Zoology has a discipline: evolution; zoology is vertically integrated, concerned with biological organisation at the level of organisms in their environment, organs, tissues, cells and molecules. This blog meanders through the animal kingdom, from aardvarks and anoles, through mouse and man, to zorillas and zebras.
A story that used to be told in the coffee rooms concerned Sir John Gaddum FRS at a time when he was assistant to who was to be become Sir Henry Dale OM PRS, Director of the National Institute of Medical Research. Dale had a long interest in the hormones of the posterior pituitary.
The two mammalian hormones, vasopressin and oxytocin, had recently been partially (but not completely) separated from pituitary extract and Gaddum, appointed by Dale in 1927, had the job of comparing their effects on blood pressure. In contrast to mammals in which an injection of vasopressin causes and increase in blood pressure, hence the -pressin part of the name, Gaddum found in a chicken that vasopressin* caused a decrease in blood pressure. Thinking he ought to check the finding, he approached Dale for permission to buy another chicken or two.
Dale’s reply and point-blank refusal went along the lines of: Why on earth would you want another? Did you not do the experiment properly? Being assured by Gaddum that the experiment had been technically fine, Dale continued: If the result was observed and even if you had another dozen chickens in which you had the opposite result, you would still have to explain why you found a decrease in blood pressure in that chicken. So no, I cannot let you waste your time and the Medical Research Council’s money. No more chickens.
Had Dad's Army been on television on a still-to-be-launched television service I think we can envisage Dale adding, 'Stupid boy'.
This recording of blood pressure (shown then as now in mm of mercury) before and after an intravenous injection of vasopressin in an anaesthetised chicken was made on a smoked drum. From Gaddum's 1928 paper.
I suspect Gaddum, who became the expert on statistical treatment and design of bioassays, must have told the story himself to members of the Institute of Animal Physiology (now the Babraham Institute) when he was Director from 1958 until shortly before his death in 1965.
I shudder to think how many important findings are missed by the modern obsession with repeatability and statistical treatment of data before, during and after an experiment. If you cannot repeat a finding you have to be able find an explanation of why you cannot repeat it, and that explanation may itself be of biological significance. Perhaps that should be called the Dale-Gaddum rule?
What has become known as Doonfoot Lagoon in Ayrshire has provided a great deal of excitement for birders and photographers. This year, as well as in 2017, a Spotted Crake (Porzana porzana), a scarce summer visitor to Britain from its wintering grounds in Africa was not only in residence but could easily be seen.
What most people visiting the locality do not realise is that the ‘lagoon’ has formed relatively recently in an area once inundated by the sea at high tide. Water flows into and out of the lagoon from the River Doon which enters the Firth of Clyde at this point on the coast. To illustrate how recent it is I have downloaded present and historic satellite views from Google Earth and brought them roughly to the same scale (judged by the length of the nearby car park). The photographs were of course taken at different states of the tide in the various years but at the start of the series (1999) the sea reached the sand dune in front of the car park. There was no lagoon at all. On the latest photograph available (2018) not only can the lagoon be seen virtually in its present state but also the presence of a now large and vegetated sand dune on its seaward side.
In the intermediate years, a shallow area filled with water, often containing seaweed or with seaweed round the edges (which rotted with that characteristic aroma) formed on occasion but was then sometimes washed away by the sea. That is what appears to be present in the 2005, 2007 and 2011 photographs. It was sometime between 2011 and 2016 that the lagoon in its present state formed, as the dune on the seaward size increased in extent.
Satellite Images from Google Earth
Flow into and out of the lagoon is now confined to passage over a shallow bar that forms a sandy bank of the River Doon. At high water, the level of water in the lagoon appears to be the same as that in the river. As the tide ebbs, the level of water in the lagoon falls.
At high tide, the water level in the 'lagoon' (left foreground) equals that in the River Doon (flowing right to left)
Having seen the various changes at Doonfoot over the past 42 years and the recent formation of the lagoon, I had always assumed the water in it would be brackish. Over the past couple of years though I began to think that, with the changing vegetation and the fact that terrestrial birds like starlings can be seen bathing in it, the salinity may be low, not qualifying even for the term ‘brackish’.
