Hearth Heart Urchin

Maretia planulata

Maretia planulata, commonly known as the Hearth Heart Urchin, is a species of sea urchin that can be identified by its heart-shaped appearance. It typically inhabits sandy intertidal zones and seagrass beds, making it well-adapted to its tropical Indo-West Pacific environment. This species is found at depths ranging from 0 to 60 meters, although the majority of recorded occurrences are shallower than 40 meters. The Hearth Heart Urchin is often seen in areas that are rich in organic matter, where it can easily access its food sources. It primarily feeds by non-selective deposit feeding, sifting through sediment to consume detritus and other organic materials. In terms of reproduction, Maretia planulata is gonochoric, meaning individuals are either male or female. Fertilization occurs externally, and brooding is a common reproductive strategy for this species. Eggs are often held on the peristome or in the concavities on the petaloids, where they develop into planktotrophic larvae. These larvae can drift in the water column for several months before settling to the sea floor and metamorphosing into juvenile urchins. Divers encountering the Hearth Heart Urchin may find it nestled among the sandy substrate or among seagrass, blending into its surroundings. Its harmless nature makes it a safe species to observe while diving. The conservation status of this species has not been evaluated, indicating a lack of specific data on its population trends.