Anderson, Robert G.

Sinclair, Clarence B.

English

UARK (University of Arkansas )

Journal of the Arkansas Academy of Science Volume 20 Article 8 1966 Additional Information on Basicladia crassa Hoffmann and Tilden Robert G. Anderson University of Missouri - Kansas City Clarence B. Sinclair University of Arkansas at Little Rock Follow this and additional works at: https://scholarworks.uark.edu/jaas  Part of the Biology Commons, and the Terrestrial and Aquatic Ecology Commons Recommended Citation Anderson, Robert G. and Sinclair, Clarence B. (1966) "Additional Information on Basicladia crassa Hoffmann and Tilden," Journal of the Arkansas Academy of Science: Vol. 20 , Article 8. Available at: https://scholarworks.uark.edu/jaas/vol20/iss1/8 This article is available for use under the Creative Commons license: Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0). Users are able to read, download, copy, print, distribute, search, link to the full texts of these articles, or use them for any other lawful purpose, without asking prior permission from the publisher or the author. This Article is brought to you for free and open access by ScholarWorks@UARK. It has been accepted for inclusion in Journal of the Arkansas Academy of Science by an authorized editor of ScholarWorks@UARK. For more information, please contact scholar@uark.edu. 1 25*Arkansas Academy of Science Proceedings, Vol. 20, 1966ADDITIONAL INFORMATION ON BASICLADIA CRASSAHOFFMANN AND TILDENRobert G. Anderson and Clarence B. SinclairThe University of Missouri at Kansas City andLittle Rock University, respectivelyThe alga Basicladia was given generic status by Hoffman and Tilden(1930) following the work of Collins (1907) and Tiffany (1926). Hoff-mann and Tilden described the two species B. crassa and B. chelonum,the latter having been identified by Collins (1907) as Chaetomorphachelonum. Tiffany (1926), as well as Hoffmann and Tilden (1930),described reproduction by means of biflagellated zoospores. The latterauthors, as well as Smith (1950, p. 218), apparently were in doubt asto whether these biflagellated cells were zoospores; but, none the less,used the term "zoospores?". Leake (1938) saw biflagellated motilecells but was uncertain whether they were zoospores or gametes. Sheindicated the filaments would not grow in water culture. Leake (1946)later described aplanospore and zcospore germination within 3-4 daysin hanging drop preparations. Kusunoki (1944) described and illustrateddeveloping sporangia and the release of large and small zoosporesthrough lateral papillae.Hamilton (1948), using a series of line drawings, described thereproductive process as the release of biflagellated, spindle-shapedgametes from a parent-cell. These gametes were of the same approxi-mate size as the motile cells described by Leake (1938). The gametesfused anteriorly to result in a spindle-shaped zygote with four (4) anter-ior flagella. If the gametes failed to fuse, they swam for 1-3 minutes,became spherical, lost their flagella, and degenerated in a few hours.Ducker (1958) described B. ramulosa as a new species obtainedfrom the back of an Australian fresh water turtle. She pointed out anincreasing morphological complexity from B. chelonum B. crassa¦ B. ramulosa, with B. ramulosa being more highly branched and fila-mentous than the other two species. Ducker did not, however, includein this series B. sinensis as described by Gardner (1937).Up to this point Basicladia has been described as growing only onthe carapace of turtles. Proctor (1958) succeeded in culturing Basicladiaon an inorganic-soil extract agar medium. The organism also grew onsponge and carapace, and "spread by means of zoospores, and possiblygametes." These flagellated structures were seen to migrate to thewalls of the glass container and to make loose attachment from whichthey were easily dislodged resulting in death of the alga. Proctorsuggested that the physical structure rather than the chemical composi-tion of the shells of turtles was important in limiting the distribution ofthe alga. He stated that pure cultures of the organism were neededfor accurate information on possible nutritional requirements. Normandin25Journal of the Arkansas Academy of Science, Vol. 20 [1966], Art. 8Published by Arkansas Academy of Science, 196626Arkansas Academy of Science Proceedingsand Taft (1959) showed that B. vivipara, a new species, grew on theshell of the snail Viviparus malleatus Reeve. Explants of the alga fromthe snail grew well on culture media containing scrapings of turtlecarapace. The reverse situation, i.e., Basicladia from turtles' backs,showed no appreciable growth in culture on shell scrapings of snail.The authors suggested the possibility of a minimum and specific growthsubstance existing in the snail shell material. They also stated thatthe cells releasing reproductive cells "should probably be considered asbeing sporangia."In a motion picture study produced in 1964 by the Film ProductionUnit and the Department of Botany and Plant Pathology at Iowa StateUniversity, the release of the zoospores of Basicladia was well illustrated.