Volume 54, Issue 2

Over the past three decades, Caribbean coral reefs have drastically changed in structure and organization due to anthropogenically driven environmental changes. The prognostic trend indicates a shift from coral- to more algal-dominated reefs coupled with a loss in biodiversity and destabilization of reef structure. This study focuses on the composition of the most common algal growth form, the turf, and investigates turf succession within a fringing Caribbean coral reef. In a field study starting October 2007, we followed succession of turf algal assemblages grown on artificial substrata for periods of 15 up to 333 days at different water depths (5, 15 and 25 m). Species composition and abundance,biodiversity, total cover, and biomass were investigated and compared in uni- and multivariate analyses. Despite the pronounced change in coral reef structure over the past years, we found little difference from primary succession patterns described 30 years earlier. Succession patterns revealed a high diversity, mainly driven by the filamentous brown algal order Ectocarpales, the crustose green alga Pringsheimiella scutata at early stage, and diverse filamentous Cyanobacteria at later stages. Overall, the study provides insight into the early successional stages of coral reef vegetation by identifying the key species and discussing possible factors determining reef development in relation to environmental change.

We tested effects of light and temperature on survival and development of spores of Chondracanthus squarrulosus to determine their influence on the in situ haploid: diploid population ratio. Initially, reproductive tissues of both phases were induced to release spores under standard laboratory conditions. As in most of the Gigartinales, larger numbers of carpospores were released relative to tetraspores (4:1). Tetraspores, however, had higher germination rates (70% vs. 30%). Gametophytes and tetrasporophytes, germinated from spores, were exposed to light and temperature gradients (45–135 μmol photons m -2 s -1 and 14–30°C). Tetrasporophyte survivorship was negatively affected by high temperatures. In contrast, gametophytes had 100% survival at all temperatures tested and their growth rates were greater than those observed in the tetrasporophytes, particularly at higher temperatures. Therefore, the low germination rate of carpospores and the greater survivorship in the first gametophyte stages at higher temperatures would help explain the dominance of the gametophytes over tetrasporophytes of C. squarrulosus in the Gulf of California. A Leslie matrix based on the number of spores released and adult plant survival demonstrated that it is possible to generate a stable adult plant ratio close to the one that we observed in the field.

We made a taxonomic study of representatives of Anadyomene occurring off the coast of Bahia State, Brazil. Six species were identified: A. lacerata, A. linkiana, A. pavonina, A. rhizoidifera, A. saldanhae and A. stellata . This is the first report of A. rhizoidifera since the original description of the species. Non-birefringent proteinaceous crystalline inclusions in the form of tetrahedrons were recorded for the first time in the genus. Fertile thalli of A. saldanhae and A. stellata were also encountered for the first time along the Brazilian coast. A. stellata has the widest distribution along the coast of Bahia State; it was found from the intertidal region to depths of 100 m. A. rhizoidifera occurred in only a single, intertidal collection. A. lacerata, A. linkiana, A. pavonina and A. saldanhae occurred only in the near-shore zone at a minimum depth of 20 m. Detailed descriptions, illustrations and comparisons with related taxa are provided.

Coral reefs have undergone profound ecological changes over recent decades. Areas formerly covered by scleractinian coral species are now often overgrown by macroalgae. In Martinique (West Indies), this phenomenon has lead to the colonisation of numerous coral reefs by algae, amongst which Sargassum is one of the most prominent. This study focuses on potential defence molecules produced by Sargassum polyceratium . The hexane dipping method was employed to extract surface molecules on fresh material, and their bioactivities were assessed against bacteria (marine and estuarine), and marine tropical invertebrates [an annelid ( Pseudonereis sp.), a bivalve ( Codakia orbicularis ) and a sea urchin ( Diadema antillarum )]. Extracts were active against all microorganisms tested (MIC=150 or 300 μg ml -1 ), early stages of development in Pseudonereis sp. (MIC=100 μg ml -1 ) and embryos of C. orbicularis and D. antillarum (MIC=5 μg ml -1 ), suggesting the production of defence compounds by S. polyceratium .

