bluuebunny/crossref_metadata_2025_split huggingface dataset:
Survival, Growth, and Feed Utilization of Pre- and Postmetamorphic American Shad Exposed to Increasing Salinity
Authors: Jia Yanju , Liu Qinghua , Goudie Cheryl A , Simco Bill A 
Published: May 2009

Abstract
The American shad Alosa sapidissima is currently an emerging aquaculture species in China, and establishing conditions required for optimal growth will play a key role in future development of American shad culture. We evaluated the effects of increasing salinity concentrations on survival, growth, and feed utilization of American shad in two separate 30-d experiments. In experiment 1, 25-d-old, premetamorphic fish (mean weight ± SD = 0.07 ± 0.04 g) were exposed to 0, 10, 20, and 30-ppt salinity (26–29°C). In experiment 2, 80-d-old, postmetamorphic fish (1.46 ± 0.52 g) were exposed to 0, 5, 10, 20, and 30-ppt salinity (21–26°C). Mortality was markedly higher at salinities of 20 ppt (52% and 74%, respectively, for pre- and postmetamorphic fish) and 30 ppt (100% and 90%, respectively) than at 0 and 5 ppt (&lt;1%). Specific growth rate (SGR) and feed conversion efficiency (FCE) were highest at 0-ppt salinity for premetamorphic fish (SGR = 8.81% per day; FCE = 1.12) and at 5-ppt salinity for postmetamorphic fish (SGR = 4.59% per day; FCE = 0.87). The SGR and FCE were lowest at 30-ppt salinity, and a significant negative relationship was demonstrated between salinity and SGR and between salinity and FCE. In both experiments, SGR and FCE were positively correlated. Our observations demonstrate that culture of young American shad may be possible at salinities up to 10 ppt, but 0–5-ppt salinity produced the best growth.
Tank Culture of Sunshine Bass Fingerlings without Using Rotifers
Authors: Ludwig Gerald M , Lochmann Steve E 
Published: May 2009

Abstract
A previously reported protocol for culture of larval sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis) to fingerling size in tanks involved an initial feeding of rotifers for several days before the larvae were weaned to nauplii of brine shrimp Artemia spp. and prepared feed. Maintaining rotifer cultures requires space, time, equipment, supplies, and trained culturists. The rotifer cultures are often unstable, which increases risk of poor sunshine bass fingerling production in tanks. Elimination of the use of rotifers would greatly enhance the feasibility of reliable tank culture of fingerlings and should reduce production cost. This experiment compared three treatments with three replicates per treatment. In one treatment, larvae were initially fed rotifers Brachionus plicatilis and then were weaned to brine shrimp nauplii (0.48 × 0.19 mm). In a second treatment, larvae were fed brine shrimp nauplii throughout the experiment. In a third treatment, larvae were fed microcyst brine shrimp nauplii (0.43 × 0.18 mm) for the entire experiment. At 4 d posthatch (dph), sunshine bass larvae were stocked into 100-L tanks at 75 larvae/L. Larvae were fed according to the three treatments to 14 dph. Survival was significantly higher for larvae fed rotifers plus brine shrimp nauplii and for larvae fed microcyst brine shrimp nauplii (93.6% and 37.9%, respectively) than for larvae fed only brine shrimp nauplii (4.3%). Larvae (7.13 mm standard length [SL]) that were fed rotifers plus brine shrimp nauplii and larvae (7.26 mm SL) that were fed microcyst nauplii were significantly longer than those (6.86 mm SL) fed brine shrimp nauplii. This experiment is the first time that sunshine bass have been cultured to 14 dph on brine shrimp nauplii without rotifers at first feeding.
Evaluation of Various Feeding Regimens in a Multiple-Batch Cropping System of Channel Catfish Production
Authors: Li Menghe H , Robinson Edwin H , Bosworth Brian G , Oberle Daniel F , Lucas Penelope M 
Published: May 2009