(Liberation of zoospores in the alga Basicladia. The Ealing Corporation,Cambridge, Mass.)It seems obvious to the writers that the true nature of the flagel-lated cells is unknown and for this reason these cells willbe referredto in this work as reproductive cells.This paper will present new evidence and illustrations of certainmorphological features of B. crassa. This investigation was carried outat the University of Missouri at Columbia during the summers of 1962-1963 on material from Du Quoin, III., supplied by David Norton, agraduate student in the N. S. F. Summer Institute. Acknowledgementis extended to him for his valuable assistance.The turtles upon which the alga was growing were identified asmale specimens of the western painted turtle, Chrysemys picta bellii(Gray), by Dr. R. S. Campbell of the Zoology Department of the Uni-versity of Missouri at Columbia. The turtles were collected at the fair-ground lake in Du Quoin, III., placed in a small darkened aeratedcontainer and transported to Columbia in the trunk of a car. The algafrom the turtles was examined after being in darkness for periods ofeight (8) to thirty-two (32) hours, and photographs were made. ThepH of the water in which the turtles were maintained and in which thealga was examined ranged from 6.9-9.0. All photographs were madewith a Spencer AO Microstar Microscope on Panatomic-X film.The general vegetative morphology observed is the same as thatpreviously described by Hoffmann and Tilden (1930), Hamilton (1948)and Smith (1950, p. 217). The alga has a rhizoidal system, modifiedas a holdfast, from which arise infrequently-branched multicellular fila-ments. The cells have a reticulate chloroplast and intercalary cell divi-sion was observed by the writers. Nowhere in the literature, however,is there mention of the cytokinetic process in the vegetative cells ofBasicladia. Fig. 4 shows that wall formation proceeded centripetally.This process pinched the chloroplast and cytoplasm into two nearly equalportions. A few terminal portions of the filaments were observed, andthe shape of the terminal and adjacent cells suggests terminal celldivision.26Journal of the Arkansas Academy of Science, Vol. 20 [1966], Art. 8https://scholarworks.uark.edu/jaas/vol20/iss1/8"27•Information on Basicladia crassaThe rhizoidal system of a single filament was highly interwovenwith those of other filaments. A complete individual rhizoidal systemwas difficult to observe for the above reason. In a few cases chloroplastswere observed in the rhizoidal outgrowths, but photographs showingthese chloroplasts could not be obtained. Walls of cells near therhizoidal system were thicker than cell walls in the upper portions ofthe filaments, and these walls were lamellated. Lamellated cell wallswere not as apparent on the vegetative and parent-cells as on cells inthe basal regions.Reproduction is initiated by the transformation of a vegetative cellinto a parent-cell. These parent-cells develop one or more papillae atvarious loci through which the motile cells may eventually escape.Papillae develop simultaneously on numerous adjacent cells. A papillabegins development as a blunted angular protrusion but soon becomessomewhat dome-shaped. Wall thickness of the papilla and that of thereproductive cell from which it is produced are approximately the samethroughout. The terminal portion of the dome-shaped projection com-pleled its development 12-15 minutes after slide preparation and gela-tinized preparatory to reproductive cell release. That more than onepapilla per cell may develop was observed in a few cases, and cellswith two (2) open papillae were observed. The parent-cell prior toeruption was highly granular, making it difficult to recognize individualreproductive cells, and there were no apparent swimming movements.The most commonly observed method of release of reproductivecells was the forceful