Colpomenia , a small genus with 11 species of globular to bullate form, occurs in temperate to tropical waters worldwide. Because morphology is highly diverse, the species-level taxonomy requires re-evaluation. We analyzed the mitochondrial cox 3 gene from 50 samples of the genus. A new species, Colpomenia claytonii sp. nov., is described based on samples collected from Korea, Japan, Hong Kong, Australia, New Zealand, South Africa, and the USA and compared with similar congeners. Compared to others, the new species is larger, and has a more irregular thallus often with a deeply infolded surface. It is usually epilithic in tide pools and in the lower intertidal and subtidal zones. In all phylogenetic analyses of cox 3 sequences, C. claytonii was consistently distinct from congeners. Colpomenia expansa is closely related to C. claytonii , and the clade containing these two species is closely related to C. peregrina . A total of 14 cox 3 haplotypes was found in C. claytonii , indicating high haplotype diversity and a recent dispersal pattern. The present study shows that C. claytonii is a widely distributed species across the Pacific Ocean to South Africa; it was previously misidentified as a variant of C. peregrina .

Seasonal samples of macrophytes were collected from April 2003 to May 2010 from the most important transitional water systems of western Greece (nine coastal lagoons) and Cyprus (two coastal saline lakes, Akrotiri and Alyki Larnaca's). Our aim was to summarize, list and provide a full inventory of benthic aquatic flora recorded in these transitional water systems. The 60 taxa found belonged to five phyla, viz., Rhodophyta, Ochrophyta, Chlorophyta, Streptophyta and Magnoliophyta. There were 56 taxa in Greek lagoons and 16 in Cypriot water bodies. Many macroalgal species recorded in these environments form attached and unattached assemblages and play integral roles in the quality status of transitional water systems. The rare charophytes (Streptophyta) Chara tenuispina and C. hispida f. corfuensis are newly recorded for the Greek study area. In Cyprus, we found four species of charophytes ( Chara aspera, C. canescens, C. vulgaris and Lamprothamnium papulosum ) and two species of spermatophytes (Magnoliophyta): Althenia filiformis and Potamogeton pectinatus , which are new records for the island. Najas marina ssp. armata, P. pussilus , and Zannichelia pallustris ssp. pedicellata are new records for the study areas on Cyprus.

Henri Van Heurck examined a sample collection of sea ice and underlying sea floor sediment material during the Belgian Antarctic Expedition (1897–1899). He described eight new taxa of the monoraphid diatom genus Cocconeis from this collection including: C . antiqua var. tenuistriata , C . gautierii var. gautierii and var. inornata , C . heydrichii , C . japonica var. antarctica , C . litigiosa , C . schuettii var. schuettii and var. minor . All these Cocconeis taxa share well-silicified sternum valves with wide, apical hyaline areas, more or less lenticular in shape, and narrow hyaline bands at mid-distance between the apical axis and the margin, while the more delicate raphe-sternum valves bear uniseriate striae, a hemistauros associated with the central raphe area, and crescent-shaped terminal hyaline areas. Since their original description in the early 20th century, these Cocconeis taxa have been rarely reported. I studied newly described Cocconeis taxa from Van Heurck's type material by light microscopy. The main valve features of C. gautierii var. gautierii and var . inornata , C. litigiosa , and C. schuettii var. schuettii and var. minor agree well with those of Cocconeis antiqua ; I propose these five taxa be reduced to synonymy of C. antiqua .

