Answer: Marine mammal
Notes: The vaquita, the world's most endangered marine mammal, faces imminent extinction with fewer than 20 individuals left in the wild. Found exclusively in the northern Gulf of California, vaquitas are small porpoises, measuring 4 to 5 feet long and weighing 65 to 120 pounds. Their decline is exacerbated by illegal gillnet fishing for totoaba, a fish of similar size. Vaquitas, known for their elusive nature and echolocation, are critically endangered due to habitat loss and bycatch.
