Biology Reference
In-Depth Information
distinct, narrow band in soft sediments immediately seaward the low tide line (e.g.,
Moreton Bay, Australia) (personal observation).
Caulerpa taxifolia
is known by the
aquarium industry as “feather
Caulerpa
” or “feather algae” and is lumped with a
number of other species of
Caulerpa
with feathery blades (e.g.,
C. sertularioides
,
C. ashmeadii
,
C. mexicana
), and this group has dominated the flora in both personal
and public saltwater aquaria for many decades (Walters et al. 2006).
15.2
Invasion History of
Caulerpa taxifolia
The aquarium strain of
C. taxifolia
has the distinction of being one of the world's
100 worst invasive species listed by the International Union for the Conservation of
Nature (ICUN) and Europe's second worst macroalgal invasion on record (www.
issg.org/database). The invasion history of the aquarium strain of
Caulerpa taxifo-
lia
(
*
aka the killer alga) started with an accidental introduction into the Mediterranean
Sea while cleaning tanks at the Monaco Oceanographic Museum in 1984 (Fig.15.3)
(Meinesz and Hesse 1991, Meinesz 1999). Reports documented expansion from a
small patch adjacent to the Museum to many areas in the Mediterranean at a rate of
approximately 50 km per year, with boating activity, fishing nets, and water currents
largely responsible for the spread (Meinesz et al. 1993, 2001; Sant et al. 1996).
Dense populations of
C. taxifolia
are concentrated in zones with extensive develop-
ment (Madl and Yip 2005). Monocultures of the aquarium strain of
C. taxifolia
now
can be found at over 100 locations in Mediterranean waters extending for hundreds
of kilometers (Madl and Yip 2005 for chronology). In the Mediterranean,
C. taxifolia
is found on steep slopes as well as flat bottom areas. Dense meadows
are found at depths ranging from a few meters to over 40 m, while sparse meadows
extend to 55 m and isolated individuals have been observed at 100 m (Meinesz and
Hesse 1991; Belsher and Meinesz 1995). Through DNA forensics, the global origin
of Mediterranean
C. taxifolia
was found to be Moreton Bay in Queensland,
Australia (Wiedenmann et al. 2001).
Caulerpa taxifolia
was imported in the early
1970s by the Wilhelmina Zoologischbotanischer Garden in Stuttgart, Germany,
which displayed the alga in its tropical aquarium (Jousson et al. 1998). Between
1980 and 1983, clones originating from Moreton Bay were given to the tropical
aquarium of Nancy in northern France and subsequently to the Monaco
Oceanographic Museum (Jousson et al. 1998). Clones were cultivated in various
aquaria for 14 years prior to being found in Monaco waters.
In Japan, Komatsu et al. (2003) surveyed 65 public aquaria for
Caulerpa
.
Sixteen of the 51 aquaria that responded to the survey cultured or exhibited
C. taxifolia
. Six purchased the alga from aquarium shops, one obtained
C. taxifolia
from another public aquarium (originally bought at a retail shop), and the rest were
uncertain about origin but stated that the alga was from somewhere in Japan.
The Notojima Aquarium staff reported temporary establishment of
C. taxifolia
in
the Sea of Japan due to culturing practices. The aquarium initially received
C. taxifolia
when purchasing “foreign shrimp” of unknown taxonomy from an aquarium shop
in Osaka. The aquarium staff grew the fragment in a tank. The fragment did well
and was transferred to an open pool of 1,000 tons of seawater with an open-circuit
