ALBERT

Description: Experiments that directly test larval fish individual-based model (IBM) growth predictions are uncommon since it is difficult to simultaneously measure all relevant metabolic and behavioural attributes. We compared observed and modelled somatic growth of larval herring (Clupea harengus) in short-term (50 degree-day) laboratory trials conducted at 7 and 13°C in which larvae were either unfed or fed ad libitum on different prey sizes (~100 to 550 μm copepods, Acartia tonsa). The larval specific growth rate (SGR, % DW d-1) was generally overestimated by the model, especially for larvae foraging on large prey items. Model parameterisations were adjusted to explore the effect of 1) temporal variability in foraging of individuals, and 2) reduced assimilation efficiency due to rapid gut evacuation at high feeding rates. With these adjustments, the model described larval growth well across temperatures, prey sizes, and larval sizes. Although the experiments performed verified the growth model, variability in growth and foraging behaviour among larvae shows that it is necessary to measure both the physiology and feeding behaviour of the same individual. This is a challenge for experimentalists but will ultimately yield the most valuable data to adequately model environmental impacts on the survival and growth of marine fish early life stages. Comparación entre crecimiento observado y predicho de larvas de arenque (Clupea harengus): analizando parametrizaciones de modelos basados en individuos. – Los experimentos que analizan directamente las predicciones de crecimiento generadas por modelos basados en individuos (IBM) son poco comunes puesto que resulta difícil medir simultáneamente todos los atributos metabólicos y conductuales. En este estudio, comparamos el crecimiento somático observado y el estimado a partir de modelos de larvas de arenque (Clupea harengus) en experimentos de laboratorio a corto plazo (50 grados-día) a 7 y 13°en los que las larvas fueron mantenidas en condiciones de ayuno o recibieron alimentación ad libitum con diferentes tamaños de presa (copépodos, Acartia tonsa, de aproximadamente 100 a 500 μm). Las estimas de tasa específica de crecimiento (SGR, % de peso seco por día) fueron, en general, sobreestimadas por el modelo, especialmente para larvas que se alimentaron con presas grandes. estimas del modelo se ajustaron a dos escenarios para explorar el efecto de 1) variabilidad temporal en la alimentación de las larvas, y 2) disminución en la eficiencia de asimilación debida una rápida evacuación del tubo digestivo a tasas de alimentación altas. Con estos ajustes, el modelo describió bien el crecimiento larvario para temperaturas, tamaños de presa y edades de las larvas, indicando que las parametrizaciones metabólicas son robustas. Aunque los experimentos llevados a cabo con grupos de larvas verificaron los modelos de crecimiento, la variabilidad en el crecimiento y conducta de alimentación entre larvas sometidas a las mismas condiciones ambientales ponen de relieve la necesidad de que las medidas fisiológicas y de conducta vayan emparejadas y sean tomadas a nivel individual. Esto representa un reto para los experimentalistas, pero a largo plazo generará datos valiosos para los modeladores encargados de simular efectos ambientales sobre las tasas vitales de estadíos tempranos de desarrollo de peces marinos.

Description: There is evidence that the importance of the different spawning grounds of North Sea autumn-spawning herring has changed. It has been hypothesised that as herring stocks collapse, the diversity of spawning sites also collapses. This was found to be the case in the Sea autumn-spawning herring, which collapsed in the late 1970s. The ICES International Herring Larval Survey has been carried out since 1972 and covers most of the potential and historic spawning grounds of herring. recovery of the stock did take place as predicted in terms of biomass, and re-colonisation of old spawning sites also did occur. We show that, despite the delayed response in re-colonisation of the southern spawning areas, there is almost no change in the number of spawning locations where the highest abundances of larvae (top 50%) are found from collapse to recovery (approximately 9 sites). It was a change in these core sites and the spread to other locations with lower larval abundance that caused the spread of herring spawning. We show that larval surveys are a useful tool for describing the dynamics of sub-stock structure in heterogeneous populations such as herring.

