Characterization of the unarmored dinoflagellate Pseliodinium pirum (Ceratoperidiniaceae) from Jiaozhou Bay,China

A strain of Pseliodinium pirum was isolated from Jiaozhou Bay, China, identified based on a recently emended classification, and further characterized for its morphology using light, scanning electron, and transmission electron microscopy, and phylogeny based on SSU and partial LSU rDNA sequences. The pigment composition, life history, and potential effects on aquatic animals were also examined. We observed the typical characteristics of Ceratoperidiniaceae, in which its apical structure complex (ASC) formed a circular loop, and the ASC of our isolate comprised four to five rows of vesicles, and connected with sulcal intrusion. Epifluorescence and transmission electron microscopy revealed a bean‐shaped, centrally located nucleus, with at least 76 chromosomes. Numerous rod‐shaped chloroplasts were in connection to the irregularly shaped pyrenoids. Pigment analysis showed that peridinin was the most abundant among all carotenoids and other pigments. Phylogenetic analyses using maximum likelihood and Bayesian inference indicated that our isolate is conspecific with the entity Cochlodinium cf. helix (accession No. KF245459), but different from Ceratoperidinium, Kirithra, and other unidentified species of the family Ceratoperidiniaceae. Pseliodinium pirum could produce sexual, thin‐walled cyst, with subspherical and spherical shape and smooth surface (without spines or rough projections). The cyst could germinate within 3 days. Bioassays did not show adverse effects of P. pirum on the finfish Oryzias melastigma and the rotifer Brachionus plicatilis, indicating it may not be a harmful species.     

The phytoplankton of S'Ena Arrubia Lagoon (Centre-Western Sardinia) between 1990 and 1995

Abstract

The phytoplankton study on the S'Ena Arrubia Lagoon started in 1990, after dystrophic events, leading to high fish mortality and consequently great economic losses. This study presents a general picture of the conditions of the lagoon between 1990 and 1995, and reports on the quali-quantitative changes in the phytoplanktonic populations, as well as the trends of temperature, salinity, pH, dissolved oxygen, algal nutrients and chlorophyll a. The lagoon was characterized by great changes in salinity between years and within the same year, by high nutrient contents and by a phytoplankton trend characterized by sudden intense blooms mostly due to the Chlorophyceae and the Bacillariophyceae. The number of species found, decreased from 1990 to 1994, followed by a slight increase in 1995. The same trend was also found for total density and chlorophyll a.     

Hierochloë odorata (L.) Beauv. confermata per la flora italiana

Abstract

On the presence of Hierochloë odorata (L.) Beauv. in Italy.—H. odorata has been found in an oligotrophic marsh in the Italian part of the Eastern Alps and therefore definitively confirmed for the flora of Italy. An extended population occurs at 1800 m above sea level near Misurina, in the Dolomites (province of Belluno). All preceding records of H. odorata for the Italian flora must be referred to H. australis (Schrader) R.&S. Differential characters and distribution of the two species are shortly discussed.     

The occurrence of potentially toxic dinoflagellates and diatoms in a subtropical lagoon, the Indian River Lagoon, Florida, USA

The occurrence of potentially toxic phytoplankton species was examined over a 5-year period in a region of the Indian River Lagoon in Florida that has recently been subject to ecologically significant events, putatively related to algal toxins. The results of the study reveal a significant presence of two species of phytoplankton that have been shown to be toxic in Florida or other regions of world, the dinoflagellate Pyrodinium bahamense var. bahamense and the diatom Pseudo-nitzschia pseudodelicatissima. Concentrations of the former species reached 638,000 cells l⁻¹ and concentrations of the latter reached 23.9 million cells l⁻¹. In addition, the abundance of one of these species, P. bahamense var. bahamense appears to have increased over the 5-year study period from 1997 to 2002. It may be hypothesized that rainfall events following a regional drought period resulted in a flushing of bioavailable phosphorus and nitrogen into the Indian River Lagoon that stimulated P. bahamense var. bahamense blooms. The significance of these results is discussed within the context of the ecology of this flow-restricted lagoon.     