I should say at this point that I do have some proprietary interest in marine birds and their existence on salt water, having written a monograph on salt glands in the 1970s and having worked for ten years on how those glands work to remove salt, ingested as part of their food or by drinking salt water, from the blood. Because salt glands need a lot of energy I often look at birds in estuaries and look for clues as to whether the salt glands are working at the time, drips off the end of the beak, swelling over the salt glands in the head, for example.
Having been fooled before about the salinity of a pool at the top of a sandy beach in Hong Kong which contained tadpoles (it was fresh water), I decided to measure the salinity of the lagoon. Having had, for 40 years, access to laboratory equipment that would have provided the answer I rather grudgingly had to buy the cheapest but best tool to do the job—a refractometer. Amazon soon had one at my door which on checking the calibration proved to have been set spot on at the factory somewhere in China.
To cut to the chase, the salinity of the lagoon was indistinguishable from Ayrshire tap water; no sign of any degree of saltiness. I also took sample from the wash over the entrance to the lagoon and from the river to the seaward side of the lagoon. Again, they were all fresh water. By contrast, at the point where on the day waves were starting to break on the shore, the salinity was 2%* (Atlantic sea water is around 3.5%). These samples were taken at high tide on 10 September. At low tide on 12 November, the lagoon and its outflow was fresh. I then walked to the furthest point of the beach I could reach seaward to the south of the lagoon to take a water sample there. It was full-strength (3.5%) sea water.
Salinity measurements mapped to GPS co-ordinates on Google Earth
What seems to be happening is that the lagoon fills from and empties into the river at a point which at high tide is above the mixing zone of fresh water flowing down the Doon and sea water in the Firth. With the incoming tide the level of the river rises not as a result of a movement of salt water but of a backup of river water. Therefore, the lagoon is partially flushed with fresh water twice a day, which would account for the fact there is no residual salt. I took the samples at times when rainfall and therefore flow down the Doon was and had been high. I am interested to see what happens on a high storm-driven tide at a time when flow down the river is relatively low. Will the mixing point be further upstream and will the lagoon turn brackish as a result? If it does, then my guess is that the salt water would soon be washed out when things returned to what appears to be the present normal state.
The appearance of bulrushes or reedmace (Typha latifolia) also gives some indication of salinity. Although it will tolerate slightly brackish water, there is in the north American populations tested a major reduction in the length of the leaves when the salinity is raised from 0 to 0.4%.
The mixing of water from rivers entering the sea is complicated. Satellite photographs show that the river water still forms a discrete moving mass well into the Firth (and birds like swans are often lined up along the flow, feeding on whatever is being brought down). Depending on the temperature difference there may be a layering of less dense fresh water over the salt. I must at this point thank Robin Turner in a discussion on Ayrshire Birding for pointing out a useful website on what happens when rivers meets the sea.
This image from Google Earth shows the channel into the Firth of Clyde made by the River Doon
The formation of the ‘lagoon’ raises several questions:
Will the ‘lagoon’ remain or will it and the sand dune which protects it be washed out in the future with the coast returning to the state it was in 1999?
Has a freshwater ‘lagoon’ formed previously and then been washed out?
Is its presence part of the phenomenon of rebound from the ice ages (with falling sea levels) in northern Britain?
Is it increasing in length?
Are changes at the mouth of the Doon connected with the state of the numerous weirs and/or flow from the dammed Loch Doon?
I find it difficult to know what to call the Doonfoot ‘lagoon’. By some definitions, since it is not sea water, it cannot be called a lagoon. Perhaps ‘inlet’ would be more appropriate.
Finally, a biological question: how do birds like the Spotted Crake—which fly by night—find a suitable habitat in which to land and live? Do they use the sense of smell to detect plants or rotting fresh water vegetation, for example? Whatever the mechanism, there is no doubt that Water Rails (Rallus aquaticus), as well as the occasional Spotted Crake, soon found this entirely new location and moved in.
