SUDANESE LUNFISHES (“UMM KURU”) AS EVIDENCE FOR THE
SUDANESE LUNFISHES (“UMM KURU”) AS EVIDENCE FOR THE
THEORY OF CONTINENTAL DRIFT
PROF. THOMAS T. GEORGE
GLOBAL AQUACULTURE CONSULTANTS (GAC)
Website: www.tilapiamiracle.com ; Email: [email protected].
In IPPC reports (2007), “climate change refers to a change in the state of the climate that can be identified by changes in the mean and/or variability of its properties and that persists for extended periods, typically decades or longer. It may be due to natural causes or the result of human activity. Its effects or impacts may be physical, ecological, social or economic.”
On March 17, 2010, DAL GROUP Environmental Forum with DFID and UNEP had held a debate through a moderator and five panelists on: “Climate change: What does it mean for Sudan and what should we do about it?” This theme was demonstrated artistically by a tree of words reading: “SUDAN IS AT THE FRONT LINE OF CLIMATE CHANGE UNLESS ALL INDIVIDUALS AT ALL LEVELS ACT NOW TO MITIGATE AND ADAPT TO THE EFFECTS OF CLIMATE CHANGE. SUDAN MAY FACE INCREASED CONFLICT AND POVERTY IN THE FUTURE. THIS EVENT WILL SERVE TO BRING TOGETHER REPRESENTATIVES FROM THE GOVERNMENT, ACADEMIA, PRIVATE SECTOR, NGOS AND THE INTERNATIONAL COMMUNITY TO DEBATE THE ISSUES AND DEVELOP IDEAS AND RECOMMENDATIONS ON THE WAY FORWARD”. I attended this interesting occasion and participated in the discussions. I appreciated very much DAL GROUP initiative for public awareness about climate change and its effects. However, although climate change will seriously affect water resources around the world, no mention was made at the debate about aquatic environment and fishes which are among the main indicators of the aquatic environment health. This has motivated me to write this article in order to inform the reader about climate change which had affected fresh water fishes since early times and how lungfishes could withstand and adapt to the effects of climate change, especially that Sudan has two out of six species of lungfishes that are surviving in the world up to now and are considered scientifically as evidence for the Theory of Continental Drift.
According to Johnson GEO CENTRE in St John’s, Newfoundland, Canada: “ In the Beginning……Over 5 billion years ago, a rapidly spinning cloud of cosmic gas and dust exploded with an unimaginable force, giving birth to our Solar System – and what eventually became our planet – Earth.
As it formed, the young Earth was a fiery ball of molten rock. Over millions of years, it began to cool, and its low lands slowly filled with water. Dry land created the first continent. However, because of the molten rocks beneath, the thin crust of the Earth was under constant, intense pressure and tension the first huge continent broke apart and formed smaller continents. These were slowly moving, colliding and separating again. As they moved, vast oceans appeared and disappeared between them”.
According to CREATION BELIEVERS:
1) “The world and all that is in it belong to the Lord; the earth and all who live on it are his. He built it
on the deep waters beneath the earth and laid its foundation on the ocean depths.” (The Holy
Bible, Psalm 24).
2) “Do not the Unbelievers see that heavens and the earth were joined together (as one Unit of
Creation), before We clove them asunder? We made from water Every living thing.
Will they Not then believe?” (The Holy Quran, Surah 21: Al Anabiya, SECTION 3).
As it can be realized, both creation believers and the Johnson GEO Centre agree that land first appeared as one piece, and then it had been inundated and finally emerged in the form of six continents which exist up to date. Thus, before Continental Drift occurred, the continents were joined together. It is interesting to know that the past and present distributions of the lungfishes or dipnoans are in support of the Theory of Continental Drift. This is because lungfishes which once had a wide distribution, now are found in few restricted freshwater localities of Africa, Australia and South America (continents without water connections between them) while they are found as fossils in the other parts of the world. Furthermore, they are represented by only three genera in three families and only six widely separated species, two of which occur in Sudan namely, Protopterus aethiopicus in the Nile and Protopterus annectans in Western Sudan.
