( ( ( sexual ( -LRB- ( ( most ( are hermaphroditic ) ) -RRB- ) ) ) ( by ( external ( or ( internal fertilization ) ) ) ) ) ( , ( gametes ( ( are ( released ( into ( the ( water current ) ) ) ) ) . ) ) ) )
(ROOT (S (S (NP (NP (JJ sexual)) (PRN (-LRB- -LRB-) (S (NP (JJS most)) (VP (VBP are) (ADJP (JJ hermaphroditic)))) (-RRB- -RRB-))) (PP (IN by) (NP (JJ external) (CC or) (JJ internal) (NN fertilization)))) (, ,) (NP (NNS gametes)) (VP (VBP are) (VP (VBN released) (PP (IN into) (NP (DT the) (NN water) (NN current))))) (. .)))
sexual (most are hermaphroditic ) by external or internal fertilization, gametes are released into the water current.
(ROOT (S (NP (NNS Amphibians)) (ADVP (RB sexually)) (VP (VB reproduce) (PP (IN through) (NP (JJ external) (CC or) (JJ internal) (NN fertilization)))) (. .)))