1063-0740/05/3104- © 2005 Pleiades Publishing, Inc.
Russian Journal of Marine Biology, Vol. 31, No. 4, 2005, pp. 243–247.
Original Russian Text Copyright © 2005 by Biologiya Morya, Skriptsova, Leletkin.
The growth zone of a Laminaria alga is situated in
the basal part of the thallus between the stipe and the
blade, where division and expansion of cells occur in
the intercalary meristem. It is known that in algae of the
Order Laminariales the processes of formation and
destruction of the blade proceed simultaneously [4, 7].
During the course of a year, the entire substitution of
the algal blade occurs through destruction of its upper
apical part and accretion at the frond basis . Under
certain conditions, the algal weight, length, and area do
not increase and can even reduce. These changes do not
formally correspond to the deﬁnition of growth. How-
ever, we do not have reason to claim the absence of
growth processes in these plants. For example, a reduc-
tion of the area, length, and weight was observed in
from the Barents Sea,
while the rate of tissue formation in the growth zone
remained high, which was shown by transposition of a
perforation hole mark from the basis to the tip of the
thallus [1, 9, 14].
The growth of a separate Laminaria thallus has be
studied most thoroughly in
Growth indicatrixes were obtained for an entire thallus;
the zones of cell division and expansion were distin-
guished; and the extension of growth zones in plants of
different ages was shown to vary in different seasons of
the year. After the publications by Kain , studies
focused on description of the life history and produc-
tion of Laminaria, as well as on ecophysiological
aspects of algal life in the natural environment and in
culture [2, 3, 11, 13, 16]. However, further investiga-
tions are needed in order to draw conclusions on the
regularities of changes in the weight and size of Lami-
naria thalli and, correspondingly, to evaluate the growth
rates in various stages of development and under differ-
ent conditions, including the period of the absence of
The goal of this study was to obtain experimental
evidence that would allow us to elucidate the following:
(1) the regularity of time-dependent changes in the
size–weight characteristics of
thalli; (2) the
extension of the growth zone on the algal thallus;
(3) the rate of formation of thallus biological material
in the absence of an increase in algal size and weight.
MATERIAL AND METHODS
One-year-old thalli of the brown alga
Aresch, 30 to 80 cm long, were used as the
study object. The alga was collected on November 7,
2002, and November 9, 2003, during low water in the
lower horizon of the littoral zone, in Rudnaya Pristan’
Bay (northwestern coast of the Sea of Japan). The
plants were transported to the laboratory within 8 hours
in a tank with seawater. Two experiments were con-
ducted on Laminaria under the same conditions of
The algae were kept in a 100-l aquarium with sea-
water at constant aeration and luminescent lighting.
The light intensity in the range of photosynthetic active
radiation (PAR) on the water surface was as high as
s, with a salinity of 30‰, and temperature
C. The water was changed every third day.
Growth of the Brown Alga
in a Laboratory Environment
A. V. Skriptsova and V. A. Leletkin
Institute of Marine Biology, Far East Division, Russian Academy of Sciences, Vladivostok, 690041 Russia
Accepted: June 22, 2004
—The growth of an individual thallus of the brown alga
was studied in a labora-
tory environment. It was found that daily accretion of the Laminaria thallus can remain constant for a long time.
The blade grew in length at a distance from 0 to 15–25 cm from the stipe–blade border, which makes up 60%
of the blade length. In width, the blade grew both in the central and in the lateral parts of the blade, 0 to 7–10 cm
from the stipe–blade border, which makes up 30% of the frond length. The transposition of a perforation hole
mark from the stipe–blade border toward the blade tip evidenced the formation of new tissue in the growth zone
even when the thallus diminished in size due to destruction of the blade tip. Based on the results of this obser-
vation, it was concluded that both restraint of accumulation and even reduction of the algal thallus in biomass
and size cannot be taken as an indication of algal growth cessation.
Laminaria, growth zone, growth.