The teeth are the name. Each of the eight or nine front teeth in the upper jaw ends not in a point but in five small ones, so the working edge of the mouth is a row of notched blades rather than a row of pegs - and the genus is called Crenidens, from the Latin for a clipped or notched tooth. Behind that front row the teeth turn granular, for grinding what the front row has cut.
It is equipment for a specific job. The fish crops algae off sand, seagrass and rubble in quiet, muddy shallows, and takes small crustaceans and worms along with it; the notched edge shears the growth off rather than scraping the surface the way a parrotfish does.
Forsskal described it in 1775 from Jeddah, which makes this coast its type locality - the third fish in this catalogue whose scientific record starts on this shore, beside the Picasso triggerfish and the blackspot emperor, all from the same expedition.
And it has been traveling. In 1970 it turned up in the Bardawil Lagoon on the northern coast of 🇪🇬 Egypt, on the wrong side of the Suez Canal (🇪🇬 Egypt), and it has since spread to 🇮🇱 Israel and Libya. The Mediterranean fish stay smaller: about 20 cm against 30 at home.
Silvery green to olive, with narrow dark stripes along the scale rows above the pectoral fin, dull yellow fins and a dark edge to the dorsal.
The genus. Crenidens Valenciennes 1830 - creni- (crenulate) + dens (teeth). ETYFish
The species. Crenidens crenidens (Forsskål 1775) - creni- (crenulate) + dens (teeth). ETYFish
- front teeth notched into five points each, giving the row a wavy edge
- silvery green to olive, with narrow dark stripes along the scale rows above the pectoral fin
- dull yellowish fins with a dark margin to the dorsal
- over quiet sand and seagrass rather than on coral
- up to 30 cm
Why it's threatened
Threat classification from the IUCN Red List.
