( ( Like ( ( fish and ) amphibians ) ) ( , ( reptiles ( ( are ( ( ( ectothermic animals ) , ) ( which ( is ( to ( say ( that ( they ( produce ( very ( little ( metabolic ( ( ( heat and ) ( their ( body temperature ) ) ) ( ( depends essentially ) ( on ( that ( of ( the environment ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN Like) (NP (NN fish) (CC and) (NNS amphibians))) (, ,) (NP (NNS reptiles)) (VP (VBP are) (NP (NP (JJ ectothermic) (NNS animals)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ is) (S (VP (TO to) (VP (VB say) (SBAR (IN that) (S (NP (PRP they)) (VP (VBP produce) (ADJP (RB very) (RB little) (JJ metabolic) (SBAR (S (NP (NP (NN heat)) (CC and) (NP (PRP$ their) (NN body) (NN temperature))) (VP (VBZ depends) (ADVP (RB essentially)) (PP (IN on) (NP (NP (DT that)) (PP (IN of) (NP (DT the) (NN environment)))))))))))))))))))) (. .)))
Like fish and amphibians, reptiles are ectothermic animals, which is to say that they produce very little metabolic heat and their body temperature depends essentially on that of the environment.
(ROOT (S (NP (NNS Reptiles)) (VP (VBP are) (VP (VBN described) (PP (IN by) (NP (NP (DT the) (NN term) (NN ectothermic)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ means) (SBAR (S (NP (PRP$ their) (JJ internal) (NN temperature)) (VP (VBZ depends) (PP (IN on) (NP (NP (DT the) (NN temperature)) (PP (IN of) (NP (PRP$ their) (NN environment))))))))))))))) (. .)))
Reptiles are described by the term ectothermic, which means their internal temperature depends on the temperature of their environment.