( They ( ( reproduce ( ( ( sexually ( in ( one host ) ) ) and ) ( then ( asexually ( in ( a ( second host ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VB reproduce) (S (S (ADVP (RB sexually)) (PP (IN in) (NP (CD one) (NN host)))) (CC and) (S (ADVP (RB then)) (ADJP (JJ asexually) (PP (IN in) (NP (DT a) (JJ second) (NN host))))))) (. .)))
They reproduce sexually in one host and then asexually in a second host.
(ROOT (S (NP (JJS Most) (NN fish)) (VP (VB reproduce) (PP (IN with) (NP (CD one) (DT another))) (ADVP (RB sexually))) (. .)))