Just as we use utensils to eat and wear seatbelts in cars, animals of all kinds exhibit similar strategies that ease their lives and guard them from threats.
Tool use is studied in land-bound species more often than marine species for one simple reason: It’s quite difficult to perform underwater observations, especially for extended periods of time.
A recent review by Janet Mann and Eric Patterson at Georgetown University determined that 30 aquatic species are known to use tools, including fish, cephalopods, mammals, crabs, urchins and possibly gastropods. This number may seem small, but keep in mind that tool use by aquatic animals is largely unobserved, with most of the ocean remaining unexplored.
Just what constitutes "tool use" is hotly debated in the scientific community. In this blog, we're taking a look at some of the cooler examples out there of possible tool use— but to the scientists out there reading ... we're not making any definitive claims. As the scientific community uncovers more information on possible tool use, we learn new facts about the animals at the National Aquarium, too!
Cetaceans often demonstrate complex tool use, and dolphins are no exception. A small subset—around 5%—of the bottlenose dolphin population in Shark Bay, Australia, has been observed tearing up sponges from the ocean floor to wear over their beaks while foraging. This protective action—called sponging—is extremely rare, and “thought to provide access to otherwise inaccessible prey,” according to the Georgetown University study.
Scientists believe that sponging is a vertically transmitted and matrilineal behavior, meaning that it is exclusively passed on from mothers to daughters.
Here’s a fun fact about animal tool use: Living animals are used as tools more often underwater than they are on land!
Several species of hermit crabs (including the striated hermit crab and the Edward’s hermit crab) are known to carry anemones on their shells as a defensive tactic. The anemone’s poisonous tentacles provide effective protection from predators, and in return they’re treated to easily accessible scraps of food left by the hermit crab.
Humans aren’t the only ones who use natural materials to build hideaways! The veined octopus has been documented using a coconut shell casing for protection. These 6-inch cephalopods will suction coconut shell halves to their underbellies and crawl into them when a hiding spot is needed. Other species of octopus use water jets when hunting and rocks to help barricade their burrows and lairs!
Some scientists believe that several species of cichlids could be demonstrating tool use when it comes to protecting their young. These oviparous fish lay their eggs on loose leaves, allowing them to move the entire nest when threatened … it’s kind of like a U-Haul, but for babies.
Looking for more tool-tally amazing animal facts? Learn more about the octopus—some may say this cephalopod is one of the greatest animal tool-users out there!