What is different about the way the genus and species names are written compared to the other taxa?

The way genus and species name are written are different from other taxa as both the genus and species name should be in italics and the first letter of genus name should be in capital and other letters should be in small and the species name should also be in small letters.

This rule is called binomial nomenclature and this rule does not follow to other taxa of the hierarchy so they are not italicized. This rule avoid confusion generated by common names by giving them a scientific name which is same and unique in every part of world.  

Example: Panthera leo is scientific name of lion.

it has to be understood that the sea water contains a huge amount of sodium and chlorine ions and if they enter the cell of the atlantic cod fish, the cell will shrivel and the fish will die. to avoid such a condition, the fish uses active transport for the purpose of removing the ions against the gradient.

explanation:

the atlantic cod is not a maritime osmoconformer. its native application of salts is less than that of the seawater it lives in. it is continually falling water from the gills to the ocean via osmosis.

countering that, the fish is going to be swallowing seawater. but since its internal collection of salts is lower than seawater, the fish will want to go free of excess salt, and since that's going upon a gradient, then active transport, requiring energy, must be used to pump out the salt. much marine fish use the organs to filter out the salt and these fish discharge very straight urine.