Viability of the Use of the Sand Dollar Mellita quinquiesperforata as a Test Organism

Abstract

The aim of this study was to investigate the viability of the use of sand dollar Mellita quinquiesperforata as a test organism in chronic experiments over short durations. For this, the protocol of the CETESB Technical Standard was used, which was designed for the regular sea urchin Lytechinus variegatus, using embryos and larvae exposed to four reference toxins, for a 24-hour period. The substances used in the toxicity tests were zinc sulfate, potassium dichromate, copper sulfate and sodium dodecyl sulfate (SDS). These substances are normally used to evaluate the relative sensitivity of marine test organisms, and to estimate the precision and reliability of the data produced in the laboratory. The proposed protocol proved to be adequate for its use with the irregular sea urchin M. quinquiesperforata, some modifications being necessary in terms of the validation requirements, due to the low egg production, low fecundation rate, and higher percentage of effect observed in the control flasks. The EC50;24h average for zinc was 50 μm L–1 (VC of 44% for n = 5), for chrome it was 1462 μg L–1 (VC of 25% for a n of 3), for copper it was 10 μg/L–1 (VC of 35% for n = 5) and for SSD it was 2145 μg L–1 (n = 2). M. quinquiesperforata presents a sensitivity similar to species registered by the NBR/ABNT, demonstrating the potential of this Echinodermate for use as a test organism, in cases where it is impossible to use species required by the environmental agencies.