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Class Pices Of Phylum Chordata

These are true, jawed vertebrates with specific organs for respiration, excretion and blood circulation. The organisms belonging to this class are poikilotherms, meaning that they cannot regulate their own body temperature. Essentially, all the fish come in this category. Characteristics of Pisces They are found in fresh, marine, and brackish water. The body is usually streamlined. Some have a spindle-shaped or elongated body as well. Their body is distributed into a head, trunk and tail. They swim with the help of their tail. Paired and unpaired fins represent the appendages. These help the fish to balance while swimming. The lateral line system functions as a sensory organ to sense the disturbances in the nearby environment. The body is covered with thick-seated scales, which helps by providing protection to the internal organelles. The gills help in respiration. Closed type blood circulation is observed. The internal skeleton is bony or cartilaginous. These are cold-blooded organisms. They may be herbivores or carnivores, oviparous or ovaviviparous. The sexes are separate. Fertilization may be external or internal. They lack extra-embryonic membranes. The digestive system is well-developed. The nervous system comprises of the brain and ten pairs of the cranial nerves. #kingdomanimalia