Review of morphological and biological studies of the carrageenophyte Solieria filiformis (Kützing) Gabrielson (Rhodophyta,Gigartinales)

Abstract

The occurrence of extensive populations of the carrageenophyte Solieria filiformis in the Mar Piccolo of Taranto (Italy, Ionian Sea) has prompted this review of the literature on the subject. S. filiformis is a subtidal alga that inhabits both sheltered and exposed habitats. Interpretation of the literature leads us to classify it as an euryecious species showing high tolerance of a broad range of temperature, irradiance and salinity. S. filiformis grows in both the attached form capable of sexual reproduction and unattached only capable of vegetative propagation. The morphology of both forms as well as of the reproductive organs have been studied in detail. Laboratory and tank cultures are being carried out to estimate growth rates and elucidate its physiological ecology. For the Mediterranean specimens fast-growing strains have been selected and the optimal growth conditions have been established. S. filiformis is a potential candidate for cultivation because of the high quality of its carregeenan and the modest requirements of its thallus.     

Partial Purification and Properties of Ornithine Transcarbamoylase from Nostoc muscorum Kützing

Ornithine transcarbamoylase (carbamoyl phosphate:l-ornithine carbamoyltransferase, EC 2.1.3.3) has been partially purified from the blue-green alga Nostoc muscorum Kützing, an organism in which the enzyme seems to be involved in a bicarbonate-fixing pathway leading to citrulline. Pertinent to possible regulation of this pathway, the enzyme shows hyperbolic substrate kinetics, has a molecular weight estimated at 75,000 daltons, and its catalytic capability is little influenced by a selection of metabolites that might conceivably act as regulators in vivo. Thus it seems unlikely that this enzyme is the control point for bicarbonate fixation. In terms of energy of activation (12.3 kcal/mole), size and Km for carbamoylphosphate, the Nostoc enzyme resembled preparations from liver and higher plants more than preparations from Streptococcus and Mycoplasma. The enzymes from Streptococcus and Mycoplasma are probably specialized for citrulline breakdown rather than citrulline synthesis. The Km for ornithine was 2.5 mm at a saturating concentration of carbamoylphosphate and the Km for carbamoylphosphate was 0.7 mm at an ornithine concentration of 2 mm. Ornithine was inhibitory at concentrations greater than 2 mm. Phosphate was a competitive inhibitor with respect to carbamoylphosphate. The pH optimum for citrulline synthesis was 9.5.     

Indoor and outdoor culture of Callophyllis variegata (Bory) Kützing (Gigartinales,Rhodophyta) in southern Chile

Callophyllis variegata (Gigartinales, Rhodophyta) is an edible species used in salads and soups in Asian countries. Research into its early stages and growth is required to develop cultivation. This study evaluated the effect of temperature and photoperiod on viability and germination in the laboratory and, subsequently, growth in the sea. Carpospores collected during different seasons from the localities of Chauman (41°47′S) and Puñihuil (41°55′S), in southern Chile, were grown in Provasoli medium at 10 and 15 °C. After 7 days, viability was higher in the photoperiod of 16:08 h (light/darkness) and 10 °C, while germination was higher at 15 °C in the same photoperiod. Viability was over 65 % in both localities in winter and spring, and germination was 74.6 and 87.5 %, respectively. Daily growth rates in the laboratory fluctuated between 2 and 10 %. Tetrasporophytic juveniles settled on cotton nets were grown on long lines at 3.5 m deep in the sea for 8 months. Growth and density of fronds were evaluated monthly. Epiphytic seaweeds such as Ulva sp. and Polysiphonia sp. were observed on the nets. C. variegata fronds grew up to approximately 8 cm, and the final density was between 10 and 40 ind/10 cm. A preliminary evaluation of culture costs is also presented.     

Length–weight relationships of six indigenous fish species from the River Cauvery and its estuary,India

The present study estimated length–weight relationships (LWRs) for six indigenous fish species (Barilius gatensis, Salmostoma acinaces, S. boopis, Puntius amphibius, Hemibagrus punctatus and Ambassis miops) based on specimens collected from River Cauvery (including estuary) during July 2017–January 2020. The sampling surveys were carried out in three distinct sampling seasons, viz., the pre-monsoon (March–May), the monsoon (July–October) and the post-monsoon (November–February). Majority of the fish specimens dealt in the study were collected from multi-meshed monofilament gill nets (mesh sizes 18, 30, 45, 60, 90, 110, 120 and 150 mm) operated by local fishers. For those sites situated in the protected areas, sampling was carried out by cast nets with prior permission from the local administration and the collected fishes were released back into river after length–weight measurements. The length measurements were noted as total length (TL) measured to the nearest 0.1 cm by using a digital Vernier caliper. A digital balance was used for weight measurements with an accuracy of 0.01 g. The study recorded a new maximum length of 48 cm for H. punctatus. The LWR data generated from the present study are significant for proper assessment of the stock status and their management, if collected together with other essential biological and physical parameters.     

