Salinity Induced Regime Shift in Shallow Brackish Lagoons

In brackish lagoons, Daphnia is replaced by calanoid copepods (Eurytemora affinis, Acartia spp.) and rotifers when a certain threshold (depending on, for instance, fish density) is reached. We hypothesize that loss of Daphnia induces a regime shift from clear to turbid at high nutrient concentrations. We conducted a factorial designed enclosure experiment with contrasting salinities (0–16‰), low fish predation (one three-spined stickleback, Gasterosteus aculeatus, m⁻²) and three levels of nutrient loading in a shallow brackish lagoon. A change point analysis suggests a strong regime shift from a clear to a turbid state at 6–8‰ salinity at low and high loading, but not for the control. From the low to the high salt regime, chlorophyll a (Chla), Chla:total phosphorus (TP) and Chla:total nitrogen (TN) ratios shifted highly significantly for all nutrient treatments, and the bacterioplankton production followed the changes in Chla. These changes occurred parallel with a shift from cladoceran and cyclopoid copepod to rotifer dominance. Monitoring data from 60 Danish brackish lagoons show increasing Chla with increasing TP and TN as well as interactive effects of TN and salinity, peaking at intermediate salinity. A relatively weak effect of salinity at low nutrient concentrations and the stronger effect at intermediate high salinity are in accordance with the experimental results. However, these data suggest a lower salinity threshold than in the experiment, which may be explained by a higher fish density. Our results have implications for the management of coastal lagoons both at present and in a future (predicted) warmer climate: (1) improved water quality can be obtained by reducing the nutrient loading or enhancing the freshwater input to a level triggering a shift to Daphnia dominance (typically <2‰), (2) fish manipulation is probably not a useful tool for brackish lagoons, unless the salinity is below the threshold for a potential shift to a clear Daphnia dominated state, and (3) more abrupt changes will expectedly occur in low-saline coastal lagoons at increasing salinity during summer in a future warmer climate.     

Primary productivity and related parameters in three different types of inland waters in Sri Lanka

Gross and net primary production together with chlorophyll-a biomass were investigated with respect to depth and diurnal changes in three categories of inland waters (reservoirs, temporary ponds, brackish water lagoons) in Sri Lanka. Ten field sites, in both the dry and wet zones of the island, were investigated. Bimodal productivity profiles were recorded in two of the three reservoirs studied. The diel pattern of net photosynthetic rate varied between sites although peak photosynthetic efficiency occurred at solar noon. Surface photoinhibition was characteristic of the reservoirs and brackish water lagoons but not of the temporary ponds. Mean gross primary production was 3.02 g C m^–2 d^–1 but was higher in the temporary ponds than in the reservoirs. The gross primary production in the brackish water Koggala Lagoon at 0.08 g C m^–2 d^–1 is a record low for tropical lagoons and was 2.5 times less than the two other lagoons investigated. Variability in net primary production between sites was similar to the variation in gross production with a relatively low mean value for tropical inland waters of 0.495 C m^–2 d^–1. Mean maximum photosynthetic rate was 0.30 mg C m^–3 h^–1 but was lower in the reservoirs than in the temporary ponds and lagoons.     

Les frontìeres naturelles et humaines du système lagunaire Ebrié Incidences sur l'hydroclimat

The hydrology of the brackish and tropical lagoon Ebrie (Ivory Coast) is dominated by large exchanges with its boundary ecosystems: atmosphere, continent, ocean and human community. Allochthonous water input is equivalent to 20 times the volume of the lagoon basin. But it is spatially and temporally heterogeneous. The eastern regions are dominated by continental waters flows, the central region is influenced by ocean and human wastes, while the western regions are relatively isolated from those different sources. Temporal variabilities of the exchanges contrast the hydroclimate which is characterized by a succession of four seasons. Small variations of one of the boundary ecosystems can lead to great perturbations of the lagoon climate, which explains considerable interannual differences. It is shown that lagoons and lakes are firstly distinguished by a large difference of intensity of their exchanges with their boundary ecosystems.

     

Quelques nouvelles données sur le phytoplancton marin et la production primaire à Tuléar (Madagascar)

Summary A list of 152 Diatoms and 158 Dinoflagellates is given and its biogeographic composition is discussed. Some quantitative data are presented: cells counts after sedimentation, spectrophotometric determination of plant pigments, and in situ primary production measurement using 14-C method. A nycthemeral study, carried out during 30 hours, shows that chlorophyll a values are highest between 15.00 and 21.00, and that photosynthesis increases from morning to evening.

