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Acrochaetium botryocarpum (Harv.) J. Ag. (Rhodophyta) in Southern Australia
Abstract
The morphology, ecology, cytology and systematics of Acrochaetium botryocarpum (Harv.) J. Ag. have been studied. This species occurs throughout the year in southern Australia and grows on a variety of hosts. The variable appearance of the prostrate system results from the effect of the substratum upon its morphology. Plants reach a height of 6 mm; cells of the erect filaments contain a single chromoplast with a variable number of pyrenoids. Tetrasporangial plants occur mainly in winter and sexual plants occur mainly in spring and early summer; the two generations are isomorphic. Stages of fertilisation have been observed and photographed. Acrochaetium polyrhizum (Harv.) J. Ag. is referred to the synonomy of A. botryocarpum, and A. codicolum Brg., A. grande (Levr.) De Toni fil. and A. rhizoideum (Drew) Sm. are regarded as probable synonyms. This study of A. botryocarpum indicates that host specificity, substrate relations, form of spermatangia and immediate post-fertilisation activity may not be as reliable as formerly thought for making taxonomic distinctions within the Acrochaetium-Rhodochorton complex.
... The only plants thus far collected in North Carolina are tetrasporic and/or monosporangiate. Monosporangia, found in all collections, are large, falling in the upper size ranges of those listed by Woelkerling (1970Woelkerling ( , 1971. Many of the monosporangia are terminal on short branches, some later becoming subtended by the short lateral filaments that produce them, becoming displaced to a lateral position. ...
An investigation of the hitherto little explored red algal family Acrochaetiaceae on the southern African coast has yielded a total of 20 species so far. They are representatives of the genera Acrochaetium (7 species), Audouinella (6 species), Colaconema (6 species) and Rhodothamniella (1 species). Of these, 4 species are described as new to science, viz., Acrochaetium hlulekaense n. sp., Audouinella balliae n. sp., Audouinella occulta n. sp. and Colaconema monorhiza n. sp. Descriptions and illustrations of all species are given, primarily based on field-collected material, but often completed from observations on culture-obtained material. It appears that, broadly speaking, the genera Acrochaetium, Colaconema and Rhodothamniella are found in the lower eulittoral and in the sublittoral fringe, whereas most Audouinella species occupy deeper sublittoral sites. With the exception of the epilithic Rhodothamniella floridula, all species usually grow on plant and animal substrates, with quite a number of them (semi-)endophytic or (semi-)endozoic. Apart from the newly described species, the western Cape acrochaetioid flora has many similarities with other temperate floras throughout the world, notably western Europe, while the Transkeian acrochaetioid flora is transitional between the temperate and known tropical/ subtropical types. S. Afr. J. Bot. 1985, 51: 291–330
An evaluation is given of some morphotaxonomic criteria used for specific distinction in the genus Acrochaetium. 59 isolates from the European Atlantic coast were compared after having been cultured under uniform conditions. As a result, three species are distinguished, primarily on the characters cell length, arrangement and length of the monosporangia. Cell diameter and shape of the monosporangia and monosporangial stalk cell may sometimes be used as additional characters for identification purposes.Recognized taxa have not undergone formal nomenclatural revision, and their identification has been provisional; they are: A. zosterae Papenfuss, A. nemalionis (De Notaris) Bornet, and A. daviesii (Dillwyn) Nägeli. Because of large intraspecific variation, differences between the three are not very clear cut. Sexual life histories are known from culture in the first two species. Comparison with relevant literature shows some of the commonly used criteria for species distinction to be of little value.The position of the genus Acrochaetium within the family Acrochaetiaceae is briefly discussed.