Abstract
A 4-year pond study was conducted to compare net production, feed conversion, processing yield, and body composition of channel catfish Ictalurus punctatus that were fed once daily, fed every other day (EOD) to satiation, or fed an amount not exceeding 110 kg·ha−1·d−1 in a multiple-batch cropping system. The greatest amount of feed administered was observed for the daily satiation group, followed by the 110-kg·ha−1·d−1 group and the EOD group (P ≤ 0.05). Net production of fish fed daily to satiation did not significantly differ from that of fish fed up to 110 kg·ha−1·d−1, but that of fish fed daily (satiation or ≤110 kg/ha) was significantly higher than that of fish fed EOD to satiation. Feed conversion ratio was significantly lower in fish fed up to 110 kg·ha−1·d−1 or EOD to satiation than that of fish fed daily to satiation. Carcass, fillet, and total meat yields did not differ among feeding regimens. Fish fed EOD to satiation had lower fillet fat and higher fillet moisture than fish fed daily to satiation. Feed restriction to no more than 110 kg·ha−1·d−1 did not significantly affect fillet composition of channel catfish compared with fish fed daily to satiation. It appears that limiting the feeding rate to 110 kg·ha−1·d−1 at a stocking density of 14,830 fish/ha would improve feed efficiency without causing significant reduction in weight gain, net production, or processing yield and would thus increase farm profits. Feeding channel catfish EOD to satiation may be acceptable as a short-term strategy when economic conditions justify it. However, it may not be economical for the long term because of lower production, increased length of the production cycle, and reduced processing yield.
Toxicity of Common Aquaculture Disinfectants to New Zealand Mud Snails and Mud Snail Toxicants to Rainbow Trout Eggs
Authors: Oplinger Randall W , Wagner Eric J 
Published: May 2009

Abstract
The New Zealand mud snail (NZMS) Potamopyrgus antipodarum is an invasive species that threatens North American fish populations. Establishment of NZMS in fish hatcheries is a concern because fish stocking practices could expedite the spread of the species. We evaluated the potential use of chemicals to remove snails that are inadvertently collected during egg take operations involving wild broodstock from the field. We exposed green eggs of rainbow trout Oncorhynchus mykiss for 5 min to several chemicals that have been proven lethal to NZMS: 1,940-ppm Hyamine 1622; Clorox Commercial Solutions 409 Cleaner, Degreaser, and Disinfectant (full strength; hereafter, Clorox Commercial 409); Pine-Sol (50% dilution); household ammonia (full strength); and a 504-ppm copper solution (as copper sulfate). All of the eggs exposed to Hyamine 1622, Clorox Commercial 409, and ammonia died within 24 h. Among eggs treated with Pine-Sol and copper sulfate, hatch and cripple rates did not differ from the control (water); however, eye-up rates among eggs treated with copper sulfate were lower than those for the control. Thus, while more research is needed, it is possible that a 50% dilution of Pine-Sol could be used to kill NZMS that are inadvertently collected during egg take operations. In a second experiment, a probit analysis provided 15-min LD50 and LD90 values for several common fish therapeutic chemicals (formalin, iodine, hydrogen peroxide, and potassium permanganate). For all chemicals, we estimated that concentrations of at least 7,500 ppm are required in 15-min treatments to kill 100% of NZMS. While these chemicals could be used to remove NZMS from hatchery facilities, concentrations required for complete mortality in 15-min exposures exceed concentrations that are considered safe for most fish species. Even though the best method for averting accidental introduction is to prevent the transportation of water from the wild into the hatchery, we feel that hydrogen peroxide may be the most effective chemical for killing NZMS that are inadvertently collected.
Morphological, Physiological, and Genetic Techniques for Improving Field Identification of Steelhead, Coastal Cutthroat Trout, and Hybrid Smolts
Authors: Kennedy Benjamen M. , Baumsteiger Jason , Gale William L. , Ardren William R. , Ostrand Kenneth G. 
Published: May 2009

Abstract
In streams with sympatric populations of steelhead Oncorhynchus mykiss and coastal cutthroat trout O. clarkii clarkii (hereafter, cutthroat trout), life history descriptions and smolt production estimates may be hampered by misclassification of hybrids as steelhead or cutthroat trout. Additionally, important morphological and physiological differences between hybrid and non-hybird smolts are often unknown. Therefore, we assessed field classification and created classification models to quantify and reduce misclassification rates among migrating steelhead, cutthroat trout, and hybrid smolts. Field misclassifications of smolts with steelhead or cutthroat trout genotypes were low (1% and 2%, respectively). However, field misclassification of fish with hybrid genotypes was high, with 11% of the hybrids being misclassified as steelhead and 42% of the hybrids being misclassified as cutthroat trout. Hybrid smolts were larger, had lower gill Na+, K+-ATPase activities, and lower condition factors than steelhead but were similar to cutthroat trout smolts in these same measurements. Additionally, statistical classification analyses using morphological traits including subterminal jaw slash intensity, hyoid teeth presence, maxillary length, breaks of pigment along outer margin of adipose fin, condition factor, and migration date improved classification error rates of hybrids from 53% to 21%. In systems with sympatric populations of steelhead and cutthroat trout, we recommend a thorough evaluation of field-based identification methods with genetic techniques to assess the effectiveness of field-based classification in addition to examining important life history differences among steelhead, cutthroat trout, and their hybrids.
Marine Distribution, Life History Traits, and the Accumulation of Polychlorinated Biphenyls in Chinook Salmon from Puget Sound, Washington
Authors: O'Neill Sandra M. , West James E. 
Published: May 2009