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Quelques nouvelles données sur le phytoplancton marin et la production primaire à Tuléar (Madagascar)

     

A multiproxy approach to inferring Holocene paleobotanical changes linked to sea-level variation,paleosalinity levels,and shallow lake alternative states in Negra Lagoon,SE Uruguay

A multiproxy analysis of diatoms, chrysophyte cysts, opal phytoliths, and palynomorphs was undertaken in Negra Lagoon, to decipher Holocene changes in paleobotanical proxies associated with sea-level changes and paleolimnological conditions. Before the Holocene transgression (7000 yr BP), a terrestrial system was inferred as no aquatic palynomorphs or biogenic silica remains were recorded. During the sea-level maximum (5200 yr BP), marine/brackish conditions were established as indicated by diatoms, Chenopodiaceae, and a high content of cysts of Peridinioideae. The catchment consisted of grasslands and wetlands as indicated by the opal phytolith data. The Holocene transgression was followed by a sea-level decrease, which led to the onset of brackish/freshwater conditions as inferred from the co-dominance of freshwater and marine/brackish diatoms. This is also supported not only by the concomitant increase in non-siliceous freshwater microalgae and emergent macrophytes, but also by the presence of Myriophyllum. As sea level continued to decrease during late Holocene, a freshwater system was observed because of the complete separation from the ocean. Chrysophyte cysts were consistently recorded and brackish diatoms exhibited reduced abundances. The observed limnological changes are consistent with the alternative states hypothesis of Scheffer’s model (1998). That is, the clear water phases were explained because of high macrophyte abundances, low phytoplankton frequencies, high cyst to diatom ratios, and increase in frequencies of benthic diatom species. Conversely, turbid phases were likely to occur when low cyst to diatom ratios together with increase in planktonic diatoms and decrease in macrophytes values were detected. This highlights the importance of this approach to detect long-term changes in shallow lake alternative states.     

Species richness of crustacean zooplankton and trophic structure of brackish lagoons in contrasting climate zones: north temperate Denmark and Mediterranean Catalonia (Spain)

We sought to identify environmental factors influencing crustacean zooplankton species richness in brackish lagoons and to elucidate whether crustacean zooplankton species richness and trophic structure of brackish lagoons differ among two regions with contrasting temperatures. We sampled 35 and 42 brackish lagoons (salinity ranging from 0.3 to 55‰) in Mediterranean Catalonia (NE Spain) and northern-temperate Denmark, respectively. No significant differences were found in total crustacean zooplankton species richness or cladoceran richness between the climatic regions. Calanoid richness was higher in Denmark than in Catalonia, while cyclopoid richness was higher in Catalonia. Salinity was the most important variable associated with zooplankton species richness in both regions, richness of total zooplankton species, cladocerans and cyclopoids being negatively related with salinity. In both regions, a shift occurred from dominance of large filter feeding cladoceran species at low salinities to copepods and small cladoceran species at higher salinities. Cladoceran richness increased with increasing total phosphorus, but was not influenced by total nitrogen or chlorophyll-a. Trophic structure in Mediterranean brackish lagoons showed a more pronounced seasonal variation than in north temperate brackish lagoons. Our results imply that the indirect effects of climate warming, such as changes in salinity and hydrology, will have a larger impact on brackish lagoon ecosystems than the increase in temperature per se.     

Prosobranchia aus dem Litoral der karibischen Küste Kolumbiens

Zusammenfassung 1. Im Litoral der karibischen Küste Kolumbiens wurden 145 Prosobranchier-Arten nachgewiesen, die 79 Gattungen und 44 Familien zugehören. Die Arten werden beschrieben und abgebildet.2. Die Aufsammlungen wurden vor allem an den Küstenstreifen von Santa Marta, Cartagena und der Halbinsel Guajira gemacht. Dabei wurden die Biotope Felslitoral, Korallenriff, Sandstrand und Brackwasserlagune erfaßt.

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Prosobranchia from the littoral of the Caribbean coast of Colombia

145 species of prosobranchs from the littoral zone of the Caribbean coast of Colombia, South America, are described and illustrated. The species belong to 79 genera of 44 families. Most of the species were collected at the coastal areas of Santa Marta, Cartagena and the peninsula Guajira. The biotopes considered are the rocky littoral zone, coral reefs, sand beaches and brackish water lagoons.

