In the research reported here, the pathology, virulence, and strain differences of Taura syndrome virus (TSV) was studied. Initial studies on TSV pathogenesis compared the survival of juveniles of a highly Taura syndrome (TS) susceptible line of Penaeus vannamei, a line of TS resistant P. vannamei, and an innately TS resistant P. stylirostris line following TSV challenge by feeding (per os) or injection methods, in the absence of horizontal transmission via cannibalism and/or absorption from the water. Per os_TSV challenge resulted in I00% survival in P. stylirostris, but challenge by per os exposure produced significant mortality commencing on about the same post-exposure day in both SPF and SPR P. vannamei (P < 0.001), suggesting that P. stylirostris is significantly (P < 0.001) more resistant toper os TSV infection and presentation of TS disease than either SPF or SPR P. vannamei. The potential roles of the cuticular lining of the stomach and hindgut and unlined portions of the gut in TSV resistance in penaeid shrimp are discussed as factors where an innate resistance mechanism was postulated to explain the observed differences between the different species and populations of shrimp in TSV susceptibility. To investigate apparent TSV strain differences, three geographic and year isolates of TSV from naturally occurring TS epizootics of cultured penaeid shrimp were obtained from Mexico (SIN98TSV and MX99TSV from P. vannamei and SON2KTSV from P. stylirostris) and one TSV isolate from Belize, Central America (BLZ02TSV from P. vannamei) were analyzed and compared to the reference TSV isolate (HI94TSV) by selected TSV diagnostic and genetic analysis methods. The results show that screening of penaeid shrimp broodstock and postlarvae by MAb I Al testing will not detect all TSV isolates, possibly leading to false negative results, further spread of TSV and re-emergence of TS in regions where it has been eradicated. The putative VP1 antigenic epitope recognized by TSV MAb 1A1 is identified, with SIN98TSV and BLZ02TSV having 70.0% and 80.0% AA homology, respectively, within the 10 AA region. There are three distinct electropherotypes and 'serotypes' of TSV, with electropherotype A (TSV Etype-A) and serotype A (TSV-A) representing those TSV isolates conforming to VP1 properties of the Hawaiian 1994 TSV isolate, electropherotype B (TSV Etype-B) and serotype B (TSV-B) representing those TSV isolates conforming to the VP1 properties of the Sinaloan 1998 TSV isolate, and electropherotype C (TSV Etype-C) and TSV serotype C (TSV-C), representing those TSV isolates conforming to the VP1 properties of the Belize 2002 TSV isolate. In a parallel activity, the University of Arizona (UAZ) Aquaculture Pathology Diagnostic Laboratory (APL) Case Database (DB) and the UAZ Aquaculture Pathology Diagnostic Laboratory Client Address Book Database (AB), relational databases, were created using FileMaker Pro software, are used to keep an up to date and accurate record of all UAZAPL diagnostic and research case and client information and may be searched and sorted to find case data and/or client information of interest.

I studied the in-water anthropogenic impacts on sea turtles, origins of sea turtles on foraging and developmental areas, their migration routes, and described regionally appropriate conservation needs. Sea turtles inhabiting Baja California waters originate on distant beaches in Japan, Hawaii, and southern Mexico. Results from genetic analyses, flipper tagging and satellite telemetry indicate loggerhead turtles (Caretta caretta) feeding along Baja California's coast are born in Japan and make a transpacific developmental migration of more than 20,000 km, encompassing the entire North Pacific Ocean and that East Pacific green turtles (Chelonia mydas) originate on and return to rookeries in Michoacan, and the Islas Revillagigedo, Mexico. Hawksbill turtles (Eretmochelys imbricata), once the target of a lucrative fishery for their shell, are now extremely scarce and only juveniles were encountered. The region's importance to the biology of sea turtles, regionally and Pacific-wide, warrants urgent conservation action. While protected legally, sea turtles are subject to furtive hunting and incidental catch. Coastal development, pollution, and boat collision are secondary threats. Annual consumption of sea turtles in the region is estimated at between 7,800 and 30,000 animals. Sea turtles are eaten regularly in most coastal communities and turtles are considered an irreplaceable traditional food. The decline of sea turtles in these waters has cost us both ecologically and culturally. Sea turtle recovery in Baja California, as all conservation activities, will be a matter of cultural and social evolution. For recovery to occur, strong, community-based incentives and educational programs are needed. In the near term, increased enforcement efforts, monitoring of mortality, and establishment of sea turtle sanctuaries are among the solutions. Without expansion to include community-specific initiatives such efforts may be futile. A long-term, multi-faceted sea turtle "conservation mosaic" program has been launched, consisting of community-based research on life history and population biology, an international education and public outreach campaign, regional sea turtle conservation areas, a monitoring and stranding network, and several policy initiatives that will permanently protect sea turtles and their habitat.

