Title Aspects of the technology of phyllosoma rearing and metamorphosis from phyllosoma to puerulus in the Japanese spiny lobster Panulirus japonicus reared in the laboratory
Authers Keisuke MURAKAMI, Tadao JINBO, Katsuyuki HAMASAKI
Keywords Panulirus japonicus, phyllosoma, rearing technology, metamorphosis, puerulus
Citation Bull. Fish. Res. Agen. No. 20, 59-67, 2007
Abstract
Japan has a long history of more than 100 years in the development of rearing technology for phyllosomas of the Japanese spiny lobster, Panulirus japonicus. The first attempt to rear newly hatched phyllosomas was made in 1899, and it took about 90 years to succeed in rearing them to the puerulus and juvenile stages. The Minamiizu Station of the National Center for Stock Enhancement, FRA, started to develop its technology for rearing the phyllosomas of this lobster in 1989, when it succeeded in rearing juveniles in the laboratory for the first time, although researchers at the station anticipated that the task would be difficult. We divided the technological development into two subject areas: development of rearing methods and development of diets. We worked on issues such as methods of treating the rearing water, optimum water temperature for rearing, new devices for mass-rearing, and measures to prevent bacterial disease, and we also set up tasks such as exploring foods and developing artificial diets to replace the gonad of the blue mussel, Mytilus galloprovincialis. We primarily used rearing tanks with a capacity of less than 50 L. As the technology developed, we were able to gradually increase the numbers of juveniles produced each year from several tens in 1994 to a few hundred in 2005.
Because of recent advances in the technology covering the period from hatching to metamorphosis into pueruli, we succeeded in observing 270 processes of metamorphosis in 2005, using final-stage phyllosomas reared for 228 to 429 days after hatching. The process of metamorphosis from phyllosoma to puerulus was divided into five stages: contraction of eyestalks, contraction of pereiopods, molting of pereiopods, molting of abdomen, and molting of antennae. We also clarified the apparent characteristics of metamorphosis and the time required for metamorphosis at each stage, and we revealed that the metamorphosis process took about 10 min from the very beginning to the end.
URI http://www.fra.affrc.go.jp/bulletin/bull/bull20/09.pdf