Morphology and taxonomy of Stephanodiscus Minutulus (Kützing) Cleve et Möller (Bacillariophyta) from Lake Dal’nee (Kamchatka)

Morphological variability of Stephanodiscus minutulus (Kützing) Cleve et Möller from Lake Dal’nee (Kamchatka, Russia) was studied. Slightly and strongly silicified morphotypes with valves elevated or depressed in the center area were shown. On the basis of the obtained data, a taxonomical place of small-celled Stephanodiscus from other Kamchatka waterbodies was specified.     

Therodamas Krøyer, 1863 (Copepoda: Ergasilidae) from the Piauí River estuary,State of Sergipe,Brazil

The pre-metamorphic female of Therodamas serrani Krøyer, 1863 is described for the first time based on new material collected from the upper reaches of Piauí River estuary, northeastern Brazil. Females are present in the plankton throughout the year, and are common during the rainy season. Five of the six currently accepted species of Therodamas are known only from metamorphic females, making identification of pre-metamorphic stages problematic. Identification of T. serrani was made on the basis of the leg setation and the very similar proportions of the two apical endopodal spines on leg 1.     

Structural characterization of sulfated arabinans extracted from Cladophora glomerata Kützing and their macrophage activation

Water-soluble sulfated heteropolysaccharides were extracted from Cladophora glomerata Kützing and fractionated by ion-exchange chromatography, which yielded two subfractions, F₁ and F₂. The crude and fractionated polysaccharides (F₁ and F₂) mostly consisted of carbohydrates (62.8–74.5%) with various amounts of proteins (9.00–17.3%) and sulfates (16.5–23.5%), including different levels of arabinose (41.7–54.4%), galactose (13.5–39.0%), glucose (0.80–10.6%), xylose (6.84–13.4%), and rhamnose (0.20–2.83%). Based on the size exclusion chromatography (SEC) profiles, the crude and fractions mainly contained one peak with shoulders having molecular weight (M_w) ranges of 358–1,501 × 10³. The F₁ fraction stimulated RAW264.7 cells to produce considerable amounts of nitric oxide and cytokines compared to the crude and F₂ fraction. The backbone of the most potent immunostimulating fraction (F₁) was α-(1→4)-L-arabinopyranoside with galactose and xylose residues as branches at O-2 position, and sulfates mainly at O-2 position as well.     

Accumulation,degradation and biological effects of lindane on Scenedesmus obliquus (Turp.) Kütz

A study was made of accumulation, degradation and biological effects of lindane (r-BHC) on Scenedesmus obliquus (Turp.) Kütz. The work was conducted in a sewage reservoir in Han-Ku, Tianjin. Experimental results show that at 0.1–10 mgl⁻¹ concentration of lindane, the growth, chlorophyll and carotene content in S. obliquus do not differ much from the control. At concentrations of 50–100 mgl⁻¹, however, growth is inhibited, and chlorophyll and carotene content is low. From the beginning of the experiment until the fifth day, growth rate and pigment content increase constantly. On the seventh day, they start to decrease. Spectrographic analysis shows that pigment content decreases, but pigment structure is not changed even at high concentration of lindane. At 1–10 mgl⁻¹ of lindane, amino acids remain unchanged, with the exception of aspartine, arginine, methionine and phenylalanine. Scenedesmus obliquus (Turp.) Kütz possesses a certain accumulating capacity for r-BHC, which is higher at 1 mgl⁻¹ than at 10 mgl⁻¹. Accumulation is enhanced with time and is better under turbulent conditions. Gas chromatograms show that after treatment for 24 h, there are two more peaks at retention time 1′32″ and 1′53″, respectively, suggesting that a certain degree of lindane degradation occurs. The nature of these degradation products awaits further study. As a conclusion S. obliquus (Turp.) Kütz holds promise in the treatment of lindane-containing wastewaters in the range of 1–10 mgl⁻¹.     

