Reproductive Response Of Bulimulus Tenuissimus (Mollusca) As An Intermediate Host Of Angiostrongylus Cantonensis (Nematoda)

Abstract

The snail Bulimulus tenuissimus is a terrestrial gastropod widely distributed in the Americas, Asia, Africa and some countries of other continents. It typically occurs in the same areas as Angiostrongylus cantonensis, which needs a mollusk as intermediate host. In spite of this, the literature is scant about the relationship of these organisms. Specimens of B. tenuissimus were experimentally infected with L1 larvae of A. cantonensis. Weekly, until the third week post exposure, the reproductive parameters were analyzed and snails were dissected for collection of hemolymph, along with the albumen gland and tissues for histological analysis. The total number of eggs laid, total number of newly hatched snails and number of newly hatched snails/eggs laid were higher in the infected snails, but the differences observed were not significant. The galactogen content in the albumen gland was significantly reduced from the second week post exposure onward. Also, in spite of presence of larvae in the gonadal region of the snail with granuloma-like structures and some histological changes, gametogenesis occurred regularly in the infected hosts. The results are worrisome, since they showed that B. tenuissimus is an intermediate host to A. cantonensis which supports infection without changes in its reproductive biology and activity. The present study sheds more light on a snail that is a newly recorded experimental and natural intermediate host of A. cantonensis, which is widely distributed and occurs in areas were neural angiostrongyliasis has been recorded. Therefore, this snail can act in the nature as an important agent for dispersion of neural angiostrongyliasis, posing a serious problem to human and animal public health.