( ( ( Exotic Species ) ( Also called ) ) ( ( introduced species ) ; ) )
(ROOT (S (NP (NP (NNP Exotic) (NNPS Species)) (VP (ADVP (RB Also)) (VBN called))) (VP (VBD introduced) (NP (NNS species))) (: ;)))
Exotic Species Also called introduced species;
(ROOT (S (NP (JJ Exotic) (NNS species)) (VP (VBP are) (ADVP (RB also)) (VP (VBN called) (NP (JJ invasive) (NNS species)) (SBAR (IN because) (S (NP (PRP they)) (VP (VBP threaten) (NP (JJ other) (NNS species))))))) (. .)))