Larval Development of Chthamalus challengeri Hoek (Cirripedia: Thoracica: Chthamalidae) with Keys to Barnacle Larvae of Korean Coastal Waters

Chthamalus challengeri Hoek was collected from intertidal rocks to rear the larvae from hatching through nauplius to cyprid in the laboratory. Larval development consists of six nauplius stages and a cyprid. Unilobed labrum with a prominent protuberance and the frontolateral horns folded under the anterior cephalic shield margin are diagnostic features through all nauplius stages. The posterior border of the cephalic shield bears no posterior shield spines in nauplius stages IV-Ⅵ. There is a specific hispid seta in the fourth group of the antennal endopodite. Morphological features such as the cephalic shield, labrum, abdominal process, antennules, antennae and mandibles in all nauplius and cyprid stages are illustrated and described. The numerical setations of the antennule are found to aid in the intraspecific identification of barnacle nauplius stages without dissection. The keys to each stage of the barnacle larvae in Korean coastal waters are provided based on the reared nauplii of seven species: Pollicipes mitella Octomeris sulcata, Chthamalus challengeri, Balanus albicostatus B. trigonus, B. amphitrite, and B. improvisus inhabiting Korean coastal waters.