Abstract
A caligid copepod was collected from the body surface of striped jack, Pseudocaranx dentex cultured in net cages in western Japan. It is identified as Caligus longipedis Bassett-Smith, 1898. Adults as well as all the developmental stages are described; morphologically they are divided into 2 nauplius, 1 copepodid, 4 chalimus, 1 preadult and 1 adult stages. Newly hatched nauplii moulted two times into copepodids in about 19 h at 22.5±2.0°C. Copepodids survived in sea water 7 days at most at 20°C. Chalimus larvae were found on the fins and body surface of fish. When free-swimming larvae were exposed to uninfected fish, they were transformed into adults on Day 10 (10 days after exposure to uninfected fish), and possessed egg sacs on Day 12 at 21.2±0.6°C. Nauplii were recovered from the rearing water on Day 13. It is thus estimated that the life cycle was completed in about 2 weeks.