The genome of a Korean isolate of Hepatopancreatic parvovirus (HPV) was partially cloned, sequenced and characterized. Random PCR amplification of viral DNA was combined with conventional cloning methods to generate three clones named HPV8 (2,136 bp insert), HPV3 (1,560 bp insert), and CP1139 (413 bp insert). DNA sequencing demonstrated overlapping regions between HPV8 and HPV3 and between HPV3 and CPII39. The combined sequence of these three clones encompass approximately 3,350 bp of the total 5,000 bp estimated for the HPV genome. A large open reading frame (1,692 bp) was found within clones HPV3/CPII39 encoding a polypeptide of 549 residues (∼60 kDa) whose amino terminus shows 100% homology with the first 12 residues sequenced from an apparently single 54 kDa (by SDS-PAGE) structural protein found in a Korean isolate of HPV. Two new gene probes EC.592 (592 bp) and EC.350 (350 bp) were developed by PCR amplification of previously constructed HPV (Korean) clones and labeled with DIG11-dUTP. These probes recognize different regions of the HPV genome. The specificity of both probes was confirmed by in situ hybridization using HPV-infected Penaeus chinensis (Korean) as a positive control and specific-pathogen free P. vannamei and IHHNV-infected P. stylirostris, as negative controls. Both probes were used in in situ hybridization to compare their reaction to HPV-type lesions detected by conventional H&E histology in 7 species of HPV-infected shrimp, and one of freshwater prawn, from 13 countries. The results of this comparison strongly suggest the existence of genomic differences among these geographic isolates. A post-embedding in situ hybridization assay at the electron microscope level was developed to detect HPV nucleic acids on HPV-infected hepatopancreata from P. chinensis and P. monodon . Hybridized probe (EC.592) was detected with an anti-DIG sheep antibody conjugated to 10 nm gold particles and subsequent silver enhancement. Hybridization signal was observed within HPV-infected hepatopancreatic cells, which was specifically located within intranuclear viral inclusions, cytoplasm, microvillous border, and associated to necrotic debris within the lumen of hepatopancreatic tubules. A non-destructive method, based on the PCR, was developed to detect HPV by examination of crude fecal samples from HPV-infected shrimp.

<p>Hatchery reared Chinook salmon from California&rsquo;s Central Valley were fed for 67 days (Apr-Jun, 2008) on fish pellets mixed with either 0, 1, 3, or 5 &micro;g&middot;g^&minus;1 methylmercury hydroxide. Weight, fork length, condition factor, and Na⁺,K⁺-ATPase measurements were determined every two weeks and a 96-h seawater challenge was conducted at the conclusion of the experiment. </p><p> Results from two-way ANOVA, with treatment and date as independent variables, indicated no significant differences for weight (F_3,32 = 1.38; P = 0.280), length (F_3,32 = 0.986; P = 0.412) and condition factor (_F3,32 = 0.239; P = 0.869). Post-hoc analysis following two-way ANOVA indicated mean ATPase activity in the high (x&macr; = 3.08, S.E. = 0.19; P = 0.008) and medium treatments (x&macr; = 2.86, S.E. = 0.57; P = 0.017) was significantly increased in early May compared with the control group (x&macr; = 1.47, S.E. = 0.34). The results from the 96 h seawater challenge were consistent with those of other studies indicating weight has the greatest influence for survival in the transition from freshwater to seawater. Overall, results from this study indicated methylmercury, a known neurotoxin, altered ATPase activity in fall-run Chinook but did not significantly affect mortality in the transition from freshwater to seawater. </p>

Thesis (Ph. D.)--University of Illinois at Urbana-Champaign, 2005. / (UnM)AAI3202116. Adviser: Arthur L. DeVries. Source: Dissertation Abstracts International, Volume: 67-02, Section: B, page: 0633.

