Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 9 of 9
Full-Text Articles in Animal Sciences
Abstracts Of Technical Papers Presented At The 101st Annual Meeting National Shellfisheries Association Savannah, Georgia March 22–26, 2009, National Shellfisheries Association
Abstracts Of Technical Papers Presented At The 101st Annual Meeting National Shellfisheries Association Savannah, Georgia March 22–26, 2009, National Shellfisheries Association
VIMS Articles
No abstract provided.
Species-Specific Differences In Long-Chain N-3 Essential Fatty Acid, Sterol, And Steroidal Ketone Production In Six Heterotrophic Protist Species, Fle Chu, Ed Lund, Pr Littreal, Ke Ruck, E Harvey
Species-Specific Differences In Long-Chain N-3 Essential Fatty Acid, Sterol, And Steroidal Ketone Production In Six Heterotrophic Protist Species, Fle Chu, Ed Lund, Pr Littreal, Ke Ruck, E Harvey
VIMS Articles
We investigated the capability and species-specific differences in long-chain n-3 essential fatty acid (LCn-3EFA), sterol, and steroidal ketone production of 6 heterotrophic protists: 3 thecate dinoflagellates (Cryptoperidiniopsis brodyi, Pfiesteria piscicida, and Luciella masanensis), 1 athecate dinoflagellate (Amphidinium longum), 1 herbivorous ciliate (Strombidinopsis sp.), and 1 bacterivorous ciliate (Uronema sp.) by feeding them algae (Rhodomonas salina or Dunaliella tertiolecta) or bacteria. The 3 thecate species did not convert algal sterols to other usual and common sterols. Instead, they produced sterols and steroidal ketones, such as dinosterol, dinostanol, dinosterone, and dinostanone, usually found in autotrophic dinoflagellates when fed R. salina or D. …
Size-Fractionated Photosynthesis/Irradiance Relationships During Phaeocystis Antarctica-Dominated Blooms In The Ross Sea, Antarctica, Ar Shields, Walker O. Smith Jr.
Size-Fractionated Photosynthesis/Irradiance Relationships During Phaeocystis Antarctica-Dominated Blooms In The Ross Sea, Antarctica, Ar Shields, Walker O. Smith Jr.
VIMS Articles
In the Ross Sea, there are two major phytoplankton functional groups: diatoms and prymnesiophytes (dominated by Phaeocystis antarctica). Phaeocystis antarctica often occurs in colonial form, but also as solitary cells, and the two forms have distinct ecological roles. A comparison of the growth characteristics of solitary and colonial forms of Phaeocystis sp. is essential to understanding the differential impact each has on biogeochemical and ecological processes, and to allow parameterization of each form in numerical models. We measured the biomass and photosynthetic responses of two size fractions (> 20 and < 20 mu m), representing colonies and solitary cells, at locations dominated by P. antarctica to assess the relative photosynthetic potential of the two forms. While the relative contribution of each form to total P. antarctica biomass differed among years, there were no significant differences between maximum photosynthetic rates of colonial and solitary forms within years. Substantial interannual variations in biomass and maximum photosynthetic rates normalized to chlorophyll a (PmB) and initial light-limited rates of photosynthesis (alpha) were observed among years for the colonial fractions; however, interannual variations in maximum rates of photosynthesis or alpha of solitary cells were not observed. A laboratory experiment with P. antarctica, together with field data, showed that growth stage of colonies strongly affected the maximum photosynthetic rates. Under nutrient-replete conditions and exponential growth, colonial cells had higher maximum photosynthetic rates than solitary cells, but as growth rate declined and senescence began, the solitary cells' rates became greater. This may be a reason for the high abundance of colonies that is often found in the Ross Sea during austral spring. Our results suggest that photosynthetic rates may influence the composition of the morphotypes of Phaeocystis, but do not appear to be the sole factor in regulating this critical biological variable.
