Question

differentiate between hondrichthyes and Osteichthyes. Give six points.

Answer 1

Answer:

see below

Explanation:

• With more than 27,000 species, osteichthyes is more diversified than chondrichthyes, which is composed of less than 100 species.

• The internal skeleton is made up of cartilages in Chondrichthyes, whereas it is a bony skeleton in osteichthyes.

• Chondrichthyes fish keep their gills open while osteichthyes fish keep those covered by an operculum.

• Chondrichthyes fish can move their upper jaw freely from the skull, but not the Osteichthyes fish.

• Outer covering is scales in osteichthyes, whereas dermal denticles cover the skin in chondrichthyes.

• Caudal fin is asymmetric in chonricthyes fish, but it is a symmetrical caudal fin in Osteichthyes.

• Pectoral fin is parallel to the longitudinal axis of the body in chondrichthyes, whereas it is perpendicular to the longitudinal axis of the body in osteichthyes.

• Chondrichthyes has a sub-terminal mouth while osteichthyes could have any type of mouth depending on the habitat of the water column.

• Chondrichthyes fish excrete urea while osteichthyes fish excrete ammonia.