Meritähtedel

Meritähtedel, commonly known as starfish or sea stars, are marine invertebrates belonging to the class Asteroidea. They are typically found in the benthic zone of oceans worldwide, from intertidal areas to the abyssal depths. Meritähtedel are characterized by their radial symmetry, most commonly exhibiting five arms, although some species can have many more. These arms radiate from a central disk. On the underside of each arm are hundreds of tiny, suction-cupped tube feet, which they use for locomotion and to grip surfaces, including prey.

The diet of meritähtedel varies significantly depending on the species. Many are predators, feeding on bivalves, gastropods, corals, and other slow-moving or sessile invertebrates. They often employ a unique feeding strategy where they evert their stomach out of their mouth, engulf their prey, and digest it externally before retracting their stomach. Some species are scavengers, consuming dead organic matter.

Reproduction in meritähtedel can be sexual, with most species releasing eggs and sperm into the water column for external fertilization. They can also reproduce asexually through fragmentation, where a portion of an arm, if it contains part of the central disk, can regenerate into a complete new individual. This regenerative ability is a remarkable characteristic of these creatures. Meritähtedel play important roles in their marine ecosystems as predators and as indicators of ocean health.