The objectives of this study were to develop a non-destructive technique for assessing maturity i n Anodonta sp. and induced gonadal release, both of them basic knowledge for larviculture process. Gonad condition of different sized individuals was assessed through dissection and microscopal examination. Glochidial release was tested using the following agents on standardized size (5.5 - 7 cm) mussels: a) KCL (0.5 Mol.) injection in the mantel cavity at 8 different concentrations (0.5, 0.1, 0.15, 0.20, 0.25, 1.0, 1.5, 2.0 ml/ind.; b) Oxytocin injection in the mantle cavity at 6 different concentrations (0.05, 0.1, 0.15, 0.2, 0.25, and 0.3 ml/ind.); c0 Immersion in alkalinized hydrogen peroxide solution (I 70 mg/l); d) Thermal shock (38-40º) at 8 different exposure times (10, 15, 20, 30, 35, 40, 45, 60 min); e) Punctures in the abductor muscle. Ripeness assessment without killing the animal was achieved by opening mussel valves with forceps and observing marsupia coloration. White was associated to unfertilized ova; brownish gray to immature glochida and reddish brown to mature glochidia. Glochidia release agent tests showed that oxytocin injection at 0.15 - 0.20 ml/ind. was the best release agent, followed by punctures at the abductor muscle. Other agents failed to induce glochidia release or resulted in mature and immature glochidia release surrounded by a gelatinous matrix, which restrained glochidia movement and hence subsequent fish infestation.