Table 17.1 Comparison of Clam to Squid Squid Clam Feeding mode Skeleton Locomoti

ID: 214063 • Letter: T

Question

Table 17.1 Comparison of Clam to Squid Squid Clam Feeding mode Skeleton Locomotion 17.3 Annelids Annelids (phylum Annelida) are the segmented worms, so called because the body is divided into a number of segments and has a ringed appearance. The circular and longitudinal muscles work against the fluid-filled coelom to produce changes in width and length (Fig. 17.6). Therefore, annelids are said to have a hydrostatic skeleton. Figure 17.6 Locomotion in the earthworm. Contraction of first circular muscles and then longitudinal muscles allow the earthworm to move forward Anterior circular longitudinal septa Suid setae muscles muscies circular muscles contract, and anterior end moves forward musclesmuscles contract, and segments catch up 220

Explanation / Answer

Clam

Squid

Feeding mode

Filder feeding- The cilia traps tiny food particles from water and move down their mouth where it is eaten and digested.

Squid feeding – Before feeding they dismember the animals into pieces with their sharp peaks and eat.

Skeleton

The inner part has no skeletal and made of muscle. The shell is the outer part which protects it.

Pen is one of the important elements of skeletal system of squid. The mantle and body of squid is supported by pen. The skeletal contains chitin

Circulation

They have open circulatory system. The systems move blood throughout the organism which helps in exchanging nutrients/oxygen with the waste products or carbon dioxide.

It has two branchial hearts at base of gills. They are responsible for sending oxygenated blood to body. They have close circulatory system

Cephalization

It shows no cephalization

Yes, it shows sense organs, well developed brain and a distinct head

Locomotion

They move with the help of foot by burrowing sand

Jet propulsion where it fills muscular mantle cavity with water and expels it out of siphon to push forward