eruption of flagellated motile cells. The earliestreleased cells were surrounded by a gelatinous membrane which soondisintegrated; latter members from the same parent-cell escaped in-dividually by swimming movements and were compressed while movingthrought the cell aperture (Figs. 1, 2). Measurements of the cell apertureof an individual parent-cell in enlarged photographs showed an increasein diameter during this escape; however, the length and width of theparent-cell remained essentially the same. Thus it would seem thatthe wall material surrounding the aperture is not of the same con-sistency as the adjacent wall material. Figs. 1 and 2 show part of therelease sequence. The above release sequence was photographed afterthe alga had been subjected to a twenty-seven (27) hour dark period.Similar release sequences were observed after an eight (8) hour darkperiod and after dark periods ranging through thirty hours.The motile reproductive cells are biflagellated, spherical to slightlyellipsoidal, with a somewhat crescent-shaped red eyespot and appearto contain many irregularly shaped parietal chloroplasts arranged poster-iorly to give a cuplike form. The flagella are located at the anteriorend which is devoid of chloroplasts (Fig. 6). The red eyespot was ob-served at different locations in the cell on both sides of the equatorialplane, but not at the extreme anterior or posterior ends. These motilecells vary in diameter from 10-20 p. Hamilton (1948) stated that thereproductive cells escaped with flagella trailing, but after escaping,swam anterior end first. This observation was confirmed by the writers27Journal of the Arkansas Academy of Science, Vol. 20 [1966], Art. 8Published by Arkansas Academy of Science, 1966'28Arkansas Academy of Science Proceedings(Fig. 2); however, cells were also observed leaving the parent-cellflagellar end foremost (Fig. 1).The writers also observed, after a thirty-two (32) hour dark period,a rather unusual release of reproductive cells. This consisted of the re-lease, through the pore of the papillae, of various sized masses offlagellated cells which adhered to each other without subsequent dis-junction. These did not exit forcefully, but were released in a slow,outpouring manner, with each mass being constricted as it passedihrough the pore (Fig. 3). Each cellular mass was surrounded by agelatinous material. The most striking characteristic of this entire groupof cells was the absence of flagellar activity, although flagella weredefinitely present. It has been suggested to the writers that the releaseof these cellular masses was the result of a physiological imbalanceinduced by the unusual environmental conditions. Actively swimmingcells were rarely seen after a thirty-two (32) hour dark period.Some reproductive cells, which were never released, were alsoobserved in parent-cells which had either closed or open papillae.In the summer of 1963, quadriflagellated reproductive ceils withred eyespots were seen on several occasions and were photographed(Fig. 5a, b). This is the first recorded evidence of quadriflagellatedreproductive cells in Basicladia. The release sequence for these cellswas similar to that of the biflagellated cell release.DISCUSSIONMany writers— Leake (1948), Hoffmann and Tilden (1930), andSmith (1950)—indicated that the biflagellated reproductive cells whichescaped from the parent cell of Basicladia were zoospores. However,Hamilton (1948) recorded the fusing of these same types of structuresand stated that they were gametes. Hamilton also stated that theorganism was homothallic. Smith (1950, page 214) stated thatCladophora reproduced asexually by means of quadriflagellate zoo-spores. Fritsch (1956) stated that certain species of Cladophora andRhizoclonium produce biflagellated zoospores. Prescott (1962) statedthat biflagellated zoospores are common, especially in Cladophora.These organisms, along with Basicladia, all belong to the OrderCladophorales (Smith, 1950; Fritsch, 1956; & Prescott, 1962). Hamilton(1948) did not report the presence of zoospores in Basicladia in hisstudies. At no time during our investigations did we see fusion of anyreproductive cells although two (2) to several cells were observed ad-hering in masses. The presence of both biflagellated and quadriflagel-lated reproductive cells without subsequent fusion only further serves to .indicate the lack of understanding of the nature and function of thesecells. The aplanospores described by Leake (1946), and the captivecells