The genus Metagoniolithon Weber-van Bosse (Corallinaceae, Rhodophyta)

1979 ◽  
Vol 27 (1) ◽  
pp. 67 ◽  
Author(s):  
SC Ducker
Keyword(s):  
Spore Germination ◽  
Coralline Algae ◽  
Cortical Tissue ◽  
Single Genus ◽  
Fusion Cell ◽  
Cell Fusions

The characters of the genus Metagoniolithon Weber-van Bosse, the single genus within the subfamily Metagoniolithoideae Johansen, are defined. The thalli are differentiated into basal crusts, genicula and intergenicula, with all the tissues displaying cell fusions but lacking secondary pit connections. Initial apical branching is dichotomous, but later the meristematic genicula produce false whorls of branches. The branches lack apical cover cells but have mucilaginous caps. The conceptacles, with their overlying mucilaginous caps, are initiated in the cortical tissue of the intergenicula. The plants are dioecious. In the cystocarpic conceptacle the fusion cell is continuous and the carpospore formation is restricted to the periphery of the fusion cell. The spermatangia develop only on the floor of the conceptacle. The uniporate roof of the tetrasporangial conceptacle is formed by the growth of filaments within the ring of developing marginal tetrasporangia. Spore germination is of the Amphiroa type. The three species are endemic and restricted to western and southern Australia: M. radiatum (Lamarck) comb. nov. is epilithic; M. stelliferum (Lamarck) Weber-van Bosse and M. chara (Lamarck) comb. nov. var, chara and var. dichotomum var, nov. are epiphytic, commonly on the seagrass Amphibolis C. Agardh. The basal crust of the epiphytic species is epiphytic on species of Hetevoderma Foslie growing on Amphibolis. The characters of the genus Metagoniolithon are compared with those of Amphiroa Lamouroux, and a key to the articulated coralline algae of southern Australia is given.

Studies of marine algae in the lesser-known families of the Gigartinales (Rhodophyta). III. The Mychodeaceae and Mychodeophyllaceae

1978 ◽  
Vol 26 (4) ◽  
pp. 515 ◽  
Author(s):  
GT Kraft
Keyword(s):  
Marine Algae ◽  
Adjacent Cell ◽  
Distinctive Pattern ◽  
Supporting Cells ◽  
New Family ◽  
Red Algal ◽  
Single Genus ◽  
Fusion Cell ◽  
Fertile Region ◽  
Axial Development

The endemic Australian red algal families Mychodeaceae Kylin and Mychodeophyllaceae fam. nov. are described and characterized in vegetative and reproductive detail. The Mychodeaceae is composed of the single genus Mychodea and 11 species which are distinguished on habit features and vegetative differences. Plants are uniaxial with a distinctive pattern of axial development, monoecious, zonately tetrasporangiate, procarpic and polycarpogonial. Supporting cells of carpogonial branches function as auxiliary cells which remain unfused to adjacent cells after diploidization and emit numerous gonimoblast filaments towards the centre of the thallus. The gonimoblasts become secondarily pitconnected to gametophytic cells which they lie next to and eventually appear to break up into isolated groups of cells which both initiate additional carposporangial precursors and enlarge directly into carposporangia themselves. Carposporangial initials can form secondary pit-connections to any type of adjacent cell, which results in irregularly branched carposporangial clusters whose cells are frequently attached to sterile gametophytic cells within and around the periphery of the cystocarp. Mature cystocarps consist of a non-ostiolate pericarp and pockets of carposporangia isolated between persistent sterile cells throughout the fertile region. The genera Neurophyllis Zanardini and Ectoclinium J. Agardh are placed in synonymy with Mychodea, and all extra-Australian records of the group are discounted or questioned. A new family, the Mychodeophyllaceae, is created for Mychodeophyllum papillitectum gen. et sp. nov. from Western Australia. Mychodeophyllum shares spermatangial and tetrasporangial features with Mychodea, as well as sexual elements such as polycarpogonial procarps, lack of a fusion cell, and multiple, inwardly growing gonimoblast initials. Gonimoblast filaments develop quite differently from Mychodea, however, and carposporangia form radiating chains around the periphery of a central placenta composed of mixed and secondarily connected gonimoblast and gametophytic filaments. Plants of the genus are also apparently rnultiaxial. The Mychodeaceae and Mychodeophyllaceae appear to be highly specialized in vegetative and carposporophyte structure, and have given rise to no known higher lines of development. It is speculated that both families may represent offshoots from ancestors at a level of carposporophyte complexit) represented by present-day Rhabdoniaceae, Solieriaceae and Rhodophyllidaceae.

