Effect of temperature on embryo-larval development of Amarilladesma mactroides (Reeve, 1854)

In this study, the effect of four temperatures-18, 20, 23 and 26 degrees C-on embryonic development, growth and larval survival of the yellow clam Amarilladesma mactroides was evaluated. In the first phase, the development of the embryos to D-larva stage was observed until all treatment groups achieved complete transformation. This process lasted approximately 28 h, with the 23 and 26 degrees C groups showing greater transformation speed, completing the stage in 20 h 49 min. In the second phase, D-larvae were submitted to the four pre-established temperatures. There was a significant difference in the growth of larvae kept at 26 degrees C when compared to 18 and 20 degrees C. Treatments 18, 20 and 23 degrees C produced viable pediveliger larvae; however, larvae kept at 18 and 20 degrees C showed the fast growth accompanied by the highest survival rate. The results of this study indicate that the embryos of this species are tolerant of a temperature variation from 18 to 26 degrees C, with the effect of this variable being a determinant in the metamorphosis. However, within the experimental conditions adopted, the larvae were dependent on lower temperatures (18 and 20 degrees C) for settling, larger size and higher survival rate.

Automated summary

This study evaluated the effect of temperature on the embryonic development, growth, and larval survival of the yellow clam Amarilladesma mactroides. The results showed that the embryos of this species are tolerant of temperature variation and the larvae demonstrate better growth and survival at lower temperatures (18℃ and 20℃).