Sap transport proteins. Recent evidence indicates that mobile proteins and RNA are part of the plant's long-distance communication signaling system. Evidence also exists for the directed transport and sorting of macromolecules as they pass through plasmodesmata." A large number of insects of the order Hemiptera (the half-wings), feed directly on phloem sap, and make it the primary component of their diet. Phloem sap is "nutrient-rich compared with many other plant products and generally lacking in toxins and feeding deterrents, [yet] it is consumed as the dominant or sole diet by a very restricted range of animals". This apparent paradox is explained
Tonlé Sap the Tonle Sap River and surrounding wetlands, waters of the lake's basin drains via the Tonle Sap River into the Mekong. As a result the Tonle Sap River (length around 115 km/71 mi) flows six months a year southeast (Mekong) to northwest (lake) and six months a year in the opposite direction. The mean annual reverse flow volume in the Tonle Sap is , or about half of the maximum lake volume. A further 10 percent is estimated to enter the system by overland flow from the Mekong. The Mekong branches off into several arms near Phnom Penh and reaches