Invertebrates & Insects

Terrestrial invertebrates — insects, crabs, snails and other land animals that lack backbones — represent an estimated 51% of the total biodiversity of the Galapagos Islands. They are present throughout the islands in every habitat and play crucial ecological roles as pollinators, links in the food chain, and as nutrient recyclers, which play an important role in soil formation and plant growth.

The ancestors of these oft-overlooked Galapagos residents originally arrived either through active flight or passive drift from the mainland. Once ashore, many species began to adapt to the unique environmental conditions of the archipelago, which eventually resulted in the creation of new distinct species. It has been estimated that over half of all terrestrial invertebrate species found here are endemic to the islands, meaning they are found nowhere else.

Some of the best-known and most interesting endemic species in this group include the giant land snails in the genus Bulimulu. With over 60 distinct species, they have adapted to inhabit a variety of highly specific microclimates and habitats – similar to how Darwin’s finches have branched out to exploit a variety of different ecological niches.

Perhaps the most photogenic of the invertebrate species is the Sally Lightfoot crab, which is bright red on the top and blue underneath. This colorful character can be found on rocky beaches throughout the archipelago and is particularly striking to behold as it scuttles over black sand and lava.

Some two-thirds (more than seventeen hundred species) of Galapagos invertebrates are insects, although you are fairly unlikely to come across or notice most of them as many are nocturnal or are only present in significant numbers after a heavy rainfall.

Some of the most attractive and easy to see insects are the butterflies. There are ten species or subspecies, three of which are thought to be endemic. There are several species of ants, beetles, centipedes, cockroaches, crickets, dragonflies, flies, grasshoppers, moths, and spiders. There are only a few wasps and one species of bee and praying mantis, each. There are two scorpions in the Galapagos. The scorpions are rarely encountered and although their sting can be painful, they are not normally dangerous.

You may also be interested in…