The occurrence and ecology of a marine hydrobiid mudsnail in the southern hemisphere: the Knysna Estuary, South Africa

Earlier published records of the gastropod Hydrobia from the warm temperate Knysna Lagoon on the Indian Ocean coast of South Africa are in error. Nevertheless, an animal hitherto identified as an Assiminea (Assimineidae) or as a Tomichia (Pomatiopsidae) is in fact a Hydrobia s.l., and it does occur intertidally within the Knysna system. The same species also occurs in salt pans in the cool temperate Great Berg Estuary on the Atlantic coast of South Africa. This extends the distribution of confirmed species of the dominant coastal hydrobiid mudsnails of the northern hemisphere into the southern hemisphere. H. knysnaensis (Krauss) occurs patchily at low density near the head of the Knysna Estuary in waters of low salinity. This appears to be a suboptimal habitat, and it is suggested that Hydrobia is restricted to this zone as a result of interference competition from potamidid mudwhelks and ocypodid crabs. The prevalence of potamidids and ocypodids in the tropics and in the temperate southern hemisphere may account for the rareness or absence of hydrobiids in these areas. Unlike its equally intertidal relative, the widespread North Atlantic/Arctic H. ulvae, H. knysnaensis develops directly like other Hydrobia.     

Rotifers from a humic coastal lagoon of Rio de Janeiro State,Brazil

Abstract

A four-year study of species composition of the zooplankton community was conducted at Lagoa Comprida, a Brazilian coastal lagoon. Forty-two species of rotifers were recorded and illustrated. All rotifer species, except Lecane boettgeri Koste, 1986 and Macrochaetus kostei, José de Paggi, Branco &; Kozlowsky-Suzuki, 2000 José de Paggi, S, Branco, C WC and Kozlowsky-Suzuki, B. 2000. A new species of Macrochaetus (Rotifera, Trichotriidae) in a coastal lagoon of Rio de Janeiro State (Brazil). Stud Neotrop Fauna &; Environm, 35: 157–160. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar], have already been found in other areas of Brazil. Some factors, which probably favored the dominant richness and density of rotifers in the zooplankton community, are discussed.     

Influence of environmental conditions on the distribution of Amphipoda,Talitridae, in the lagoon complex of Ghar El Melh (north‐east of Tunisia)

The study of the spatiotemporal distribution of talitrid amphipods was carried out along a transect in three stations belonging to the lagoon complex of Ghar El Melh, namely the supralittoral zones of the old harbour of Ghar El Melh, the opposite to Boughaz and Sidi Ali Mekki lagoon. Four species belonging to Talitridae family with two different genera were identified at all stations. These species are Orchestia gammarellus, Orchestia mediterranea, Orchestia stephenseni and Platorchestia platensis. The first two species were collected during the four seasons. The study of the density showed that the most important global mean density in talitrid was found in the supralittoral zone of opposite to Boughaz. In addition, statistical analysis showed a significant difference in the seasonal distribution of amphipods based on plant associations. Furthermore, the highest diversity of talitrid was observed in the winter in the supralittoral zone of opposite to Boughaz and in summer in the supralittoral zones of Sidi Ali Mekki lagoon and the old harbour of Ghar El Melh. Results showed that at all stations, a highly significant correlation of amphipod community with Cymodocea banquette was observed. Moreover, principal component analysis showed that the distribution of the different species depends on climatic and edaphic factors.     

Water current velocity as an environmental factor regulating the distribution of amphipod species in Gamo lagoon, Japan

The role of current velocity as an environmental factor affecting the distribution of amphipod species was investigated in the brackish Gamo lagoon, Japan. Two gammaridean amphipod species, Eogammarus possjeticus and Melita setiflagella, were found inhabiting stations of different water current with same substrates. E. possjeticus and M. setiflagella selected substrates at low and high water current, respectively. The lifestyles and anatomical features of these two free-living amphipods contributed to their adaptation to habitats with different water currents. The results of field and experimental observations suggest the existence of some type of interspecific competition between the two species. The presence of E. possjeticus caused a displacement of the fundamental niche of M. setiflagella. Received: October 10, 2000 / Accepted: August 17, 2001     

