the spines of this sea urchin and its appearance is mimicked by the mantis shrimp, Echinosquilla guerinii'', which conceals itself in a hole in the rock with only its spiny telson visible. Copper is having a detrimental effect to larvae at 0.02 mg/L, and adults have 48- and 96-h TL50 values of 0.54 and 0.30 mg/L. Fertilization success was also reduced to 50% in 0.18 mg/L, and cleavage of the 8-cell stage as well, at 0.42 mg/L of Cu++. References External links Echinometridae Animals described in 1825