Biology Commons^™

Zooplankton Communities Of Selected Stations Of Lake Victoria, Rk Waya, Ja Mwambungu

Tanzania Journal of Science

Species composition and diversity of zooplankton communities of Lake Victoria (Tanzanian waters) were studied. In the shallow waters zooplankton were collected between March and April, and between August and December 2000. In deeper waters zooplankton were collected in August 2001. Overall, 20 genera and 29 species of zooplankton were observed in the shallow waters whereas 12 genera and 20 species of zooplankton were encountered in the deeper waters. The highest abundance was recorded in the deeper waters (2,481,633-2). In the shallow waters the cyclopoid copepods dominated the zooplankton community, the common species being Thermocyclops emini and Thermocyclops neglectus. In the …

The Diversity Of Benthic Mollusks Of Lake Victoria And Lake Burigi, Ja Mwambungu

Tanzania Journal of Science

Molluscan diversity, abundance and distribution in sediments of Lake Victoria and its satellite lake, Lake Burigi, were investigated. The survey was carried out in January and February 2002 for Lake Victoria and in March and April 2002 for Lake Burigi. Ten genera were recorded from four zones of Lake Victoria while only three genera were recorded from Lake Burigi. In Lake Victoria the most diverse zone was Mara zone. The mollusca communities comprised of Bellamya, Gabbiella, Melanoides, Bulinus, Biomphalaria and Cleopatra (Gastropoda) and Corbicula, Eupera (Byssanodonta), Caelatura and Sphaerium (Bivalvia). Lake Burigi comprised of Melanoides, Bulinus and Biomphalaria. Melanoides tuberculata …

Phytoplankton And Nutrients Studies In Magu Bay, Speke Gulf, Lake Victoria, (Tanzania) Following The 2001 Principal Rain Season, Jf Machiwa, C Lugomela, Ann Muzuka

Tanzania Journal of Science

Phytoplankton abundance and species composition in relation to some physico-chemical parameters were studied in Magu Bay, Lake Victoria, in May 2001. Investigations on the influence of Simiyu River on the biological and physical characteristics of the Bay were carried out. Surface and bottom currents flowed in the northeast direction close to the river mouth but were completely reversed after about 1.5 km from the river mouth. Most suspended particles brought in by the river were deposited within 0.5 km after entering the lake. Nutrient concentrations were generally high towards the eastern part of the bay as compared to the rest …

Species Composition And Biomass Estimates Of Zooplankton In Some Water Bodies Within Lake Victoria Basin, Rk Waya, Ai Chande

Tanzania Journal of Science

Zooplankton communities were identified and their abundance and biomass estimated in some selected satellite lakes and Mara River in Lake Victoria basin, during wet and dry seasons in 2002. Samples were collected from eight water bodies. Three stations were sampled from each water body using a plankton net (40 µm mesh size) hauled vertically through the water column. The zooplankton community comprised mainly crustacea and rotifers. The results show that the number of species collected during the wet and dry seasons was 31 species and 28 species, respectively. The Shannon wiener diversity indices were not significantly different (Mann-Whitney U Test …

Spatial Distribution Of Parasites Along The Gut Of The Catfish Clarias Gariepinus (Burchell, 1822) (Clariidae) From The Mwanza Gulf, Lake Victoria, G Nkwengulila, C Mwita

Tanzania Journal of Science

The diversity, abundance and spatial distribution of parasites in the alimentary tract of Clarias gariepinus from the Mwanza Gulf were investigated. Ten parasite species were recovered; the Trematoda, Cestoda and Nematoda were each represented by three species while Dolops ranarum was the only crustacean recovered from the posterior part of the buccal cavity. Parasites diversity was highest in the small intestine and the stomach. Although the gut community of C. gariepinus studied was rich in intensity and individual numbers of helminth species, helminth infection in most sections of the gut comprised of monospecific infection and thus cohabiting interspecific interaction was …

Phytoplankton Species Diversity And Abundance In Satellite Lakes Of Lake Victoria Basin (Tanzanian Side), Bc Sekadende, Ase Mbonde, S Shayo, Tj Lyimo

