Over the course of millions of years, deep-sea beasts have evolved their own creative means of attracting and securing mates, thus ensuring that their genes – and species – will carry on into the future. There are several ways that deep-sea creatures might mate.

Many different species of animals utilize pheromones that are produced in various glands around the body. These can be used for communication, but they are also closely linked to reproduction and the attraction of a mate. In the depths of the ocean, animals like sea lampreys, anglerfish, and many other fish species release pheromones into the water, which can be detected by other species members, even from long distances, drawing potential mates for a rare breeding interaction.

One of the most beautiful adaptations in nature is bioluminescence, and is found in many different creatures, from jellyfish and sharks to more than 1,000 species of fish. Bioluminescence is the production of light by living creatures, typically yellow, green, or blue in nature. Even some terrestrial creatures boast bioluminescence, such as fireflies, certain land snails and beetles, among others. In the pitch-black depths of the ocean, being able to illuminate and glow is one of the most effective means of attracting a mate. Creatures like lanternfish and anglerfish, as well as some cnidarians, crustaceans and mollusks, use bioluminescence to shine a light in the darkest corners of the sea.

Some sea creatures can release hardy eggs and sperm into the water that can survive for long periods of time, until other members of their species come across the reproductive materials. The release of the eggs and sperm is often in conjunction with environmental triggers, such as tidal changes, temperature, seasonal changes and lunar cycles. This is known as spawning, and relies heavily on chance of sperm moving through the water and inseminating the eggs. Some fish species also build “nests” and release their eggs in a specific area, often close to a male whose sperm she wants for her eggs. Char, cod and salmon are some fish that use external fertilization. Some species will also gather at mass breeding sites for both internal and external fertilization.

When encountering another member of your species is so rare, it helps if you have both sets of sexual organs. Some species are unable to asexually reproduce, but if they meet another viable partner, they are able to reproduce, thus improving their chances to pass along their genetic material. There are more than 20 families of fish that are natural hermaphrodites, including grouper, parrotfish, sea bass and snook.

If conditions aren’t appropriate for bearing offspring, some creatures are able to store sperm from a previous sexual encounter with another of their species. Certain sea turtles, for example, can store sperm until conditions are optimal and their offspring have the best chance of survival.
spam fails_task lang_mismatch pii not_appropriate hate_speech sexual_content quality toxicity humor helpfulness creativity violence