Doctor of Philosophy / Department of Biology / Keith B. Gido / A large scale habitat manipulation was conducted to assess the effects of establishing an emergent macrophyte, American water willow Justicia americana, on littoral reservoir communities. Coves in three large (>1,800 ha) Kansas impoundments were chosen and half planted with water willow. Sampling was conducted during the summer from 2001 to 2004. I found that water willow coves had more complex habitat as well as higher abundance and diversity of fishes, macroinvertebrates, and zooplankton than control coves. However, strong temporal variation in water levels influenced the amount of inundated water willow available in these systems. The effects of water willow on density, growth, condition, and diet of age-0 largemouth bass Micropterus salmoides were assessed. Significantly higher densities of age-0 largemouth bass were found in water willow coves, but growth, condition, and diet did not differ between water willow and control coves. Therefore, water willow was able to support higher abundances of age-0 largemouth bass than control coves without affecting growth, condition, or diet. Characteristics of age-0 largemouth bass from the water willow coves were compared to those from two small impoundments (<80 ha) with abundant macrophyte and healthy largemouth bass populations. Small impoundments had higher densities of age-0 largemouth bass than water willow coves in the three large impoundments, but individuals on average also had lower growth, condition, and fewer fish in their diet. Thus, largemouth bass populations in small impoundments may be more regulated by density dependent factors than populations in large impoundments. Overall, water willow is beneficial to littoral areas, supporting an increase in both abundance and diversity of assemblages. Finally, I used a field experiment to test the inundation and desiccation tolerance of water willow for different depths and durations. Water willow was susceptible to inundation, but resistant to desiccation. My findings provide information that can be used to select candidate reservoirs for water willow establishment based on expected water-level fluctuations.

The presence of pharmaceuticals in the aquatic environment is a growing area of concern. The objective of this thesis was to examine the effects of statin drugs, a class of pharmaceuticals prescribed to lower endogenous cholesterol production by inhibiting 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCoAR), in the rainbow trout Oncorhynchus mykiss. The study also aimed to provide some insight into mechanisms governing the control of HMGCoAR in fish. Two statin drugs were used in this study, cerivastatin (CVT) and atorvastatin (AVT). Cerivastatin inhibited hepatic microsomal and brain homogenate HMGCoAR activities when incubated in vitro and following an in vivo intra-peritoneal injection. Atorvastatin reduced HMGCoAR activity in vitro following incubation with liver microsomes and brain homogenates. Fasting trout for 14 days resulted in a significant decrease in plasma cholesterol and glucose levels compared with the fed-controls. A significant decrease was observed in brain homogenates prepared from fish fasted for 14 days and re-fed for 7 days. Phosphorylation is an important regulator of mammalian HMGCoAR activities. In trout a significant decrease in HMGCoAR activity was observed when liver microsomes were incubated in a buffer that should stimulate AMPK. Two HMGCoAR subtypes were found in rainbow trout. HMGCoAR-1 mRNA is present in higher quantities than HMGCoAR-2 however HMGCoAR-1 is located in a limited number of tissues. HMGCoAR-2 mRNA appeared in all tissues assessed. The results of this thesis indicate that HMGCoAR shares some similar control mechanisms with mammals. These results also demonstrate that statin drugs in the aquatic environment have the potential to disrupt HMGCoAR in fish.

Results from the present study found for the first time that the use of bacterial strains of Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium thermophilum, and Enterococcus faecium from the commercial product PrimaLac® had the potential to act as a possible probiotic for juvenile red drum. The addition of PrimaLac® probiotics [whether as a water-soluble probiotic (WSP) or in a probiotic enhanced starter feed (PESF)] reduced mortality (%M), enhanced growth rates (MW, LT, SGR, and DGR), improved feed conversion efficiencies (FCEs), and physical condition factors in the juvenile red drum. Improvement was quantified using external morphological condition indices (MCIs) and blood physiological condition indices (PCIs). Results showed a strong positive relationship between MCIs and PCIs, which suggested that probiotics treated fish were in better health (lower MCIs) with lower fasting blood glucose and lactate levels than control fish. Addition of probiotics also resulted in improved water quality (lower nitrate, nitrite, and ammonia) in the treatment tanks compared to controls. Application of PrimaLac® probiotics on the morphology and histology of three different regions of the intestine (proximal, mid-and distal) improved intestinal length (Li), mass (Mi), and digesta mass (Md). In 5μm histological sections examined for differences among treatments (probiotics vs. controls), five variables within each intestinal region were also quantified: (i) perimeter ratio (PR) between the internal perimeter (IP) of the intestinal lumen and the external perimeter (EP) of the intestine where, PR = IP/EP; (ii) width of lamina propria (wLP); (iii) thickness of the muscle layer (tM); (iv) the number of goblet cells per segments (GC); and (v) height of enterocytes (hE). Overall, Li and Mi significantly increased by 13.4 ± 1.2% and 11.8 ± 0.9%, respectively, and Md decreased by 33.2 ± 1.21% compared to controls. Significant increases in microvilli heights, PR (by 21.3 ± 1.2%), tM (by 18.4 ± 0.9%), and increased numbers of GC (by 35.1 ± 2.8%) provided evidence that bacteria species from PrimaLac® (whether in WSP or PESF) affected the intestinal histomorphology of juvenile red drum. Collectively, these changes were partially responsible for increased feed assimilation (supported by reduced digesta) and improved overall juvenile red drum growth and condition. These results will add significantly to the limited database on how probiotics, as possible standard practice at the fish farm, may offer significant benefits for fish production and fish health. Addition of probiotics will also be of benefit to most aquaculture species and not only for red drum, but also for other high-value carnivorous species, such as Atlantic salmon, without threat to natural populations or damaging fisheries-based ecosystems that are already on the edge of collapse from over fishing and pollution.

