Community structure of a rhodolith bed from cold-temperate waters (southern Australia)

2008 ◽  
Vol 56 (5) ◽  
pp. 437 ◽  
Author(s):  
A. S. Harvey ◽  
F. L. Bird
Keyword(s):  
Community Structure ◽  
Red Algae ◽  
Growth Form ◽  
The Other ◽  
Growth Forms ◽  
Free Living ◽  
Coralline Red Algae ◽  
Reliable Identification

Rhodolith beds are aggregations of free-living non-geniculate coralline red algae (Corallinales, Rhodophyta), with a high biodiversity of associated organisms. This is the first detailed study of a rhodolith-bed community from the cold-temperate waters of southern Australia. This bed, located at 1–4-m depth in Western Port, Victoria, is composed of four rhodolith-forming species (Hydrolithon rupestre (Foslie) Penrose, Lithothamnion superpositum Foslie, Mesophyllum engelhartii (Foslie) Adey and Neogoniolithon brassica-florida (Harvey) Setchell & Mason). M. engelhartii has a foliose growth form and the other three species have fruticose growth forms. Detailed descriptions are provided for all species, allowing reliable identification. Comparisons with other rhodolith beds and reported rhodolith-forming species, both in Australia and worldwide, are also provided. The invertebrate cryptofaunal community was quantified for two rhodolith-forming species. The density of cryptofauna inhabiting foliose and fruticose rhodolith growth forms did not differ significantly and neither did abundance of individual phyla. Mean density of fauna was 0.4 invertebrates cm–3, the majority of which were polychaete worms. Comparisons of fauna associated with other rhodolith beds are also provided. A study of the vitality of the rhodolith bed showed dead rhodoliths are more abundant than live rhodoliths. Possible reasons for reduced bed vitality are explored.

Growth-forms in Non-geniculate Coralline Red Algae (Coralliinales, Rhodophyta)

1993 ◽  
Vol 6 (4) ◽  
pp. 277 ◽  
Author(s):  
WJ Woelkerling ◽  
LM Irvine ◽  
AS Harvey
Keyword(s):  
Red Algae ◽  
Growth Form ◽  
Focal Point ◽  
Focal Points ◽  
Growth Forms ◽  
Coralline Red Algae ◽  
The World ◽  
Considerable Confusion ◽  
Consistent Application

Although differences in growth-form have been widely used in delimiting taxa of non-geniculate coralline red algae (Corallinales, Rhodophyta), there has been no consistent application of the more than 100 terms employed to describe the growth-forms present, and considerable confusion has resulted. This study of over 5000 populations of non-geniculate corallines from all parts of the world has shown that an intergrading network of growth-forms with 10 focal points is present: unconsolidated, encrusting, warty, lumpy, fruticose, discoid, layered, foliose, ribbon-like and arborescent. This focal point terminology can be used to describe any specimen or species of non-geniculate coralline in a consistent, easily interpretable manner. Details of the system are provided, the relationships of the system to past proposals are discussed, and the extent to which differences in growth-forms can be used as taxonomic characters in the non-geniculate Corallinales is reviewed.

Growth and vegetative spread of Schizachyrium scoparium var. littoralis (Poaceae) in sand dune microhabitats along a successional gradient

1999 ◽  
Vol 77 (2) ◽  
pp. 219-229
Author(s):  
Teresa Valverde ◽  
Irene Pisanty
Keyword(s):  
Phenotypic Plasticity ◽  
Clonal Growth ◽  
Sand Dune ◽  
Growth Form ◽  
The Other ◽  
Schizachyrium Scoparium ◽  
Growth Forms ◽  
La Mancha ◽  
Reciprocal Transplants ◽  
Vegetative Spread

The architecture resulting from the iteration of modules during plant growth affects resource capture. Phalanx and guerrilla growth forms have been described as ends of a continuum regarding the spacing of modules in plants. In this study we investigated the growth form of the perennial, tussock-forming grass Schizachyrium scoparium Michx. var. littoralis (Nash) Hitchc. in three dune microhabitats at El Morro de la Mancha, southeastern Mexico: a mobile, a semi-mobile, and a stabilized site. We followed the growth of 15 genets at each site for two consecutive years and found that daughter-tussock formation was more frequent in the stabilized than in the semi-mobile or the mobile sites. Individual tussocks had a higher number of tillers in the mobile site than in the other two. Tiller production occurred within parental tussocks in the mobile site and in the form of daughter tussocks in the stabilized site. Reciprocal transplants suggested that phenotypic plasticity was responsible for the differences observed. Fertilization enhanced tiller production within parental tussocks but did not affect daughter tussock formation. Clearing experiments resulted in enhanced tiller production within tussocks. In these experiments, daughter-tussock production did not occur directionally towards nutrient-rich microsites. It appears that S. scoparium tillers are spaced at longer distances when resources are scarce and intraclonal competition is severe.Key words: clonal growth, growth form, nutrient availability, phalanx-guerrilla continuum.