*I am using percentage (%) to express salinity. Geographers and industry usually uses parts per thousand (0/00) while physiologists work in molarity or molality. Percentage is most easily understood by all.
Peaker M, Linzell JL. 1975. Salt Glands in Birds and Reptiles. Cambridge: Cambridge University Press
The second paragraph of Sir Vincent Wigglesworth’s (1899-1994) biographical memoir for the Royal Society reads:
His father was imaginative, encouraging his children to collect material for demonstrations such as the microscopic life in a drop of pond water or the circulating corpuscles in the web of a frogs foot. Many years later, V.B.W. mentioned the fascination of the frog preparation to Sir Charles Sherrington, then living in Master’s Lodge at Caius. He said he used it as the ‘acid test’ for identifying research students. Less dedicated students glanced down the microscope and passed on, but future ‘physiologists’ were unable to tear themselves away from the view of blood cells bustling along capillaries.
I am delighted to report that I unknowingly passed Sherrington’s test too. I was given what was little more than a toy microscope around the age of fifteen and was transfixed first by watching the blood circulation in a tadpole’s tail and then a frog’s web.
An old school friend dug this out of his loft before moving house earlier this year. We had identical microscopes made by J & L Randall under the trading name of SEL (Signalling Equipment Ltd). The magnification was fixed at 100x. My father made a case for both of us but mine along with the microscope have long gone
Sir Charles Sherrington (1857-1942) (Wellcome Images)
I looked for a good demonstration on YouTube or in commercial libraries; they can be found with a simple Google search. However, I was disappointed since the magnification used is sometimes too great and the ability to rack the focus up and down is missing. The extraordinary contortions of the red cells are evident as well as some of the jostling as vessels branch. But there is nothing like the real experience.
In the Wellcome Library’s collection I did find an old gem, made in 1923, shot in black-and-white. One of the photographers was August Krogh (1974-1949), the Nobel Laureate famous for his work on control of capillary circulation.
Liddell EGT. 1952. Charles Scott Sherrington 1857-1952. Biographical Memoirs of Fellows of the Royal Society 8, 241-270
Locke M. 1996. Sir Vincent Brian Wigglesworth, C. B. E., 17 April 1899 - 12 February 1994. Biographical Memoirs of Fellows of the Royal Society 42, 541-553.
A fact, noted in a biography of one of them, is that all three authors of the editions of The British Amphibians & Reptiles and its successor in the Collins New Naturalist Series published from 1951 onwards were medically qualified
There was very little academic interest in reptiles and amphibians in Britain. Yes, of course, there were the famous herpetologists at the Natural History Museum in London but their interests in the 20th century were taxonomy and systematics, again not of burning interest to the biologists of the day. And there were those using amphibians to study developmental processes and basic physiology for which the frog is ideal. Comparative studies also included reptiles and amphibians but generally only en passant. Famous British palaeontologists devoted much of their lives to reptiles and amphibians but of the physiology, behaviour and ecology of living forms there was virtually nothing. Thus in a directory of research in British universities in 1960-61, only three individual entries refer to research in herpetology (other than a very specific interest in, for example, the structure of a particular organ) or developmental biology. They were: Angus Bellairs at St Mary’s Hospital (reptilian anatomy), London, Eric T.B. Francis in Sheffield (reptilian physiology) and C.L. Smith in Liverpool (amphibian physiology).
I think there are two reasons why research on reptiles and amphibians in Britain was not a topic of interest in the universities. The first is obviously the sparsity of species. The second is that research solely on one group of vertebrates, as opposed to a wider comparative approach, might have seen to have been unimportant in that there were unlikely to be discoveries made of wide biological significance. Whatever the reasons, it is not surprising that the major advances in reptilian ecological physiology, particularly thermoregulation, were made in the U.S.A. in the middle years of the 20th century where there is a rich herpetofauna and considerable academic interest.