AbstractPolychlorinated biphenyl (PCB) levels and the factors affecting PCB accumulation in subadult and maturing Chinook salmon Oncorhynchus tshawytscha from Puget Sound were characterized. Specifically, we (1) determined PCB levels in Chinook salmon from Puget Sound and compared them with levels in Chinook salmon from other West Coast populations, (2) determined whether PCB accumulation mainly occurred in the freshwater or marine habitats, and (3) quantified the relative importance of fish age, fish size (fork length), lipid content, and saltwater age (the number of winters spent in saltwater) on PCB concentration. The average PCB concentration measured in skinless muscle tissue samples of subadult and maturing Chinook salmon collected from Puget Sound was 53 ng/g (wet weight), which was 3‐5 times higher than those measured in six other populations of Chinook salmon on the West Coast of North America. Concentrations in the Puget Sound samples varied from 10 to 220 ng/g. A comparison of PCB body burdens between subyearling smolts and returning adults revealed that almost all of the PCBs (>96%) were accumulated in the marine habitats. Surprisingly, although PCBs were mostly accumulated in marine habitats, PCB exposure was lowest in the largest fish that spent the most time in saltwater. Collectively, saltwater age, fish size, and lipids only accounted for 37% of the observed variation in PCB concentration, indicating that some other attribute of the fish's marine ecology accounted for the variation in PCB levels among Puget Sound Chinook salmon and for their elevated PCB levels relative to other West Coast populations. We hypothesized that residency in the contaminated Puget Sound environment was a major factor contributing to the higher and more variable PCB concentrations in these fish. This hypothesis was supported with an independent data set from a fishery assessment model, which estimated that 29% of subyearling Chinook salmon and 45% of yearling out‐migrants from Puget Sound displayed resident behavior.
Recent and Historical Spatial Distributions of Juvenile Rockfish Species in Rocky Intertidal Tide Pools, with Emphasis on Black Rockfish
Authors: Studebaker Rebecca S. , Cox Karah N. , Mulligan Timothy J. 
Published: May 2009

AbstractUnderstanding the full complement of habitats used by juvenile fish is essential for species management and the protection of habitat. This study evaluated the distribution of juvenile rockfish Sebastes spp. in northern Pacific rocky intertidal habitats. Observations were made along the northern California and Oregon coasts in an attempt to better define the geographical extent of intertidal habitat use. Juvenile rockfish were observed in rocky intertidal habitats ranging from MacKerricher State Park, California, to Ecola State Park, Oregon. Museum collections were also searched to examine the historical ranges of rocky intertidal use by juvenile rockfish. A total of 12 species of juvenile rockfish were identified in rocky intertidal habitats, black rockfish S. melanops being the dominant species identified. Our observations, along with museum records, showed that juvenile rockfish, especially black rockfish, use rocky intertidal habitats over a large geographic range.
The Genetic Legacy of Stocking Muskellunge in a Northern Minnesota Lake
Authors: Miller Loren M. , Mero Steven W. , Younk Jerry A. 
Published: May 2009