scholarly journals Rhodolith forming coralline algae in the Upper Miocene of Santa Maria Island (Azores, NE Atlantic): a critical evaluation

Phytotaxa ◽  
2014 ◽  
Vol 190 (1) ◽  
pp. 370 ◽  
Author(s):  
Ana Cristina Rebelo ◽  
Michael Rasser ◽  
Rafael Riosmena-Rodríguez ◽  
Ana Isabel Neto ◽  
Sérgio Ávila
Keyword(s):  
Sea Level ◽  
Late Miocene ◽  
Critical Evaluation ◽  
Coralline Algae ◽  
Ne Atlantic ◽  
Southeastern Coast ◽  
Santa Maria ◽  
Thallus Surface ◽  
Number Of Cells ◽  
Cell Fusions

The Late Miocene Malbusca outcrop is located in the southeastern coast of Santa Maria Island (Azores, NE Atlantic), interspersed in volcanic formations. At ~20 meters above present sea level, a prominent discontinuous layer of rhodoliths seizes with an extension of ~250 meters. This paper presents the first taxonomic record of fossil rhodolith forming coralline algae for the Miocene of the Azores. The preserved taxonomic features used were the following: (1) arrangement of basal filaments, (2) epithallial cells (when observable), (3) presence of cell fusions, (4) conceptacle type, (5) number of cells layers which conceptacle chamber floors are situated below the surrounding thallus surface and (6) for the sporangial pores, the orientation of the filaments around the conceptacle pores. Based on these characters, six taxa were identified encompassing three Corallinaceae (Lithophyllum prototypum, Lithophyllum sp., Spongites sp. and Hydrolithon sp.) and one Hapalidaceae (Phymatolithon calcareum and cf. Phymatolithon sp.). An unidentified coaxial thallus was also present, the coaxial construction ascribing the specimens to the genus Mesophyllum or Neogoniolithon. Taxonomic accounts for the identified taxa are described, illustrated and an identification key is provided. The report of L. prototypum represents the first Miocene record and the preservation of the specimens is very good. Miocene coralline algae seem very consistent among deposits but some species are relevant for particular areas, like in the Azores.

Contributions to Australian Bryology. I. The structure, development and systematic affinities of Monocarpus sphaerocarpus gen. et. sp. nov. (Marchantiales)

1956 ◽  
Vol 4 (2) ◽  
pp. 175 ◽  
Author(s):  
DJ Carr
Keyword(s):  
Spore Germination ◽  
Systematic Position ◽  
Growth Substances ◽  
Structure Development ◽  
Single Genus ◽  
Mode Of Development ◽  
Western Victoria ◽  
The Relationship ◽  
North Western

A new thallose hepatic with characters intermediate between those of the Sphaerocarpineae (sensu Müller) and the section Caudiciformes of the Marchantiineae has been discovered on saltpans in north-western Victoria. The female thallus bears a single spherical involucre which has air chambers and specialized pores and contains a single sporophyte. The male plants have not been found. Details are given of the structure and mode of development of the involucre, air chambers, and pores, the early embryogeny of the sporophyte, spore germination, and the development of the thallus. The systematic position of the new plant (Monocarpus sphaerocarpus) is discussed and the literature on the relationship between the Sphaerocarpineae and other thallose hepatics is reviewed. The characters of Monocarpus are shown to support the view that phaerocarpus and allied genera should be placed within the Marchantiales rather than with the Jungermanniales. It is proposed to raise a new suborder of the Marchantiales, Monocarpineae, for the single genus, Monocarpus. Certain problems of morphogenesis are raised and it is suggested that the enciosure of more than one archegonium in an involucre is conducive to the inhibition of development of more than one sporophyte within the involucre. It is also suggested that growth substances released during meiosis in the sporangium control the post-fertilization growth of the thallus and involucre.

scholarly journals Application of neontological taxonomic concepts to Late Eocene coralline algae (Rhodophyta) of the Austrian Molasse Zone

1999 ◽  
Vol 18 (1) ◽  
pp. 67-80 ◽  
Author(s):  
Michael W. Rasser ◽  
Werner E. Piller
Keyword(s):  
Relative Length ◽  
Reproductive Organs ◽  
Late Eocene ◽  
Coralline Algae ◽  
Diagnostic Features ◽  
Diagnostic Characters ◽  
Fossil Material ◽  
Cell Fusions

