Toxicity Testing Using Marine Mollusks' Larvae

Abstract

The phylum Mollusca is the second most abundant phylum of animals after arthropods (more than one million known species) and before chordates (almost seventy thousand species) (Halanych 2004). It comprises more than 200,000 living species and 60,000 in the fossil registry and it is divided in eight taxonomical classes with Gastropoda as the largest group (about 80% of all mollusks) and Bivalvia ranking second (Halanych 2004). Mollusks are characterized by a huge morphological and physiological diversity that leads to their biological success (Moreira et al. 2019). They have colonized almost all ecological niches: from terrestrial habitats over 3000 m above sea level to coastal ecosystems and deep- sea hydrothermal vents, coping with adverse environmental conditions as high and low temperatures, salinity, CO2 and pH changes, desiccation periods and even extreme levels of pollution (Moreira et al. 2019). This diversity is mainly due to an early evolutive radiation in the Late Cambrian era that allowed them to occupy different environments (Plazzi and Passamonti 2010).