S. neumayeri. This study demonstrated the use of red spherule cells as biomarkers
for heat stress because they increase in numbers under acute stress. In addition,
a significant increase in phagocytic indexes was observed at 2 °C coinciding with a
significant increase of iron intranuclear crystalloids at the same temperature.
Moreover, alterations in cell adhesion and spreading were observed. Hsp70
expression was not found in this study and ultrastructural analysis of coelomocytes
did not show any significant difference. This was the first study of the innate
immune response alterations with an increase in temperature (Branco et al. 2011).
Some investigations compared Antarctic echinoderms with tropical species.
One of these studies determined the oxygen consumption in two species of sea
urchins, the tropical L. variegatus and the polar S. neumayeri. In sealed respirometry L. variegatus had a higher consumption of oxygen than S. neumayeri. This
is probably due to diet and temperature. The relation of O:N between S. neumayeri
and L. variegatus was the same, showing that the substrate metabolized of the two
animals is similar (Borges et al. 2012).
Phagocytosis was studied in vitro at 0 °C using the coelomic fluid of the
Antarctic sea star Odontaster validus and the types of amoebocytes involved were
identified. This was the first study of this kind on an Antarctic invertebrate. Rates
of phagocytosis were similar to, or higher than, previously reported for temperate
sea stars. However, this conclusion must be considered with caution because of the
scarcity of data and the different methods used. On the other hand, the data do
suggest that one of the animals’ main defenses against infection may be well
adapted to low temperatures in O. validus. The phagocytosis and germicide
capacity of S. cerevisiae by phagocytic amoebocytes (PA) of the Antarctic sea star
O. validus was also studied in vivo at 0 °C (Silva and Peck 2000; Silva et al.
2001).
9.2.5 Echinoderm Ecotoxicological Research
Bioassays are a valuable approach to evaluate and predict harmful effects of
pollutants on the biota at different levels of organization (Environmental Canada
1992, 2011; Nascimento et al. 2002; Losso and Volpi-Ghirardini 2010). In this
context, echinoderms have a great importance on ecotoxicological and environmental risk assessment studies.
Toxicity tests for environmental quality analyses in Brazil began in the 1970s
with the standardization by the São Paulo State Environmental Agency (Companhia Ambiental do Estado de São Paulo—CETESB) of tests using freshwater
organisms (Resgalla and Laitano 2002; Zagatto 2006). Afterwards, standard protocols for marine organisms were published (CETESB 1991, 1992, 1999; Resgalla
and Laitano 2002; Zagatto 2006). Since then, toxicity tests with sea urchin
embryos have been used extensively in environmental pollution monitoring
(Prósperi 1993, 2002; Mastroti 1997; Abessa et al. 2003; Nilin et al. 2007).
9 Echinoderm from Brazil
311
for heat stress because they increase in numbers under acute stress. In addition,
a significant increase in phagocytic indexes was observed at 2 °C coinciding with a
significant increase of iron intranuclear crystalloids at the same temperature.
Moreover, alterations in cell adhesion and spreading were observed. Hsp70
expression was not found in this study and ultrastructural analysis of coelomocytes
did not show any significant difference. This was the first study of the innate
immune response alterations with an increase in temperature (Branco et al. 2011).
Some investigations compared Antarctic echinoderms with tropical species.
One of these studies determined the oxygen consumption in two species of sea
urchins, the tropical L. variegatus and the polar S. neumayeri. In sealed respirometry L. variegatus had a higher consumption of oxygen than S. neumayeri. This
is probably due to diet and temperature. The relation of O:N between S. neumayeri
and L. variegatus was the same, showing that the substrate metabolized of the two
animals is similar (Borges et al. 2012).
Phagocytosis was studied in vitro at 0 °C using the coelomic fluid of the
Antarctic sea star Odontaster validus and the types of amoebocytes involved were
identified. This was the first study of this kind on an Antarctic invertebrate. Rates
of phagocytosis were similar to, or higher than, previously reported for temperate
sea stars. However, this conclusion must be considered with caution because of the
scarcity of data and the different methods used. On the other hand, the data do
suggest that one of the animals’ main defenses against infection may be well
adapted to low temperatures in O. validus. The phagocytosis and germicide
capacity of S. cerevisiae by phagocytic amoebocytes (PA) of the Antarctic sea star
O. validus was also studied in vivo at 0 °C (Silva and Peck 2000; Silva et al.
2001).
9.2.5 Echinoderm Ecotoxicological Research
Bioassays are a valuable approach to evaluate and predict harmful effects of
pollutants on the biota at different levels of organization (Environmental Canada
1992, 2011; Nascimento et al. 2002; Losso and Volpi-Ghirardini 2010). In this
context, echinoderms have a great importance on ecotoxicological and environmental risk assessment studies.
Toxicity tests for environmental quality analyses in Brazil began in the 1970s
with the standardization by the São Paulo State Environmental Agency (Companhia Ambiental do Estado de São Paulo—CETESB) of tests using freshwater
organisms (Resgalla and Laitano 2002; Zagatto 2006). Afterwards, standard protocols for marine organisms were published (CETESB 1991, 1992, 1999; Resgalla
and Laitano 2002; Zagatto 2006). Since then, toxicity tests with sea urchin
embryos have been used extensively in environmental pollution monitoring
(Prósperi 1993, 2002; Mastroti 1997; Abessa et al. 2003; Nilin et al. 2007).
9 Echinoderm from Brazil
311