of its unique hollow spine fins. Coelacanths are large, plump,
lobe-finned fish that grow up to 1.8 meters. They are nocturnal piscivorous drifthunters. The body is covered in cosmoid scales that act as armor. Coelacanths
have 8 fins – 2 dorsal fins, 2 pectoral fins, 2 pelvic fins, 1 anal fin, and 1 caudal
fin. The tail is very nearly equally proportioned and is split by a terminal tuft of
fin rays that make up the caudal lobe of the tail. The eyes of the coelacanth are
Gazelle : The Palestinian Biological Bulletin – Number 112 – April 2014