Behavior of Biomphalaria glabrata, the intermediate host snail of Schistosoma mansoni, at different depths in water in laboratory conditions

Abstract

Using three columns of different depths (1.10m, 8.40m and 10.40m), we investigated the possibility of Biomphalaria glabrata moving towards deep regions. In the 1.10m column, we noted that locomotion can occur in two manners: 1) when the foot is in contact with the substrate: a) sliding descent; b) sliding ascent; c) creeping descent; d) creeping ascent, 2) when the foot is not in contact with the substrate: a) sudden descent without emission of air bules; b) sudden descent with emission of air bules; c) sudden ascent. In the 8.40m column containing food on the bottom (experimental group), the snails remained longer at this depth when compared to those of the group which received no food (control). The sliding behavior was characteristic of locomotion occurring at 0 to 1m both in upward and downward directions. Creeping behavior was typical for the ascent of the snails that reached deeper levels. When the snails were creeping, the shell remained hanging as if it were heavier, a fact that may have been due to water entering the pulmonary chamber. In the 10.40m column, the snails slid downward to a depth of 4m or descended suddenly all the way to the bottom. Ascent occurred by creeping from the bottom to the surface. In the 8.40m and 10.40m columns, copulation, feeding and oviposition occurred at the deepest levels.

Changes in the locomotory and reproductive behavior of Biomphalaria glabrata infected with Schistosoma mansoni

“…Changes in the locomotory activity of B. glabrata infected with S. mansoni have been studied by several authors, including its movement in relation to various stimuli, such as light, depth and the use of molluscicides (Jurberg et al, 1987(Jurberg et al, , 1988(Jurberg et al, , 1995Pieri and Jurberg, 1981;Sarquis et al, 1998). Boissier et al (2003) reported that uninfected snails moved greater distances at faster rates and with shorter rest periods in comparison with infected snails.…”

Modelling of the distribution of Biomphalaria glabrata and Biomphalaria straminea in the metropolitan region of Recife, Pernambuco, Brazil

“…In the rainy season (May to August), Biomphalaria spp. populations decrease due to flooding, but there is accelerated snail growth and production of new individuals leading to repopulation of breeding sites, which mainly occurs at the end of the rainy season (September to December), when increasing the number of stagnant water (Paraense, 1972;Grisolia and Freitas, 1985;Juberg et al, 1987). Despite being basically harmful, established snail populations may flush out snails leading to the formation of new habitats (WHO, 1957).…”

A Study of Schistosomiasis Prevalence and Risk of Snail Presence Spatial Distributions Using Geo-Statistical Tools

“…Another adaptation of molluscs is the acceleration of development during the rainy season to ensure the production of new individuals and thus the colony can withstand the next dry season. (Paraense, 1955(Paraense, , 1972Grisolia & Freitas, 1985;Juberg et al, 1987). The mollusc's reproductive mechanism has a fundamental role in the species' perpetuation.…”