Research Article
Dec 23, 2010
This study was undertaken to define the effects of temperature on the energy and protein partial utilisation efficiencies of juvenile Barramundi. The experiment used a factorial design with four temperatures (25ºC, 29ºC, 32ºC, and 36ºC) and three ration levels (low, moderate, satiety) to examine the response of Barramundi to varying digestible energy (DE) and digestible protein (DP) intake. Energy and protein deposition with varying intakes at most temperatures were linear, though aberrations occurred at 36ºC relative to the other temperatures. The coefficients of DE utilisation were relatively consistent at 0.56 ± 0.02 (mean ± SEM) between 25ºC and 32ºC, though at 36ºC this declined to 0.42 ± 0.04. Similarly the maintenance DE demand for the fish was relatively constant across the range 25ºC to 32 ºC (~40 kJ DE/metabolic body weight (MBW)/d), but at 36ºC dramatically increased to around 110 kJ DE/MBW/d. The coefficients of DP utilisation were also relatively consistent at 0.51 ± 0.02 between 25ºC and 32ºC, though at 36ºC this declined to 0.28 ± 0.12. Similarly, the maintenance DP demand at 36ºC dramatically increased from around 0.5 g DP/PBW/d to 1.5 g DP/PBW/d. These results demonstrate that at high temperatures Barramundi protein demand and utilisation is significantly compromised and this affects their ability to efficiently convert dietary protein to tissue growth.
Research Article
Dec 06, 2010
Bacterial infection is a major cause of high mortality in juvenile sea turtles at the Sea Turtle Conservation Centre, Chonburi Province, Thailand. The attempt is to identify sources of bacterial accumulation and contamination in order to reduce the number of infections. The aim of this study was to determine the effects of live rocks and captivity parameters on microbiological water quality. Microbiological results indicated that the presence of live rocks in juvenile green turtle containers resulted in a reduction of haemolytic bacteria in seawater. Additionally, the high stock density of animals in the captivity has influence on the increased bacterial levels in the water, while temperature of the water was found to have an influence on bacterial growth. The results of this study implied that the environments of captivity have great impact on the bacterial levels in the water, which should be considered for the management of sea turtles as well as other aquatic animals.
Research Article
May 24, 2010
Cirrhina mrigala (63 ± 2 g) were intramuscularly (i.m.) administered with 2.3 x 107 CFU ml-1 of Aphanomyces invadans (isolate B99C). The hematological and biochemical parameters were studied in the experimental and control groups for 30 days. In infected untreated group (I), the white blood cell count (WBC: 106mm-3) was significantly increased (P < 0.05) from the control, while no change was seen in groups fed probiotics, herbal and azadirachtin supplementation diets. Similar trend was noted in the haemoglobin (Hb: g/dL) and haematocrit (Hct: %) levels. Interestingly, infected fish fed probiotics, herbal and azadirachtin supplementation diets, did not differ (P > 0.05) from the control. A similar trend prevailed in the percentage of lymphocytes (LYM), monocytes (MON), eosinophils (EOS), and neutrophils (NEU). The total protein (TP: g dl-1), glucose (GLU: mg dl-1), calcium (CAL: mmol l-1), and cholesterol (CHO mmol l-1) levels were affected (P < 0.05) in the infected group. The present study suggests that the administration of probiotics, herbal, and azadirachtin supplementation diets for 30 days protects the hematological and biochemical parameters in C. mrigala from A. invadans.
Research Article
Mar 06, 2010
A geospatial database of spotted seatrout (Cynoscion nebulosus) abundance along the Texas shoreline was generated, using 33 years of intensive gill net sampling data by the Texas Parks and Wildlife Department. The resulting landscape demographic data was used to identify areas of low individual abundance, which were evaluated as putative subpopulation boundaries. Quantitative population genetic analysis was conducted using a recently published genetic data set of mitochondrial DNA haplotypes, and a new data set of nuclear microsatellites. A significant mtDNA AMOVA result was obtained when samples were pooled into northern, mid-coast and southern spatial partitions based upon geospatial data (Fct = 0.030, P = 0.003). This three-partition model captured more genetic divergence at the group level than any other model examined. Similarly, the three-partition model resulted in a small but significant group association in the microsatellite AMOVA (Fct = 0.003, P = 0.009). Multivariate cluster analyses of both data sets indicated that at least three distinctive subpopulations of spotted seatrout exist within Texas waters. The genetic data are consistent with previous studies that indicate the presence of distinctive subpopulations of spotted seatrout in Texas coastal waters, and with geospatial abundance data indicating areas of low abundance between adjacent subpopulations along the northern and southern Texas coastline.