Tanzania Journal of Science

Studies on phytoplankton species diversity and abundance were carried out in 8 selected satellite lakes within the Lake Victoria basin during two wet seasons (March-April 2002 and January-February 2003) and one dry season (August-September 2002). Higher species richness (76 species) of phytoplankton species was recorded in rain season than in dry season (47 species). The observed species represents six classes, cyanophytes, chlorophytes, cryptophytes, basillariophytes, euglenophytes and dinophytes, of fresh water algal flora. Species diversity was generally low, with diversity indices (H\') ranging from 0.21 for Lake Kyarano to 0.09 for Lake Ikimba. On the contrary, Lake Katwe was richer in …

Diurnal Feeding Patterns And Food Habits Of Lates Niloticus In The Speke Gulf, Lake Victoria, Ha Mhitu, Ai Chande

Tanzania Journal of Science

Twenty four hour sampling sessions were conducted to investigate the feeding patterns and food habits of Lates niloticus in the Speke Gulf, Lake Victoria during January/February, July/August and December 2002. Feeding activity was more pronounced during daytime mostly in morning hours than during the night. The most dominant food item was haplochromines. There was a significant difference in the occurrence of food items in the gut of L. niloticus with time. However, there was no significant difference in the occurrence of food items in the habitat at different times. The study concludes with a recommendation for fishermen to set their …

Fish Species Composition, Size Structure And Distribution In Non-Trawlable Areas Of Lake Victoria (Tanzania) With Emphasis On Mwanza Gulf And Mori Bay, Jdr Bayona, B Msuku, S Mzighani

Tanzania Journal of Science

Fish diversity studies in littoral non-trawlable areas of Lake Victoria (Tanzania) were undertaken during six systematic surveys (November 2000 to December 2002). Information on fish species composition, size structure as well as spatial and temporal distribution was generated from gill-netting, beach-seining and electric fishing. Lates niloticus, indicated a declining trend in composition from 78.9% in March 2001 to 5.1% in July 2002. The species, however, increased to 40.6 % in catch composition as of December 2002, exhibiting somewhat inverse trends in distribution with Oreochromis niloticus and haplochromines in the lake fisheries. The surveys identified over 50 species for which 42 …

Diel Vertical Migration Of Zooplankton In The Tanzanian Waters Of Lake Victoria, Rk Waya

Tanzania Journal of Science

The diel vertical migration of zooplankton was studied in the Southern part of Lake Victoria in January and July 2002. A van dorn water sampler was used to collect zooplankton. In January 2002, zooplankton showed a pronounced diel vertical migration whereby zooplankton were moving upward at around sunset and swimming downward at sunrise. In July 2002 zooplankton showed diel vertical migration, but at around midnight Thermodiaptomus galeboides, Thermocyclops emini, Tropocyclops tenellus, cyclopoid copepodites, nauplius larvae and some rotifers showed downward movement. The diel vertical migration of zooplankton seems to be influenced by food, predation and light.

Total Mercury Concentration In Common Fish Species Of Lake Victoria, Tanzania, J F Machiwa

Tanzania Journal of Science

Total mercury (THg) concentration was analysed in muscles of common fish species of Lake Victoria in the eastern and southern parts of the lake using cold vapour Atomic Absorption Spectrophotometric technique. Mercury concentration in all fish species was generally lower than the WHO maximum allowable concentration (500 ng/g ww) in edible fish parts. The maximum concentration of THg in Lates niloticus samples was 396 ng/g ww. Samples of Oreochromis niloticus had THg concentration ranging between <0.01 and 419 ng/g ww. Clarias gariepinus had THg concentration ranging between 1.2 and 239.1 ng/g ww. All less common fish species, such as, Labeo victirianus, Synodontis victoriae, Oreochromis leucostictus, Schilbe intermedius, Brycinus jacksonii, B. sadleri, Tilapia rendalii, Tilapia zilii and Haplochromines had THg concentration below the WHO maximum allowable limit (500 ng/g ww). The study showed that Hg from small-scale gold mining activities in Lake Victoria basin is not transported to the lake by fluvial discharge. Other possible pathways of Hg input to Lake Victoria are discussed.