Temporal variability of the ichthyofauna in a Northern Aegean coastal lagoon (Greece). Influence of environmental factors

The ichtyofauna of the Porto-Lagos Lagoon in northern Greece was sampled over 17 months, using a bag-seine net, to investigate factors influencing species seasonal composition and abundance. Of the 35 resident, migrant and straggler species caught, representing 22 families, the most numerically dominant species were Atherina boyeri (46.4% of total catch), which today is the most economically important species, followed by Pomatoschistus marmoratus (28% of total catch) and Aphanius fasciatus (9.1% of total catch). Mugilidae and Sparidae were the most diverse families. According to various diversity indices, the lagoon’s ichthyofauna was found to be most diverse in May 1990; taxonomic spread however, as shown by the taxonomic distinctness index (Δ*), was lowest in July 1990, when the greatest monthly water temperature range was observed (13.5 °C). Overall fish relative abundance was positively correlated with the maximum monthly water temperature (r²=0.32, p < 0.05). The NMDS and cluster analysis performed on the bag seine catches showed four groupings, based mainly on the life history of the species. The main group consisted of all the resident species of the lagoon and four mugilid species that were present throughout most of the sampling period. The second group consisted of marine migrant species that spent a short period of their life in the lagoon. Marine migrants and one marine straggler that were found once or twice formed the third group, while the fourth group consisted of species with casual presence. The importance of Porto-Lagos Lagoon as nursery and feeding area for marine species was confirmed by the catch of young individuals of several marine species.     

Phytoplankton biomass and species composition in a Mediterranean coastal lagoon

Phytoplankton populations were investigated weekly at a central station in the Fusaro lagoon (Mediterranean Sea) from 27 November 1989 to 18 June 1990 to assess species composition, temporal succession and standing stock of the different species. Chlorophyll concentrations varied from 1.2 to 73.2 µg 1^–1 in surface waters, and from 1.3 to 53.5 µg 1^–1 at the 4.5 m depth. Phytoplankton communities were dominated by Prorocentrum micans Ehrenberg in December and January, and by small-sized diatoms in the rest of the sampling period. In surface waters, a maximum biomass of 9.5 mg C 1^–1 was measured in January, in correspondence with high concentrations (8.1 × 10⁶ cells 1^–1) of P. micans, whereas an abundance peak of 159.9 × 10⁶ cells 1^–1 was registered on the last sampling date due to a massive bloom of a very small diatom, Minutocellus polymorphus (Hargraves & Guillard) Hasle, von Stosch & Syvertsen. On the whole, phytoplankton populations of the Fusaro lagoon showed distinct characters as compared to those of southern Tyrrhenian coastal waters and of other lagoons.     

Composition of a molluscan assemblage associated with macrophytes in Menzel Jemil (Bizerte lagoon,SW Mediterranean Sea)

The molluscan species composition and diversity associated with macrophytes was studied throughout 1 year at Menzel Jemil station (Bizerte lagoon, north‐west of Tunisia). A total of 7,539 individuals belonging to 13 species were collected. The molluscan assemblage was mainly composed of gastropods (98.12%, nine species), followed by bivalves (1.88%, four species). Hydrobia acuta ranked first with 49.97% of total abundance, followed by Bittium reticulatum (17.97%), Tritia mutabilis (11.38%), Haminoea navicula (8.98%), Phorcus articulatus (5.17%) and Cerithium vulgatum (3.94%). The large number of juvenile molluscs collected confirms the importance of macroalgae and seagrass for mollusc recruitment. Significant temporal variations of species richness, density and diversity indices of the mollusc assemblage have been observed during the year. Multivariate analyses applied to our data revealed significant relationships between the macrophyte composition and associated molluscan assemblage. The BIOENV analysis indicated that water temperature, phosphates concentration and macrophyte biomass were environmental variables most closely associated with the temporal variation of molluscan assemblage.     