Master of Science / Department of Biology / Craig Paukert / I evaluated sampling strategies and the effects of dike structure modifications in the lower Missouri River to better develop sampling and mitigation strategies to protect and enhance native river fishes. Sampling occurred in the lower 1,212 km of the Missouri River during October-June (coldwater season) and June-October (warmwater season) with stationary gill nets (GN), drifted trammel nets (TN), towed otter trawls (OT), and mini fyke nets (MF) from 2003-2006. We compared probabilities of detection (p), variability (coefficient of variation; CV) in catch per unit effort, and lengths for 25 species. Over 80% of adult large-bodied fishes were collected in GN during coldwater, >90% of chub spp. (Macrhybopsis) were collected in OT, and >90% of nine small-bodied and juvenile fishes were collected in MF. Trammel nets never had the highest p during coldwater, but had the highest or equally high p for 85% of adult large-bodied fishes during warmwater. Mean CV was lowest with GN for adult large-bodied fishes; chub spp. had the lowest CV in OT. Mean lengths were typically greater in GN and TN. Large river monitoring programs might best achieve the highest p, lowest variability, and widest size range of fishes by employing GN and OT during coldwater and TN, OT, and MF during warmwater sampling periods. We also compared fish community composition and the probability an un-notched and notched dike structure and channel sand bar (referred to as channel structures) was occupied by various fish species. Few differences in species richness and diversity were evident among channel structures. Notching a dike structure had no effect on proportional abundance for any habitat guild. Catch per unit effort (CPUE) was greater at notched dikes for only three (lake sturgeon Acipenser fulvescens, paddlefish Polyodon spathula, and shovelnose sturgeon Scaphirhynchus platorynchus) of 12 great river species. Occupancy at notched dikes increased for blue catfish Ictalurus furcatus and decreased for blue sucker Cycleptus elongatus, but did not differ for 17 (81%) other species. No distinct increase in occupancy at natural channel sand bars compared to engineered dike structures was evident. Mean CPUE was higher in dike structures than channel sand bars for four great river species (goldeye Hiodon alosoides, lake sturgeon, paddlefish, and shortnose gar Lepisosteus platostomus), but did not differ for ten. Our results suggest dike structures may provide necessary habitats for many fluvial species when compared to channel sand bars, but notching did not increase abundance or occupancy of most native Missouri River fishes.

<p> The purpose of this project to was to 1) develop, 2) instruct, 3) evaluate, and 4) revise a 5^th-12^th grade fisheries conservation engineering outreach program entitled <i>Smart Fishing and the Bering Sea</i> (SFBS).</p><p> Fishery resources are important to Alaska and Alaskans, but present complex conservation challenges including user conflicts and concerns about unsustainable fishing practices. Increasing Alaska residents' environmental literacy will enhance natural resource management decisions regarding fisheries. The intent of the SFBS program is to introduce students to ecological and economical factors that drive conservation engineering in the Bering Sea pollock fishery. I instructed the SFBS program to 93 students from four different public and private institutions in Anchorage, Alaska. My observations and participants' pre- and post-program concept maps were used to evaluate the effectiveness of the SFBS curriculum. Participants gained content knowledge from this fishery outreach program about the Bering Sea and commercial fishing. Program evaluation analysis and results were used to revise the curriculum and make suggestions to SFBS stakeholders.</p>