Hermit crab increased prevalence of marine debris, but also due to depletion of seashells from beaches due to humans collecting them. Hermit crab species range in size and shape, from species with a carapace only a few millimetres long to "Coenobita brevimanus", which can live 12–70 years and can approach the size of a coconut. The shell-less hermit crab "Birgus latro" (coconut crab) is the world's largest terrestrial invertebrate. The young develop in stages, with the first two (the nauplius and protozoea) occurring inside the egg. Most hermit crab larvae hatch at the third stage, the zoea. In this larval stage, the
On the Origin of Species an incipient species" and that "species are only strongly marked and permanent varieties". He argues for the ubiquity of variation in nature. Historians have noted that naturalists had long been aware that the individuals of a species differed from one another, but had generally considered such variations to be limited and unimportant deviations from the archetype of each species, that archetype being a fixed ideal in the mind of God. Darwin and Wallace made variation among individuals of the same species central to understanding the natural world. In Chapter III, Darwin asks how varieties "which I have called incipient species"