Observations on Some Species of Chaetoceros (Bacillariophyceae) with Reduced Number of Setae from a Tropical Coastal Lagoon

Species of Chaetoceros with less than four setae per cell are not common. In this study, five different taxa presenting this characteristic were found in the Sontecomapan lagoon, Mexico, a small tropical coastal lagoon on the Gulf of Mexico:Chaetoceros minimus, C. subtilis var. abnormis f. abnormis, C. subtilis var. abnormis f. simplex, C. throndsenii var. throndsenia, and C. thondsenii var. trisetosa. Using an electron microscope to make observations of C. subtilis var. abnormis f. simplex made evident the absence of rimoportulae suggesting a close relationship to C. minimus. According to our observations, we believe that the reduction in the number of setae in Chaetoceros is related to solitary forms. The five species studied here are associated with quiet brackish-water enclosed environments and can be considered worldwide-distributed organisms.     

Fisheries enhancement and biodiversity assessment of fish,prawn and mud crab in Chilika lagoon through hydrological intervention

The degraded state of the fragile ecosystem of Chilika lagoon on the east coast of India caused by natural changes and anthropogenic pressure was in the process of restoration through an effective hydrological intervention during 2000 after thorough scientific investigation including EIA study. The rich fisheries of Chilika lagoon that support livelihood of 0.2 million local fisherfolk was in dwindling state during the eco-degradation phase. Studies on fisheries and fish biodiversity of the lagoon for 4 years before and 4 years after the intervention showed the stark and rapid recovery of fishery immediately after opening of the new mouth with sixfold increase in average annual landing. The average productivity (11.3 t km⁻²) and CPUE (6.2 kg boat-day⁻¹) during post intervention phase registered 528 and 464% increase, as compared to Pre-intervention years. In total, 277 species of fish and shell fish were documented as occurring in Chilika lagoon before the hydrological intervention. Inventory survey for fish and shell fish species diversity during and after hydrological intervention documented 68 and 97 species, respectively. New records of 56 species of fish and shell fish (7 freshwater, 20 brackishwater and 29 marine) were documented from Chilika lagoon after the hydrological intervention. Analysis of commercial catches showed that the migratory species contributed to the bulk of catches (75% by species and 68% by catch weight). Fish yield and biodiversity seemed to be very sensitive to salinity and hydrologic dynamics of the lagoon. Correlation analysis indicated inverse relationship between water transparency and fish catch (R ² = 0.715; d.f. = 25; P < 0.01). Positive correlation between salinity and prawn landing (R ² = 0.542; d.f. = 25; P < 0.01) and salinity and mud crab landing (R ² = 0.628; d.f. = 25; P < 0.001). Average salinity for the whole lagoon was significantly increased by 42.7% (P < 0.007) as compared to pre-intervention situation. Maintenance of estuarine character of Chilika’s ecosystem particularly the salinity gradient, un-hindered auto-recruitment of fish and shell fish and prevention of destructive fishing are the key factors for fisheries enhancement. Unless carefully planned conservation and regulation measures are ensured with the active participation of local communities during the early phase of restoration, the present scenario of fisheries enhancement may not sustain for longer time.     

Locomotor activity patterns of two sympatric species Orchestia montagui and Orchestia gammarellus (Crustacea,Amphipoda)

Freshly adult individuals of two sympatric species, Orchestia gammarellus and Orchestia montagui, collected in spring from the supralittoral zone of Bizerte lagoon (Northern of Tunisia) at Menzel Jemil, were housed in a controlled environment cabinet. Locomotor activity rhythm was recorded in isolated individuals and groups by infrared actograph every 20 min by a data-logger, at a constant temperature of 18 ± 0.5 °C under constant darkness. According to double-plotted actograms and waveform curves, results showed the presence of two different locomotor patterns; in fact, individuals of O. gammarellus concentrated their activity during the hours of subjective night, whereas O. montagui were active during the subjective night and beyond the subjective dawn. Furthermore, whatever the species studied, periodogram analysis indicated a distinct circadian pattern of activity. Moreover, whatever the experiment condition is, the most clearly defined rhythms were found in O. gammarellus. In contrary to O. gammarellus, the group effect on the locomotor rhythm parameters seems to be less marked in O. montagui. On the other hand, a highly inter-individual variability was observed in the activity time for these two species and especially for O. montagui groups.     

Butyltin compounds in sediment and biota from the lagoon of Bizerte (northern Tunisia): Potential risk for consumers?

