text: what are some endangered aquatic species?   here are some listed as critically endangered by the iucn (world conservation union):  baltic sturgeon (acipenser sturio) duck-billed buntingi (adrianicthys kruyti - possibly extinct) chinese alligator (alligator sinensis) axolotl (ambystoma bombypellum) australian freshwater limpet (ancylastrum cumingianus) chinese giant salamander (andrias davidianus - largest amphibian in the world) cave squeaker (arthroleptis troglodytes) pondicherry shark (carcharhinus hemiodon) dumb gulper shark (centrophorus harrissoni) malayan water shrew (chimarrogale hantu) central american river turtle (dermatemys mawii) leatherback turtle (dermochelys coriacea - largest turtle in the world) goliath grouper (epinephelus itajara) greek lamprey (eudontomyzon hellenicus) noel's amphipod (gammarus desperatus) coelacanth (latimeria chalumnae) bloody bay poison frog (mannophryne olmonae) mediterranean monk seal (monachus monachus) ethiopian amphibious rat (nilopegamys plumbeus) mekong giant catfish (pangasianodon gigas - largest living freshwater fish) harbour porpoise (phocoena sinus)