Ottelia mesenterium

Ottelia mesenterium is an aquatic plant endemic on the Indonesian island Sulawesi. It is only found in lakes Matano, Towuti and Mahalona, all three of them belonging to the Malili Lake System well-known in aquaristics mainly due to its spectacular shrimp and snail species.
This very decorative Ottelia characterised by its strongly undulate leaves is not really new in the aquarium hobby, as it was imported to Europe (Italy) as early as 1974. More recently, collecting it for export and trade purposes has been resumed.

However, much has been tried to cultivate it, and all of it in vain. It is not clear yet which factors are decisive for keeping this Ottelia in the aquarium over a longer period of time. It is probably highly specialised and adapted to the conditions of the lakes of the Malili system. Thus, even though O. mesenterium is a true aquatic plant it cannot be recommended as aquarium plant. It is endemic to a rather small area and thus might be at least potentially endangered - all the more reason to leave it where it is.

Christel Kasselmann (1995) listed the following water conditions from the natural habitats of O. mesenterium (Lakes Matano and Towuti, 1981):
-Water depth 0.8-3 m
-rhizomes rooted deeply and firmly in the substrate, even the onset of the leaves is covered
-temperature 25-29°C
-GH 6.0 / 3.4 °dH, KH 1.8 / 1.4 °dH
-Conductivity 185 / 125 microsiemens/cm
-pH neutral to slightly alcaline.