title: Continuous and simultaneous cultivation of benthic food diatom Nitzschia sp. and abalone Haliotis sieboldii by using deep seawater.
abstract: By using low-temperature, clean, and nutrient-rich properties of deep seawater (DSW; seawater below the euphotic layer), a continuous and simultaneous cultivation system for a benthic food diatom, Nitzschia sp., and juvenile abalone was established. Cell suspension of Nitzschia sp. was added to a bioreactor made of acrylic pipe (7 cm diameter x 50 cm long) containing short vinyl tubes (2 cm diameter x 2 cm long) as substrata. DSW collected from 320 m depth at Muroto City, in Kochi Prefecture, Japan, was supplied to the reactor and incubated under natural light (ca. 6000 lux) with a continuous DSW flow rate of 40 turnovers per hour. After growing enough benthic diatoms in the reactor, juveniles of abalone, Haliotis sieboldii (shell length ca. 10-20 mm) were put into a reactor, and cultivated simultaneously with food diatoms in the continuous flow system. During the four-month incubation, 7-month-old abalone juveniles with a shell length of 12.4 (average) +/-0.2 (SD) mm were grown to 19.4 (+/-1.7) mm in the reactor. Daily growth rates of abalones were 50-110 µm/day. These results indicate that the continuous cultivation system with DSW supports the growth of juvenile abalone without any supply of seaweed until it grows to release size.
authors.affiliation: Laboratory of Aquatic Environmental Science (LAQUES), Kochi University, Nankoku-shi, Kochi 783-8502, Japan
authors.initials: K
authors.lastname: Fukami
authors.initials: A
authors.lastname: Kawai
authors.initials: M
authors.lastname: Asada
authors.initials: M
authors.lastname: Okabe
authors.initials: T
authors.lastname: Hotta
authors.initials: T
authors.lastname: Moriyama
authors.initials: S
authors.lastname: Doi
authors.initials: T
authors.lastname: Nishijima
authors.initials: M
authors.lastname: Yamaguchi
authors.initials: M
authors.lastname: Taniguchi