Culture of Calanoid Copepods in Synthetic Sea Water

1969 ◽  
Vol 26 (1) ◽  
pp. 150-153 ◽  
Author(s):  
Donald R. Heinle
Keyword(s):  
Sea Water ◽  
Acartia Tonsa ◽  
Calanoid Copepods ◽  
Sea Salts ◽  
Eurytemora Affinis

The calanoid copepods Acartia tonsa and Eurytemora affinis were successfully cultured in two commercial synthetic sea salts. Success of a medium was measured by its ability to sustain a population of copepods that was subjected to moderate rates of harvest.

scholarly journals Groundwater Chemistry of Some Selected Areas in Southeastern Norway

1980 ◽  
Vol 11 (1) ◽  
pp. 33-54 ◽  
Author(s):  
Jens-Olaf Englund ◽  
Jan Aug Myhrstad
Keyword(s):  
Land Surface ◽  
Mineral Water ◽  
Sea Water ◽  
Electrical Conductance ◽  
Reservoir Rock ◽  
Rock Fractures ◽  
Sea Salts ◽  
Reservoir Rocks ◽  
Rock Types ◽  
Groundwater Samples

Within three areas in Southeastern Norway, Lake Mjøsa district, Ås and Moss - Jeløy, groundwater samples for chemical analysis were collected during the years 1971–77 from 98 drilled wells in bedrocks. The water was taken at depths ranging from 15 m to 110 m below the land surface. The groundwater surface is usually present well below the overlying unconsolidated deposits of glacial, glacifluvial or marine origin. The movement of groundwater within the aquifers investigated is so slow that regional changes in water quality is not only dependent on weathering in the unsaturated zone, but also dependent on the solution of reservoir rocks below the groundwater surface. Variations in specific electrical conductance (20°C) largely reflects the different reservoir rock types. The highest values, around 550 μS/cm, are typically found in dark calcareous shales, while sandstones and gneisses give values around 300 μS/cm. The areas Ås and Moss-Jeløy are situated below the Late-Postglacial marine limit. The groundwater is here more or less influenced by ancient sea salts, perhaps also by fossil sea water, left over in sediments or in rock fractures. Brackish groundwater was also found. The composition of groundwater is largely governed by mineral-water equilibria. Most investigated water samples have not reached equilibrium with their surrounding minerals.

scholarly journals Association of Vibrio cholerae O1 El Tor and O139 Bengal with the Copepods Acartia tonsa and Eurytemora affinis

2007 ◽  
Vol 73 (24) ◽  
pp. 7926-7933 ◽  
Author(s):  
Tonya K. Rawlings ◽  
Gregory M. Ruiz ◽  
Rita R. Colwell
Keyword(s):  
Vibrio Cholerae ◽  
Aquatic Environment ◽  
Acartia Tonsa ◽  
Copepod Species ◽  
Life Stages ◽  
Eurytemora Affinis ◽  
Rural Bangladesh ◽  
Laboratory Microcosm ◽  
Vibrio Cholerae O1 ◽  
El Tor

ABSTRACT The association of Vibrio cholerae with zooplankton has been suggested as an important factor in transmission of human epidemic cholera, and the ability to colonize zooplankton surfaces may play a role in the temporal variation and predominance of the two different serogroups (V. cholerae O1 El Tor and O139) in the aquatic environment. To date, interactions between specific serogroups and species of plankton remain poorly understood. Laboratory microcosm experiments were carried out to compare quantitatively the colonization of two copepod species, Acartia tonsa and Eurytemora affinis, by each of the epidemic serogroups. V. cholerae O1 consistently achieved higher abundances than V. cholerae O139 in colonizing adults of each copepod species as well as the multiple life stages of E. affinis. This difference in colonization may be significant in the general predominance of V. cholerae O1 in cholera epidemics in rural Bangladesh where water supplies are taken directly from the environment.