Red algal systematics is in a state of flux unparalleled since the early decades of this century. Ultrastructural and biochemical studies are providing features for a revised classification at ordinal and supraordinal ranks, whereas characters of vegetative and reproductive morphology continue to establish discontinuities among taxa at lower ranks. Cytological, biosystematic, and chemotaxonomic contributions are viewed as useful in defining relationships at specific and infraspecific ranks. Chemotaxonomic studies, depending on the properties of the taxa that are being studied, are applicable at all taxonomic levels. The taxonomic importance of life histories and themes of vegetative morphology, including spore germination, heterotrichy, initiation and differentiation of thalli are discussed at length. Homologies of auxiliary cells, carpogonial branches, and connecting filaments are examined in the context of relationships among Corallinales, Cryptonemiales, Gigartinales, and Rhodymeniales, and their included families. Based on a phylogenetic analysis, we provide a synopsis of our classification of Rhodophyta, together with the features that define each order.
Despite a considerable increase in information during the past 30–40 years regarding life histories of organisms referred to the Nemaliales, there are still many aspects for which information is incomplete or unsatisfactory. Consolidation of available life history data produces further evidence that the criteria used presently for the discrimination of Orders within the Florideophyceae and of Families within the Nemaliales are not entirely satisfactory.
The family names related to acrochaetioid algae are briefly surveyed and Rhodochortaceae Nasr is adopted as the correct name of the family based on the nomenclatural priority. A historical review of several generic classification schemes is presented. A new classification scheme is provided on the basis of asexual reproduction as the primary criterion and the chloroplast morphology as an additional criterion for distinguishing genera of the family. Under the new scheme, Audouinella Bory is restricted to taxa producing monosporangia and having parietal laminate or ribbon-shaped chloroplasts, Acrochaetium Naegeli to taxa producing monosporangia and having stellate chloroplasts, and Rhodochorton Naegeli to taxa having asexual cycles with tetraspores and not monospores.
Male, female and cystocarpic specimens of Audouinella arcuata (Drew) Garbary, Hansen et Scagel were collected from British Columbia, Canada, and the details of reproductive morphology are described for the first time. The plants consist of one to four branched axes which arc upward from a unicellular base. Each cell contains a single stellate chloroplast with a central pyrenoid. The thalli are mostly bisexual although small plants may bear only male or female gametangia. Spermatangia develop in short, two-celled filaments which are clustered apically on swollen terminal cells of the main axes. Carpogonia are conical with short bulbous trichogynes and generally terminate short lateral branches. After fertilization a compact monopodial carposporophyte develops which may have up to seven cells in the primary axis and bear up to 25 ovoid carposporangia. Audouinella vaga commonly co-occurs with A. arcuata and is proposed as the possible tetrasporophyte. The reproductive features of A. arcuata are compared to other Audouinella species, and variation in gametangial and carposporophytic morphology is discussed for the family.
Audouinella botryocarpa is reported for the first time from the British Isles. On the west and south coasts of Ireland and in the Isle of Man it grows in the intertidal on wave-splashed limpet shells and rock surfaces. Populations examined monthly in Galway Bay formed monosporangia throughout the year and tetrasporangia from December to March and May but no gametangial plants were found. Plants isolated into culture from monospores formed monosporangia at daylengths of 8, 10, 12, 14 and 16 h at 6.5, 8, 10, 11 and 15°C; the same plants formed tetrasporangia at daylengths ≤10 h at 8, 10 and 11°C but not at 6.5 and 15°C. Spores isolated from these plants gave rise to further monosporangial plants that also formed tetrasporangia under inductive conditions. Night-breaks of 1 h in a 16 h night prevented tetrasporangial reproduction and a critical daylength of ∼10 h was found at 10°C. British Isles Audouinella botryocarpa typically has 6 rounded or irregularly-shaped chloroplasts per cell, each of which has a single, centrally-placed pyrenoid. The chloroplasts grow together in mature cells, typically giving the appearance of a single plate-like chloroplast with 6 pyrenoids. The implications of these observations for the generic classification of acrochaetioid algae is discussed and it is concluded that chloroplast morphology, number and the presence or absence of pyrenoids may provide the basis for a future generic realignment of acrochaetioid algae.
1.
A short survey of the experimental approach of morphological variability and life cycles of algae is given.
2.
The taxonomical implications of experimental investigations is illustrated with respect to some multi-cellular blue-green, red, brown and green algae.
