Research

Intensive Cultivation of the Calanoid Copepod Bestiolina similis

Intensive Cultivation of the Calanoid Copepod Bestiolina similis

Copepod nauplii are marine zooplankton invertebrates that have been shown to be advantageous as a food source for larval finfish ornamentals when the larvae first begin to feed. Despite this potential, copepod nauplii have up not been reared in sufficient quantities to sustain the large-scale feeding of ornamental finfish in captivity until this point. The aim of this scientific investigation was to develop a protocol for the effective cultivation and collection of eggs from the calanoid copepod, Bestiolina similis, and to compare the rates of mortality and egg production in response to additions of various food sources and concentrations to optimize animal longevity and reproductive performance.

The Isolation and Identification of Diatoms from Lake Waiau Sediments

The Isolation and Identification of Diatoms from Lake Waiau Sediments

The creation of a paleohydrologic record for the Hawaiian Islands is essential to understanding future implications of climate change. Determining the oxygen isotope composition of diatoms present in Lake Waiau cores will allow the paleohydrology of the lake to be reconstructed, which can be related to the hydrologic history of the entire Hawaiian Islands. Prior to the isotopic analysis of the diatoms, they must be isolated from the rest of the sediment. This study attempts to determine an effective method for this isolation, as well as to identify the diatom species that were isolated.

Polyphasic Characterization of Bacteria Isolated from Shrimp Larva

Polyphasic Characterization of Bacteria Isolated from Shrimp Larva

The 16S rDNA genes of fourteen bacterial isolates derived from shrimp larvae were successfully amplified, cloned and sequenced. Comparison of the sequences with those available at the NCBI web site using BLAST (nr database) allowed for bacterial classification based on similarity indices of greater than or equal to 96%. These identifications were consistent with previous phenotypic analyses of the same isolates by their carbon source utilization patterns and fatty acid methyl esters (FAME). Use of 16S sequencing to identify bacteria to species level is not without problems.

Relationship Between Gene Expression and Cell Metabolism in the Marine Bacterium Streptomyces tenjimariensis

Relationship Between Gene Expression and Cell Metabolism in the Marine Bacterium Streptomyces tenjimariensis

The marine bacterium Streptomyces tenjimariensis is known to produce an array of primary and secondary metabolites. The mechanisms of genetic regulation and control of these metabolic production pathways have yet to be elucidated. In this study, two specific aspects of metabolism and gene expression in S. tenjimariensis were investigated: the expression of enzymes involved in the biosynthesis of aminoglycoside antibiotics and the extracellular breakdown of starch.

Correlations Between Turbidity and Sources of Physical Forcing on the South Shore of Oahu

Correlations Between Turbidity and Sources of Physical Forcing on the South Shore of Oahu

Although water quality is extremely important to the Hawaiian Islands in terms of tourism and coastal ecology, very few studies have been done to investigate water turbidity along the south shore of Oahu. The reintroduction of sediments from the sea floor to the water column plays a major role in the turbidity of this area, and is heavily influenced by physical oceanographic forces such as currents, swells, and tides. This study focuses on using Acoustic Doppler Current Profiler (ADCP) echo intensity to examine the relationship between the aforementioned physical forces and changes in suspended sediment concentration on the south shore of Oahu.

Bacterial composition of surface associated microbes found in three Hawaiian coral species: Porites compressa, Porites lobata, and Montipora capitata

Bacterial composition of surface associated microbes found in three Hawaiian coral species: Porites compressa, Porites lobata, and Montipora capitata

In the last few years, the severity of coral bleaching events and disease observances has increased worldwide. Very little is known about disease in the Hawaiian Islands, although it is a commonly held belief that conditions are generally unfavorable for disease development/establishment due to Hawaii's open ocean circulation and low human population. This study focuses on characterizing bacterial communities found on healthy and lesioned Montipora capitata, Porites compressa, and Porites lobata collected from various sites around Oahu, Hawaii including the North Shore, Hanauma Bay, Kaneohe Bay and Kahe Point.

Virus-induced gene silencing in Nicotiana benthamiana using a DEAD-box helicase sequence derived from Dunaliella salina

Virus-induced gene silencing in Nicotiana benthamiana using a DEAD-box helicase sequence derived from Dunaliella salina

Viral vectors can be used to introduce sequences that cause gene silencing in plants. In this study, a sequence from the salt-tolerant green alga Dunaliella salina was used to silence a DEAD box helicase gene in Nicotiana benthamiana, a plant related to tobacco. Phenotypic changes due to silencing were observed, and changes in expression of the DEAD box helicase gene were quantified using real-time PCR. The results suggest that the gene is involved in critical RNA processing functions. More generally, it was demonstrated that although N. benthamiana is only distantly related to D. salina, gene silencing could be induced in N. benthamiana using a sequence from D. salina; this indicates that it may be possible to use gene silencing in N. benthamiana to characterize genes from a wide variety of organisms.

Effects of the Growth Hormone Secretagogue, CP-477335, on the GH/IGF-I Axis in Tilapia, Oreochromis mossambicus

Effects of the Growth Hormone Secretagogue, CP-477335, on the GH/IGF-I Axis in Tilapia, Oreochromis mossambicus

In 1977, a series of functional growth hormone secretagogues (GHS), which activate the endogenous receptor of the stomach peptide ghrelin, were synthesized in order to stimulate growth hormone secretion from the pituitary gland. Following this work, subsequent efforts concentrated on the development of an orally active GHS with a long lasting effect and high bioavailability. This paper discusses the effect of the functional growth hormone GHS CP-477335 on the GH/IGF-I axis in tilapia, Oreochromis mossambicus, using both in vivo and in vitro experiments.

Effects of Heptachlor and DDE on the GH-IGF axis in female tilapia, Oreochromis mossambicus

Effects of Heptachlor and DDE on the GH-IGF axis in female tilapia, Oreochromis mossambicus

Through human activities, endocrine disrupting compounds (EDCs) have become ubiquitous in the aquatic environment. Although much research has examined the effects of these chemicals on reproduction, there remains a paucity of information regarding effects on growth. In order to study the effects of EDCs on growth, hepatocytes (liver cells) and pituitary cells were cultured from female tilapia, Oreochromis mossambicus, and exposed to heptachlor, a pesticide, and DDE, a by-product of the pesticide DDT. Cells and media were assayed for liver vitellogenin, IGFBPs, and pituitary GH.

Quantification of Single-Species Marine Biofilm with Alcian Blue

Quantification of Single-Species Marine Biofilm with Alcian Blue

Biofouling is the process by which living tissue or inert objects placed into aqueous environments are covered with a complex community of micro and macro organisms. The process begins with the formation of a microbial biofilm that subsequently serves as a suitable surface to which the larvae of macrofoulers attach and undergo metamorphosis into adult organisms. Biofilms can also coat medical devices imbedded in the human body and provide microbial pathogens a measure of protection from antibiotics. As such, the formation of microbial biofilms is a significant problem and strategies to inhibit their formation are needed.

Virulence and Antibiotic Resistance Gene Combinations among Staphylococcus aureus Isolates from Coastal Waters of Oahu, Hawaii

Virulence and Antibiotic Resistance Gene Combinations among Staphylococcus aureus Isolates from Coastal Waters of Oahu, Hawaii

Staphylococcus aureus is often found passively colonizing human skin and nasal passages. As an opportunistic pathogen, the bacterium can also cause infections that vary widely in their severity and in their susceptibility to antibiotic treatment. This variability is caused by differences in gene content among strains. One source of exposure to novel, potentially more virulent strains of S. aureus is recreational swimming areas, since S. aureus is readily shed from humans into water.