The man who pulled all the information of British amphibians and reptiles together, including that gathered by very gifted amateur naturalists in Britain as well as in continental Europe, was Malcolm Arthur Smith (1875-1958). He was keen on amphibians and reptiles as a child but knew the only way he could pursue that activity was by earning a living as a doctor. After qualifying at Charing Cross Hospital and practice in London he went off to Bangkok as medical officer to the British Legation. That job was then extended to physician to the royal household. During his time in Siam, now Thailand, he was active in natural history, collecting specimens and writing accounts of the herpetofauna of south-east Asia. In 1925 at the age of 50 he retired to London where he was given space at the Natural History Museum. From there until his death he published extensively particularly on the reptiles of south and south-east Asia. From its founding in 1947, Smith was president of the British Herpetological Society. It was when he was over 70 that he turned to the British herpetofauna again, with the first edition of the New Naturalist volume appearing in 1951.
Angus d’Albini Bellairs (1918-1990) was co-editor of the fifth edition onwards of Smith’s New Naturalist book. Keen in reptiles as a boy he included zoology in his pre-clinical medical course at Cambridge. After qualifying in medicine from University College Hospital, London, he served in the Royal Army Medical Corps in north Africa, Italy and Burma, collecting reptiles throughout and sending preserved specimens back to London. After the war he published two papers with Malcolm Smith. One, on the head gland of snakes, read to the Linnean Society in 1944, must have been the result of work done while he was a medical student or while he was still in the army; the material was mainly that collected by Smith in Siam before 1925. The second paper, published in 1953, was on the egg-tooth of snakes. By that time he had been appointed lecturer in the anatomy department at the London Hospital medical school by James Dixon Boyd (1907-1969) who had been one oh his lecturers at Cambridge and who had stored Bellairs’s specimens from overseas. They published a paper together. Boyd took Bellairs back to Cambridge with him in 1951 but Bellairs preferred London and faced with a heavy teaching load in human anatomy he moved to St Mary’s Hospital medical school in 1953. Many anatomy departments had interests in comparative anatomy and Bellairs became the torchbearer for academic herpetology in Britain, albeit with an emphasis on anatomy, since he was self-avowedly ignorant of the advances in physiology, behaviour and ecology.
Joining Bellairs as co-editor of Smith’s book and then the sole author of the follow-up volume in the same series, Reptiles and Amphibians in Britain, Deryk Frazer had a somewhat similar history but this time came from medicine to become a professional working in conservation via physiology. John Francis Deryk Frazer (1916-2008) was born of a professor of anatomy at St Mary’s, John Ernest Sullivan Frazer (1870-1946). Switching from maths to physiology at Oxford he qualified in medicine in 1942. For the rest of the war he served as a surgeon in the Royal Navy on the new frigate HMS Helford in the Indian and Pacific Oceans. He then became Assistant Lecturer in Physiology at St Mary’s, a famous department headed by Arthur St George Joseph McCarthy Huggett FRS (1897-1968) engaged in fetal physiology and growth. Frazer worked on factors affecting fertility in the rat which formed the basis of his London PhD thesis awarded in 1953 (a mistake in a biography mistakenly attributed his PhD to work on toad movements). From St Mary’s he moved to the department of physiology at Charing Cross Hospital medical school where his main work was again on fetal growth and survival in collaboration with Huggett. However in 1959 he ditched academia to join the Nature Conservancy where he was a member of the British delegation at the first CITES convention. He did, however, continue his interests in fetal growth, publishing a paper in 1970 with the then late Professor Huggett. He continued his early interest in amphibians and reptiles into retirement particularly in Kent.
I knew both Bellairs and Frazer but only when writing this did I realise that Frazer was the older man.
Smith and Frazer from Contributions to the History of Herpetology (see below); Bellairs from Herpetological Journal
It was not unusual, of course, for those in medical practice to indulge in biological hobbies but the involvement of the the three authors was something on a much greater scale. Britain’s medical schools, which I have to explain were and are very different from those, say, in the U.S.A., produced many qualified doctors who did not want to become doctors in the first place but persisted under parental pressure, were attracted to biological research but who finished their clinical studies in order to gain a qualification, or who simply found they did not like medical practice once they had qualified. Direct entry into the biological sciences was often difficult especially for boys since biology was not taught at all in what were considered the good schools.
