Zander
Otolith description
The general shape of the otolith is ovally pointed to lanceolate. The sulcus runs straight over of the length of the otolith. The sulcus is clearly visible and open at the ostium. Ostium and cauda are not clearly separated. The surface of the inside and outside is smooth. The dorsal margin is lobate or jagged. The lobation is variable but in larger specimens the otoliths are generally more jagged. The ventral margin is slightly rounded. The rostrum is well-developed and pointed, while the antirostrum is small and also pointed. There is a small indentation between the rostrum and antirostrum. The posterior end is pointed. The inside is convex and the outside concave. The otolith is thin.
Otoliths of zander are similar to perch Perca fluviatilis otoliths. The otolith length-width ratio of zander is larger than of perch otoliths. The rostrum of zander is not as well-developed as in perch. The sulcus of zander is straight and not pointing down at the posterior and the posterior margin is pointed instead of round and jagged as in perch otoliths. Zander can also be separated from perch by other skeletal remains. Zander often leaves jaws with large tooth in diet samples; perch leaves spiny preoperculae and scales shaped like baseball gloves.
When eroded the sulcus becomes indistinct. The rostrum and posterior end remain pointed. The margins are smoothed.
Fish length and distribution
Zander can grow up to 130 cm. Zander is a fresh water fish found in lowland rivers and large lakes. It is found inactive and close to the bottom during daytime, while at night it hunts its prey higher up in the water column. Spawning takes place from April to June in shallow waters (Wheeler, 1978, Nijssen and De Groot, 1987).
Zander is very common and found throughout Europe.
Sample origin
Northern part of the Netherlands.