AbstractThe effects of stocked fish on native populations of the same species are poorly understood. During the 1960s‐1980s, the Minnesota Department of Natural Resources (MNDNR) stocked muskellunge Esox masquinongy derived from Shoepack Lake in the Hudson Bay drainage of northern Minnesota into Moose Lake in the Upper Mississippi River drainage. In the mid‐1980s, the MNDNR recognized that stocked Shoepack Lake‐strain fish (hereafter, Shoepack strain) were not attaining large sizes, and sources were switched statewide; subsequently, muskellunge from a Wisconsin hatchery were stocked once into Moose Lake. We used 14 microsatellite DNA markers to estimate the genetic contribution by each source population to muskellunge sampled in four different years from 1981 to 2004, and we evaluated the effects of Shoepack‐strain ancestry on fish size. Two samples in the 1980s had mostly fish with a single ancestry; thus, these fish were probably Shoepack‐strain fish stocked a few years earlier or native fish. By 2004, when most fish would have been naturally produced in the lake, contributions from all three source populations were detected, including admixed individuals from crosses among all ancestral sources. The estimated ancestry by source was 52% native Moose Lake ancestry, 29% Wisconsin strain, and 19% Shoepack strain, with 24% of the individuals having pure Moose Lake ancestry. Fish without Shoepack‐strain ancestry had a greater median length than did those with Shoepack‐strain ancestry and had a greater proportion of legal‐sized individuals (total length ≥ 1,016 mm) in the population. In contrast, Moose Lake and Wisconsin‐strain descendents were common among all sizes of fish. Management options include doing nothing, accepting that extensive introgression has already occurred, or manipulating the population by either stocking to dilute Shoepack‐strain ancestry or genetic screening to purge the population of Shoepack‐strain ancestry.
Effect of Hook Removal on Recapture Rates of 27 Species of Angler‐Caught Fish in Australia
Authors: Wilde Gene R. , Sawynok William 
Published: May 2009

AbstractWe used data from a cooperative angler tagging program to assess the potential benefit of leaving hooks in fish captured and released by anglers. We assembled 248,010 records of angler catches of 27 species of Australian fish. Hooks were left in only 1.1% of released fish, and the overall recapture rate was 8.8%. We used relative risk, that is, the probability of an event (recapture) in a treatment group (those with hooks not removed) divided by the probability of that event in a control group (those with the hook removed), to assess the potential effects of leaving hooks in released fish. Relative risk ranged from 0.30 to 7.6 and differed from 1.0 in only 3 of the 27 species studied. Thus, there was little evidence that hook removal affected recapture probability. Similarly, there was no evidence of any difference in relative risk among fish species grouped by habitat type. Pooling results across all species and habitats yielded an overall relative risk of 1.18 (95% confidence interval, 1.02‐1.36), which suggests that the recapture rate of fish from which hooks were not removed before release was 18% greater than that for fish from which the hooks were removed. Overall, our results indicate that not removing hooks benefits recapture rate, which can be considered as a surrogate measure of the survival of released fish.
Balancing Aquatic Habitat Fragmentation and Control of Invasive Species: Enhancing Selective Fish Passage at Sea Lamprey Control Barriers
Authors: Pratt T. C. , O'Connor L. M. , Hallett A. G. , McLaughlin R. L. , Katopodis C. , Hayes D. B. , Bergstedt R. A. 
Published: May 2009

AbstractBarriers to prevent spawning migrations of sea lampreys Petromyzon marinus remain an important component of an integrated sea lamprey management program in the Laurentian Great Lakes. Concerns about effects on nontarget fishes have led to the construction of specially designed vertical‐slot trap‐and‐sort fishways to mitigate potential barrier effects. To improve passage at these fishways, we used passive integrated transponder technology to assess the performance of two fishways located on low‐head sea lamprey barriers. Fishways on the Big Carp River (which flows into Lake Superior) and Cobourg Brook (which flows into Lake Ontario) were assessed for attraction efficiency, trap attraction and retention, and passage efficiency. Based on the results of these assessments, fishways were modified by increasing the trap volume and altering the funnel characteristics to reduce escapement from the trap and then reassessed. Attraction efficiency for all tagged fish was high (≥80%) at both sites in all years. Fishway modifications improved passage from 35% in 2003 to 88% and 64% in 2004 and 2005, respectively, at the Big Carp River. As expected, white suckers Catostomus commersonii, an obligate migrant, had higher attraction and passage efficiency, fewer passage attempts, and shorter migration delay than did rock bass Ambloplites rupestris, a facultative migrant. No improvements were seen at Cobourg Brook, where passage efficiency remained low (7% in 2003, 10% in 2005), probably because of the loss of attraction flow. At both fishways, individual fish averaged 3‐10 attempts to pass through the fishways and had their migrations delayed 1‐2 weeks. The observed improvements to the Big Carp River fishway, which resulted in high fishway attraction and passage rates for white suckers, suggest that vertical‐slot fishways can help mitigate the effects of low‐head barriers for some species. Our study provides a rigorous quantifiable approach to assessing fishway performance that can be employed widely and successfully to assess initial fishway design and subsequent modifications.
Sablefish Predation on Juvenile Pacific Salmon in the Coastal Marine Waters of Southeast Alaska in 1999
Authors: Sturdevant M. V. , Sigler M. F. , Orsi J. A. 
Published: May 2009

