What is a common cause of marbling observed postmortem?

Marbling, a characteristic discoloration of the skin that occurs in decomposing bodies, is primarily caused by the action of putrefactive bacteria. These bacteria, which thrive in the anaerobic conditions of decomposing tissues, release gases and pigments that result in the distinct patterns of greenish or brownish discoloration observed on the skin.

In terms of physiological processes, during putrefaction, red blood cells break down, and the hemoglobin released can undergo various transformations. Sulfur methemoglobin refers specifically to a form of methemoglobin that can arise from the presence of sulfur compounds in the body or environment, but it is not a primary cause of marbling.

Other options, like hemorrhagic fever or acidic conditions, are not directly linked to the phenomenon of marbling either; hemorrhagic fevers mostly lead to different types of postmortem changes related to blood loss and coagulation, while acidic conditions primarily affect tissue integrity rather than causing surface discoloration typical of marbling.

Thus, understanding the role of putrefactive bacteria in the decomposition process clarifies why it is the correct choice regarding the common cause of marbling observed postmortem.