This is a watercolor painting of a pufferfish. The fish is depicted in a side view, showcasing its rounded, balloon-like body. Its coloration is a mix of dark blue-gray on the upper body, transitioning to a lighter, almost white underside. Small, dark spots are scattered across its body. The fish has a prominent, slightly protruding eye with a yellow ring around the pupil. Its fins are a pale yellow, and its tail fin is rounded. The painting is done on a cream-colored paper with visible texture. There are handwritten notes and labels in the margins, including the scientific name 'Diodon hystrix' and the date 'Sept. 5, 1839'. The style of the painting is detailed and realistic, typical of scientific illustrations from the 19th century.