The objective of this work was to evaluate aspects related to the reproductive cycle of the armored catfish Parauchenipterus striatulus in Ribeirão das Lajes Reservoir, state of Rio de Janeiro, Brazil. Gonadal stage, morphology, variations in the gonadosomatic index, weight:length relationship, condition factor and gonadal condition were described. Fish sampling was carried out bi-monthly, between April 1996 and May 1997, using gill nets 100m long, 4m wide, and 25-65mm of mesh sizes gill nets. Three hundred and thirty-nine fishes, corresponding to 40% of the total number, were capture. Five maturation stages were determined by macroscopic analysis of both sexes: immature, mature I, mature II, ripe and spawned (females) or empty (males). The gonadosomatic index was higher from October to March for both sexes, suggesting an ample spawning period, while the condition factor was higher from February to June, showing an inverse relationship between these two characteristics. Weight:length relationship for males was W = 0.0095L3.0862 and for females W = 0.0116L3.0126, with no significant differences between sexes in the allometric coefficient.
Catfish; Parauchenipterus striatulus; reproduction