An example from our time as students in the 1960s was the famous insect physiologist, Sir Vincent Wigglesworth FRS (1899-1994). All his spare time as a medical student was spent studying insects. Medical graduates turning to zoology were always described as ‘having seen the light’.
Biographies of all three are in the three volumes of Contributions to the History of Herpetology, edited by Kraig Adler, Society for the Study of Reptiles and Amphibians.
Frazer D. 1983. Reptiles and Amphibians in Britain. London: Collins
Smith M. 1951. The British Amphibians and Reptiles. London: Collins
I have written previously (here) about the Tamaraw (Bubalus mindorensis), the small buffalo found only on the island of Mindoro in the Philippines and of how I had seen one in Manila Zoo in 1967. When I wrote that article I had found that an attempt to create a captive-breeding group of this critically endangered species had failed. Yesterday I read in the latest edition of Keeper Contact (165, November 2020) that the last animal in that group had died:
An interesting observation of fluorescence in ultraviolet (UV) light has been reported in museum specimens of the Platypus (Ornithorhynchus anatinus); the fur shone green-cyan. The Platypus has thus joined a handful of other mammals in displaying this phenomenon.
The functional significance, if any, remains unknown. The authors come up with a suggestion that absorption of UV (with emittance of light of longer wavelengths) might reduce the animal’s visibility to predators equipped with an ability to see UV. How this might work in a crepuscular or nocturnal animal I do not know. Or it could it could increase visibility of one platypus to another platypus by shifting invisible UV radiation to the visible range as darkness falls. Or it could have no biological significance whatsoever, being merely a physical property of the fur that has not been selected against; an epiphenomeon, in other words.
An example I quote when talking about animal coloration is that biochemical pathways that produce coloured compounds may be selected against in animals that live in daylight. By contrast in the lightless depths of the ocean or in caves an animal can be any colour. It just does not matter. If a biochemical pathway advantageous to, say, conserving energy, were to produce a colourful compound as an intermediate, it would be of no consequence. Similarly, blind cave fish or salamanders are often white. Why waste energy producing pigment when nothing can see them?
As I was writing this Jerry Coyne has also commented on this paper here. He also raises the possibility that it is a biological epiphenomenon.
This is clearly a phenomenon to investigate even if it turns out to be biologically unimportant. I can already envisage a few Australians out in the bush shining a UV lamp at platypuses in the water. If I were there I would be. I like watching them anyway, having been lucky enough to see them wherever we went looking for them in Queensland and Tasmania.
I must also tell my physicist friends. Just what is it in the fur of these few species that is acting as fluorophore?
Anich PS, Anthony S, Carlson M, Gunnelson A, Kohler AM, Martin JG, Olson ER. 2020. Biofluorescence in the platypus (Ornithorhynchus anatinus). Mammalia https://doi.org/10.1515/mammalia-2020-0027 published online October 15, 2020
The freshwater chelonians, terrapins in English usage and turtles in American, of China and south-east Asia generally are in big trouble. Extensive trade for the human food and ‘medicine’ markets, the pet market, as well as loss of habitat have brought many to the status of ‘Endangered’.
As a result of reading a paper on one of the species in Vietnam I found a video taken recently in Hong Kong of Beale’s Terrapin, Sacalia bealei, where they are very rare and strictly protected. They are nocturnal, occurring in and around mountain streams. The location of sightings is being kept secret because it is thought poaching may still be going on.
Beale’s Terrapin was first described and named by John Edward Gray at the British Museum in 1831. Of the members of the Beale family who worked in India and China, the most likely candidate for the eponym is Thomas Beale (ca 1775-1841) a wealthy merchant in Macau who kept a large collection of exotic birds, including a bird-of-paradise, at his mansion. He with his partners in Magniac & Co (which morphed into the mighty hong, Jardine, Matheson & Co) dealt in opium, cotton and tea. For a time he was immensely wealthy but after dealing in opium futures and investing in some dodgy businesses in Brazil he ended up owing the East India Company the equivalent of many millions of pounds. His body was found washed ashore several weeks after he disappeared from his house.