seen by Hamilton (1948) may very well be different time stagesof the same type structure. We did not observe and nowhere in theliterature is mention made of the presence of akinetes.28Journal of the Arkansas Academy of Science, Vol. 20 [1966], Art. 8https://scholarworks.uark.edu/jaas/vol20/iss1/829iInformation on Basicladia crassaThe factors responsible for the forceful and/or extrusive release ofreproductive cells are unknown. Actively swimming reproductive cellswhich remained within the parent-cell eventually escaped by autonomousmovements. Although there was some apparent synchronization ofrelease of biflagellated cells from groups of three or four parent-cells,there was no observable acropetal or basipetal sequence of release. Itis probable that this release of reproductive cells is the result of lightstimulus (Hamilton, 1948). The time of actual reproductive cell forma-tion (prior to, or after, light stimulus) within the parent cell is not known.The authors have shown that papillae formation occurs during the first15 minutes of the light period.SUMMARYObservations and photographs of Basicladia crassa are presented.The vegetative cells have a reticulate chloroplast and divide by con-strictive cytokinesis; cell division is intercalary and also appears to beterminal. Rhizoidal outgrowths from the basal cell may or may nothave chloroplasts. The reproductive parent-cells were formed fromvegetative cells and were seen to release both biflagellated and quad-riflagellated motile cells. Quadriflagellated reproductive cells are re-ported for the first time for this organism. The flagellated cells werereleased through pores of rapidly formed papillae by means of forcefulexpulsion and by autonomous swimming movements, and an extrusive,slowly escaping movement. Some reproductive cells were never re'easedfrom the parent-cells.LITERATURE CITEDCollins, F. S. 1907. Some new green algae. Rhodora. 9:197-202.Ducker, Sophie C. 1958. A new species of Basicladia on Austral-freshwater turtles. Hydrobiologia. 10:157-174.Fritsch, F. E. 1956. The structure and reproduction of algae. Vol. I.Cambridge University Press.Gardner, N. L. 1937. A new species of Chaetomorpha from China.Madrono. 4:28-32.Hamilton, John Meacham. 1948. Sexual reproduction in the genusBasicladia (Thallophyta, Chlorophyceae). Trans. Amer. Microsc.Soc. 67:201-205.Hoffmann, Wm. E., and Josephine E. Tilden. 1930. Basicladia, a newgenus of Cladophoraceae. Bot. Gaz. 89:374-384.Kusunoki, Seikan. 1944. Zur fortpflanzung der konjugaten, IIIUnter-suchungen uber besondere amoboide zustanda von zoosporen.(Basicladia crassa und andere). Cytologia. 13:297-322.Leake, Dorothy V. 1938. Preliminary note on the production of motilecells in Basicladia. Proc. Oklahoma Acad. Sci. 19:109-111.29Journal of the Arkansas Academy of Science, Vol. 20 [1966], Art. 8Published by Arkansas Academy of Science, 1966¦30IArkansas Academy of Science Proceedings1946. Studies of development and germina-tion of aplanospores and zoospores of Basicladia crassa, Hoffmannand Tilden. Amer. Jour. Bot. 33:823-824.Normandin, Robert F., and Clarence E. Taft. 1959. A new species ofBasicladia from the snail Viviparus malleatus, Reeve. Ohio Jour.Sci. 59:58-62.Prescott, G. W. 1962. Algae of the Western Great Lakes Area. Wm.C. Brown Co. Inc., Dubuque, Iowa.Proctor, Vernon W. 1958. The growth of Basicladia on turtles. Ecology.39:634-645.Smith, Gilbert AA. 1950. The fresh-water algae of the United States.Second edition. McGraw-Hill Book Company, Inc., New York.1955. Cryptogamic Botany. Vol. I. Algaeand fungi. Second edition. McGraw-Hill Book Company, Inc.,New York.Tiffany, L. H. 1926. The filamentous algae of northwestern Iowa withspecial reference to the Oedogoniaceae. Trans. Amer. Microsc.Soc. 45:69-132.30Journal of the Arkansas Academy of Science, Vol. 20 [1966], Art. 8https://scholarworks.uark.edu/jaas/vol20/iss1/831/'Information on Basicladia crassa"igs. 1-6. -Figs. 1-2. Two cells in normal release sequence. -Fig. 1.Anterior end foremost. X43 obj. -Fig. 2. Posterior end foremost.X43 obj. -Fig. 3. Extrusive release of clumps of reproductive cells.X43 obj. -Fig. 4. Centripetal wall formation dividing reticulatechloroplast and cell into two (2) unequal parts. X20 obj. -Fig. 5.Quadriflagellated reproductive cells at a and b. X90 obj. -Fig. 6.Jiflagellated reproductive cells with crescent shaped red eyespor at a.X90 obj.31Journal of the Arkansas Academy of Science, Vol. 20 [1966], Art. 8Published by Arkansas Academy of Science, 1966