Cryptococcus mollis Kützing,type species of the genus Cryptococcus: investigation of the type material

The legitimacy of the name Cryptococcus mollis for the type of the genus Cryptococcus is shown. The type material, available in the Rijksherbarium at Leiden University was investigated by transmission electron microscopy. The cell wall of most of the cells showed a structure, similar to that of basidiomycetous yeasts. Bud scars were also found.     

Dynamics of microtubule reassembly and reorganization in the coenocytic green alga Ernodesmis verticillata (Kützing) Børgesen

The dynamics of microtubule (MT) disassembly and reassembly were studied in the green alga Ernodesmis verticillata, using indirect immunofluorescent localization of tubulin. This alga possesses two distinct MT arrays: highly-ordered, longitudinally-oriented cortical MTs, and shorter perinuclear MTs radiating from nuclear surfaces. Perinuclear MTs are very labile, completely disassembling in the cold (cells on ice) within 5–10 min or in 25 μM amiprophos-methyl (APM) within 15–30 min. Although cortical MTs are generally absent after 3 h in APM, it takes 45–60 min before any cold-induced depolymerization is apparent, and some cortical MTs persist after 6 h of cold treatment. The extent of immunofluorescence of cytoplasmic (depolymerized?) tubulin is inversely proportional to the abundance of cortical MTs. Recovery of MT arrays upon warming or upon removal of APM occurs within 30–60 min for the perinuclear MTs, but the cortical arrays take much longer to regain their normal patterns. The cortical MTs initially reappear in a random distribution with respect to the cell axis, but within 3–4 d of warming (or 24–36 h of removing APM) they are nearly parallel to each other and to the cell's longitudinal axis. Thus, although the timing differs, the actual patterns of depolymerization and recovery are similar, irrespective of whether physical or chemical agents are used. Longer-term treatments in 1 μM APM indicate that despite the rapid disappearance of perinuclear MTs, a loss of the uniform nuclear spacing occurs gradually over 1–6 d. Similar disorganization of nuclei is obtained with long-term treatment with 1 μM taxol, where a gradual loss of perinuclear MTs is accompanied by an increased abundance of mitotic spindles. This implies that perinuclear MTs can disassemble in vivo in the presence of taxol, and that they are not the sole components involved in maintaining nuclear spacing in these coenocytes. The results indicate that both nuclear and cortical sites of MT nucleation may exist in this organism, and that MT reassembly and re-organization are temporally distinct events in cells that have highly-ordered arrays of long MTs.     

The removal of ρ-chlorophenol in aqueous cultures with free and alginate-immobilized cells of the microalga Tetraselmis suecica

The present study aimed at evaluating the ability of some isolated cyanobacterial and microalgal strains for the removal of ρ-chlorophenol (ρ-CP), an environmentally harmful contaminant. To identify the most efficient species, a screening program was carried out using 15 microalgal and cyanobacterial strains. Among them, Tetraselmis suecica was able to remove 67 % of the ρ-chlorophenol at an initial concentration of 20 mg L^?1 from the medium within a 10-day period. The efficacy of the process was dependent on the ρ-chlorophenol concentration. At concentrations above 60 mg L^?1 of the pollutant, no removal was observed due to the inhibitory effect of ρ-chlorophenol on the T. suecica cells. The effect of cell immobilization in alginate beads on T. suecica removal capacity was also examined. Using this technique, the removal efficacy for the initial ρ-CP concentration of 20 mg L^?1 increased up to 94 %.     

A study to assess the microbial contamination of Mya arenaria clams from the north shore of the St Lawrence River estuary, (Québec, Canada)

The aims of the present study were to assess the microbial quality of Mya arenaria clams from the north shore of the St. Lawrence River estuary and to validate various microbial indicator microorganisms of bivalve mollusks contamination. Clams were collected from nine sites, including four harvesting sites closed by virtue of the Canadian Shellfish Sanitation Program (CSSP). Six contamination indicators (fecal coliforms, somatic coliphages, F-specific coliphages, fecal streptococci, Clostridium perfringens, and Escherichia coli) and four pathogens (Campylobacter sp., Cryptosporidium parvum, Giardia sp., and Salmonella sp.) were identified in the clams. Indicators sensibility, specificity and predictive values with respect to the presence of pathogens were calculated. Pathogenic microorganisms detection frequency in clams was important (92%). Globally, pathogens tend to be less frequently detected in opened harvesting sites (p = 0.086). Although the assessed indicators were not perfect, when F-specific coliphages are associated with E. coli or fecal coliforms, a good sensibility (62%-64%) and good positive predictive value (88%) with respect to the investigated pathogens are obtained.     