Description: Two Gram-positive, aerobic actinomycete strains, designated YIM 48771(T) and YIM 48782(T), were isolated from virgin forest soil samples collected in Hunan Province, China. 16S rRNA gene sequence similarities of the two novel isolates ranged from 96.3 to 97.6% with species of the genus Sphaerisporangium with validly published names but, in the tree based on 16S rRNA gene sequences, the isolates formed distinct phyletic lines. The level of 16S rRNA gene sequence similarity between the two novel isolates was 97.1%. DNA-DNA hybridization of strains YIM 48771(T) and YIM 48782(T) with recognized species of the genus Sphaerisporangium revealed that the level of DNA-DNA relatedness was below 70%. The DNA G+C contents of strains YIM 48771(T) and YIM 48782(T) were 67.1 and 71 mol%, respectively. Chemotaxonomic data [major menaquinone, MK-9(H(4)); major polar lipids, diphosphatidylglycerol, phosphatidylinositol mannoside, phosphatidylethanolamine and phosphoglycolipids; major fatty acids, iso-C(16:0) and 10-methyl C(17:0)] supported the affiliation of the two isolates with the genus Sphaerisporangium. The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of the two isolates from recognized Sphaerisporangium species. Based on morphological, chemotaxonomical and phylogenetic data, strains YIM 48771(T) and YIM 48782(T) are considered to represent two novel species of the genus Sphaerisporangium, for which the names Sphaerisporangium flaviroseum sp. nov. (type strain, YIM 48771(T)=DSM 45170(T)=KCTC 19393(T)) and Sphaerisporangium album sp. nov. (type strain, YIM 48782(T)=DSM 45172(T)=CCTCC AA 208026(T)) are proposed.

Description: A Gram-positive, milk-white coloured, aerobic strain, YIM 48868(T), was isolated from the rhizosphere soil of Maytenus hookeri Loes in Xishuangbanna, China. 16S rRNA gene sequence similarity studies showed that strain YIM 48868(T) was a member of the genus Actinopolymorpha, showing 96.8% sequence similarity to Actinopolymorpha singaporensis IM 7744(T) and 97.0% similarity to Actinopolymorpha rutila YIM 45725(T). Chemotaxonomic data (peptidoglycan type 1, LL-diaminopimelic acid; sugar pattern C, glucose, rhamnose and ribose; polar lipids PI, diphosphatidylglycerol, phosphaticlylglycerol, phosphatidylinositol mannosides and phosphatidylinositol) were characteristic of the genus Actinopolymorpha. A phylogenetic tree based on 16S rRNA gene sequences showed that strain YIM 48868(T) formed a distinct phylogenetic lineage within the genus Actinopolymorpha. Strain YIM 48868(T) could be differentiated from recognized species by means of phenotypic properties and the predominant menaquinones [MK-9(H(6)), MK-9(H(8)), MK-10(H(6)), MK-10(H(8))]. The DNA G+C content was 66.6 mol%. The DNA-DNA relatedness values between strain YIM 48868(T) and the type strains of A. singaporensis and A. rutila were 48.7% and 53.1%, respectively. These data, in combination with phenotypic and chemotaxonomic data, demonstrate that strain YIM 48868(T) represents a novel species in the genus Actinopolymorpha, for which the name Actinopolymorpha alba sp. nov. is proposed. The type strain is YIM 48868(T) (=CCTCC AA 208030(T) =DSM 45243(T)).

Description: A spherical-shaped, phototrophic, purple sulfur bacterium was isolated in pure culture from anoxic sediment in a marine aquaculture pond near Bheemli (India). Strain JA142T is Gram-negative and non-motile. It has a requirement for NaCl (optimum of 2 % and maximum of 6 % w/v NaCl). Intracellular photosynthetic membranes are of the vesicular type. In vivo absorption spectra indicate the presence of bacteriochlorophyll a and carotenoids of the okenone series as photosynthetic pigments. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that strain JA142T is related to halophilic purple sulfur bacteria of the genera Thiohalocapsa and Halochromatium, with the highest sequence similarity to Thiohalocapsa halophila DSM 6210T (97.5 %). Morphological and physiological characteristics differentiate strain JA142T from other species of the genera Halochromatium and Thiohalocapsa. Strain JA142T is sufficiently different from Thiohalocapsa halophila based on 16S rRNA gene sequence analysis and morphological and physiological characteristics to allow the proposal of a novel species, Thiohalocapsa marina sp. nov., with the type strain JA142T (=JCM 14780T =DSM 19078T). The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain JA142T is AM491592. A phase-contrast micrograph of cells of strain JA142T, whole-cell and acetone absorption spectra and 16S rRNA gene sequence-based neighbour-joining, maximum-likelihood, minimum-evolution and maximum-parsimony trees are available as supplementary material with the online version of this paper.