Community structure of nongeniculate coralline red algae (Corallinales, Rhodophyta) in three boulder habitats in southern Australia

Phycologia ◽  
1999 ◽  
Vol 38 (2) ◽  
pp. 138-148 ◽  
Author(s):  
Sabine Daume ◽  
Sascha Brand-Gardner ◽  
William J. Woelkerllng
Keyword(s):  
Community Structure ◽  
Red Algae ◽  
Coralline Red Algae

scholarly journals A molecularly based phylogeny reconstruction of mushroom corals (Scleractinia: Fungiidae) with taxonomic consequences and evolutionary implications for life history traits

2011 ◽  
Vol 80 (2) ◽  
pp. 107-132 ◽  
Author(s):  
Arjan Gittenberger ◽  
Bastian T. Reijnen ◽  
Bert W. Hoeksema
Keyword(s):  
Life History Traits ◽  
Growth Form ◽  
Morphological Characters ◽  
Potential Effect ◽  
Internal Transcribed Spacers ◽  
Phylogeny Reconstruction ◽  
Growth Forms ◽  
Free Living ◽  
Reef Corals ◽  
Mitochondrial Cytochrome Oxidase

The phylogenetic relationships of the Fungiidae, a family of predominantly free-living, zooxanthellate, reef corals, were studied by sequencing a part of the mitochondrial Cytochrome Oxidase I (COI) and the complete ribosomal Internal Transcribed Spacers (ITS) I & II of specimens from various locations in the Indo-West Pacific. Some sequences were retrieved by using fungiidspecific primers on DNA-extracts from parasitic gastropods living with these corals. The analyses were performed both including and excluding intraspecific variation to investigate the potential effect of saturation. Even though the present molecular phylogeny reconstructions largely reflect those based on morphological characters, there are some distinct differences. Three major clades are distinguished, one of which consists of species with relatively long tentacles. The two other major clades cannot yet be clearly separated from each other morphologically. Several polyphyletic taxa were detected and some genera and species that previously were considered closely related to each other, appear not to be so. Proposed nomenclatorial changes include amongst others the upgrading of subgenera in Fungia to genus level. A few species moved from one genus to another. Among all Fungiidae, the loss of the ability to become free-living appears to have evolved independently as reversals in four separate clades, including two that were previously assumed to be sister groups. The evolution of corals with additional (secondary) mouths leading to polystomatous growth forms from corals with only a single primary mouth (monostomatous growth form) appears to have occurred independently ten times: seven times by extrastomatal budding and three times by intrastomatal budding. In two clades, Herpolitha and Polyphyllia, both mechanisms co-evolved. In general there is no clear relationship between the loss of a freeliving phase and the evolution of multiple mouths.

The occurrence of Phlyctidium bumilleriae on two growth forms of Staurastrum pinque and other Staurastrum spp., in Lake Manitoba

1971 ◽  
Vol 49 (9) ◽  
pp. 1637-1641 ◽  
Author(s):  
Margaret J. Masters
Keyword(s):  
Growth Form ◽  
The Other ◽  
Growth Forms ◽  
Intermediate Growth ◽  
Intermediate Cells

Phlyctidium bumilleriae Couch was observed attacking Staurastrum pinque, S. chaetoceros, S. muticum, and S. cuspidatum var. divergens in Lake Manitoba during the summers of 1965–1968. S. pinque, the host present in the greatest numbers in the phytoplankton, occurred in a three-radiate, a four-radiate, and an intermediate growth form with three radii on one semicell and four on the other. Both in 1966 and 1967 the four-radiate form was more heavily attacked by Phlyctidium than the three-radiate form although the latter was present in greater numbers. In July 1968, it was the four-radiate form which was more numerous but still it was this form which Phlyctidium most heavily attacked. Intermediate cells succumbed to the fungus in proportions similar to the four-radiate form.

