Mortality and Abnormalities Observed After Experimental
Hg Exposure in the Polychaete Eurythoe complanata (Pallas)
from Mazatlan, Mexico
Nuria Me
´
ndez Æ Carlos Green-Ruı
´
z Æ
Ramo
´
nVa
´
zquez-Nu
´
n
˜
ez
Received: 20 February 2009 / Accepted: 25 June 2009 / Published online: 5 August 2009
Ó Springer Science+Business Media, LLC 2009
Abstract Lethal effects of Hg on Eurythoe complanata
held under laboratory conditions were evaluated (LC
50
and
LT
50
). Worms were exposed to 0–900 lg/L of Hg for
10 days. Mortality occurred in all the treatments, being faster
at 200–900 lg/L, which was confirmed by a Friedman
ANOVA non-parametric test. The 4-day LC
50
= 197.15 lg/
L (200 lg/L LT
50
= 3.4 days) was similar to that reported
for other Hg tolerant annelids. Abnormalities were observed
in worms exposed to all the treatments, becoming more
severe as Hg concentrations increased: body darkening,
rough, white and opaque skin, everted and swollen proboscis
and gut evisceration.
Keywords Fireworm Á Hg Á Metal Á LC
50
Á LT
50
Mercury is one of the most toxic metals for polychaetes
(Reish et al. 1976; Reish 1988). Field concentrations
reported for coastal areas can reach up to 0.06 lg Hg/L
(Roth and Hornung 1977); however, levels recorded from
factory effluents from several chloralkali plants in Europe,
which eventually discharge into the coastal systems, can
range from 1,600 to 7,600 lg/L (von Canstein et al. 1999).
Some polychaete species have been considered as good
candidates for ecotoxicological studies in the laboratory
(Reish 1980). Effects of Hg on cultured annelids have been
poorly studied on polychaete mortality (Reish et al. 1976;
Reish and Carr 1978; Reish 1988; Reish and LeMay 1991)
and oligochaete morphological abnormalities (Vidal and
Horne 2003).
The fireworm Eurythoe complanata (Pallas 1766)is
widely distributed in tropical and sub-tropical regions
especially on both sides of the American continent, in
intertidal and sublittoral rocky shores (Fauchald 1977). It
has been used as a test organism for toxicological studies in
the laboratory (Reish et al. 1989; Marcano et al. 1996;
Nusetti et al. 1998), but none of these bioassays have been
performed with Hg. Recently, we studied bioaccumulation
and elimination of Hg on this species kept in laboratory
conditions (Va
´
zquez-Nu
´
n
˜
ez et al. 2007). Thus, the aim of
this study was to analyze the effect of Hg on mortality of E.
complanata after exposure to solutions with different
concentrations under laboratory conditions. Moreover,
abnormalities produced by this metal, which have not been
reported previously, are described here.
Materials and Methods
Worms were collected under rocks from the mesolittoral
zone of Cerritos Beach, Mazatlan (23°18
0
30
00
N 106°
29
0
22
00
W) during August 2003. About 300 organisms (13–
15 cm length) were maintained in aquarium tanks con-
taining 20 L of seawater (34 PSU), a 5 cm layer of sand,
and rocks with attached algae from the same collection site,
to simulate natural conditions. Stock cultures were main-
tained at room temperature (26–28°C) in semi-dark con-
ditions for 17 days prior to the experiments. The rocks
were replaced every 8 days to allow animals to feed on the
algae. In addition, 1 g of fish food (Sera Vipan) was added
weekly as a complementary food source. Water exchange
was performed every 4 days.
In order to select the Hg concentrations, data from the
literature were taken into account. Reish et al. (1976) and
N. Me
´
ndez (&) Á C. Green-Ruı
´
z Á R. Va
´
zquez-Nu
´
n
˜
ez
Unidad Acade
´
mica Mazatla
´
n, Instituto de Ciencias del Mar y
Limnologı
´
a, Universidad Nacional Auto
´
noma de Me
´
xico, Joel
Montes Camarena s/n, Mazatla
´
n Sinaloa, Mexico
e-mail: nuri@ola.icmyl.unam.mx
123
Bull Environ Contam Toxicol (2009) 83:488–492
DOI 10.1007/s00128-009-9820-7