A Study of Grazing Behavior of Copepods Using Digital Holographic Cinematography

2008 ◽  
Author(s):  
Siddharth Talapatra ◽  
Jiarong Hong ◽  
Jian Sheng ◽  
Becky Waggett ◽  
Pat Tester ◽  
...  
Keyword(s):  
Flow Field ◽  
Spatial Resolution ◽  
High Speed ◽  
Acartia Tonsa ◽  
Copepod Species ◽  
Calanoid Copepods ◽  
Grazing Behavior ◽  
Karlodinium Veneficum ◽  
Different Strains ◽  
Neutrally Buoyant

Generating proper feeding currents for entraining prey is one of the important features in the grazing behavior of (∼1mm) copepods. These feeding currents vary with the copepod species, as well as with the species or strains and concentration of prey (∼10 μm) dinoflagellates. Calanoid copepods also hover for a while, while slowly sinking, and then intermittently jump to a different location. In our study, we employed high speed digital holographic cinematography to measure elements of the flow field around copepods in an environment seeded with dinoflagellates. In most cases, the flow field and feeding currents were characterized based on the trajectories of the dinoflagellates. However, in some of the tests we also added neutrally buoyant 20 μm particles as independent flow tracers. At low magnifications, we simultaneously recorded two perpendicular views to obtain the same spatial resolution in all directions. Data were recorded at varying magnifications and frame rates. In recent experiments, we exposed the copepods to different strains of the same dinoflagellate species that have varying levels of toxicity, and measured the resulting changes to the grazing behavior of the copepods. Here we present results from two of these experimental setups: Acartia tonsa with Karlodinium veneficum (non toxic strain) and Acartia tonsa in particle seeded flow. Issues such as swimming characteristics, feeding classification (raptorial vs. filter feeding approaches) and copepod response to different environmental settings were addressed.

scholarly journals Effects of water of reduced salinity on the vertical migration of zooplankton

1962 ◽  
Vol 42 (2) ◽  
pp. 131-154 ◽  
Author(s):  
Joan Lance
Keyword(s):  
Vertical Migration ◽  
Developmental Stages ◽  
Marked Effect ◽  
Sea Water ◽  
Acartia Tonsa ◽  
Upward Migration ◽  
Southampton Water ◽  
Water Columns ◽  
Temora Longicornis ◽  
Centropages Typicus

SUMMARYEffects of water of reduced salinity on the vertical migration of the zooplankton of Southampton Water were investigated in the laboratory using the adults of six copepod species (Acartia tonsa, A. bifilosa, A. discaudata, A. clausi, Centropages hamatus, Temora longicornis) and the larvae of one decapod species (Porcellana longicornis). Additional observations were made on Centropages typicus adults taken off Plymouth.Salinity discontinuity layers had a marked effect on the vertical migration of zooplankton. A single discontinuity layer formed by placing less dense diluted sea water over full strength sea water acted as a barrier to animals attempting to swim toward the surface of an experimental water column and no individuals were able to enter the zone of reduced salinity when an extreme dilution was used. Comparison of the behaviour of various species and of different sexes or developmental stages of a particular species suggests that vertical distribution was partly dependent on the salinity tolerances of individuals. Upward migration was also restricted by a vertical series of discontinuity layers.The swimming activity of copepods was depressed in homogeneous water columns of reduced salinity. Activity depended both on the degree of dilution and on the period of immersion. There were indications that behaviour varied according to the salinity tolerances of the different species.

scholarly journals Attachment of the peritrich epibiont Zoothamnium intermedium Precht, 1935 (Ciliophora, Peritrichia) to artificial substrates in a natural environment

2008 ◽  
Vol 68 (4) ◽  
pp. 795-798 ◽  
Author(s):  
LRP. Utz
Keyword(s):  
Chesapeake Bay ◽  
Natural Environment ◽  
Acartia Tonsa ◽  
Artificial Substrates ◽  
Copepod Species ◽  
Field Observations ◽  
Marine Environments ◽  
Eurytemora Affinis ◽  
Free Swimming ◽  
Living Organisms

Peritrich ciliates are commonly found as epibionts, colonizing living organisms, or attached to non-living substrates in freshwater, estuarine and marine environments. Several species of peritrich epibionts are obligate, which means that they are able to only colonize other organisms, while others are facultative attaching to living or non-living substrates. The peritrich Zoothamnium intermedium is commonly found as epibiont on the copepod species Acartia tonsa and Eurytemora affinis in Chesapeake Bay, USA. Previous studies demonstrated that Z. intermedium is not able to attach to non-living substrates in the laboratory; with free-swimming stages (telotrochs) dying when living substrates are not available for colonization. The present study investigated the ability of Z. intermdium to colonize artificial substrates in the field. Observations were carried out while the peritrich ciliate was colonizing copepods in Rhode River, a tributary of Chesapeake Bay. Results demonstrated that four species of Zoothamnium were recovered from artificial substrates, but none of them was Z. intermedium. At the same time, Z. intermedium was colonizing adults and copepodites of E. affinis and A. tonsa during the whole study period. These results, in addition to laboratory observations, suggest that Z. intermedium is an obligate epibiont.

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