Deep-Sea Mystery Solved: Astonishing Larval Transformations And Extreme Sexual Dimorphism Unite Three Fish Families, Gd Johnson, Jr Paxton, Tt Sutton, Tp Satoh, T Sado, M Miya
Deep-Sea Mystery Solved: Astonishing Larval Transformations And Extreme Sexual Dimorphism Unite Three Fish Families, Gd Johnson, Jr Paxton, Tt Sutton, Tp Satoh, T Sado, M Miya
VIMS Articles
The oceanic bathypelagic realm (1000-4000 m) is a nutrient-poor habitat. Most fishes living there have pelagic larvae using the rich waters of the upper 200 m. Morphological and behavioural specializations necessary to occupy such contrasting environments have resulted in remarkable developmental changes and life-history strategies. We resolve a long-standing biological and taxonomic conundrum by documenting the most extreme example of ontogenetic metamorphoses and sexual dimorphism in vertebrates. Based on morphology and mitogenomic sequence data, we show that fishes currently assigned to three families with greatly differing morphologies, Mirapinnidae (tapetails), Megalomycteridae (bignose fishes) and Cetomimidae (whalefishes), are larvae, males and females, …
The Bridge Web Site Growing And Sustaining Partnerships Between Ocean Science And Education, Vp Clark, La Lawrence, C Petrone, L Larkin
The Bridge Web Site Growing And Sustaining Partnerships Between Ocean Science And Education, Vp Clark, La Lawrence, C Petrone, L Larkin
VIMS Articles
No abstract provided.
Effects Of Food On Bacterial Community Composition Associated With The Copepod Acartia Tonsa Dana, K Tang, C Dziallas, K Hutalle-Schmelzer, Hp Grossart
Effects Of Food On Bacterial Community Composition Associated With The Copepod Acartia Tonsa Dana, K Tang, C Dziallas, K Hutalle-Schmelzer, Hp Grossart
VIMS Articles
The estuarine copepod Acartia tonsa naturally carried diverse strains of bacteria on its body. The bacterial community composition (BCC) remained very conservative even when the copepod was fed different axenic algal species, indicating that the food per se did not much affect BCC associated with the copepod. In xenic algal treatments, however, copepod-associated BCC differed with each alga fed, even though the same bacterial source was used to inoculate the algae. In addition, starved copepods taken at the same location but at different times significantly differed in their BCC. Algal species composition and copepod life history therefore serve to regulate …
Survival And Recovery Of Phaeocystis Antarctica (Prymnesiophyceae) From Prolonged Darkness And Freezing, Kw Tang, Walker O. Smith Jr., Ar Shields, Dt Elliott
Survival And Recovery Of Phaeocystis Antarctica (Prymnesiophyceae) From Prolonged Darkness And Freezing, Kw Tang, Walker O. Smith Jr., Ar Shields, Dt Elliott
VIMS Articles
The colony-forming haptophyte Phaeocystis antarctica is an important primary producer in the Ross Sea, and must survive long periods of darkness and freezing temperature in this extreme environment. We conducted experiments on the responses of P. antarctica-dominated phytoplankton assemblages to prolonged periods of darkness and freezing. Chlorophyll and photosynthetic capacity of the alga declined nonlinearly and independently of each other in the dark, and darkness alone would potentially reduce photosynthetic capacity by only 60 per cent over 150 days (approximately the length of the Antarctic winter in the southern Ross Sea). The estimated reduction of colonial mucous carbon is higher …
Microbial Activities Accompanying Decomposition Of Cladoceran And Copepod Carcasses Under Different Environmental Conditions, Kw Tang, Sl Bickel, C Dziallas, Hp Grossart
Microbial Activities Accompanying Decomposition Of Cladoceran And Copepod Carcasses Under Different Environmental Conditions, Kw Tang, Sl Bickel, C Dziallas, Hp Grossart
VIMS Articles
Cladoceran and copepod carcasses in both marine and freshwater environments represent concentrated reservoirs of organic substrates for water column bacteria. We studied the microbial abundance, activities, and diversity associated with decomposing carcasses of different zooplankton species over short and long time scales, and in oligotrophic vs. eutrophic environments. Fresh carcasses of Daphnia cucullata, Diaphanosoma brachyurum, and Eudiaptomus gracilis were rapidly colonized by bacteria, which reached peak abundances within 1.5 d at 20 degrees C and then decreased. Cell-specific exoenzymatic activity on protein and lipid analogs and production rate of bacteria associated with the carcasses were all higher than in the …
Simple Staining Method For Differentiating Live And Dead Marine Zooplankton In Field Samples, Dt Elliott, Kw Tang
Simple Staining Method For Differentiating Live And Dead Marine Zooplankton In Field Samples, Dt Elliott, Kw Tang
VIMS Articles
We describe and evaluate a method for the use of neutral red staining to differentiate live and dead zooplankton in marine field samples. The protocol can be easily incorporated into shipboard zooplankton sampling. The use of neutral red in laboratory studies is common, but its application for quantifying natural live/dead zooplankton composition under field conditions has not been evaluated in detail. We tested the accuracy and precision of the method for a range of salinities and temperatures, and for common estuarine zooplankton groups. Detailed descriptions of staining intensities and patterns are provided. In addition, we evaluated potential artifact mortality due …