Crustacea usually have gills that are modified appendages. Jawed vertebrates are typified by paired appendages, fins or legs, which may be secondarily lost. They have to be incapacitated by shooting their tentacles and appendages off. The abdomen and the thorax with its thoracic appendages develop later. They commonly have basal and/or apical appendages. Most arachnids lack extensor muscles in the distal joints of their appendages. Along with ingestion, the microplastics stick to the appendages and exoskeleton of the zooplankton. Exarate pupae have their legs and other appendages free and extended. The remaining appendages are used for locomotion. Obtect pupae are compact, with the legs and other appendages enclosed. The underside of the opisthosoma was covered in structures evolved from modified opisthosomal appendages. The last is the , six long piercing tentacle-like appendages worn on his torso. The arthropod body plan consists of segments, each with a pair of appendages. In insects, an ovipositor consists of a maximum of three pairs of appendages. There are five more pairs of appendages on the abdomen.