Melampus coffeus (Linnaeus, 1758) is a pulmonate, macrodetritivore gastropod, important in energy flows in neotropical mangroves, but its distribution in different spatial scales is still unknown in Brazil. The objective of this study was to evaluate the distribution of M. coffeus: 1) among the mangrove trees Rhizophora mangle Rhizophoraceae and Laguncularia racemosa Combretaceae; 2) in relation to the position of R. mangle prop roots and 3) among mangroves with different tree heights. Further, its behavior along one tidal cycle was also described. The densities of M. coffeus did not differ between R. mangle and L. racemosa, but the largest snails were found on R. mangle. The distribution of snails found on the sediment differed relative to the position of the prop roots, with the highest density in the center and largest size in the edge of the studied areas. However, this distribution was not related with the availability of food resources provided by decayed leaves. Higher densities were also recorded in intermediate and low-stature mangroves when compared with taller ones, but no differences in snail's sizes among mangroves were found. During the high tide, M. coffeus individuals climb nearby trees. These results are possibly related to the availability of resources and shelter supplied by R. mangle. Thus, studies on the distribution of M. coffeus in diverse conditions are essential, because mangroves are being intensively disturbed.
Distribution; density; mangrove; northeastern Brazil; mollusc