Description: We employed 3-D biophysical modeling and dispersion kernel analysis to explore inter-annual and inter-specific differences in the drift trajectories of eggs and yolksac larvae of plaice (Pleuronectes platessa), Atlantic cod (Gadus morhua), sprat (Sprattus sprattus) and horse mackerel (Trachurus trachurus) in the North Sea. In this region, these four species exhibit peak spawning during the boreal winter, late winter/early spring, late spring/early summer, and mid-summer respectively, but utilize the same spawning locations (our simulations included Dogger Bank, Southern Bight and the German Bight). Inter-annual differences in the temperature history, and an increase in the area of dispersion and final distribution at the end of the yolksac phase were more pronounced (and related to the North Atlantic Oscillation) for winter- and early spring-spawners compared to late spring/summer spawners. The progeny of the latter experienced the largest (up to 10-fold) inter-annual differences in drift distances, although absolute drift distances were modest (~2 to 30 km) when compared to those of the former (~ 20 to 130 km). Our results highlight the complex interplay that exists between the specific life history strategies of the different species and the impacts of the variability in (climate-driven) physical factors during the earliest life stages of marine fish. Resumen: Diferencias interanuales e interespecíficas en la deriva de huevos y larvas lecitotróficas en el mar Norte: Aproximación a través un modelo biofísico. – En este trabajo utilizamos un modelo 3-D físico-biológico y un análisis de dispersión del núcleo para investigar las diferencias interespecíficas e interanuales en las trayectorias de la deriva de huevos y larvas lecitotróficas de la solla (Pleuronectes platessa), el bacalao Atlántico (Gadus morhua), el espadín (Sprattus sprattus) y el jurel (Trachurus trachurus) en el Mar del Norte. En esta región, las especies estudiadas muestran distintos picos de distintos desoves en el tiempo: invierno boreal, invierno tardío/primavera temprana, primavera tardía/verano temprano y mitad del verano, respectivamente, aunque comparten las mismas zonas de desove. Las simulaciones efectuadas corresponden a tres de estas zonas: Dogger Bank, Southern Bight y German Bight. Los resultados mostraron diferencias interanuales en la temperatura experimentada por las larvas, en el área de dispersión y en el patrón de distribución al final del estadio lecitotrófico, que fueron más evidentes en el bacalao Atlántico, en comparacion con el espadín. Así mismo, estos factores estuvieron correlacionados con la Oscilación del Atlántico Norte. La progenie del espadín, además, mostró la mayor variación interanual en la distancia de dispersión, siendo hasta 10 veces mayor, aunque la distancia absoluta alcanzada fue relativamente modesta (~2-30 km) en comparación con la observada para el bacalao Atlántico (~20-130 km). Nuestros resultados subrayan la compleja interacción que existe, durante los estadios tempranos del desarrollo de peces marinos, entre las estrategias ecológicas

Description: The small pelagic sprat (Sprattus sprattus) is a key ecologic player in the Baltic Sea. However, there is long-term variability in recruitment which is thought to be influenced by fluctuations in abiotic and biotic conditions experienced during the early life stages. This study concentrates on the influence of different ambient salinities on sprat egg development, egg buoyancy and survival as well as early yolk sac larval morphometric traits. Egg buoyancy significantly decreased with increasing salinity experienced during fertilization and/or incubation experiments. Field egg buoyancy measurements in 2007 and 2008 exhibited annual and seasonal differences in specific gravity, potentially associated with changes in adult sprat vertical distribution. Neither egg development time nor the duration of the yolk sac phase differed among salinity treatments. At eye pigmentation, larval standard length exhibited high variance among individuals but did not differ among treatments. The largest ecological impact of salinity experienced during spawning was the modification the buoyancy of eggs and yolk sac larvae, which determines their vertical habitat in the Baltic Sea. There are strong thermo- and oxyclines in the Baltic Sea, and thus salinity can indirectly impact