     

Notes on the Diatomaceae of Ahmedabad and its environs

Synopsis In this note the Diatoms from the Gujarat College compound are systematically described and some notes or remarks are given on their occurrence, ecology and distribution in the region of Ahmedabad.Summary While summarizing the results of the present investigation, the following could be stated:that with the exception of two small notes by the author there exists little information of the Diatomflora of Ahmedabad region.The diatoms of the present area are a special kind of biotopes characterised by small size. However, the causes leading to this nannism remain to be determined.The observations regarding Caloneis beccariana (Grun.) Cl. and Amphiprora paludosa W S m. v. subsalina Cl., found to be in close harmony with those of HUSTEDT and CLEVE, respectively and further it is confirmed that they are very variable species.The water of the present locality could be called somewhat brackish on the basis of a large number of salt-loving diatoms being found here. Moreover, they are all alkaliphilous even the new entities with the exception of two which are known to be indifferent for the pH.In light of the existing Halobion data and local observations some of the new entities and a few others are assigned their Halobion status. The spectrum relating to the same is also given.The distribution of these diatoms is indicated for the region of Ahmedabad.With regard to their periodicity recorded for over a year it was observed that almost all the species were perennials and a few among them showed slight rises any time from September to December.Lastly, in all twenty-three diatoms are recorded from the present area representing ten genera. Of these, six are new records for India and three species and one variety is considered to be new.     

Environmental influences on the qualitative and quantitative composition of phytoplankton and zooplankton in North African coastal lagoons

Within the framework of the international research project MELMARINA, seasonal dynamics of plankton communities in three North African coastal lagoons (Merja Zerga, Ghar El Melh, and Lake Manzala) were investigated. The sampling period extended from July 2003 to September 2004 with the aim of evaluating hydrological and other influences on the structure, composition and space-time development of these communities in each lagoon. Phytoplankton in Merja Zerga showed a quasi-permanent predominance of marine diatoms in the open sea station and in the marine inlet channel. Dinoflagellates were abundant in summer and early autumn in the marine inlet and extended into the central lagoon station. In Ghar El Melh, marine species (especially diatoms and dinoflagellates) dominated despite occasional winter inflows of freshwater. In Lake Manzala, freshwater species generally predominated and the planktonic communities were comparatively very diverse. Chlorophyceae contributed 39% of the total species recorded and diatoms and cyanophyceans were also common; the Dinophyceae, Euglenophyceae, Chrysophyceae and Cryptophyceae less so. Zooplankton communities in both Ghar El Melh and Merja Zerga were dominated by marine copepods. Rotifera, Copepoda, Ostracoda, and Cladocera were recorded in both lagoons as were meroplanktonic larvae of Polychaeta, Cirripedia, Mysidacea and Gastropoda and free living nematodes. Ghar El Melh was the more productive of these two lagoons with spring and early summer being the productive seasons. Zooplankton communities in Lake Manzala were generally dominated by rotifers and highest zooplankton abundances occurred in April (2003). Sampling stations near the marine inlets showed the highest diversity and the zooplankton communities showed considerable spatial variation within this large lagoon. The three lagoons represent very different water bodies contrasted strongly in terms of tidal effects and freshwater availability. Yet, there are some similarities in ecosystem structure. Space-time development of the plankton communities was similar especially in Merja Zerga and Ghar El Melh. Species abundances and specific diversities indicated that seasonal changes in salinity and nutrient concentrations were the main influential factors. Lake Manzala was the most productive lagoon and all the three sites supported toxic algal species. Relatively low plankton biomass in Merja Zerga and Ghar El Melh probably resulted from a combination of factors including highly episodic nutrient inputs, light suppression (by turbidity) and nutrient competition with benthic algae. Water quality variables were largely driven by the hydrological regime specific to each lagoon. Nutrient enrichment and, particularly for Lake Manzala, sea level rise threaten the sustainability of the planktonic ecosystems in all three lagoons. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Guest editors: J. R. Thompson & R. J. Flower Hydro-ecological Monitoring and Modelling of North African Coastal Lagoons     

