Phocaena sinus is a scientific name given to the vaquita porpoise which is a rare species found in the Gulf of California. There are various synonyms for this species, including the Cochito, California Gulf Porpoise, and Gulf of California Harbor Porpoise. The vaquita porpoise has distinctive physical features such as a small head, dark rings around its eyes, and a black line running from lips to fins. In recent years, this species has been facing a significant threat due to illegal fishing practices, leading to its declining population. Therefore, conservation efforts are in place to protect this unique species and ensure their survival in the future.