Cheng made a chart to list the functions of certain fish structures which headings correctly complete the chart?

a) x: fin

y: swim bladder

z: lateral line

b) x: fin

y: lateral line

z: swim bladder

c) x: lateral line

y: swim bladder

z: fin

d) x: lateral line

y: fin

z: swim bladder

About the question:

You will find the chart in the attached files

b) x: fin

   y: lateral line

   z: swim bladder  

Explanation:

The dorsal fin is found in the dorsal region of the fish body. Depending on the species, there can be one or two dorsal fins. Membranous structures and bony or cartilaginous ratios compose the fins. One of the main functions is to stabilize the body in water, providing equilibrium. When the dorsal fin is erect, it acts as a keel, helping the fish not to turn aside. Fishes also use these fins as protection because the cartilaginous or bony ratios act as spines. The animal uses these spines to defend itself from predators. The morphological variety of dorsal fins in the different species is used in taxonomy.

The Lateral Line is a system or sensory organ composed of special receptors called neuromasts, which can be found all along the lateral region of the animal. The lateral line perceives information from the environment, such as light, sound, or water movement, among others. These signs are translated into nervous messages. The lateral line is useful to detect prey, predators, other animals moving, objects, etcetera. It is significant for intraspecific interaction, especially during swimming motions in schools. The lateral line receives perturbations of short distance, generated by other living beings or by objects. Some studies confirm that the lateral line is also sensitive to chemical stimuli.

The swim bladder is a neumatic sac-like structure filled with gases coming from the blood. Its main function is to allow neutral floating and let the animal in suspension at any depth, with no need for muscular effort. The animal can regulate the size of the bladder. This organ can be found in most pelagic fishes, while the benthonic ones or the ones that actively swim lack it.