Biological Invasion of Fish Parasite (Harada, 1930) (Copepoda: Ergasilidae) in Lake Grand Laoucien, France: A Field Study on Life Cycle Parameters and Reasons for Unusual High Population Density.

The fish parasite, (Harada, 1930), native to Eastern Siberia and the Amur River catchment area, invaded European water bodies in the middle of the last century, possibly due to the human-mediated distribution of fish in the Amur complex (i.e., the genera and ).

Male Differentiation in the Marine Copepod Reveals the Development of a New Nervous Ganglion and Lin12-Notch-Repeat Protein-Associated Proteolysis.

Copepods are among the most numerous animals, and they play an essential role in the marine trophic web and biogeochemical cycles. The genus Oithona is described as having the highest density of copepods. The Oithona male paradox describes the activity states of males, which are obliged to alternate between immobile and mobile phases for ambush feeding and mate searching, respectively, while the female is less mobile and feeds less.

Investigating population-scale allelic differential expression in wild populations of (Cyclopoida, Claus, 1866).

Acclimation allowed by variation in gene or allele expression in natural populations is increasingly understood as a decisive mechanism, as much as adaptation, for species evolution. However, for small eukaryotic organisms, as species from zooplankton, classical methods face numerous challenges. Here, we propose the concept of allelic differential expression at the population-scale (psADE) to investigate the variation in allele expression in natural populations.

Chitin distribution in the digestive and reproductive systems revealed by fluorescence microscopy.

Among copepods, which are the most abundant animals on Earth, the genus is described as one of the most numerous and plays a major role in the marine food chain and biogeochemical cycles, particularly through the excretion of chitin-coated fecal pellets. Despite the morphology of several species is well known, knowledge of its internal anatomy and chitin distribution is still limited. To answer this problem, and individuals were stained by Wheat Germ Agglutinin-Fluorescein IsoThioCyanate (WGA-FITC) and DiAmidino-2-PhenylIndole (DAPI) for fluorescence microscopy observations.

New insights into global biogeography, population structure and natural selection from the genome of the epipelagic copepod Oithona.

In the epipelagic ocean, the genus Oithona is considered as one of the most abundant and widespread copepods and plays an important role in the trophic food web. Despite its ecological importance, little is known about Oithona and cyclopoid copepods genomics. Therefore, we sequenced, assembled and annotated the genome of Oithona nana.

Role of DOP on the alkaline phosphatase activity of size fractionated plankton in coastal waters in the NW Mediterranean Sea (Toulon Bay, France).

The particulate material was fractionated into 5 size classes (>90μ, 50-90μ, 6-50μ, 1-6μ, and <1μ). DOP was analysed as easily (DOPh, DOPpa) and less easily hydrolysable compounds (DOPox). Based on Vmax, 94% of the high affinity AP activity was due to <50μ cells and 77% to <1μ cells.

Ocean plankton. Environmental characteristics of Agulhas rings affect interocean plankton transport.

Agulhas rings provide the principal route for ocean waters to circulate from the Indo-Pacific to the Atlantic basin. Their influence on global ocean circulation is well known, but their role in plankton transport is largely unexplored. We show that, although the coarse taxonomic structure of plankton communities is continuous across the Agulhas choke point, South Atlantic plankton diversity is altered compared with Indian Ocean source populations.

Comprehensive model of annual plankton succession based on the whole-plankton time series approach.

Ecological succession provides a widely accepted description of seasonal changes in phytoplankton and mesozooplankton assemblages in the natural environment, but concurrent changes in smaller (i.e. microbes) and larger (i.

Analysis of the role of DOP on the particulate phosphatase activity in Toulon Bay (N.W. Mediterranean Sea, France).

Alkaline phosphatase (AP) activity was studied on homogenates of particulate material in relation to the concentrations of AP-hydrolysable (DOPpa) and AP-non hydrolysable (DOPr) phosphorus. AP activity had high and low Km components. The high affinity activity came from ectoenzymes.

The relationships between particulate and soluble alkaline phosphatase activities and the concentration of phosphorus dissolved in the seawater of Toulon Bay (NW Mediterranean).

The activities of particulate and soluble phosphatase were analyzed monthly for 1 year in the coastal ecosystems of the NW Mediterranean Sea. The mean contribution of the particulate activity increased from 56% at an MUF-P concentration of 30 μM to 77% at 0.04 μM.

Role of sea water DIP and DOP in controlling bulk alkaline phosphatase activity in N.W. Mediterranean Sea (Toulon, France).

The regulation of alkaline phosphatase activity by dissolved inorganic (DIP) and organic phosphorus (DOP) and the contribution of DOP as phosphorus source were studied monthly in Toulon Bay (NW Mediterranean, France) in 2005-2006. The concentrations of DIP and DOP varied respectively from 0 to 0.185μM and from 0 to 0.

Protein expression from zooplankton communities in a metal contaminated NW mediterranean coastal ecosystem.

Bidimensional and monodimensional polyacrylamide gel electrophoresis were used to study protein expression from zooplankton collected in thirteen stations of Toulon Bay (NW Mediterranean). In this ecosystem, Little Bay showed higher trace metal concentrations (13.5-23.

In situ heavy metals (copper, lead and cadmium) in different plankton compartments and suspended particulate matter in two coupled Mediterranean coastal ecosystems (Toulon Bay, France).

We monitored the concentrations of copper, lead and cadmium in seawater, in suspended particulate matter (SPM) and in bacteria, phyto- and zooplankton communities separated from abiogenic particles, over a one year cycle in two coupled Mediterranean coastal ecosystems (Little Bay (LiB) and Large Bay (LaB)). Metals were present in seawater in the order Cu>Pb>Cd in both bays and showed important variations within the same month than among months. In LiB, their concentrations were between 0.

Origin and characteristics of the zooplankton phosphatase activity in a coastal ecosystem of the Mediterranean sea (Toulon Bay).

In Toulon Bay (France), very high phosphatase activities have been found in the zooplankton fraction>90 microm. This work was intended to specify their origin. For that purpose, larvae, juvenile and adult Crustacea (Copepods: Calanoids, Cyclopoids, Branchiopods: Cladocera, and Cirripeds) were isolated.

Seasonal changes in phosphatase activities in Toulon Bay (France).

We studied the characteristics of the phosphatase activity (Km and Vmax) in total seawater and in particulate material of the three main plankton classes (0.25-5, 5-90 and >90 microm) in a coastal marine ecosystem of Toulon Bay (French Mediterranean Sea). The measurement of the hydrolysis of sodium paranitrophenylphosphate (pNPP), a substrate of phosphatase, revealed low and high affinity components in unfiltered seawater and in particulate matter.

Seasonal changes in zooplanktonic alkaline phosphatase activity in Toulon Bay (France): the role of Cypris larvae.

We studied zooplankton contribution to the total particulate phosphatase activity, the kinetics of this activity, the relation to the different taxonomic groups and the role of particle-bound bacteria. The activity of total particulate material collected from a liter of seawater was more elevated in May, June and August than during the rest of the year. These high activities resulted from a high contribution of the >90 microm fraction which account then for more than 60% of the total particulate activity.