John Reeves (1774-1856) sent the specimens back to London. He was working largely in Macau as Inspector of Tea for the East India Company. Gray named Reeves’s Terrapin, Chinemy reevesi, after him, also in the 1831 publication.
The species is sometimes called Beale’s Four-eyed Terrapin because of the eye-like spots on the top of the head. However, since another currently-recognised species from further south in China, Laos and Vietnam, Sacalia quadriocellata, is usually known as the Four-eyed Terrapin, it seems better just to use Beale’s for the species from further north. Just to confuse matters, the two were often considered the same species with the Four-eyed as Sacalia (originally Clemmys) bealei quadriocellata). Both forms have four ‘eye’ spots. Mitochondrial DNA analysis suggests two species but I am not wholly convinced they constitute more than one’ biological species’.
It was not until 1977 that one was found in the wild in Hong Kong, or at least recognised as such, a point I will come back to later.
My mind was taken back to late 1966 or early 1967 when a lecturer in biology at Hong Kong Baptist College brought some terrapins she had bought in a market in Kowloon over on the Star Ferry to HKU. She left them for me to have a good look at. After I returned them she was going to release them somewhere in the New Territories. I know she was keeping a regular eye on the terrapins appearing in the markets and I suspect she rescued more. Unfortunately and infuriatingly, I cannot remember her name and our correspondence has also been lost.
The most interesting species she had acquired were Beale’s Terrapin which we could see seemed to occur in two colour forms. I see that this variation is now ascribed to a difference between the sexes. The male is what was called the ‘pink’ form, with dark brown or black with dark spots and squiggles especially on the leading edge. The neck has pink stripes and the iris of the eye is also pink. The female is the ‘yellow’ form; the carapace is yellowish-brown; the stripes on the neck are yellow, as is the iris.
We photographed the individuals on the roof of the later-demolished Northcote Science Building. Unfortunately I used Agfacolor CT18 film which deteriorates markedly with age. However, I have three photographs which are worth showing here. The ocelli or eye spots can be seen in what is obviously a female—a feisty female. She shot her neck out to bite the rubber gloves my wife had in her hand and was about to put on since she was trying to keep her hands dry while terrapin wrangling. The rubber gloves make an accidental appearance in several photographs at that time since her (wife, not terrapin) hands were suffering the effects of exposure to the histologist’s favourite solvent, xylol (xylene). The ones I photographed were around 13 cm or 5”, not far off the maximum length of about 18 cm.
Beale's Terrapin - male
Same individual as above
Beale's Terrapin - female Note the 'eye' spots on top of the head
It was impossible to find out if the ones that appeared in the Kowloon market (we never saw this species in Hong Kong Central Market which we kept an eye on if in town) had been caught in Kong Kong or had been brought in from China. Since they had not then been found in the wild in Hong Kong we assumed they had been brought over the border.
More information and modern photographs can be found here.
This is the video I found:
While it is true that the number of people looking for reptiles in Hong Kong increased markedly in the 1970s, with many more species, especially snakes, being found, I cannot help wondering how many Beale’s Terrapins my friend bought in the market and then released. And did others do the same? So is it just within the bounds of possibility that at least some of the Beale’s Terrapins living in Hong Kong are descended from those released individuals? Could there have been an unrecorded but successful re-introduction?
Beolens B, Watkins M, Grayson M. 2011. The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins
Karsen SJ, Lau M W-N, Bogadek A. 1998. Hong Kong Amphibians and Reptiles. Second Edition. Hong Kong: Provisional Urban Council
Le MD, McCormack TEM, Hoang HV, Duong HT, Nguyen TQ, Ziegler T, Nguyen HD, Ngo HT. 2020. Threats from wildlife trade: The importance of genetic data in safeguarding the endangered Four-eyed Turtle (Sacalia quadriocellata). Nature Conservation 41, 91-111. https://doi.org/10.3897/natureconservation.41.54661
