1063-0740/04/3005- © 2004
Russian Journal of Marine Biology, Vol. 30, No. 5, 2004, pp. 358–360.
Original Russian Text Copyright © 2004 by Biologiya Morya, Janecki, Rakusa-Suszczewski.
(Koehler 1911) is one of the most
abundant species of starﬁsh in Admiralty Bay (King
George Island, South Shetland Islands), occurring in a
wide depth range . The wet weight of
reach up to 50 g . This starﬁsh is omnivorous; but it
can be a predator, a necrophage, or a phytophage [3, 11].
Thus far, the chemical composition of the body of this
species has remained unknown. The behavioral features
and metabolic reactions of
have been studied
by Kidawa . According to observations [7, 8, 14],
glutamic acid inﬂuences the metabolic rate of some Ant-
arctic invertebrates. It changes their heartbeat frequency
and causes changes in behavior. An important role of
glutamic acid as a chemical stimulus has also been noted
for marine animals.
The aim of this work is a chemical analysis of
and further study of reactions of this species
to glutamic and kynurenic acids.
MATERIALS AND METHODS
The research was conducted in January 2001 at the
“N. Arctowski” Antarctic Station and in Poland. Speci-
were collected from a depth of
30 m and then kept in seawater aquaria at a temper-
ature of 1.0
C. For chemical analysis, 10 live speci-
were transported to Poland in sea-
water in cold storage. During the 35-day journey, the
starﬁsh were not fed, but the water in the storage tanks
was changed regularly. All animals arrived at their des-
tination starved but in good condition.
The dry body weight and protein, fat (ether extract),
and ash contents were determined using standard meth-
ods . After hydrolysis (22 h, 6N HCl), amino acids
were analyzed using a 6300 Beckman amino acid ana-
lyzer. Methionine and cysteine were determined
according to Moore , and tryptophan, according to
Eggum’s method .
The respiration experiments were conducted in a
cooled laboratory at the “N. Arctowski” Station. A few
were maintained for 2 h in
1460 ml airtight sealed glass tanks in well-aerated sea-
C, 34.5‰). Oxygen uptake was measured
with a WTW-LF 197 oxygen meter. The concentrations
of L-glutamic and kynurenic acids in seawater were
10 mM/liter and 0.1 mM/liter, respectively. Experimen-
Chemical Composition of the Antarctic Starfish
(Koehler 1911) and Its Reactions
to Glutamic and Kynurenic Acids
T. Janecki and S. Rakusa-Suszczewski
Department of Antarctic Biology, Polish Academy of Sciences,
Ustrzycka 10/12, Warsaw 02-141, Poland
e-mail: firstname.lastname@example.org; email@example.com
Received February 11, 2004
—The protein content in the dry body weight of the starﬁsh
is 30%. The compo-
sition of amino acids is characterized by a very high level of glycine (27%). Glutamic acid (Glu) in a concen-
tration of 10 mM/liter in seawater causes an increase in the metabolic rate of starved
As the period
of starvation increases, this reaction is enhanced. A two-hour exposure to kynurenic acid (Kyn) in a concentra-
tion of 0.1 mM/liter blocks the reaction to glutamic acid.
glutamic acid, kynurenic acid, starﬁsh,
Basic chemical composition of
Body weight, g
Proteins* Lipids* Ash*
* In percent of dry body weight.
Note: Here and in Table 2, n is the number of specimens.