Lytechinus

Lytechinus is a genus of sea urchins that belong to the family Toxopneustidae. They are typically found in tropical and subtropical regions, inhabiting shallow, coastal waters with coral reefs, rocky substrates, or sandy bottoms. The body of Lytechinus urchins is rounded, characterized by a rigid, hard test or skeleton, which provides protection against predators.

These urchins are primarily herbivorous, feeding on a variety of algae and other plant matter, including seaweeds. They use their stomachs to break down and extract nutrients from their food sources. Some species of Lytechinus are known to be nocturnal, remaining hidden in crevices or burrows during the day and emerging to forage at night.

Lytechinus urchins have long, sharp, and flexible spines that they use for defense. These spines may also be used for interaction and mating with other urchins. Males typically deposit sperm into the water column where it can be fertilized by female urchins, which may release multiple eggs simultaneously. After fertilization, the zygotes develop into larvae and then settle on the reef substrate to begin their new life as adult urchins.

Lytechinus species are generally small to medium in size and display a range of colors depending on the species, including reddish-brown, blue, and green. Some species are highly prized for their striking colors by aquarium hobbyists and conch collectors. Commonly referenced species within the Lytechinus genus include Lytechinus variegatus, Lytechinus peregginus, and Lytechinus gastrulus, with each showcasing unique coloration patterns and adaptation habits.