Tall-Ribbed Limpet

Patelloida alticostata

Patelloida alticostata features a robust shell that tapers towards the front and is broadest at the rear. The shell is characterized by 13 to 26 prominent axial ribs, and its margin is distinctly crenulated. Inside, the shell is a smooth white, often displaying a spatula that can be black, grey, or brown. While the exterior may show signs of erosion, it typically retains unique black cobweb-like lines between the ribs. This limpet generally measures around 35 mm in length, with the potential to reach up to 56 mm. It is found along the coast of Australia, from New South Wales to Western Australia, including Tasmania, where it occupies exposed rocky shores in both the low intertidal and shallow subtidal zones. In areas around Sydney, it is more commonly located subtidally than intertidally, favoring bare rock surfaces for its habitat. Ecologically, Patelloida alticostata is a benthic organism typically residing at depths of 1 to 3 meters. This species is endemic to the Indo-West Pacific region, particularly in Australian waters. It primarily feeds on algae, grazing on the surfaces of its rocky environment. As a gonochoric species, it reproduces through broadcast spawning, with embryos developing into planktonic larvae before settling as juveniles. When divers encounter this limpet, they may find it firmly attached to rocks, allowing for observation of its distinctive shell features. The conservation status of Patelloida alticostata has not been assessed, but it is commonly found in various marine habitats.