Mermaid Anatomy- Natural History of the Fantastic

Mermaids are non-mammalian, belonging to a category of warm-blooded aquatic animals adapted for foraging in shallow seas. Their resemblance to human women is a result of tens of thousands of years of sustained unintentional artificial selection by sailors across multiple continents and cultures.

Originally, their hairless streamlined bodies more closely resembled other more familiar sea creatures, with the notable exception of two dexterous forward appendages adapted to pulling open shellfish, and a bowling pin shaped body that gave the vague impression of a human “head”. Pictures in the book. They were, at least initially, only vaguely and incidentally humanoid in appearance. Early cultures fishing for the mermaid’s ancestors would toss back those that looked the most human, generally as a ritualistic appeasement for taking the less beautiful ones as food. This tendency, combined with the creature’s brief lifespan and prolific breeding began to heavily influence the appearance of surviving mermaids. As human influence expanded across much of the known world mermaids followed and continued to adapt (often moving into new ecosystems and taking the place of other coastal aquatic species less favored by humanity).

Soon technical efficiency became less important to mermaid survival than traits that appealed to the aesthetic preferences of the humans whose company they kept. In the modern world most humans no longer hunt or eat mermaids specifically because of their unsettling appearance, and the species has continued to thrive. Both male and female mermaids now highly resemble stereotypically attractive human women, as the “breasts” are a favorable accumulation of insulating fat without nipples or function beyond their buoyancy. Female mermaids deposit eggs in long strands of mucus and males fertilize them by passing near and ejecting sperm. You’ll see a collection of rougher scales surrounding a fin near the bottom of the picture (near the Kickstarter logo) this is the cloaca-like opening for their reproductive and waste disposal systems.

Hope that made sense, I'm having to sort of work backwards from existing concepts that are silly and non-scientific and explaining how they work in (sorta) believable and interesting ways. The fun part was imagining and illustrating a lineage of mermaid-like species that felt like they had a believable incidental resemblance to humans (fish+manatee-ish?). I was intrigued by the idea of a species that looked very human, but was in no way related and had come by this resemblance in a different way. There's a lot more info and illustration in the book, along with first-person accounts by sailors and naturalists studying and interacting with these creatures.

CHECK OUT MORE ART FROM A NATURAL HISTORY OF THE FANTASTIC- HERE