NOSTOC PRUNIFORME- THREE BILLION YEARS OLD LIVING FOSSIL OF GOA
World largest living organism by area occupied is a fungus
Armillaria found in Oregon, USA spread over
nine sq. kms. Goa’s largest living organism
by area could be the massive colony of the alga Nostoc pruniforme found at
Bambolim-Taleigao-Dona paula plateau spread over more than ten sq. kms.
This species can be declared as “official cyanobacterial species of Goa”. The millions
of Nostoc spherules are Goa’s own ,
least discussed “mare’s eggs”. Such sites like the one found at Harriman
Springs Resort, near Rocky Point, Oregon are preserved in USA for their ecological and
scientific value. But who cares for microbial heritage in Goa
when there are rich rewards to be reaped by harping on more familiar and
popular species?. It is amazing that in our own university campus such
sites are systematically being destroyed under the pretext of biodiversity
enrichment. We lost several locations where my students used to do ecological
studies on Nostoc spherules. Here no biological impact assessment is ever conducted when
earth moving equipments move in to blindly destroy entire habitats and
communities. The Nostoc empire on this plateau could also be one of the oldest
coastal prokaryotic colony. It is an ancient photosynthetic prokaryote, a
cyanobacteria which has the capacity to fix atmospheric nitrogen. Such a useful
natural species is completely neglected by landscape managers, agriculturists, photobiologists
and biotechnologists due to their ignorance and
indifference. The main monsoon vegetation on this lateritic plateau and similar coastal plateaus in Goa are the grasses. This property had compelled communidades of Goa to reserve such areas as “gavthans’ or community pastures. A rare species of Gondwana wild rices is also found on such plateaus. How these grasses can grow so fast and dense in just three months without any external nutrient subsidies in a nutrient poor soil?. I found the answer by closely looking at the root zones of the grasses. It is the processing of dry crust of dead Nostoc biomass which returns nitrogen rich nutrients to soil which are taken up by the roots of grasses. There are large patches of grass roots entwined by the Nostoc colonies. During the dry months if one pulls out a patch of these dry grass roots then a large dry Nostoc mat gets easily separated exposing the surface of the laterite. The plateau experiences a drying and wetting cycle with a five months wet spell and seven months dry spell. Nostoc colonization is maximum between June to middle of August. Once intensity and duration of rains decrease Nostoc colonies also become dry and almost unrecognizable. Like desert varnish the dry crust of these colonies create continuous greenish black carpets which outwardly look as cakes of cowdung but once intensive showers take place and sunshine is cut off these crustose mats suddenly revive and the action of movement of rainwater over the carpets creates something not found documented by anyone. Yellowish green to dark green, semi transparent cerebroid gelationous or jelly like spherules appear. These are often found in groups of 10 to hundreds. It is a joy to stand on the wind swept plateau with the rain beating on the umbrella and the rainwater washing your feet. And right in front of you is the magic of nature-a phenomenon totally neglected by all those blinded by only precision laboratory science. The Nostoc spherules get dislodged with flowing turbulent sheets of water and begin rolling on the plateau, while getting entangled by the grass roots, natural depressions and cavities and crevices in the spongelike lateritic rock surface. I have seen translocation of some spherules for a distance of several metres before their final entanglement. Generally the rolling speed is high on an incline or gradient and slow on a flat surface. The force of the current also disperses these spherules over large distances. So colonies of same species get dispersed year after year and then come to establish a giant clonal colony. The Nostoc pruniforme spherules collected and examined by my students showed uniquely buoyant property when dropped in water indicating their low density and probable presence of air cavities in the gelatinous matrix. The gelatinous nature also showed presence of an unidentified compound with exceptional swelling properties- similar to Jalshakti water absorbing synthetic polymer foam produced by National Chemical laboratory, Pune. We did not try using powdered dry and old biomass of Nostoc to check whether it can be revived as spherules after absorbing water. The unique wetting, swelling, expanding and then drying, contracting, collapsing feature of spherule forming ecotype, genotype and biotype of Nostoc pruniforme makes it a special case in algal biotechnology. This form is sensitive
to humidity, temperature and light and prefers high to very high humidity, moderate temperature and only diffused light. Direct sunlight causes the spherules to shrink. This species is Goa’s natural factory of nitrogenous biofertilizers. If its’ wild habitat is conserved and studied scientifically then intelligent scientific clues can be obtained to control its’ production. The relative ease of drying the spherules after water loss makes it an excellent candidate for mass propagation and biofertilizer formulation. Nostoc spherules could be easily mistaken as heaps of herbivores dung. Their colour merges with the ground vegetation. During the dry spell the spherules simply vanish and one finds a thin greenish mat on their original location. Such morphological mode switching from two dimensional stationary mats to three dimensional rolling, dynamic spherules and vice versa remains relatively under investigated in the area of phycology- the science of study of algae. This property also makes the species another excellent model in developmental biology and molecular morphogenesis. A time lapse series of photographs of the filamentous mat transforming into rolling spherules would be so interesting that it would open a new line of research in ecological genetics. The “mare’s eggs’ of Goa, is a living fossil, a primary producer, with high photosynthetic and Nitrogen fixing capacity and deserves its’ due place among the list of important species to be protected. Compared to known species there is more danger of extinction of relatively less known or unknown species like Nostoc pruniforme which may simply vanish after land use change, habitat modification and ecological simplification. The spherules have evolved in tune with the rocky plateau. The rare spherule forming Nostoc pruniforme , the unsung cyanobacterial species of Goa is as important as tigers and turtles, frogs and fish. But who cares?. Even the agriculture department has not heard of this species.
