No, they have a very narrow opening for a mouth, as they eat plankton.
Rip current
Rip current
Slot
spinal cord
Water does not escape freely from a narrow-mouthed bottle when it is suddenly inverted because of surface tension. The surface tension of water causes it to form a concave meniscus at the opening, creating a barrier that prevents water from flowing out easily. Additionally, air pressure inside the bottle resists the flow of water out of the narrow opening.
In protostome ("first mouth") the blastopore, or the first opening formed becomes the mouth. In deuterostomes ("second mouth"), the blastopore forms the anus and the mouth develops from a second opening.
Chanelled into a narrow opening.
crack!
The Mediterranean
The urethra.
Yes, waves can bend as they pass through a narrow opening. This phenomenon is known as diffraction. The degree of bending depends on the wavelength of the wave and the size of the opening.