Differentially expressed genes in Dunaliella salina grown under super saturated salt stress (5.5  m ) were isolated by subtractive hybridization, cloned and classified for further biotechnological and industrial exploration. Sequence homology analysis showed that 26% of the library represented salt responsive genes for metabolic enzymes, viz., fructose-1,6-diphosphate aldolase ( AldP ), glucose-6-phosphate dehydrogenase, carbonic anhydrase, phosphoglycerate kinase etc., while 6% of library clones contained hypothetical/unknown genes. Six clones (8% of the library) contained genes that differentially expressed under salt stress, however, 6–8% of the library represented genes over expressed under salt stress and involved in photosynthesis, defense, cell rescue (chaperon/protease inhibitor) and protein sorting. About 39% were other genes of which 6% and 14% were transcription factors and house keeping genes (putative enzymes/signaling) respectively, while the remaining 19% of genes had miscellaneous functions.

Hydrogen peroxide content in Dunaliella salina cells increases concomitantly with salinity, and maximum content occurred at 5.0  m NaCl concentration. Activity of the antioxidant enzyme superoxide dismutase (SOD, EC 1.15.1.1) increased significantly by two- and three-fold in 1.0 and 2.0  m salt concentrations, respectively, thereafter declining significantly. Unlike SOD, catalase (EC 1.11.1.6) activity decreased in tandem with salinity; however, there was no significant decrease in catalase activity up to 2.0  m salt concentration (compared to 0.5  m salinity). There was no significant decrease in catalase activity from 2.0  m to 5.0  m salinity, whereas a significant decrease was observed in 4.0 and 5.0  m salinity (compared to 1.0  m salinity). Ascorbic acid peroxidase (EC 1.11.1.11) activity decreased concurrently with salt stress up to 2.0  m , thereafter no significant change was observed in cells grown in varying salt concentrations (0.5–5.0  m NaCl). Detailed study of hydrogen peroxide content and antioxidant enzymes in response to varying salinity (0.5–5.0  m NaCl) has not been reported previously in Dunaliella salina . Antioxidant enzymes and H 2 O 2 scavenging systems have short-term adaptation mechanisms for protection against salt stress and are not important in imparting salt stress tolerance to Dunaliella salina at high salinity because of production of secondary antioxidant metabolites, like β-carotene, which protect the alga against salt induced oxidative damages.

Enhalus acoroides is the largest tropical seagrass species. It is common and highly productive in coastal ecosystems. The objective of this study was to investigate temporal growth and reproduction of E. acoroides in Haad Chao Mai National Park, Thailand, which is located on the eastern shore of the Indian Ocean. Growth of E. acoroides was significantly different among months. Average leaf elongation rate was 2.07±0.04 cm day -1 and the average leaf plastrochrone interval was 26.1±0.6 days. New leaf production, leaf elongation rate and leaf surface area tracked definite patterns of seasonal change. There were two peaks of growth during the transitional season. All growth variables correlated with water temperature. Recruitment rate of new shoots was low from January to March (0.009–0.007 shoots shoot -1 day -1 ). Flower production was low, with male and female flowers occurring at densities of 0.10±0.05 m -2 and 0.13±0.10 m -2 , respectively. No fruits were found in experimental plots throughout the study.

Forty-eight fungi (34 Acomycota, 13 anamorphic fungi and one Basidiomycota) were collected from 141 driftwood samples collected from one sandy and one rocky beach around Yokosuka city in two seasons (summer and winter). Of these, 28 (58%) fungi are new records for Japan including 16 (33%) potentially new taxa. Thirty-six and 26 fungi were recorded from Hakkeijima and Umikaze beaches, respectively, in both seasons. Ceriosporopsis halima and Corollospora maritima were the dominant taxa at both locations. Common fungi include: Clavatospora bulbosa , Corollospora portsaidica , Lignincola laevis and Naufragella spinibarbata . Fungi recorded from the two beaches were markedly different, with only 14 species common to both sites. Members of the order Halosphaeriales with 30 species (representing 62.5% of the fungi) were the dominant mycota at the two sites. Anamorphic fungi included eight hyphomycetes and one coelomycete, a Phoma species. Potentially new species were sequenced (partial LSU and SSU rDNA) to determine their identity.