Levels of butyltins (BTs) were monitored in sediment samples and in seven fish species (Boops boops, Diplodus sargus, Sarpa salpa, Serranus scriba, Spicara smaris, Trachurus draco, and Trachinus mediterraneus), five bivalve species (Cerastoderma glaucum, Chlamys flexuosa, Mytilus galloprovincialis, Pinna nobilis, and Ruditapes decussatus), two gastropod species (Bolinus brandaris and Hexaplex trunculus), cuttlefish (Sepia officinalis), and shrimp (Penaeus notialis), most of which are commonly consumed in Tunisia. Samples were collected from Bizerte lagoon during March 2012. Average concentrations of total BTs found in sediment and the muscle of fishes, bivalves, gastropods, cuttlefish, and shrimp were 17.7, 11.5, 31.8, 36.9, 8.1, and 9.4 ng Sn g^?1 dw, respectively. The calculation of tolerable average residue levels and non-cancer hazard quotient for tributyltin (TBT) showed that daily exposure of these seafood to TBT is unlikely to cause any deleterious effects to humans, thus indicating that consumers may not be at risk through the inclusion of these species in their regular diet.     

Intra‐annual variation of the spatiotemporal distribution and abundance of Talitridae and Oniscidea (Crustacea,Peracarida) at Bizerte Lagoon (northern Tunisia)

During 1 year from spring 2007 to winter 2008, we conducted four seasonal samplings along a transect in the supralittoral zone of Bizerte Lagoon at Menzel Jmil (Tunisia) to study the intra‐annual variation of Peracarida diversity, Talitridae and Oniscidea. For each season, one transect was studied and quadrates were placed successively from the shoreline to the road backing the shore. Talitridae and Oniscidea were the most abundant taxa in our samples reaching highest densities in summer, when fourteen species were found. The minimum and maximum values of species richness of Talitridae were observed in winter (four species) and summer (eight species), respectively, while for Oniscidea, species richness ranged from one species in winter and five species in spring. Both Talitridae and Oniscidea exhibited intra‐annual variation in their spatial distribution; in that, they moved away from the shoreline in winter and were found near the waterline in the other seasons. ANOVA test shows a high significant correlation between both Talitridae with Suaeda maritima and Oniscidea with the plants S. maritima,Salicornia arabica and Obione portulacoides.     

Synopsis of <Emphasis Type="Italic">Mickelia</Emphasis>, a newly recognized genus of bolbitidoid ferns (Dryopteridaceae)

Our recent molecular phylogenetic study revealed a previously unrecognized clade of six species that is sister to Elaphoglossum. Within this clade, four species are currently classified in Bolbitis, one in Lomagramma, and one in Acrostichum. For this clade, we propose the name Mickelia, with M. nicotianifolia as the type species. We also make new combinations for the species in our phylogenetic study shown to belong to Mickelia (M. bernoullii, M. guianensis, M. hemiotis, M. nicotianifolia, M. oligarchica, and M. scandens) and two other species believed to belong to the clade based on morphology (M. lindigii, M. pergamentacea). A new hybrid and two new species are also described (M. ×atrans, M. furcata, and M. pradoi). In total, Mickelia consists of ten species and one hybrid. It is entirely neotropical. We provide a key to the genera of bolbitidoid ferns and a synopsis of Mickelia that gives for each species a complete synonymy, geographical distribution, comparative discussion, and illustration.     

A review of the Malagasy endemic genus Cyrtolophus Fairmaire and description of Pseudocyrtolophus n. gen. (Coleoptera: Scarabaeidae: Rutelinae: Adoretini)

Summary

After lectotype designations for both names, the synonymy between Cyrtolophus grandicornis Fairmaire, 1895 and Cyrtolophus viduus Ohaus, 1912, n. syn., is proposed. Pseudocyrtolophus n. gen. is described to accommodate Cyrtolophus limbicollis Ohaus, 1912, its type species, and a second species, Pseudocyrtolophus australis n. sp., which is described and compared to its most related species. The lectotype of Cyrtolophus limbicollis is designated. All species are illustrated. A map showing their distribution in Madagascar is given.