DIATOMS AS HOSTS FOR OTHER DIATOMS: OBSERVATIONS FROM SOUTHERN CALIFORNIA

Large epiphytic and epilithic diatom species hosting other diatoms were observed in several fresh‐ and brackish water sites in Southern California. The most commonly encountered hosts were species forming long filaments attached to rocks or macroalgae, Hydrosera whampoensis (Schwarz) Hendey, Melosira varians Agardh, Pleurosira laevis (Ehrenberg) Compere and Terpsinoe musica Ehrenberg. These large diatoms often had smaller diatoms attached, usually to the girdle bands and occasionally to the mucilage pads connecting the cells. For example, cells of T. musica were observed supporting growth of a diverse diatom assemblage composed of species of the genera Achnanthes, Achnanthidium, Amphora, Cocconeis and Tabularia; Synedra sp. was attached to M. varians and B. paxillifer; and Cocconeis placentula was seen on H. whampoensis. Thus, large epiphytic and epilithic diatoms seem to provide suitable sites for attachment of small epiphytic diatom species, and it appears that this phenomenon is more common than previously thought.     

Diatom assemblages in tsunami deposits associated with the 2004 Indian Ocean tsunami at Phra Thong Island, Thailand

Diatom assemblages in sandy deposits of the 2004 tsunami at Phra Thong Island, Thailand may provide clues to flow conditions during the tsunami. The tsunami deposits contain one or more beds that fine upward, commonly from medium sand to silty very fine sand. Diatom assemblages of the lowermost portion of the deposit predominantly comprise unbroken beach and subtidal species that live attached to sand grains. The dominant taxa shift to marine plankton species in the middle of the bed and to a mix of freshwater, brackish, and marine species near the top. These trends are consistent with expected changes in current velocities of tsunami through time. During high current velocities, medium sand is deposited; only beach and subtidal benthic diatoms attached to sediment can be incorporated into the tsunami deposit. High shear velocity keeps finer material, including planktonic diatoms in suspension. With decreasing current velocities, finer material including marine plankton can be deposited. Finally, during the lull between tsunami waves, the entrained freshwater, brackish, and marine species settle out with mud and plant trash. Low numbers of broken diatoms in the lower medium sand implies rapid entrainment and deposition, whilst selective breakage of marine plankton (Thalassionema nitzschioides, and Thalassiosira and Coscinodiscus spp.) in the middle portion of the deposit probably results from abrasion in the turbulent current before deposition.     

Study of phytoplankton characteristics in Tolo Harbour,Hong Kong,by HPLC analysis of chemotaxonomic pigments

Spatial and seasonal characteristics of phytoplankton in Tolo Harbour, Hong Kong, were studied by microscopic observation of phytoplankton samples and HPLC analysis of chemotaxonomic pigments. Diatoms dominated the phytoplankton. Common diatoms included Skeletonema costatum and species of Cerataulina, Leptocylindrus, Pseudo-nitzschia and Thalassiosira. Dinoflagellates occurred sporadically and mainly in the inner part of the harbour. The dinoflagellate Scrippsiella trochoidea was the causative organism for the red tide occurrences in March, April and September 2001. Significant positive correlations between fucoxanthin and diatoms and between peridinin and dinoflagellates suggested that fucoxanthin and peridinin were valuable chemotaxonomic markers for diatoms and dinoflagellates, respectively. Analysis of pigment ratios revealed that red tide events caused by dinoflagellates were marked by increase in the value of PERI:chl a and decrease in the value of FUCO:chl a. Increase in the value of FUCO:chl a also revealed the presence of a dense population of Pseudo-nitzschia that was not indicated by increase in chlorophyll a and fucoxanthin concentrations. Pigment analysis also revealed the presence of cyanobacteria, silicoflagellates, cryptophytes and green algae in the surface waters of Tolo Harbour.     

Inbreeding among endogamous groups in three multicaste villages of Srikakulam district,Andhra Pradesh,India

Abstract

In the present paper 702 families have been studied belonging to different endogamous groups in three multicaste villages of Srikakulam District, Andhra Pradesh. It is observed that 33.76 per cent of families are consanguineous marriages. With regard to the types of marriages, 12.11 per cent are uncle‐niece; 14.10 per cent are matrilateral cross‐cousins; 5.84 per cent are patrilateral cross‐cousins; 0.57 per cent are first cousins once removed, and 1.14 per cent are second cousins. There are only six couples (0.86 per cent) in intercaste marriages. The coefficient of inbreeding for autosomal and sex‐linked genes, 0.045 and 0.059, respectively, for Chakalis which are higher than Kalingas (F = 0.03; F1 = 0.038), Segidis (F = 0.031; F1 = 0.041), Velamas (F = 0.026; F1 = 0.036), Vysyas (F = 0.027; F1 = 0.034), Malas (F = 0.017; F1 = 0.026), and others (F = 0.026; F1 = 0.032). The t‐tests for mean marriage distances are statistically significant among all castes, but chi‐squares for intergroup difference of consanguineous and nonconsanguineous marriages are statistically significant only among Kalingas and Chakalis, Vysyas and Chakalis, and Malas and Chakalis.     