Heat induces a number of premutational lesions (for example, the deamination of cytosine to uracil) in DNA and RNA. These kinds of errors occur in resting as well as replicating polynucleotides. However, an increase in temperature also raises the probability of copying error occurring in nucleic acids because of increased thermal noise in the replicative machinery. In most modern genetic systems, the majority of heat-induced lesions are efficiently repaired. It follows that the importance of heat-induced error increases as the effectiveness of repair declines. We show in this paper that the error rate of enzymatic polynucleotide copying is expected to increase monotonically with temperature. We also explore the effects of temperature variations on the early evolution of biological information transmission mechanisms.
The phases of the life-cycle of the alga are described, from both wild and cultured material. The whole sequence of generations has been found to take place in uni-algal culture. The possible relationship between epiphyte and host is considered. A brief account of the taxonomy of the plant is appended and reasons are given for its inclusion in the genus Rhodochorton.
In vitro unialgal cultures of two endophytes, Acrochaetium endophyticum and A. asparagopsis, and of the endozoic species A. infestans have been established. In studies on the liberation of spores the monospores showed amoeboid changes of shape immediately after release and for periods up to 60 min. Early developmental stages of sporelings have also been studied. Monospores of A. endophyticum are able to withstand protracted periods of storage in the dark or at very low light intensity, and begin development on return to ‘normal’ light conditions. Filaments survive up to 4 months dark storage, and after 2 months release viable spores soon after return to ‘normal’ light conditions. Monospore release was obtained in a light intensity range of 19–420 lumens/sq.ft but spores quickly bleached and died at 480–500 lumens/sq.ft. ‘Healthy’ sporeling and filament growth were obtained at intensities up to 300 lumens/sq.ft, and slow growth at 19 lumens/sq.ft. Repeated monosporangium formation was found under a long day/summer temperature regime; sporangia were not obtained under a short day/low temperature regime. Growth and sporulation were obtained in a salinity range 0.5–1.4 times that of normal sea water, and significant differences in cell size were found in media of high and low salinity. Filaments survive protracted periods of exposure to low temperature and subsequently released spores. The upper thermal death point lies between 27–30°C. Filament growth and spore liberation were obtained in media of pH range 6–9. Spore settlements were obtained on endophyte-free plants of Heterosiphonia and ‘infection’ stages have been studied. In experiments with other animals and plants, endozoic growths of A. endophyticum have been induced in a hydroid organism. A. asparagoposis and A. infestans form distinctive epiphytic growths on substrata other than their normal ‘host’ material. A. endophyticum formed Erythrocladia-like growths on the rhizoids of Heterosiphonia. A. endophyticum penetrates into calcareous substrata and the filaments show shellboring properties, but this property was not observed with A. asparagopsis and A. infestans.
Monospore release is effected mainly by an apical tear accompanied by momentary spore distortion, and sometimes with a distinct ‘blow-out’ of the sporangium apex; orientation of the paths of spore release is seen with serially arranged sporangia. Sporangium proliferation is common in cultures, but spore germination in situ is rare. Attempts at experimental induction of the process resulted in some sporangia with early developmental stages coming to resemble tetrasporangia.
A description is given of a filamentous red alga which was found growing within a sponge collected from the sublittoral off Santander, Spain. The plant appears to be closely related to Acrochaetium spiculiphilum Dawson. A survey is given of the specific characters available for the typification of the known partially and completely endozoic Acrochaetium species, and some suggestions made on the more important lines of study.
Introduction
During the summer of 1957 some specimens of the keratinous sponge Haliclona were collected from the sublittoral off Santander, Spain, by Mr G. R. Forster. Certain of the specimens bore extensive areas of red, and on preliminary examination this colour was found to be due to the filaments of a red alga showing an extensive ramifying growth within the skeleton of the sponge. The drawings and cell measurements to be reported were made from the plant material by A. D. B. soon after its collection. This information has been retained pending a more comprehensive study of endophytic and endozoic red algae. Work is now in progress on these lines (mainly by E. B. W.), and a re-examination of the Santander material has enabled us to make a critical study of the data available for a precise typification of plants of this habit. Further, since the association of endozoic filamentous red algae with sponges appears to be of rare occurrence, any examples need to be fully described.
