Chelicerates are a group of arthropods characterized by having chelicerae, which are specialized appendages located in front of the mouth. They belong to the subphylum Chelicerata, which includes diverse organisms such as spiders, scorpions, horseshoe crabs, and mites.
Chelicerates can be further divided into two classes: the Merostomata and the Arachnida. The Merostomata include horseshoe crabs, which are marine arthropods with a hard exoskeleton, a pair of large compound eyes, and a long tail-like structure. Arachnids, on the other hand, comprise a wide range of organisms like spiders, scorpions, and ticks. They possess four pairs of legs, two main body segments (the cephalothorax and abdomen), and simple eyes or sometimes no eyes at all.
One of the defining features of chelicerates is their chelicerae, which are used for various purposes depending on the group. They can be modified into fangs in spiders and scorpions, used for capturing and injecting venom into their prey. In horseshoe crabs, the chelicerae are mainly used for manipulating and crushing food.
Chelicerates exhibit a remarkable diversity of forms, habitats, and lifestyles. Although many are terrestrial, some chelicerates are also found in marine, freshwater, and even underground environments. They play important roles in various ecosystems, serving as predators, scavengers, or decomposers. Due to their ecological and evolutionary significance, chelicerates have been the subject of extensive scientific research, contributing to our understanding of arthropod biology.