Calmodulin and wound healing in the coenocytic green alga Ernodesmis verticillata (Kützing) Børgesen

The involvement of calmodulin (CaM) in wound-induced cytoplasmic contractions in E. verticillata was investigated. Indirect immunofluorescence of CaM in intact cells showed a faint, reticulate pattern of fluorescence in the cortical cytoplasm. Diffuse fluorescence was evident deeper within the cytoplasm. In contracted cells, CaM co-localizes with actin in the cortical cytoplasm in extensive, longitudinal bundles of microfilaments (MFs), and in an actin-containing reticulum. No association of CaM with tubulin was ever observed in the cortical cytoplasm at any stage of wound-healing. When contraction rates in wounded cells are measured, a lag period of 2 min is followed by a rapid, steady rate of movement over the subsequent 10 min. The delay in the initiation of longitudinal contraction corresponds to the time necessary for the assembly of the longitudinal MF bundles. Cytoplasmic motility was inhibited in a dose-dependent manner by CaM antagonists. In these inhibited cells, MF bundles did not assemble, or were poorly formed. In the latter case, CaM was always found associated with MFs. These results indicate a direct spatial and temporal correlation between CaM and actin, and a potential role for CaM in regulating the formation of functional MF bundles during wound-induced cytoplasmic contraction in Ernodesmis.Abbreviations CaM calmodulin - DMSO dimethyl sulfoxide - EGTA ethylene glycol-bis(-aminoethyl ether)-N,N,N,N-tetraacetic acid - MF(s) microfilament(s) - MT(s) microtubule(s) - TFP trifluoperazine - w-5 N-(6-aminohexyl)-1-naphthalenesulfonamide - W-7 N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide We are especially grateful to: Dr. J.A. West (University of California, Berkeley) for the original algal isolates; Dr. L. Van Eldik (Vanderbilt University School of Medicine) and Dr. J.L. Lessard (University of Cincinnati College of Medicine) for graciously providing CaM and actin antibodies, respectively; Dr. S.J. Roux (University of Texas, Austin) for the gift of purified oat CaM; Dr.H. Green (Smith, Kline and French Laboratories, Philadelphia, Penn., USA) for providing the trifluoperazine; and M.E.T. Scioli for assistance with the statistical analyses. Portions of this work were supported by National Science Foundation grant DCB 8402345 and U.S. Department of Agriculture grant 87-CRCR-1-2545 to J.W.L.     

Oogonial release in Turbinaria conoides (J. Agardh) Kützing (Fucales,Sargassaceae)

The oogonium in Turbinaria conoides (J. Agardh) Kürzing at the time of release is 8-nucleate and consists of 3 wall layers namely exochiton, mesochiton and endochiton. The exochiton contains alginic acid. The mesochiton a mixture of alginic acid and sulphated polysaccharides. The endochiton that is evident in the unreleased 8-nucleate oogonium, stains for sulphated polysaccharides, but is PAS negative. In a released oogonium, the endochiton is Alcian blue and PAS positive and consists of both alginic acid and sulphated polysaccharides.Polysaccharide granules are secreted near the perinuclear region and in thecytoplasmic vacuoles during the initiation of mesochiton. Furthermore, at the distal end the mesochiton froms a pad that fuses with the exochiton. The pad consists of alternate thick and thin bands. The exochiton opens at one side due to the swelling of the oogonium and accumulation of sulphated polysaccharides between exochiton and mesochiton followed by formation and elongation of a mesochiton stalk. The 8-nucleate oogonium is, thus, extruded from the conceptacle, but remains attached to the exochiton by means of a long mesochiton stalk. The secretory paraphyses, at the time of oogonial release, produce copious amounts of polysaccharides. The oogonium is, thus, extruded through the ostiole by the combined efforts of the 3 wall layers that are histochemically and histologically different, in combination with secretion produced by secretory paraphyses.     

Photoacclimation in a tropical population of Cladophora glomerata (L.) Kützing 1843 (Chlorophyta) from southeastern Brazil.