Factors influencing the occurrence of males in natural populations of Synchaeta spp.

Changes in the temporal abundance of females and males of Synchaeta spp. were followed for one year (1983) at two stations in the brackish northern Baltic proper. Males were found only when the abundance of females was increasing and the phytoplankton biomass was dominated by large diatoms.     

DIATOMS (BACILLARIOPHYTA) OF ISOLATED ISLANDS: NEW TAXA IN THE GENUS NAVICULA SENSU STRICTO FROM THE GALáPAGOS ISLANDS1

The diatoms (Bacillariophyta) from a coastal lagoon from the Diablas wetlands (Isla Isabela, the Galápagos Islands) were studied in material from surface samples and a sediment core spanning the past 2,700 years in order to examine evidence of diatom evolution under geographic isolation. The total number of taxa found was ～100. Ultrastructural variation in valve morphology between members of Galápagos taxa was used to describe 10 species from the genus Navicula sensu stricto, which are new to science. Four taxa: N. isabelensis, N. isabelensoides, N. isabelensiformis, and N. isabelensiminor, shared several key characteristics that may be indicative of a common evolutionary heritage; these species therefore provide possible evidence for the in situ evolution of diatoms in the Galápagos coastal lagoons. Shared morphological characteristics include: (i) stria patterning in the central area, (ii) an elevated and thickened external raphe‐sternum, (iii) external central raphe endings that are slightly deflected toward the valve primary side, and (iv) an arched valve surface. To explain these findings, two models were proposed. The first suggested limited lateral diatomaceous transport of Navicula species between the Galápagos and continental South America. Alternatively, these new species may be ecological specialists arising from the unique environmental conditions of the Galápagos coastal lagoons, which restrict the colonization of common diatom taxa and enable the establishment of novel, rare species. The Diablas wetlands are an important site for diatom research, where local‐scale environmental changes have combined with global‐scale biogeographic processes resulting in unique diatom assemblages.     

On the cell wall composition of the apiculate yeasts

Summary Sonic oscillation was used for the purpose of obtaining clean, chemically intact cell walls. The rate of disruption was determined for cells ofHanseniaspora uvarum andSaccharomyces cerevisiae. The carbohydrate fractions of cell walls ofHanseniaspora uvarum, H. valbyensis, Kloeckera apiculata, Saccharomycodes ludwigii andSaccharmyces cerevisiae were shown to be similar. Chromatography of cell wall hydrolysates of all these species demonstrated that glucose and mannose were the only sugars present (in about equal amounts) besides traces of glucosamine. The cell walls ofH. uvarum contained 78.1 per cent carbohydrates, 7 per cent protein and approximately 0.05 per cent of chitin. Fractionation of the polysaccharides lead to a recovery of 83.3 per cent of the carbohydrates present (30.4 per cent glucan and 34.9 per cent mannan). Saccharomyces cerevisiae cell walls were found to have a carbohydrate content of 82.8 per cent, 6.5 per cent protein and a trace of chitin (0.04 per cent). Nadsonia elongata contained a relatively large amount of chitin (ca. 5 per cent) and lacked mannan in its cell walls. It was concluded thatHanseniaspora andSaccharomycodes are closely related to theSaccharomyceteae but they have little in common with species ofNadsonia.     

