Efeito do cálcio no desenvolvimento do gastrópode Pomacea dolioides (Reeve, 1856)

Abstract

The Amazon region is known for having great aquatic biodiversity and the most important tropical basin on the planet. Along the Amazon River and most of its tributaries, the high annual rainfall results in extensive flooded areas, called floodplains. In this context, snails of the genus Pomacea constitute an important part of the native freshwater fauna. Seeking to understand the relationship of calcium in mollusks in the Amazon, the objective of this work was to evaluate the effect of different concentrations of calcium on the development and regeneration of the shells of the gastropod Pomacea dolioides. Initially, a survey of gastropods was made in the municipality of Itacoatiara-AM, where they were collected, identified and analyzed for the occurrence of damage to the shells. We also collect water samples to determine calcium in the environment. Subsequently, gastropods were distributed in six treatments with different concentrations of Ca2 +, this experiment lasted 60 days, where we verified the growth, fattening, calcium concentration in the whole animal and the microstructure of the shell. In addition, we analyzed the regeneration process of shells subjected to different concentrations of calcium, with two types of cut (triangle and rectangle) and two inductions. The results showed that there was no relationship between shell damage and calcium concentration in the environment. Experimentally, calcium dissolved in water was essential for the gastropod P. dolioides, since, in the absence of calcium, the gastropods did not survive for more than 40 days. These showed better development from the concentrations of 60, 80 and 100 mg / L of calcium sulfate tested. The regeneration time of the shells did not differ between treatments with different concentrations of calcium. Gastropods showed the ability to regenerate damaged areas with different types of incisions and inductions in a relatively short time with a high survival rate. From these results, we conclude that the presence of damage to the shells in the environment may be related to other factors and not only to the concentration of calcium and that there is a relationship between calcium dissolved in water and the development of gastropod P. dolioides in relation to length, inorganic and organic weight and calcium from the shell and the whole snail. As a result, it is important to consider the external environment in the process of acquiring Ca2 + ions and not just the calcium absorbed via food.