Studies On The Fisheries And Biology Of Oreochromis Urolepsis (Pisces: Cichilidae) In The Mtera Resorvoir (Tanzania), F M M Chale

Tanzania Journal of Science

The fisheries and some aspects of the biology of Oreochromis urolepis of the Mtera Reservoir (Tanzania) were examined in August 2002. It was observed that there was no proper management of the reservoir's fisheries. Beach seine fishing dominated the fishery. Nearly all the O. urolepis caught by this type of gear were juveniles. The number of fish caught by the beach seines was very high, some times up to 4,000 fish per haul. The beach seines also destroy the spawning sites for the tilapias. Mean total lengths of O. urolepis caught in gillnets of legal mesh sizes (ranging from 88 …

Changes In Population Structures Of The Major Species In Selected Satellite Lakes Around Lake Victoria Following Changes In Fishing Effort, E F B Katunzi, M A Kishe

Tanzania Journal of Science

This paper evaluates the impacts of reduction in effort, increase in mesh sizes, and prohibition of illegal fishing gears in selected satellite lakes around Lake Victoria. The study was carried out in six satellite lakes by making investigations on fish collected from experimental and artisanal fisheries. The fishes were analysed for length frequencies, weight and numbers caught to determine the population structure of the fishes. Indiscriminate fishing by deploying illegal gears and increased fishing effort due to open access policy, the catch and diversity of the species in these lakes has declined. Establishment of Conservation Management Units (CMUs) as an …

Parasites Of Clarias Gariepinus (Burchell, 1822) (Pisces: Clariidae) From The Mwanza Gulf, Lake Victoria, C Mwita, G Nkwengulila

Tanzania Journal of Science

Seventeen species of parasites were recovered from 1071 Clarias gariepinus examined from the Mwanza Gulf of Lake Victoria. The parasite fauna comprised of four ectoparasites, a Monogenea, Hirudinea, crustacean and a Digenea; and fourteen endoparasites, five nematodes, five trematodes and three cestodes. Twelve parasite species were adults and five were larval forms. Ten were identified to species, six to genus and one to family level. Many species recorded are common to C. gariepinus, a few, e.g. Tylodelphys species is a first record in fish of Africa, thus represents a new host record. Spinitectus petterae is reported for the first time …

Phytoplankton Species Diversity And Abundance In The Near Shore Waters Of Tanzanian Side Of Lake Victoria, Ase Mbonde, S Shayo, Bc Sekadende, Tj Lyimo

Tanzania Journal of Science

The survey was carried out in January/February and July/August 2002 to investigate phytoplankton species diversity, spatial distribution, numerical abundance and total biomass (chlorophyll a concentration) in 10 selected stations on the Tanzanian side of Lake Victoria. At each station, samples for diversity data were collected by plankton net, which was towed at the surface water, while those for spatial distribution and abundance were collected using a 1 l Van Dorn water sampler. A total of 113 species belonging to 52 different genera were identified. Cyanobacteria were the most diverse group in both seasons. The concentration of chlorophyll a ranged from …

Episodic Physical Forcing And The Structure Of Phytoplankton Communities In The Coastal Waters Of New Jersey, Mark A. Moline, Shelley M. Blackwell, Robert Chant, Matthew J. Oliver, Trisha Bergmann, Scott Glenn, Oscar M.E. Schofield

Biological Sciences

The high variability in physical, biological, and chemical properties in coastal waters have limited our ability to sample the appropriate timescale and space scale to resolve physical forcing of the ecosystem. To improve our understanding, a multiplatform adaptive sampling program at the Long-term Ecosystem Observatory(LEO-15) off the coast of New Jersey examined the relationship between episodic summertime upwelling and downwelling events and the corresponding dynamics in bulk phytoplankton biomass and community structure. Inherent and apparent optical properties were concurrently measured to evaluate the use of optics to improve future sampling coverage in coastal regions. Results indicate peak chlorophyll biomass tracked …

Effect Of Stocking Density On Sunshine Bass (Morone Chrysops X M. Saxatilis) Production And Water Quality At Minor Clark Fish Hatchery, Kentucky, Todd A. Leonard

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the Requirements for the Degree of Master of Science by Todd A. Leonard on December 15, 2004.

Phylogenetic Relationships Of African Microhylid Frogs Inferred From Dna Sequences Of Mitochondrial 12s And 16s Rrna Genes, Simon P. Loader, David J. Gower, Kim M. Howell, Nike Doggart, Mark-Oliver Rödel, Barry T. Clarke, Rafael O. De Sá, Bernard L. Cohen, Mark Wilkinson

Biology Faculty Publications

The phylogenetic relationships of microhylid frogs are poorly understood. The first molecular phylogeny for continental African microhylids is presented, including representatives of all subfamilies, six of the eight genera, and the enigmatic hemisotid Hemisus. Mitochondrial 12S and 16S rRNA sequence data were analysed using parsimony, likelihood and Bayesian methods. Analyses of the data are consistent with the monophyly of all sampled subfamilies and genera. Hemisus does not nest within either brevicipitines or non-brevicipitines. It is possibly the sister group to brevicipitines, in which case brevicipitines might not be microhylids. Phrynomantis and Hoplophryne potentially group with non-African, non-brevicipitine microhylids, in …