Protists in Arctic drift and land‐fast sea ice

Global climate change is having profound impacts on polar ice with changes in the duration and extent of both land‐fast ice and drift ice, which is part of the polar ice pack. Sea ice is a distinct habitat and the morphologically identifiable sympagic community living within sea ice can be readily distinguished from pelagic species. Sympagic metazoa and diatoms have been studied extensively since they can be identified using microscopy techniques. However, non‐diatom eukaryotic cells living in ice have received much less attention despite taxa such as the dinoflagellate Polarella and the cercozoan Cryothecomonas being isolated from sea ice. Other small flagellates have also been reported, suggesting complex microbial food webs. Since smaller flagellates are fragile, often poorly preserved, and are difficult for non‐experts to identify, we applied high throughput tag sequencing of the V4 region of the 18S rRNA gene to investigate the eukaryotic microbiome within the ice. The sea ice communities were diverse (190 taxa) and included many heterotrophic and mixotrophic species. Dinoflagellates (43 taxa), diatoms (29 taxa) and cercozoans (12 taxa) accounted for ~80% of the sequences. The sympagic communities living within drift ice and land‐fast ice harbored taxonomically distinct communities and we highlight specific taxa of dinoflagellates and diatoms that may be indicators of land‐fast and drift ice.     

The zooplankton of fresh and brackish waters of the Cape Thompson Area,Northern Alaska

Summary A survey was made of the occurrence of zooplankton in fresh and brackish waters at Cape Thompson, Alaska between June 28, 1960 and August 7, 1961.Fourteen species of Cladocera and 38 species of Copepoda (13 Calanoida, 11 Cyclopoida and 14 Harpacticoida) were distinguished in collections from 10 lakes, 8 lagoons, and 111 pools.Males of Daphnia middendorffiana are illustrated and their geographical significance discussed. Cyclops scutifer had the only hibernal developmental cycle; all others had developmental cycles during early summer or throughout the summer and fall.Relatively complete seasonal developmental cycles are presented for Holopedium gibberum, Daphnia middendorf iana, Heterocope septentrionalis, Eurytemora canadensis, E. gracilicauda, Limnocalanus johanseni, Diaptomus pribilofensis, D. arcticus, Cyclops scutifer, and C. magnus.

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Zusammenfassung Eine Übersicht des Vorkommens vom Zooplankton in der Zeit zwischen dem 28. juni, 1960 and dem 7. August 1961 im Süsswasser und im Brackwasser des Kaps Thompson, Alaska wird hier gegeben.Von den Sammlungen aus 10 Seen, 8 Lagunen and 111 Teichen sind 14 Spezies der Cladoceren and 38 Spezies der Copepoden (darunter 13 der Calanoiden, 11 der Cyclopoiden, und 14 der Harpacticoiden) unterschieden worden.Die männlichen der Daphnia middendorfliana werden hierin illustriert und die geographische Bedeutung erläutert. Cyclops scutifer hatte den einzigen winterlichen Entwicklungszyklus; die anderen hatten Entwicklungszyklen früh in dem Frühling oder während des ganzen Sommers and Herbstes.Jahreszeitliche Entwicklungszyklen, die verhältnismässig vollkommen sind, werden für die folgenden vorgeführt: Holopedium gibberum, Daphnia middendorffiana, Heterocope septentrionalis, Eurytemora canadensis, E. gracilicauda, Limnocalanus johanseni, Diaptomus pribilofensis, D. arcticus, Cyclops scutifer, und C. magnus.

     

Herpetofaunal communities at Muni Lagoon in Ghana

A herpetofaunal survey of Muni-Pomadze Lagoon, during the main rainy season (May–June), recorded a total of 32 species (13 amphibians and 19 reptiles). Three species are the first records for coastal habitats in Ghana: Kinixys homeana, Calabaria reinhardti, and Bothrophthalmus lineatus. None of the surveyed species are restricted to Ghana. The most diverse herpetofaunal community occurs in grassland thicket, with 26 species (81% of the sampled herpetofauna). Freshwater ponds include 12 species, while only three species (all amphibians) occur in brackish lagoons. Herpetofaunal conservation efforts at these sites should focus on protecting and monitoring grassland coastal thicket and freshwater ponds. Currently, freshwater pond habitats appear to be stable, but coastal thicket is being lost to provide new agricultural land at Muni. Hyperolius reedfrogs, pythons (Python regius) and monitor lizards (Varanus exanthematicus and V. niloticus) appear to offer the greatest potential for undertaking long-term monitoring of the coastal lagoon herpetofauna, because they can be more readily surveyed, and are likely to be sensitive to a broad range of environmental stressors.     

Auxosporenbildung und Systematik bei pennaten Diatomeen und die Cytologie vonCocconeis-Sippen

Ohne Zusammenfassung

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Auxospore formation and systematics in pennate diatoms and the cytology ofCocconeis races