Description: A novel alphaproteobacterium, strain LD81(T), was isolated from the marine macroalga. Laminaria saccharina. The bacterium is mesophilic and shows a typical marine growth response. It is a chemoheterotrophic aerobe with the potential for denitrification. Growth optima are 25 degrees C, pH 5.5 and 3% NaCl. Strain LD81(T) has a unique phylogenetic position, not fitting any of the known families of the Alphaproteobacteria. The 16S rRNA gene sequence revealed a distant relationship to species of several orders of the Alphaproteobacteria, with less than 90% sequence similarity. Phylogenetically, strain LD81(T) is related to the type strains of Terasakiella pusilla (88.4% 16S rRNA gene sequence similarity) and the three Thalassospira species (88.9-89.2%. It forms a cluster with these bacteria and a novel as-yet undescribed isolate (KOPRI 13522; 96.6% sequence similarity). Strain LD81(T) has a relatively low DNA G + C content (51.1 mol%) and, due to its distant phylogenetic position from all other alphaprotecibacteria, strain LD81(T) (=NCIMB 14374(T) =JCM 14845(T)) is considered as the type strain of a novel species within a new genus, for which the name Kiloniella laminariae gen. nov., sp. nov. is proposed. The genus Kiloniella represents the type of the new family Kiloniellaceae fam. nov. and order Kiloniellales ord. nov.

Description: Multiple biochemical measurements were evaluated as an indirect measure of juvenile fish growth rate. Juvenile two-spotted gobies, Gobiusculus flavescens (Fabricius), caught in the Kiel Bight, were incubated in a temperature gradient table at 7 different temperatures ranging from 9 to 22.7°C for up to 28 days and sampled weekly. RNA/DNA ratios (RNA/DNA), protein and lipid amounts were measured in whole fish homogenates and compared with calculated weight-based growth rates of the individuals. RNA/DNA values were not significantly correlated with weight-specific growth rates. Lipid- and protein-based growth rates, on the other hand, were highly correlated with weight-specific growth (R2 of 0.4-0.5) and lipid-based growth rate explained 45.8% variability of weight-based growth in a linear growth model. Weight-based growth rates showed a dome-shaped relationship to temperature with a maximum around 16°C, a trend mirrored in lipid-based growth rates. The results indicate a stage-dependent shift in energy storage and metabolism with a decoupling of RNA/DNA as an index of weight-based growth rate as the juvenile gobies mature and lipids become the main determinant of weight-based growth in these fish.

Description: During studies of moderately halophilic strains of Ectothiorhodospira from steppe soda lakes, we found a novel group of bacteria related to Ectothiorhodospira haloalkaliphila with salt optima at 50–80 g NaCl l”1. Phylogenetic analysis using 16S rRNA gene sequences of strains from soda lakes in Mongolia, Egypt and Siberia revealed separation of the group of new isolates from other Ectothiorhodospira species, including the closely related Ect. haloalkaliphila. DNA–DNA hybridization studies demonstrated that the new isolates form a homogeneous group at the species level, but at the same time are distinct from related species such as Ect. haloalkaliphila, Ect. vacuolata, Ect. shaposhnikovii and Ect. marina. The new isolates are considered to be strains of a novel species, for which the name Ectothiorhodospira variabilis sp. nov. is proposed, with the type strain WN22T (5VKM B-2479T 5DSM 21381T). Photosynthetic pigments of the novel species are bacteriochlorophyll a and carotenoids of the spirilloxanthin series with spirilloxanthin and derivatives thereof, together with small amounts of lycopene and rhodopin. Gas vesicles are formed by most of the strains, particularly in media containing yeast extract (0.5 g l”1) and acetate (0.5–2.0 g l”1). Sequence analysis of nifH (nitrogenase) and cbbL (RuBisCO) confirmed the assignment of the strains to the genus Ectothiorhodospira and in particular the close relationship to Ect. haloalkaliphila. The novel species Ect. variabilis is found in soda lakes separated by great geographical distances and is an alkaliphilic and halophilic bacterium that tolerates salt concentrations up to 150–200 g NaCl l”1.