Additional Information on Basicladia crassa Hoffmann and Tilden

ScholarWorks@UARK

Journal of the Arkansas Academy of ScienceVolume 20 Article 81966Additional Information on Basicladia crassaHoffmann and TildenRobert G. AndersonUniversity of Missouri - Kansas CityClarence B. SinclairUniversity of Arkansas at Little RockFollow this and additional works at: http://scholarworks.uark.edu/jaasPart of the Biology Commons, and the Terrestrial and Aquatic Ecology CommonsThis article is available for use under the Creative Commons license: Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0). Users are able toread, download, copy, print, distribute, search, link to the full texts of these articles, or use them for any other lawful purpose, without asking priorpermission from the publisher or the author.This Article is brought to you for free and open access by ScholarWorks@UARK. It has been accepted for inclusion in Journal of the Arkansas Academyof Science by an authorized editor of ScholarWorks@UARK. For more information, please contact scholar@uark.edu, ccmiddle@uark.edu.Recommended CitationAnderson, Robert G. and Sinclair, Clarence B. (1966) "Additional Information on Basicladia crassa Hoffmann and Tilden," Journal ofthe Arkansas Academy of Science: Vol. 20 , Article 8.Available at: http://scholarworks.uark.edu/jaas/vol20/iss1/81 25*Arkansas Academy of Science Proceedings, Vol. 20, 1966ADDITIONAL INFORMATION ON BASICLADIA CRASSAHOFFMANN AND TILDENRobert G. Anderson and Clarence B. SinclairThe University of Missouri at Kansas City andLittle Rock University, respectivelyThe alga Basicladia was given generic status by Hoffman and Tilden(1930) following the work of Collins (1907) and Tiffany (1926). Hoff-mann and Tilden described the two species B. crassa and B. chelonum,the latter having been identified by Collins (1907) as Chaetomorphachelonum. Tiffany (1926), as well as Hoffmann and Tilden (1930),described reproduction by means of biflagellated zoospores. The latterauthors, as well as Smith (1950, p. 218), apparently were in doubt asto whether these biflagellated cells were zoospores; but, none the less,used the term "zoospores?". Leake (1938) saw biflagellated motilecells but was uncertain whether they were zoospores or gametes. Sheindicated the filaments would not grow in water culture. Leake (1946)later described aplanospore and zcospore germination within 3-4 daysin hanging drop preparations. Kusunoki (1944) described and illustrateddeveloping sporangia and the release of large and small zoosporesthrough lateral papillae.Hamilton (1948), using a series of line drawings, described thereproductive process as the release of biflagellated, spindle-shapedgametes from a parent-cell. These gametes were of the same approxi-mate size as the motile cells described by Leake (1938). The gametesfused anteriorly to result in a spindle-shaped zygote with four (4) anter-ior flagella. If the gametes failed to fuse, they swam for 1-3 minutes,became spherical, lost their flagella, and degenerated in a few hours.Ducker (1958) described B. ramulosa as a new species obtainedfrom the back of an Australian fresh water turtle. She pointed out anincreasing morphological complexity from B. chelonum B. crassa¦ B. ramulosa, with B. ramulosa being more highly branched and fila-mentous than the other two species. Ducker did not, however, includein this series B. sinensis as described by Gardner (1937).Up to this point Basicladia has been described as growing only onthe carapace of turtles. Proctor (1958) succeeded in culturing Basicladiaon an inorganic-soil extract agar medium. The organism also grew onsponge and carapace, and "spread by means of zoospores, and possiblygametes." These flagellated structures were seen to migrate to thewalls of the glass container and to make loose attachment from whichthey were easily dislodged resulting in death of the alga. Proctorsuggested that the physical structure rather than the chemical composi-tion of the shells of turtles was important in limiting the distribution ofthe alga. He stated that pure cultures of the organism were neededfor accurate information on possible nutritional requirements. Normandin25Journal of the Arkansas Academy of Science, Vol. 20 [1966], Art. 8Published by Arkansas Academy of Science, 196626Arkansas Academy of Science Proceedingsand Taft (1959) showed that B. vivipara, a new species, grew on theshell of the snail Viviparus malleatus Reeve. Explants of the alga fromthe snail grew well on culture media containing scrapings of turtlecarapace. The reverse situation, i.e., Basicladia from turtles' backs,showed no appreciable growth in culture on shell scrapings of snail.The authors suggested the possibility of a minimum and specific growthsubstance existing in the snail shell material. They also stated thatthe cells releasing reproductive cells "should probably be considered asbeing sporangia."In a motion picture study produced in 1964 by the Film ProductionUnit and the Department of Botany and Plant Pathology at Iowa StateUniversity, the release of the zoospores of Basicladia was well illustrated.