Capture of conspecific planktonic larvae by the suspension-feeding gastropod Crepipatella peruviana: association between adult and larval size

2021 ◽  
Vol 87 (1) ◽  
Author(s):  
G A Rivera-Figueroa ◽  
J A Büchner-Miranda ◽  
L P Salas-Yanquin ◽  
J A Montory ◽  
V M Cubillos ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Larval Mortality ◽  
Feeding Preference ◽  
The Other ◽  
Suspension Feeding ◽  
Adult Size ◽  
Free Living ◽  
Larval Size ◽  
Suspension Feeders ◽  
Planktonic Larvae

ABSTRACT Free-living, planktonic larvae can be vulnerable to capture and ingestion by adult suspension-feeders. This is particularly the case for larvae that settle gregariously in benthic environments where suspension-feeders occur at high densities. Larvae of gregarious suspension-feeding species are at particularly high risk, as adults of their own species often serve as cues for metamorphosis. We conducted laboratory experiments to assess the extent to which adults of the suspension-feeding caenogastropod Crepipatella peruviana would capture and ingest their own larvae. Experiments were conducted with adults of different sizes, with larvae of different ages and sizes, and in the presence or absence of phytoplankton. Adults captured larvae in all experiments. The presence of microalgae in the water did not influence the extent of larval capture. On average, 39% of larvae were captured during the 3-h feeding periods, regardless of adult size. However, up to 34% of the larvae that were captured on the gill were later discarded as pseudofaeces; the other 64% were ingested. The extent of capture by adults was not related to adult size, or to larval size and, thus, to larval age. Our results suggest that the filtration of congeneric larvae by adult C. peruviana is a result of accidental capture rather than a deliberate feeding preference. Such ingestion could, however, still be an important source of larval mortality, especially when the advanced larvae of this species are searching for a suitable substrate for metamorphosis.

Comparative leaf development of aerial and aquatic growth forms of Myriophyllum aquaticum

Botany ◽  
2013 ◽  
Vol 91 (7) ◽  
pp. 421-430 ◽  
Author(s):  
M.D. Shafiullah ◽  
Christian R. Lacroix
Keyword(s):  
Apical Meristem ◽  
Epidermal Cells ◽  
The Other ◽  
Developmental Study ◽  
Growth Forms ◽  
Myriophyllum Aquaticum ◽  
Stages Of Development ◽  
Qualitative And Quantitative ◽  
Early Stages ◽  
Other Hand

Myriophyllum aquaticum (Vell.) Verdc. produces two morphologically different forms of leaves based on whether they are aerial or aquatic. The objective of this study was to determine whether there are any similarities or differences between these two growth forms during their early stages of development. A comparative developmental study of aerial and aquatic growth forms of M. aquaticum was conducted from a qualitative and quantitative perspective using a scanning electron microscope. The pattern of leaf and lobe initiation such as their origin and shape were similar in both growth forms until the fourth plastochron (stage P4). Differences between the two growth forms became evident from stage P5 onward, where a larger shoot apical meristem (SAM), elongated epidermal cells, shorter and slightly more numerous lobes, as well as the presence of appendage-like structures characterized aquatic growth forms. On the other hand, aerial growth forms had smaller SAM, bulb-like epidermal cells, and longer and slightly less numerous leaf lobes. Significant differences between growth forms were noted for parameters such as volume of SAM, length of terminal, first, and middle lobes, as well as the length from first to last lobes. The volume of the SAM of aquatic shoot tips was always greater than aerial forms. On the other hand, lobes of aerial forms were always longer than the aquatic counterpart during early stages of development. This study on the development of M. aquaticum shows that the aerial and aquatic growth forms diverge from their early stages of development.

A field study of reproductive interactions in Bosca's newt, Triturus boscai

1995 ◽  
Vol 16 (4) ◽  
pp. 357-374 ◽  
Author(s):  
Manuel Mouta Faria
Keyword(s):  
Field Study ◽  
Natural Population ◽  
Wild Population ◽  
Short Circuit ◽  
The Other ◽  
Courtship Behaviour ◽  
Laboratory Studies ◽  
Free Living ◽  
Spermatophore Transfer ◽  
Sexual Interference

AbstractObservations of a free-living population of Bosca's newt, Triturus boscai, show that courtship behaviour in nature is similar to the behaviour observed in earlier laboratory studies. Complementary evidence was obtained on the behaviour called flick, which is sometimes inserted at the end of the static display phase, and may be viewed as an equivalent behaviour to the retreat display of the other small-bodied newt species. Sexual interference in the natural population was mainly caused by males. Two characteristic male behaviour patterns were recognised, the waiting position and the push-tail. Females tend to withdraw from situations of interference. Courtship sequences solely consisting of orientation and spermatophore transfer phases, so-called short-circuit sequences, may be interpreted as a male strategy to avoid the very severe male-to-male interference that exists in a wild population.

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