What are the salient features of phylum arthropoda?
Answers
triploblastic
bilateral symmetry
they can be found in soli water land
ANS: Characteristics of arthropods include:
A segmented body with a head, a thorax, and abdomen segments.
Appendages on at least one segment. They can be used for feeding, sensory reception, defense, and locomotion. In addition to legs, antennas and mouth parts are considered modified appendages.
A nervous system.
A hard exoskeleton made of chitin, which gives them physical protection and resistance to drying out. In order to grow, arthropods shed this outer covering in a process called molting.
An open circulatory system with hemolymph, a blood-like fluid. A series of hearts move the hemolymph into the body cavity where it comes in direct contact with the tissues. Hemolymph is involved with oxygen distribution.
A complete digestive system with a mouth and an anus.
Aquatic arthropods use gills to exchange gases. These gills have a large surface area in contact with the water, so they can absorb more oxygen.
Land-living arthropods have internal surfaces that help exchange gasses. Insects and most other terrestrial species have a tracheal system, where air sacs lead into the body from pores in the exoskeleton. These pores cover a large part of their external body surface. Others use book lungs, gills modified for breathing air.