Distribuição espaço-temporal do gastrópode Melampus coffea ao longo do estuário do Rio Pacoti, Ceará, Brasil

Abstract

The mangrove forest is an ecosystem that exists in the intertidal zone. All over Brazil's coast, 91% of it is composed of mangrove forests, going from North to South of the country. Melampus coffea, also known as the “coffee-bean snail” is a gastropod of the family Ellobiidae. This species shows the transition from the sea to land environment, having both primitive and derived characteristics, feeding of organic matter that accumulates in the low tide. To study this snail, gatherings were made in 3 different areas by the Pacoti river, in different places of the river course. The gathering was made by dividing the area in 3 transects (replics) with 3 parcels (10 x 10m), from the furthest to the closest spot from the river. The timespan was 20 minutes by parcel, and the animals were taken to the laboratory for measurement of length and width, they were later returned back to the mangrove. Temperature, from the air, water, and soil were also collected, and so was the salinity. The data was analyzed using the software Statistica 7, and Primer. As a result, it was established that temperature and salinity both have an effect in the spatial and time distribution of the gastropod, while the plants have the influence in the density. Water proximity didn't have an influence in the distribution of the snail.