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(The Gist of Science Reporter) Bizarre World of Plant-Animal Chimaera [JANUARY-2019]

(The Gist of Science Reporter) Bizarre World of Plant-Animal Chimaera

The term ‘chimaera’ is used to refer to organisms with their bodies encompassing parts from other organisms. As a figment of human imagination, one can find chimaeras in mythologies around the world.
Many humans have also claimed to possess plant-like photosynthetic attributes. The concept of breatharianism or “Inedia” (Latin for fasting) is based on the belief that human beings have plant-like essence within, and can live without food forever; all we need is water and sunlight. However, most of these claims have been invalidated by modern scientific research; breatharianism is now considered to be a form of pseudoscience.

Hatena arenicola is one such extraordinary animal discovered in the year 2000 by two Japanese scientists. The scientists observed single-celled animals (flagellate eukaryotes) living on a beach in Japan with chloroplasts the photosynthesising organelle.
Animal cells usually do not contain chloroplasts one of the principal distinguishing characteristics between animals and plants.
Endosymbiosis (endo = inside, symbiosis = living together) is a prominent theory in cell biology first formulated by Russian botanist Konstantin Mereschkowski in 1905 explaining the origin of organelles intracellular membrane–bound structures of eukaryotes (cells with true nucleus and organelles). The theory posits that eukaryotes originated when a prokaryote (bacteria) ingested yet another bacteria. The ingested bacteria, instead of getting digested, stayed there and evolved into an organelle that divides when its host cell divides.

A relationship with algae has been reported for yet another amphibian, the American toad (Anaxyrus americanus). Tadpoles of this toad secrete inorganic nutrients that render green algae of the genus Chlorogonium attracted to it. The algae grow on the tadpoles as an appendage, providing oxygen and food to the developing frog. The tadpole provides nutrients and carbon dioxide for the growth of the algae.
The mutualism between tadpoles and algae is an example of symbiosis long-term interaction of two organisms – and is different from endosymbiosis. The key difference is that in the case of endosymbiosis, one organism becomes an organelle within the cells of another organism, while in the case of symbiosis both the organisms are separate living entities. Animal-plant symbiosis is indeed a well-documented phenomenon.

There are some animals that can harvest solar energy without these algal partners; they don’t even need chloroplasts. Like the pigment chlorophyll, xanthopterin traps sunlight and converts it into electricity. The voltage through biochemical intermediates including ATPs (Adenosine Triphosphate, the ubiquitous intracellular fuel), powers the hornet’s locomotion. Stored electricity is also released as light during darkness.

There are several plant-like animals, such as sea anemones, northern corals, hydroids, bryozoans, tube worms, barnacles, sponges, sea squirts and so on.
These sessile (immobile) marine animals would look like plants for a non-specialist diver.
Keeda jadi (“Insect Plant”), a pricey mountain product especially from Uttarakhand region and an ingredient in traditional medicine with supposedly aphrodisiac properties, is not exactly a plant. It is the product of entomopathogenic fungal (Ophiocordyceps sinensis) fruiting bodies parasitizing on ghost moth (Hepialus humuli) caterpillars, and contain a dangerous amount of heavy metal arsenic.