AbstractAt‐sea observations of predation by age‐1 and older (age‐1+) sablefish Anoplopoma fimbria on juvenile Pacific salmon Oncorhynchus spp. were combined with laboratory studies to determine gastric evacuation rates and were used to estimate summer predation impact in the northern region of Southeast Alaska. In June and July 1999, up to 63% of sablefish examined from trawl catches in strait habitat had each consumed one to four juvenile pink salmon O. gorbuscha, chum salmon O. keta, or sockeye salmon O. nerka. In two laboratory experiments, field‐captured sablefish were acclimated without food in compartmentalized flow‐through tanks with conditions manipulated to reflect the photoperiod and temperature regimes of summer. These sablefish were each offered one whole, preweighed juvenile chum salmon; consumption events were observed, and the sablefish were then sacrificed at predetermined time intervals. Prey biomass remaining in the stomach of each sablefish predator was weighed, and an exponential model of the decline in percent biomass over time was used to yield instantaneous evacuation rates of 0.049 at 12°C and 0.027 at 7°C. From field data combined with model‐derived estimates of meal frequency, we estimated that 0.8‐6.0 million juvenile salmon were consumed by age‐1+ sablefish in the 500‐km2 area of Icy Strait during a 33‐d period. Moreover, a 10‐year time series of catches indicated that 1999 was a year of unusually high age‐1+ sablefish abundance and relatively low juvenile salmon abundance. We speculate that sablefish predation in 1999 could have affected abundance of out‐migrating juveniles and contributed to low harvests of returning adult pink salmon in 2000 and adult chum salmon in 2002. Our results suggest that sablefish predation on juvenile Pacific salmon can occur during episodic strong year‐classes of sablefish and may affect adult salmon returns.
A New Genus and New Species of Neotropical Reinwardtiini (Diptera: Muscidae)
Authors: Savage J 
Published: May 2009

Abstract
The adult of a new genus and new species of Muscidae, Callainireinwardtia woodi sp. nov, gen. nov., is described from Costa Rica. This new genus is placed in the tribe Reinwardtiini and can be distinguished from other members of the group as well as other New World Muscidae by the presence of a striking blue to blue-green metallic color combined with a bare anepimeron, setulose metepisternum, a plumose arista, and wings without clouds or spots. Conflicting data on the phylogenetic position of the reinwardtiine genera is summarized and potential avenues for future research are suggested.
Molecular Validation of a Morphological Character for Distinguishing Between the Armored Scale Insects Chionaspis pinifoliae and Chionaspis heterophyllae (Hemiptera: Diaspididae)
Authors: Philpott Dominic E , Berlocher Stewart H , Mitchell Robert F , Hanks Lawrence M 
Published: May 2009

Abstract
The armored scale insects Chionaspis pinifoliae (Fitch) and Chionaspis heterophyllae Cooley (Hemiptera: Diaspididae) overlap broadly in host range and geographic distribution and are so similar in morphology that they can be distinguished only by a subtle morphological character of the adult females: the form of the median pygidial lobes. However, this character is quite variable for both species. We used allozyme electrophoresis and DNA sequencing of a region that included the mitochondrial genes COI and COII to determine whether two species really exist and, if so, whether the morphology of the pygidial lobes is a reliable character to use to discriminate between them. Material for genetic analysis was collected as third instar females from five Illinois populations of each species (as identified by morphology of the pygidial lobes). Chionaspis species were difficult to analyze electrophoretically, but fixed allelic differences were found at three allozyme loci: malic acid dehydrogenase (Mdh), phosphoglucose isomerase (Pgi), and an esterase (Est). The 572-bp (alignment length) mitochondrial region was invariant within species but differed between the species for both base substitutions (p-distance = 0.091) and insertion-deletion differences. Estimated divergence time was at least 3.8 million yr. The consistent absence of heterozygotes at the three allozyme loci and the large mitochondrial sequence difference confirms that the morphology of the pygidial lobes is a reliable and convenient character for identifying C. pinifoliae and C. heterophyllae and supports the hypothesis that they are not only separate, but very old species.