Photoacclimation of photosynthesis was investigated in a tropical population of C. glomerata (S?o Paulo State, southeastern Brazil, 20 degrees 48' 24" S and 49 degrees 22' 24" W) by chlorophyll fluorescence parameters and chlorophyll a content. Plants were acclimated to two levels of irradiance: low (65 +/- 5 micromol.m(-2).s(-1)) and high (300 +/- 10 micromol.m(-2).s(-1)) and exposed short-term (4 days) and long-term (28 days) under a light-dark cycle of 12:12 hours. Photosynthesis-irradiance (PI) curves revealed distinct strategies of photoacclimation. In long-term exposure, plants acclimated by altering the photosynthetic units (PSU) number and keeping fixed the PSU size, revealed by increased rates of maximum photosynthesis (Pmax), lower photosynthetic efficiency (alpha) and higher values of the saturation parameter (Ik) under high irradiance. The short-term acclimation strategy consisted of changing the PSU size, with a fixed number of PSUs, as revealed by similar Pmax but higher alpha and lower Ik under low irradiance. Chlorophyll a contents followed the general pattern reported in green algae of higher concentrations under lower irradiance. Dark/light induction curves revealed consistently higher values of potential quantum yield under low irradiance. Initial and final values showed a higher recovery capacity in the short (84.4-90.6%) term exposure than in the long-term case (81.4-81.5%). ETR (electron transport rate) and NPQ (non-photochemical quenching) values were consistently higher under low irradiance. ETR showed a continuous and steady increase along the light exposure period in the short and long-term experiments, whereas NPQ values revealed a rapid increase after 15 seconds of light exposure, kept a slightly increasing trend and stabilized in most treatments. Lower photosynthetic performance (ETR) and recovery capacity of potential quantum yield were observed, particularly in long-term exposure, suggesting that this population is constrained by the typical high light environment of tropical regions.     

Karyotypic characterization and NOR analysis by different banding techniques of Rhamdia quelen (Pisces, Pimelodidae) from the first plateau of the Iguaçu River (Brazil)

A population of R. quelen from the first plateau of the Igua?u River (Paraná State, Brazil) was analyzed cytogenetically. A diploid set of 58 chromosomes was constituted by 32 M, 16 SM, 6 ST and 4 A (FN=116). In one individual a 2n=59 karyotype was determined due to the presence of one additional metacentric heterochromatic chromosome. NORs, detected by AgNO3 and CMA3 staining as well as fluorescence in situ hybridization with an 18S rDNA probe, are located at a terminal position on the short arms of a ST chromosome pair. C-banding marks the NORs and other weak bands distributed on telomeric regions of some chromosomes. These results give evidence that Rhamdia constitute, in terms of karyotypic macrostructure, a conserved group and support the idea that several synonymous species may be included in this genus.     

Calmodulin and wound healing in the coenocytic green alga Ernodesmis verticillata (Kützing) Børgesen: Ultrastructure of the cortical cytoskeleton and immunogold labeling

Ultrastructural changes in the cortical cytoskeleton during wound-induced cytoplasmic contraction were examined in the coenocytic green alga Ernodesmis verticillata. Both calmodulin (CaM) and actin were localized in intact and contracting cells by immunogold labeling. Within 5 min after wounding, compact microfilament (MF) bundles were observed which increase in diameter as cytoplasmic contraction proceeds. Calmodulin labeling is associated with amorphous material studding the MF bundles, whereas actin labeling occurs along the individual MFs. No MF bundles were ever observed during contraction that were not also labeled with anti-CaM antibodies. In cells treated with the CaM antagonist W-7 (N-[6-aminohexyl]-5-chloro-1-naphtha-lenesulfonamide), MF bundles do not form, and the formation of loosely arranged MFs (similar to nascent bundles in untreated cells) is greatly retarded. We propose that CaM binds indirectly to actin by activating an actin-binding regulatory protein which functions in early stages of the transduction sequence leading to functional MF bundles. Additionally, ultrastructural evidence is presented for a plasma-membrane skeleton or undercoating in this alga.Abbreviations CaM calmodulin - MF(s) microfilament(s) - MT(s) microtubule(s) - W-7 N-[6-aminohexyl]-5-chloro-1-naphthalenesulfonamide We are especially grateful to Dr. J. A. West (University of California, Berkeley, USA) for the original algal isolates and to Dr. L. Van Eldik (Vanderbilt University School of Medicine, Vanderbilt, Tenn., USA) for the generous gift of CaM antibodies. Portions of this work were supported by National Science Foundation grant DCB 84-02345 and U. S. Department of Agriculture grant 87-CRCR-1-2545 to J.W.L.