indifference. The main monsoon vegetation on this lateritic plateau and similar coastal plateaus in Goa are the grasses. This property had compelled communidades of Goa to reserve such areas as “gavthans’ or community pastures. A rare species of Gondwana wild rices is also found on such plateaus. How these grasses can grow so fast and dense in just three months without any external nutrient subsidies in a nutrient poor soil?. I found the answer by closely looking at the root zones of the grasses. It is the processing of dry crust of dead Nostoc biomass which returns nitrogen rich nutrients to soil which are taken up by the roots of grasses. There are large patches of grass roots entwined by the Nostoc colonies. During the dry months if one pulls out a patch of these dry grass roots then a large dry Nostoc mat gets easily separated exposing the surface of the laterite. The plateau experiences a drying and wetting cycle with a five months wet spell and seven months dry spell. Nostoc colonization is maximum between June to middle of August. Once intensity and duration of rains decrease Nostoc colonies also become dry and almost unrecognizable. Like desert varnish the dry crust of these colonies create continuous greenish black carpets which outwardly look as cakes of cowdung but once intensive showers take place and sunshine is cut off these crustose mats suddenly revive and the action of movement of rainwater over the carpets creates something not found documented by anyone. Yellowish green to dark green, semi transparent cerebroid gelationous or jelly like spherules appear. These are often found in groups of 10 to hundreds. It is a joy to stand on the wind swept plateau with the rain beating on the umbrella and the rainwater washing your feet. And right in front of you is the magic of nature-a phenomenon totally neglected by all those blinded by only precision laboratory science. The Nostoc spherules get dislodged with flowing turbulent sheets of water and begin rolling on the plateau, while getting entangled by the grass roots, natural depressions and cavities and crevices in the spongelike lateritic rock surface. I have seen translocation of some spherules for a distance of several metres before their final entanglement. Generally the rolling speed is high on an incline or gradient and slow on a flat surface. The force of the current also disperses these spherules over large distances. So colonies of same species get dispersed year after year and then come to establish a giant clonal colony. The Nostoc pruniforme spherules collected and examined by my students showed uniquely buoyant property when dropped in water indicating their low density and probable presence of air cavities in the gelatinous matrix. The gelatinous nature also showed presence of an unidentified compound with exceptional swelling properties- similar to Jalshakti water absorbing synthetic polymer foam produced by National Chemical laboratory, Pune. We did not try using powdered dry and old biomass of Nostoc to check whether it can be revived as spherules after absorbing water. The unique wetting, swelling, expanding and then drying, contracting, collapsing feature of spherule forming ecotype, genotype and biotype of Nostoc pruniforme makes it a special case in algal biotechnology. This form is sensitive
to humidity, temperature and light and prefers high to very high humidity, moderate temperature and only diffused light. Direct sunlight causes the spherules to shrink. This species is Goa’s natural factory of nitrogenous biofertilizers. If its’ wild habitat is conserved and studied scientifically then intelligent scientific clues can be obtained to control its’ production. The relative ease of drying the spherules after water loss makes it an excellent candidate for mass propagation and biofertilizer formulation. Nostoc spherules could be easily mistaken as heaps of herbivores dung. Their colour merges with the ground vegetation. During the dry spell the spherules simply vanish and one finds a thin greenish mat on their original location. Such morphological mode switching from two dimensional stationary mats to three dimensional rolling, dynamic spherules and vice versa remains relatively under investigated in the area of phycology- the science of study of algae. This property also makes the species another excellent model in developmental biology and molecular morphogenesis. A time lapse series of photographs of the filamentous mat transforming into rolling spherules would be so interesting that it would open a new line of research in ecological genetics. The “mare’s eggs’ of Goa, is a living fossil, a primary producer, with high photosynthetic and Nitrogen fixing capacity and deserves its’ due place among the list of important species to be protected. Compared to known species there is more danger of extinction of relatively less known or unknown species like Nostoc pruniforme which may simply vanish after land use change, habitat modification and ecological simplification. The spherules have evolved in tune with the rocky plateau. The rare spherule forming Nostoc pruniforme , the unsung cyanobacterial species of Goa is as important as tigers and turtles, frogs and fish. But who cares?. Even the agriculture department has not heard of this species.