Description of Plant
The cells were of variable shape and size, and contained much-dissected parietal chromatophores (Fig. 1 a ). Individual filaments tended to be closely packed together within the host (Fig. 1 b ), and there was no extensive growth of erect filaments outside of the host material.
The chromosomes, certain intracellular structures and gross anatomical details of many red algae, which, as a class, have proved technically difficult material, can be demonstrated by staining with aceto-carmine after a mordant bath of iron alum. Acetic-alcohol mixtures are used as nuclear fixatives and formalin-acetic-alcohol and other similar fluids for preservation of anatomical features. The tougher more cartilaginous thalli of some species can be softened, if squashes are desired, by prolonging fixation (24-48 hr.) in acetic alcohol and subsequent washing. The fixatives are washed out of the material before the latter is transferred to 0.5-5.0% ferric ammonium sulphate, the concentration of which may be altered according to the material. Excess mordant is removed by washing and the material stained in Belling's aceto-carmine containing a trace of ferric acetate as a “ripener”. The degree of heating before covering is critical as it controls the quality of the staining. Squashing must be very thorough to spread the chromosomes which are usually very small but only slight controlled pressure is necessary when diffuse structures such as carposporophytes, nemathecia or medullary filaments are being demonstrated. Paraffin sections mounted on slides can also be stained by this method.
Review of the Acrochaetium-Rhodochorton complex of the red algae
- G F Papenfuss
PAPENFUSS, G. F., 1945. Review of the Acrochaetium-Rhodochorton complex of the red algae.
Univ. Calif. Pubis. Bot., 18, 299-334.
Some Liagora-inhabitating species of Acrochaetium
- I A Abbott
ABBOTT, I. A., 1962. Some Liagora-inhabitating species of Acrochaetium. Occ. Pap. Bernice P.
Bishop Mus., 23, 77-120.
A check list and key to the Rhodophyceae of New Zealand
- D J Chapman
CHAPMAN, D. J., 1962. A check list and key to the Rhodophyceae of New Zealand. Trans. R.
Soc. N.Z., 1 (11), 127-137.
Morphology and reproduction of the red alga Acrochaetium pectinatum in culture
WEST, J. A., 1968. Morphology and reproduction of the red alga Acrochaetium pectinatum in
culture. J. PhycoL, 4, 89-99.
Ueber die Entwicklungsgeschichte yon Batrachospermum moniliforme
- H Kylin
KYLIN, H., 1917. Ueber die Entwicklungsgeschichte yon Batrachospermum moniliforme. Bet. dt.
bot. Ges., 35, 155-164.
Studies on Australian marine algae. IIL Geographical records of various species and observations on Acrochaetium botryocarpum
- V May
MAY, V., 1947. Studies on Australian marine algae. IIL Geographical records of various
species and observations on Acrochaetium botryocarpum (Harv.) J. Ag. and Pterocladia
eapillacea (Gmel.) Born. Proc. Linn. Soc. N.S.W., 71,273-277.
Cytological and life-history studies in the genus Rhodochorton
- F Knaggs
KNAGGS, F., 1964. Cytological and life-history studies in the genus Rhodochorton. Br. phycoL
Bull., 2, 393.
Structure and reproduction of Trichogloea requienii, with a comparison of the genera of the Helminthocladiaceae
- G F Papenfuss
PAPENFUSS, G. F., 1946. Structure and reproduction of Trichogloea requienii, with a comparison
of the genera of the Helminthocladiaceae. Bull. Torrey bot. Club, 73, 419-437.
Zur Kenntnis der Algenflora yon Kullen an der schwedischen Westktiste
- T Levmng
LEVmNG, T., 1935. Zur Kenntnis der Algenflora yon Kullen an der schwedischen Westktiste.
Acta Univ. lund., 31 (4), 1-63.