Kinetics And Relative Importance Of Phosphorolytic And Hydrolytic Cleavage Of Cellodextrins And Cellobiose In Cell Extracts Of Clostridium Thermocellum, Yie.-Heng P. Zhang, Lee R. Lynd

Dartmouth Scholarship

Rates of phosphorolytic cleavage of 􏰁-glucan substrates were determined for cell extracts from Clostridium thermocellum ATCC 27405 and were compared to rates of hydrolytic cleavage. Reactions with cellopentaose and cellobiose were evaluated for both cellulose (Avicel)- and cellobiose-grown cultures, with more limited data also obtained for cellotetraose. To measure the reaction rate in the chain-shortening direction at elevated temper- atures, an assay protocol was developed featuring discrete sampling at 60°C followed by subsequent analysis of reaction products (glucose and glucose-1-phosphate) at 35°C. Calculated rates of phosphorolytic cleavage for cell extract from Avicel-grown cells exceeded rates of hydrolytic cleavage by >20-fold …

Exogenous Vasotocin Alters Aggression During Agonistic Exchanges In Male Amargosa River Pupfish (Cyprinodon Nevadensis Amargosae), Sean C. Lema, Gabrielle A. Nevitt

Biological Sciences

Pupfishes in the Death Valley region have rapidly differentiated in social behaviors since their isolation in a series of desert streams, springs, and marshes less than 20,000 years ago. These habitats can show dramatic fluctuations in ecological conditions, and pupfish must cope with the changes by plastic physiological and behavioral responses. Recently, we showed differences among some Death Valley populations in brain expression of arginine vasotocin (AVT). As AVT regulates both hydromineral balance and social behaviors in other taxa, these population differences may indicate adaptive changes in osmoregulatory and/or behavioral processes. To test whether AVT is relevant for behavioral shifts …

Historical Biogeography Of Lowland Species Of Toads (Bufo) Across The Trans-Mexican Neovolcanic Belt And The Isthmus Of Tehuantepec, Benson H. Morrill

Undergraduate Honors Capstone Projects

The eastern extension of the massive Trans-Mexican Neovolcanic Belt 1 (TMNB) contacts the Atlantic Coast in central Veracruz, Mexico. Although it is not a massive structure at this eastern terminus, the TMNB has nonetheless effected vicariance and subsequent speciation in several species groups, including bufonid toads and freshwater fishes. In this study, we examined mtDNA sequences (cyt b, 16S) from populations of two different species groups of toads (B. marinus, and the B. nebulifer-B. valliceps species pair) from a lowland transect across the eastern end of the TMNB. We also included samples from outside this region (e.g., Costa …

Distribution Of Chemistry And Sexual Fecundity In The Lichenized-Fungi, Xanthoparmelia Cumberlandia And Xanthoparmelia Coloradoensis On Boulder Mountain, Aquarius Plateau, Ut, Heather Bird Jackson

Theses and Dissertations

Three aspects of Xanthoparmelia cumberlandia and Xanthoparmelia coloradoënsis populations found at two elevations are explored: clustering of secondary chemicals and the resulting implications for taxonomic distinctions, the usefulness of thallus size as an indirect measure of sexual fecundity, and the frequency of sexual reproduction.

First, we use clustering of 46 chemicals produced by X. cumberlandia and X. coloradoënsis to evaluate the adequacy of the current taxonomic distinction between them. Using principal components analysis and UPGMA, we find that the currently recognized species boundaries indicated by the presence of stictic acid in X. cumberlandia and salazinic acid in X. coloradoënsis are …

Monitoring Heart Rate In Drosophila Larvae By Various Approaches, Sameera Dasari, Robin L. Cooper

Biology Faculty Publications

No abstract provided.

Monitoring Carbon Dioxide Production By Drosophila Larvae, Robin L. Cooper, D. Nicholas Mcletchie

Biology Faculty Publications

No abstract provided.

Monitoring Activity Of Drosophila Larvae: Impedance & Video Microscopy Measures, Ann Simone Cooper, Robin L. Cooper

Biology Faculty Publications

No abstract provided.

