Concerning the cohabitation of animals and algae – an English translation of K. Brandt’s 1881 presentation “Ueber das Zusammenleben von Thieren und Algen”

Abstract

Keywords Symbiosis . Cnidaria . Zoochlorella . Zooxanthella . Coral Reefs . Hydra IntroductionBThis investigation shows that self-formed chlorophyll is absent in animals. If chlorophyll can be found in animals, it is due to invading plants that have kept their morphological and physiological independence^. This conclusion, published by the German botanist Karl Andreas Heinrich Brandt in 1881, represents the final quintessence of a number of ideas and experimental findings in the field of symbiosis research at that time. Karl Brandt, corroborating and adding to the work of others, determined through observational and experimental evidence that the green and yellow cells in some marine and freshwater animals were indeed independent organisms that live together with their host.One of the fundamental topics of endosymbiotic research in the second half of the nineteenth century concerned the presence of green pigment in animals. This simple observation sparked two related and far-reaching questions: (1) Does this colouration indicate the presence of plant chlorophyll? And if so, (2) is this chlorophyll of endogenous animal origin, remnant of ingested food, or due to the presence of chlorophyllcontaining microorganisms? Siebold (1849) had already stated that the greenish bubbles and grains in Hydra, Turbellaria and some infusoria Bare likely closely related to chlorophyll, if not identical^, but it was only later that chemical and spectroscopical characterization confirmed the presence of chlorophyll in these animals (reviewed in Buchner 1953). In addition to the general interest in green animals, the British biologist Thomas Huxley initiated another line of research, when he made a rather unremarkable observation about the occurrence of Bspherical bright yellow cells^in the colonial radiolarian Thallasicolla while on board the H.M.S. Rattlesnake (Huxley 1851). Things became particularly interesting when Leon Cienkowski reported that these yellow cells continued to grow and divide even after the degradation of the radiolarian colony. Although Cienkowski did not explicitly state their independent nature, he did pose a fundamental question: do the yellow cells really have to be regarded as an essential part of the radiolarian body? (Cienkowski 1871). Surprisingly, the obscure nature of both green and yellow cells and their relationship with both marine and freshwater organisms was more or less resolved within a 7-year period between 1876 and 1883, thanks to a series of independent experiments and observations mainly put forward by Géza Entz, Richard and Oscar Hertwig, Patrick Geddes, and Karl Brandt.Karl Brandt presented his findings in two presentations in 1881, the first to the Berlin Physiological Society on the 11th of November and the second to the Berlin Society of Friends of Natural Science on the 15th of November. His presentation entitled BUeber das Zusammenleben von Thieren und Algen( Concerning the cohabitation of animals and algae) was subsequently published three times in near-identical form by the...

Validation and description of Symbiodinium microadriaticum, the type species of Symbiodinium (Dinophyta)

“…Loeblich and Sherley () argued that the name Symbiodinium was a subjective synonym of Zooxanthella and made the combination Zooxanthella microadriatica , also invalid. However, they failed to realize that the dinoflagellates living in symbiosis with pelagic radiolarians, originally named Zooxanthella by Brandt (Krueger ), were dissimilar to the symbionts found in cnidarians. Probert et al.…”

“…Loeblich and Sherley (1979) argued that the name Symbiodinium was a subjective synonym of Zooxanthella and made the combination Zooxanthella microadriatica, also invalid. However, they failed to realize that the dinoflagellates living in symbiosis with pelagic radiolarians, originally named Zooxanthella by Brandt (Krueger 2017), were dissimilar to the symbionts found in cnidarians. Probert et al (2014) showed definitively that dinoflagellates associated with many polycystine radiolarians, including Collozoum inerme examined by Brandt 1881, are members of the order Peridiniales, and thus extremely divergent from Symbiodinium in the order Suessiales.…”

Revival of Philozoon Geddes for host-specialized dinoflagellates, ‘zooxanthellae’, in animals from coastal temperate zones of northern and southern hemispheres

“…Karl Brandt (1881) published the first detailed papers to formally describe the yellow cells found in protists (Radiolaria) and in animals. In these, he established the genus Zooxanthella K.Brandt and coined the term "zooxanthellae" (Krueger, 2016). The experiments of Patrick Geddes on these 'yellow' cells supported Brandt's findings, and included characterization of their cell wall composition and demonstrated how animals with them were photosynthetic when exposed to light (Geddes, 1882a).…”

The influence of nutrient availability on the thermotolerance of symbiotic dinoflagellates of family Symbiodiniaceae

“…In 1881, the endosymbiotic dinoflagellates of family Symbiodiniaceae were originally taxonomically defined as members of the novel genus Zooxanthella (Krueger, 2017), of which there was considered to be only a single species. Kawaguti (1944) observed that the coccoid symbionts of the reef coral Acropora corymbosa, formed gymnodinioid-like zoospores when in culture, and he therefore assigned them to the dinoflagellate genus Gymnodinium.…”