Abstract. Traditionally, different diagnostic characters have been used in the identification of fossil and Recent coralline algal genera. The taxonomy of fossil coralline algae has focused on well calcified features such as basal filaments and conceptacle perforation. In contrast, the taxonomy of Recent material uses a combination of several features with a low fossilization potential, such as epithallial cells and structures of sexual reproductive organs. In the studied material of the Late Eocene Austrian Molasse Zone Lithoporella, Neogoniolithon, Spongites, Phymatolithon and Sporolithon are identified and described applying features of neontological taxonomic concepts. These features are: (1) the arrangement of basal filaments; (2) the occurrence of cell fusions; (3) the relative length of subepithellial initials; (4) the conceptacle perforation; (5) the orientation of filaments around the conceptacle pore; and (6) the type of conceptacle roof formation. Some of these features were thought to be unpresentable in fossil material until recently. The fossilization potential of diagnostic features and the identification of the documented genera and species are discussed in detail. Moreover, a checklist for the description of fossil taxa is provided.

Experimental effects of kelp canopies on subtidal coralline algae

2001 ◽  
Vol 26 (1) ◽  
pp. 102-108 ◽  
Author(s):  
A. J. Melville ◽  
S. D. Connell
Keyword(s):  
Coralline Algae

A STUDY ON ICHTHYO-DIVERSITY OF MUNTJIBPUR POND OF ALLAHABAD (U.P.) INDIA

2017 ◽  
Vol 23 (1) ◽  
Author(s):  
ASHOK KUMAR VERMA
Keyword(s):  
Single Species ◽  
Single Genus ◽  
One Year

An attempt was made to find the ichthyo-diversity of Muntjibpur pond of Allahabad. Systematic surveys were conducted during a period of one year. A total of 13 species of fishes belonging to 12 genera, 8 families and 5 orders were identified. Siluriformes order is represented by 5 genera and 5 species while Cypriniformes order by 4 genera and 5 species. Each of the orders Clupeiformes, Osteoglossiformes and Ophiocephaliformes is represented by single genus and single species.

Interaction between parathyroid hormone and prostaglandin E1 on cyclic AMP metabolism in rat kidney

1980 ◽  
Vol 93 (3) ◽  
pp. 339-345 ◽  
Author(s):  
Naokazu Nagata ◽  
Yuriko Ono ◽  
Narimichi Kimura
Keyword(s):  
Parathyroid Hormone ◽  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Rat Kidney ◽  
Prostaglandin E ◽  
Cortical Tissue ◽  
Newborn Rat ◽  
Simultaneous Addition ◽  
Renal Cortical Tissue ◽  
Subsequent Addition

Abstract. The interaction between parathyroid hormone (PTH) and prostaglandin E1 (PGE1) in influencing cyclic AMP metabolism in rat renal cortical tissue was examined. PTH and PGE1 stimulated additively the adenylate cyclase activity in the homogenate of the tissue. Both PTH and PGE1 enhanced the level of cyclic AMP in the incubated renal cortical tissue, but the effect of their simultaneous addition did not exceed the effect induced by PTH alone. Cyclic AMP accumulated in the incubation medium by stimulation by PTH was decreased by the simultaneous addition of PGE1. When the tissue was pre-incubated for 30 min with 2 to 10 μg/ml of PGE1, the magnitude of the increase of cyclic AMP caused by PTH subsequently added was lessened. However, the response to PTH of adenylate cyclase preparation obtained from the homogenate of PGE1-pre-treated tissue was not decreased. When first PTH was added to the incubating renal cortical tissue, the subsequent addition of PGE1 accelerated the decrease of cyclic AMP content in the tissue and decreased the amount of cyclic AMP released from the tissue. The interaction of PTH and PGE1 on cyclic AMP metabolism in the renal cortical tissue was in contrast to that seen in newborn rat calvaria where PGE1 and PTH acted additively in enhancing the level of cyclic AMP.

Effects of light, temperature and pH on spore germination and early gametophytic development of Alsophila metteniana

2009 ◽  
Vol 17 (2) ◽  
pp. 182 ◽  
Author(s):  
Du Honghong ◽  
Li Yang ◽  
Li Dong ◽  
Dai Shaojun ◽  
Jiang Chuangdao ◽  
...  
Keyword(s):  
Spore Germination

Influence of coralline algae on biodiversity of macrobenthic community in intertidal zone of Nanji Islands

2014 ◽  
Vol 22 (5) ◽  
pp. 640 ◽  
Author(s):  
Tang Yanbin ◽  
Liao Yibo ◽  
Shou Lu ◽  
Zeng Jiangning ◽  
Gao Aigen ◽  
...  
Keyword(s):  
Intertidal Zone ◽  
Macrobenthic Community ◽  
Coralline Algae ◽  
Nanji Islands
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