(Liberation of zoospores in the alga Basicladia. The Ealing Corporation,Cambridge, Mass.)It seems obvious to the writers that the true nature of the flagel-lated cells is unknown and for this reason these cells willbe referredto in this work as reproductive cells.This paper will present new evidence and illustrations of certainmorphological features of B. crassa. This investigation was carried outat the University of Missouri at Columbia during the summers of 1962-1963 on material from Du Quoin, III., supplied by David Norton, agraduate student in the N. S. F. Summer Institute. Acknowledgementis extended to him for his valuable assistance.The turtles upon which the alga was growing were identified asmale specimens of the western painted turtle, Chrysemys picta bellii(Gray), by Dr. R. S. Campbell of the Zoology Department of the Uni-versity of Missouri at Columbia. The turtles were collected at the fair-ground lake in Du Quoin, III., placed in a small darkened aeratedcontainer and transported to Columbia in the trunk of a car. The algafrom the turtles was examined after being in darkness for periods ofeight (8) to thirty-two (32) hours, and photographs were made. ThepH of the water in which the turtles were maintained and in which thealga was examined ranged from 6.9-9.0. All photographs were madewith a Spencer AO Microstar Microscope on Panatomic-X film.The general vegetative morphology observed is the same as thatpreviously described by Hoffmann and Tilden (1930), Hamilton (1948)and Smith (1950, p. 217). The alga has a rhizoidal system, modifiedas a holdfast, from which arise infrequently-branched multicellular fila-ments. The cells have a reticulate chloroplast and intercalary cell divi-sion was observed by the writers. Nowhere in the literature, however,is there mention of the cytokinetic process in the vegetative cells ofBasicladia. Fig. 4 shows that wall formation proceeded centripetally.This process pinched the chloroplast and cytoplasm into two nearly equalportions. A few terminal portions of the filaments were observed, andthe shape of the terminal and adjacent cells suggests terminal celldivision.26Journal of the Arkansas Academy of Science, Vol. 20 [1966], Art. 8http://scholarworks.uark.edu/jaas/vol20/iss1/8"27•Information on Basicladia crassaThe rhizoidal system of a single filament was highly interwovenwith those of other filaments. A complete individual rhizoidal systemwas difficult to observe for the above reason. In a few cases chloroplastswere observed in the rhizoidal outgrowths, but photographs showingthese chloroplasts could not be obtained. Walls of cells near therhizoidal system were thicker than cell walls in the upper portions ofthe filaments, and these walls were lamellated. Lamellated cell wallswere not as apparent on the vegetative and parent-cells as on cells inthe basal regions.Reproduction is initiated by the transformation of a vegetative cellinto a parent-cell. These parent-cells develop one or more papillae atvarious loci through which the motile cells may eventually escape.Papillae develop simultaneously on numerous adjacent cells. A papillabegins development as a blunted angular protrusion but soon becomessomewhat dome-shaped. Wall thickness of the papilla and that of thereproductive cell from which it is produced are approximately the samethroughout. The terminal portion of the dome-shaped projection com-pleled its development 12-15 minutes after slide preparation and gela-tinized preparatory to reproductive cell release. That more than onepapilla per cell may develop was observed in a few cases, and cellswith two (2) open papillae were observed. The parent-cell prior toeruption was highly granular, making it difficult to recognize individualreproductive cells, and there were no apparent swimming movements.The most commonly observed method of release of reproductivecells was the forceful eruption of flagellated motile cells. The earliestreleased cells were surrounded by a gelatinous membrane which soondisintegrated; latter