Due to climate change, most surviving bony-fish types moved into the sea and as a result lost their lungs or converted into a hydrostatic organ, the swimming bladder. However, as an aid under conditions of drought, the lungfishes retained their lungs. The African Protopterus and South American Lepidosiren have a pair of lungs and depend very much on them because their original gills became reduced in number and size while the Australian Neoceratodus has only one lung and does not depend much on it for breathing because it has full complement of gills.
Considering the Sudanese lungfishes (“Umm Kuru”), other amazing adaptations had taken place to make them survive only in regions where conditions of seasonal drought prevail, i.e. swampy conditions. The paired lungs enabled Protopterus to spend the dry season in a state of aestivation whereby its lowered metabolism minimizes water loss and reduced their need for nutrients and oxygen. In other words, when the rains cease and the tropical sun dries up its environment, Protopterus digs deep burrows in the mud and surrounds itself with a slimy desiccation retarding cocoon with an air channel extending to the surface of the soil, in which it can stay up to 4 years. In the cocoon it forms a U-shape with the head and tail upwards, with the tail covering the head and gets the energy needed for survival from the breakdown of muscle tissues. Correlated with aerial respiration, are modifications which occurred in the heart of Protopterus that provided a marked improvement in blood circulatory efficiency. Another important adaptation is the development of the enzyme system necessary to convert ammonia into less toxic urea, i.e. while in the water, Protopterus excretes its waste nitrogen as ammonia but during aestivation, it switches over to urea production like humans. Besides, it possesses remarkable power of rejuvenation: if the pectoral fin is damaged as many as three branches may arise from the damaged end!!
Furthermore, the fins in an ordinary fish are reduced in Protopterus only to four threadlike fleshy fins, two anterior and two posterior. These fins combined with the wiggling movement of the body, help Protopterus to crawl, and combined with air-breathing ability allow the fish to move from a dried up body of water to a better, wetter environment. Finally, in connection with a diet of shelled invertebrates and plant material, teeth are not present along the edges of the jaws of Protopterus which instead, developed specialized fan- shaped upper and lower plates for crushing and cutting.
Now, the six living species of lungfishes represent an important organizational advance somewhere on the march for aquatic vertebrates to land-living vertebrates and are extremely important in support of the Theory of Continental Drift. Therefore, any threat to the existence of these remaining species will have great natural and scientific repercussions on this primitive group of lungfishes. For example, water pollution due to extensive and careless overuse of pesticides, herbicides, and fertilizers, particularly in Africa, poses a real threat to the habitats of Protopterus and other aquatic organisms. Irrational activities by fisherman and people, also pose a threat to the very existence of Protopterus as it becomes a vulnerable target to be caught especially, when it is in a state of aestivation. Besides, prolonged droughts can drastically affect the very survival of Protopterus!!!
In conclusion, I believe that it is in the interest of the Sudanese people the following recommendations be taken seriously and without delay with respect to the Sudanese lungfishes in particular and the climate change and its effects at large:
1) The Fisheries Administration Department and Fisheries Research Center work together to execute a
project that protects the two species of Sudanese lungfishes from water pollution due to misuse of
pesticides, herbicides, fertilizers, etc. and ensure its continued survival through rational activities .
2) All concerned bodies, be they Government Officials, Academia, the Private Sector, NGOs and the
International Community join their efforts together to execute a single, well-coordinated National
Plan and Program about climate change to mitigate and adapt to its affects
3) A “ Protopterus National Protection Society” should be formed.
In conclusion, it is alarming to know the following facts about climate change:
- it will impact agriculture and food production around the world due to effects of elevated carbon
dioxide, higher temperature, alter precipitation and transpiration regimes, increased frequency of
extreme events, and modified weed, pest, and pathogen pressure;
- for about a 1-3 Degrees Celsius global temperature increase, there would be productivity
decreases for some cereals in low latitudes, and productivity increases in high latitudes;
- semi-arid and arid regions are particularly exposed to the impacts of climate change on freshwater;
- with respect to marine ecosystems and biodiversity, a warming of 2 Degrees Celsius above 1990
levels would result in mass mortality of coral reefs globally; - with respect to freshwater systems,
- above a 4 Degrees Celsius increase in Global mean temperature by 2100, many freshwater species
would become extinct!!!