Constriction crawling, recoil, swimming, upright swimming, floating

A, contraction crawling: sea cucumber

Movement mode as if the gastropods like "directional monotropic" movement, its movement for the inchworm-like creeping movement. The movement is like an inchworm-like creeping movement. When the movement starts, the body is fully stretched first, and then the rear part of the body starts to contract and the tail advances, and the contraction of the rear part of the body is like a wave-like wave that reaches the front part of the body. At the same time, the tube feet attached to the substrate from the rear start to leave the attachment in order forward, and attached at the front end of the body a little behind, and then as a base, the front part of the body to the front, according to this action repeatedly.

Two, recoil: squid

The squid's body has many holes on the side, and there is a peculiarly shaped funnel in front. Squid through the holes in the side of the body and the funnel in front of the water sucked into the gills cavity, and then through the funnel to discharge the water out of the body. In this way, its body is given the power to move forward quickly by being propelled from behind.

Three, swimming: fish

Use the contraction of the trunk and tail muscles to make the body repeatedly twisted from side to side, pressing the water backward and prompting the body to move forward, rely on the fins to swing pawing the water forward, the use of gill holes spraying water backward to the impulse to make the body move forward.

Four, upright swimming: seahorses

Seahorses often live in the coral bush or seaweed bush nearby, but also live in the seabed near the rock, because it swims very slowly, so it is easy to be other fish predators. To protect itself, the seahorse then adopts a very strange position for swimming: swimming upright.

V. Floating: Jellyfish

Changes the volume of its inner cavity by contracting its outer shell and squeezing it, spewing out the water in the cavity, and moving by means of jet propulsion. There is also drifting by following the current.