members from the same parent-cell escaped in-dividually by swimming movements and were compressed while movingthrought the cell aperture (Figs. 1, 2). Measurements of the cell apertureof an individual parent-cell in enlarged photographs showed an increasein diameter during this escape; however, the length and width of theparent-cell remained essentially the same. Thus it would seem thatthe wall material surrounding the aperture is not of the same con-sistency as the adjacent wall material. Figs. 1 and 2 show part of therelease sequence. The above release sequence was photographed afterthe alga had been subjected to a twenty-seven (27) hour dark period.Similar release sequences were observed after an eight (8) hour darkperiod and after dark periods ranging through thirty hours.The motile reproductive cells are biflagellated, spherical to slightlyellipsoidal, with a somewhat crescent-shaped red eyespot and appearto contain many irregularly shaped parietal chloroplasts arranged poster-iorly to give a cuplike form. The flagella are located at the anteriorend which is devoid of chloroplasts (Fig. 6). The red eyespot was ob-served at different locations in the cell on both sides of the equatorialplane, but not at the extreme anterior or posterior ends. These motilecells vary in diameter from 10-20 p. Hamilton (1948) stated that thereproductive cells escaped with flagella trailing, but after escaping,swam anterior end first. This observation was confirmed by the writers27Journal of the Arkansas Academy of Science, Vol. 20 [1966], Art. 8Published by Arkansas Academy of Science, 1966'28Arkansas Academy of Science Proceedings(Fig. 2); however, cells were also observed leaving the parent-cellflagellar end foremost (Fig. 1).The writers also observed, after a thirty-two (32) hour dark period,a rather unusual release of reproductive cells. This consisted of the re-lease, through the pore of the papillae, of various sized masses offlagellated cells which adhered to each other without subsequent dis-junction. These did not exit forcefully, but were released in a slow,outpouring manner, with each mass being constricted as it passedihrough the pore (Fig. 3). Each cellular mass was surrounded by agelatinous material. The most striking characteristic of this entire groupof cells was the absence of flagellar activity, although flagella weredefinitely present. It has been suggested to the writers that the releaseof these cellular masses was the result of a physiological imbalanceinduced by the unusual environmental conditions. Actively swimmingcells were rarely seen after a thirty-two (32) hour dark period.Some reproductive cells, which were never released, were alsoobserved in parent-cells which had either closed or open papillae.In the summer of 1963, quadriflagellated reproductive ceils withred eyespots were seen on several occasions and were photographed(Fig. 5a, b). This is the first recorded evidence of quadriflagellatedreproductive cells in Basicladia. The release sequence for these cellswas similar to that of the biflagellated cell release.DISCUSSIONMany writers — Leake (1948), Hoffmann and Tilden (1930), andSmith (1950) — indicated that the biflagellated reproductive cells whichescaped from the parent cell of Basicladia were zoospores. However,Hamilton (1948) recorded the fusing of these same types of structuresand stated that they were gametes. Hamilton also stated that theorganism was homothallic. Smith (1950, page 214) stated thatCladophora reproduced asexually by means of quadriflagellate zoo-spores. Fritsch (1956) stated that certain species of Cladophora andRhizoclonium produce biflagellated zoospores. Prescott (1962) statedthat biflagellated zoospores are common, especially in Cladophora.These organisms, along with Basicladia, all belong to the OrderCladophorales (Smith, 1950; Fritsch, 1956; & Prescott, 1962). Hamilton(1948) did not report the presence of zoospores in Basicladia in hisstudies. At no time during our investigations did we see fusion of anyreproductive cells although two (2) to several cells were observed ad-hering in masses. The presence of both biflagellated and quadriflagel-lated reproductive cells without subsequent fusion only further serves to .indicate the lack of understanding of the nature and function of thesecells. The aplanospores described by Leake (1946), and the captivecells seen by Hamilton (1948) may very well be different time stagesof the same type structure. We did not observe and nowhere in theliterature is mention made of the presence of akinetes.28Journal