Marine algae from the Canary Islands. III. Rhodophyceae. Part I. Bangiales and Nemalionales. K. danske Vidensk
- F Borgesen
BORGESEN, F., 1927. Marine algae from the Canary Islands. III. Rhodophyceae. Part I. Bangiales and Nemalionales. K. danske Vidensk. Seisk. Biol. Medd., 6 (6), 1-97.
The marine algae of the Danish West Indies. II. Rhodophyceae. Dansk bot
BORGESEN, F., 1915. The marine algae of the Danish West Indies. II. Rhodophyceae. Dansk
bot. Ark., 3, 1-80.
Notes on marine algae from Tasmania
- A B Crmb
CRmB, A. B., 1956. Notes on marine algae from Tasmania. Pap. Proc. R. Soc. Tasm., 90,
183-188, p. 1-3.
A revision of the genera Chantransia, Rhodochorton, and Acrochaetium, etc
- K M Drew
DREW, K. M., 1928. A revision of the genera Chantransia, Rhodochorton, and Acrochaetium,
etc. Univ. Calif. Pubis. Bot., 14 (5), 139-224.
Ueber die Befruchtung und Reduktionsteilung bei Nemalion multifidum
- H Kylin
KYLIN, H., 1916. Ueber die Befruchtung und Reduktionsteilung bei Nemalion multifidum. Ber
dt. hot. Ges., 34, 257-27I.
Observations on nuclear structure in the Florideae
- M A Westbrook
WESTBROOK, M. A., 1935. Observations on nuclear structure in the Florideae. Beih. bot. ZbL,
53, 564-585.
Zytologisch-entwicklungsgeschichtliche Studien ueber Scinaiafurcellata
- N Svedelius
SVEDELIUS, N., 1915. Zytologisch-entwicklungsgeschichtliche Studien ueber Scinaiafurcellata.
Nova Acta R. Soc. Scient. upsaL, Ser. 4, 4 (4), 1-55.
Deux Chantransia corymbifera Thuret Acrochaetium et Chantransia
BORNET, E., 1904. Deux Chantransia corymbifera Thuret. Acrochaetium et Chantransia. Bull.
Soc. bot. Ft., 51 (Suppl.), xiv-xxiii.
The marine algae of Denmark. I. Rhodophyceae 1. K. danske Vidensk
- L K Rosenvange
ROSENVaNGE, L. K., 1909. The marine algae of Denmark. I. Rhodophyceae 1. K. danske
Vidensk. Selsk. Skr., 7 (1), 1-151.
Observations on an endozoic red alga
- A D Boney
- E B Wmax
BONEY, A. D. & Wmax, E. B,, 1967. Observations on an endozoic red alga. J. mar. bioL Ass.
U.K., 47, 223-232.
Acetocarmine stain in the cytological investigation of some marine algae of the Pacific Coast
- K Cole
COLE, K., 1963. Acetocarmine stain in the cytological investigation of some marine algae of the
Pacific Coast. Proc. 1X Pacif. Sci. Congr., 4, 313-315.
The Rhodophyta order Acrochaetiales and its classification
- J Feldmann
FELDMANN, J., 1962. The Rhodophyta order Acrochaetiales and its classification. Proc. IX
Pacif. Sci. Congr., 4, 219-221.
Recherches sur les genres Acrochaetium Naeg. et Rhodochorton Naeg. Dissertation
- G Hamel
HAMEL, G., 1927. Recherches sur les genres Acrochaetium Naeg. et Rhodochorton Naeg. Dissertation. Paris.
Further contributions toward an understanding of the Acrochaetium-Rhodochorton complex of the red algae
- G F Papenfuss
PAPENFUSS, G. F., 1947. Further contributions toward an understanding of the Acrochaetium-Rhodochorton complex of the red algae. Univ. Calif. Pubis. Bot., 18, 433--447.
The use of picric acid with the gram stain in plant cytology
- F H Smrrh
SMrrH, F. H., 1934. The use of picric acid with the gram stain in plant cytology. Stain TechnoL,
9, 95-96.
- Smith F.H.
- Drew K.M.
- Cleland R.E.