Fish Aquatic Animals )Zoo-521) Jawaher Al-Zahrani & Hana Hakami

Scientific classification Kingdom: Animalia Phylum: chordate Class: Osteichthyes Subclass : Neopterygii Order: Cypriniformes Family: Cyprinideae Genus: Cyprinus Species: carpio COMMON CARP Subclass: Actinopterygii Order: Perciformes ..  Next slide 

Scientific classification Kingdom: Animalia Phylum: chordate Class: osteichthyes Subclass: Actinopterygii Order: Perciformes Family: Cichlideae Genus: Oreochromis Species: niloticus NILE TILAPIA Family: Serranidae Genus: Epinephelus Species: chlorostigma HAMOUR Family: Chaetodontodae Genus: Chaetodon Species: BUTTERFLY FISH

2- The branchia cover is circular. 3- The scale is ctenoid. Cyprinion sp Carps 1- The mouth is frontal. 2- The branchia cover is circular. 3- The scale is ctenoid. 4- The caudal fin is split(forked). 5- It has barbels.

Oreochromis niloticus Nile tilapia 1- The mouth is frontal. 2- The branchia cover is circular. 3- The scale is cycloid. 4- The caudal fin is circular.

2- The branchia cover is triangle. 3- The scale is ctenoid. Epinelphelus sp. 1- The mouth is terminal. 2- The branchia cover is triangle. 3- The scale is ctenoid. 4- The caudal fin is circular. 5- The dorsal fin has spines.

2- The branchia cover is circular. 3- The scale is ctenoid. Chaetodon sp. 1- The mouth is frontal. 2- The branchia cover is circular. 3- The scale is ctenoid. 4- The caudal fin is fan shaped . 5- The dorsal fin ends with spines.

Scales Most fish have scales. Some fish such as catfish have no scales and are said to be "naked.“ Scales are used for protection Scales also have color pigments which give the fish its coloration. The scales along the side, which make up the lateral line, contain sensory receptors which enable the fish to detect wave vibrations in the water. That is how a fish hears.

Types of scale There are three different kinds of scales that may be found on bony fish: A ctenoid (teen-oid) scale has small sharp spines on one end. A cycloid (syk-loid) scale is a smooth scale. A ganoid (gan-oid) scale is a thick platelike scale found on sturgeons and gars.

Ctenoid Cycloid

Ctenoid scales Cycloid scale

Parts of scale The center (focus) of an older fish's scale represents the scale when the fish was newly hatched. Scales produce small circular growth rings around themselves. These growth rings are called circuli.

Parts of scale A fish grows faster in the summer and slower during the winter. Circuli formed during the summer are widely spaced. Circuli formed in the winter spaced very close together. A dark ring is formed where the circuli are spaced close together. The darker ring of circuli is called the annulus.

Age Determining The age of a fish can be determined by counting the number of annuli on its scales.

Scale slide preparation Activity Scale slide preparation