of the Arkansas Academy of Science, Vol. 20 [1966], Art. 8http://scholarworks.uark.edu/jaas/vol20/iss1/829iInformation on Basicladia crassaThe factors responsible for the forceful and/or extrusive release ofreproductive cells are unknown. Actively swimming reproductive cellswhich remained within the parent-cell eventually escaped by autonomousmovements. Although there was some apparent synchronization ofrelease of biflagellated cells from groups of three or four parent-cells,there was no observable acropetal or basipetal sequence of release. Itis probable that this release of reproductive cells is the result of lightstimulus (Hamilton, 1948). The time of actual reproductive cell forma-tion (prior to, or after, light stimulus) within the parent cell is not known.The authors have shown that papillae formation occurs during the first15 minutes of the light period.SUMMARYObservations and photographs of Basicladia crassa are presented.The vegetative cells have a reticulate chloroplast and divide by con-strictive cytokinesis; cell division is intercalary and also appears to beterminal. Rhizoidal outgrowths from the basal cell may or may nothave chloroplasts. The reproductive parent-cells were formed fromvegetative cells and were seen to release both biflagellated and quad-riflagellated motile cells. Quadriflagellated reproductive cells are re-ported for the first time for this organism. The flagellated cells werereleased through pores of rapidly formed papillae by means of forcefulexpulsion and by autonomous swimming movements, and an extrusive,slowly escaping movement. Some reproductive cells were never re'easedfrom the parent-cells.LITERATURE CITEDCollins, F. S. 1907. Some new green algae. Rhodora. 9:197-202.Ducker, Sophie C. 1958. A new species of Basicladia on Austral-freshwater turtles. Hydrobiologia. 10:157-174.Fritsch, F. E. 1956. The structure and reproduction of algae. Vol. I.Cambridge University Press.Gardner, N. L. 1937. A new species of Chaetomorpha from China.Madrono. 4:28-32.Hamilton, John Meacham. 1948. Sexual reproduction in the genusBasicladia (Thallophyta, Chlorophyceae). Trans. Amer. Microsc.Soc. 67:201-205.Hoffmann, Wm. E., and Josephine E. Tilden. 1930. Basicladia, a newgenus of Cladophoraceae. Bot. Gaz. 89:374-384.Kusunoki, Seikan. 1944. Zur fortpflanzung der konjugaten, IIIUnter-suchungen uber besondere amoboide zustanda von zoosporen.(Basicladia crassa und andere). Cytologia. 13:297-322.Leake, Dorothy V. 1938. Preliminary note on the production of motilecells in Basicladia. Proc. Oklahoma Acad. Sci. 19:109-111.29Journal of the Arkansas Academy of Science, Vol. 20 [1966], Art. 8Published by Arkansas Academy of Science, 1966¦30IArkansas Academy of Science Proceedings1946. Studies of development and germina-tion of aplanospores and zoospores of Basicladia crassa, Hoffmannand Tilden. Amer. Jour. Bot. 33:823-824.Normandin, Robert F., and Clarence E. Taft. 1959. A new species ofBasicladia from the snail Viviparus malleatus, Reeve. Ohio Jour.Sci. 59:58-62.Prescott, G. W. 1962. Algae of the Western Great Lakes Area. Wm.C. Brown Co. Inc., Dubuque, Iowa.Proctor, Vernon W. 1958. The growth of Basicladia on turtles. Ecology.39:634-645.Smith, Gilbert AA. 1950. The fresh-water algae of the United States.Second edition. McGraw-Hill Book Company, Inc., New York.1955. Cryptogamic Botany. Vol. I. Algaeand fungi. Second edition. McGraw-Hill Book Company, Inc.,New York.Tiffany, L. H. 1926. The filamentous algae of northwestern Iowa withspecial reference to the Oedogoniaceae. Trans. Amer. Microsc.Soc. 45:69-132.30Journal of the Arkansas Academy of Science, Vol. 20 [1966], Art. 8http://scholarworks.uark.edu/jaas/vol20/iss1/831/'Information on Basicladia crassa"igs. 1-6. -Figs. 1-2. Two cells in normal release sequence. -Fig. 1.Anterior end foremost. X43 obj. -Fig. 2. Posterior end foremost.X43 obj. -Fig. 3. Extrusive release of clumps of reproductive cells.X43 obj. -Fig. 4. Centripetal wall formation dividing reticulatechloroplast and cell into two (2) unequal parts. X20 obj. -Fig. 5.Quadriflagellated reproductive cells at a and b. X90 obj. -Fig. 6.Jiflagellated reproductive cells with crescent shaped red eyespor at a.X90 obj.31Journal of the Arkansas Academy of Science, Vol. 20 [1966], Art. 8Published by Arkansas Academy of Science, 1966

https://scholarworks.uark.edu/cgi/viewcontent.cgi?article=3084&amp;context=jaas

Additional Information on Basicladia crassa Hoffmann and Tilden

Abstract

Similar works

Full text

Available Versions

UARK (University of Arkansas )

ScholarWorks@UARK