Mastelis

Mastelis is a genus of marine bivalve mollusks belonging to the family Mactridae. These clams are characterized by their equivalve and inequilateral shells, meaning both halves of the shell are of equal size and shape, but the umbo (the oldest part of the shell) is not centrally located. The shells are typically smooth or have fine concentric growth lines.

The genus Mastelis is found in various marine environments worldwide, often inhabiting sandy or muddy substrates in shallow to moderately deep waters. They are infaunal, meaning they live buried within the sediment. Like other bivalves, they are filter feeders, using their siphons to draw in water and strain out food particles.

Reproduction in Mastelis follows the typical pattern for bivalves, with external fertilization. Larvae are planktonic before settling to the bottom and metamorphosing into juvenile clams. The exact number of species within the genus Mastelis can vary depending on taxonomic classification, but it is generally considered to contain a small number of distinct species.

While not a major commercial species, Mastelis can be part of the diet of other marine organisms and play a role in benthic ecosystems. Their presence and distribution can be indicators of the health of their marine habitats. Further research continues to refine our understanding of the genus's phylogeny and ecological significance.