Soil Biota Facilitate Exotic Acer Invasions In Europe And North America, Kurt O. Reinhart, Ragan M. Callaway

Biological Sciences Faculty Publications

The primary hypothesis for successful exotic plant invasions is that the invaders have escaped the specialist consumers that control them (Enemy Release Hypothesis). However, few studies have rigorously tested this assertion with biogeographical experiments or considered the effects of soil organisms. We tested the Enemy Release Hypothesis and the enhanced role of mutualisms by comparing density patterns of the North American Acer negundo and European A. platanoides trees in their native and nonnative ranges. Invaders that have escaped their natural enemies are predicted to attain greater densities in nonnative than native ranges. To determine whether interactions with soil biota could …

Loss Of Enemy Resistance Among Introduced Populations Of St. John's Wort (Hypericum Perforatum), John L. Maron, Montserrat Vilà, John Arnason

Biological Sciences Faculty Publications

The Evolution of Increased Competitive Ability (EICA) hypothesis predicts that introduced plants should lose enemy resistance and in turn evolve increased size or fecundity. We tested the first prediction of this hypothesis by growing introduced North American and native European genotypes of St. John's Wort (Hypericum perforatum) in common gardens in the state of Washington, USA, and in Girona, Spain. In both gardens we measured levels of hypericin and pseudohypericin (and in Washington, hypericide)— compounds known to be toxic to generalist pathogens and herbivores. In a third common garden, in Spain, we experimentally manipulated native pathogen pressure (by …

Bergmann's Clines In Ectotherms: Illustrating A Life-History Perspective With Sceloporine Lizards, Michael J. Angilletta Jr., Peter H. Niewiarowski, Arthur E. Dunham, Adam D. Leache, Warren P. Porter

Biology Faculty Research

The generality and causes of Bergmann's rule have been debated vigorously in the last few years, but Bergmann's clines are rarely explained in the context of life-history theory. We used both traditional and phylogenetic comparative analyses to explore the causes of latitudinal and thermal clines in the body size of the eastern fence lizard (Sceloporus undulatus). The proximate mechanism for larger body sizes in colder environments is delayed maturation, which results in a greater fecundity but a lower survival to maturity. Life-history theory predicts that a higher survivorship of juveniles in colder environments can favor the evolution of a Bergmann's …

Development And Characterization Of Monoclonal Antibodies Directed Against Tanapox Virus, Michael Franz

Masters Theses

The initial symptoms of a Tanapoxvirus (TPV) infection are indistinguishable from smallpox, which is caused by variola virus (VV). In the post-9/11 area, reagents that can quickly differentiate a TPV infection from smallpox are very desirable, but currently unavailable. Monoclonal antibodies (mAbs) directed specifically against TPV can be used for this purpose. Six mAbs were developed and characterized that specifically bind to TPV infected owl monkey kidney (OMK) cells, but not uninfected cells. The apparent molecular mass of the TPV protein(s) recognized by 5 mAbs were calculated using the Western blot technique. One mAb demonstrated no binding using the Western …

Neglected Taxonomy Of Rare Desert Fishes: Congruent Evidence For Two Species Of Leatherside Chub, Jerald B. Johnson, Thomas E. Dowling, Mark C. Belk

Faculty Publications

Conservation biologists rely heavily on taxonomy to set the scope for biological monitoring and recovery planning of rare or threatened species. Yet, taxonomic boundaries are seldom evaluated as falsifiable hypotheses that can be statistically tested. Here, we examine species boundaries in leatherside chub (Teleostei, Cyprinidae), an imperiled desert fish native to the Bonneville Basin and upper Snake River drainages of western North America. Recent molecular data hint that this fish could be composed of two distinct taxa that are geographically separated into northern and southern species. To formally test this hypothesis, we evaluated leatherside chub using several different categories of …

Planting Date Effects On The Germinability And Seedling Vigor Of Abutilon Theophrasti Seeds, R E. Nurse, A Ditommaso, Ricardo A. Ramirez

Biology Faculty Publications

Abutilon theophrasti (Malvaceae) is a troublesome annual weed in many maize and soybean cropping systems of Canada and the United States. Seeds of A. theophrasti exhibit physical dormancy. Differences in the growing environment of parent plants may influence the germinability of seeds and vigour of seedlings produced by this species because of variation in resource allocation to seed development. Thus, the germinability of seeds and subsequent seedling vigour were examined for A. theophrasti plants grown in monoculture at a density of 4.2 plants m -2 under varying natural photoperiods in central New York State. Treatments were established by transplanting A. …