Comparative study of the fecundity and fertility of Biomphalaria glabrata (Say, 1818) and Biomphalaria straminea (Dunker, 1848) in a laboratory through self-fertilization and cross-fertilization

Abstract

The aim of this study was to compare the fecundity and fertility of B. glabrata and B. straminea by cross- and self-fertilization. To attain this objective, laboratory-raised strains of B. glabrata and B. straminea were used. The former originated from natural breeding grounds in the municipality Paulista, state of Pernambuco, Brazil. The latter originated from irrigation ditches in the municipality of Petrolândia, in the same state. Snail populations of B. glabrata and B. straminea were maintained for 240 days in laboratory. Their fecundity was evaluated by noting the number of egg-masses, eggs and eggs per mass. Their fertility was evaluated by the number of viable eggs and the hatching rate. B. straminea was markedly more fecund than B. glabrata through cross- and self-fertilization, namely: greater egg-mass; higher egg production and more eggs per mass. Regarding fertility, there seemed to be no preferential period for occlusion to occur or a trend in the rhythm of producing viable eggs.

INFLUÊNCIA DOS PARÂMETROS ABIÓTICOS NA ABUNDÂNCIA DE Biomphalaria straminea (BASOMMATOPHORA: PLANORBIDAE) EM UMA LAGOA TEMPORÁRIA NO SEMIÁRIDO DE PERNAMBUCO, BRASIL

“…Para o pH (R 2 = 0,062, p = 0,685, gl = 4; Figura 4c) e a condutividade elétrica (R 2 = 0,001, p = 0,99, gl = 4; Figura 4d) não houve relação significativa. (Costa et al 2004). Já P. lineata possui desova de 20 a 80 ovos e um período de incubação mais longo que a B. straminea, tendo duração de 15 a 23 dias (Kretzschmar & Heckman 1995).…”

“…Já P. lineata possui desova de 20 a 80 ovos e um período de incubação mais longo que a B. straminea, tendo duração de 15 a 23 dias (Kretzschmar & Heckman 1995). Entretanto, a desova de B. straminea ocorre normalmente nos períodos chuvosos, que é menos comum na região do estudo, já que a lagoa está inserida na Caatinga (Andrade & Carvalho 1979, Souza & Lima 1990, Costa et al 2004. Em relação ao tamanho das conchas dos indivíduos, de acordo com Souza & Lima (1990), esse elevado número de gastrópodes com maior tamanho de concha pode estar vinculado ao crescimento rápido das espécies registradas e ao oxigênio na água, maior a abundância de B. straminea.…”

Patterns of Mating‐system Evolution in Hermaphroditic Animals: Correlations Among Selfing Rate, Inbreeding Depression, and the Timing of Reproduction

“…Mean ± SD across one (Costa et al 2004) and one (this study) populations (2) 0.44 (2) (1) ME, mean ± SD across six populations (Njiokou et al 1994) [A]…”

Biological, biochemical and histopathological features related to parasitic castration of Biomphalaria glabrata infected by Schistosoma mansoni

“…The fecundity (number of egg masses per snail, number of eggs per egg mass and number of eggs per snail) and fertility (rate of eggs hatched per snail) were measured weekly as previously described (Costa et al, 2004). Beginning on day 30, the snails were individually exposed to light (60-watt incandescent bulb for 4 h) to look for the release of cercariae.…”