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Assessing feeding competition between lake whitefish Coregonus clupeaformis and round whitefish Prosopium cylindraceum

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Current Zoology 2010年第1期56卷 109-117页

作者： Andrew MACPHERSON John A.HOLMES Andrew M.MUIR David L.G.NOAKES Axelrod Institute of Ichthyology and department of Zoology University of Guelph Faculty of Architecture Landscape and Design University of Toronto Pacific Biological Station Fisheries and Oceans Canada Golder Associates fisheries and Wildlife department and Oregon Hatchery Research Center Oregon State University

We collected lake whitefish Coregonus clupeaformis and round whitefish Prosopium cylindraceum from the main basin of Lake Huron and Georgian Bay in the Laurentian Great Lakes of North America to investigate details of diet and feeding tactics of these species in different seasons. Lake whitefish supports important commercial fisheries in Lake Huron and both species make use of habitats near the Bruce Nuclear Power Development, on the eastern shore of Lake Huron. Most fish of both species showed generalist feeding behavior, but some lake whitefish appeared to show specialist prey selection. The invasive spiny water flea Bythotrephes longimanus was an important component of the diet of both species. There was considerable dietary overlap between the whitefish species, but the ecological implications of these dietary overlaps are mitigated by the fact that dominant prey species differed in most seasons. We conclude that the potential for ecologically significant interactions between lake whitefish and round whitefish resulting from competition for similar benthic food resources in the main basin of Lake Huron is probably low [Current Zoology 56 （1）： 109-117, 2010].

关键词： Lake Huron Diet Feeding tactics Seasonal variation Invasive species

Reducing dietary sodium of dairy cows fed a low-roughages diet affect intake and feed efficiency,but not yield

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Animal Nutrition 2023年第1期12卷 1-6页

作者： Yehoshav A.Ben Meir Yoav Shaani Daniel Bikel Yuri Portnik Shamai Jacoby Uzi Moallem Joshua Miron Eyal Frank department of Ruminant Science Institute of Animal ScienceAgricultural Research Organization(ARO)Rishon Lezion 7528809Israel department of Animal Production Extension ServiceMinistry of AgricultureRishon Lezion 7528809Israel

Wastewater from dairy farms has become a major environmental and economical *** residue in treated and untreated wastewater from dairy farms used for irrigation can lead to soil and groundwater salinization,with the risk of soil *** examined the effect of reducing sodium fed to mid to late lactating cows from 0.61%(high sodium[HS])to 0.45%(low sodium[LS])of dry matter on dry matter intake(DMI),milk and milk-component yields,eating behavior,apparent total track digestibility,feed efficiency,and sodium excretion into the *** randomly assigned 28 multiparous high-yielding(>35 kg milk/d)cows to 1 of 2 treatment groups(LS or HS)in a crossover design,with 7 d of adaptation and 28 d of data *** sodium in the diet reduced sodium intake from 171 to 123 g/d while lowering sodium excreted in the manure by 22%.Energy corrected milk(ECM)yield(37.4 kg/d)and sodium excretion in the milk(33.7 g/d)were similar for both *** DMI of LS cows was lower than that of HS cows(27.3 vs.28 kg/d)and consequently,feed efficiency of the LS cows was higher(1.40 vs.1.35 ECM/DMI).Eating rate,meal and visit frequency,and eating time were similar for both treatments;meal and visit duration were longer for the HS cows,and meal and visit sizes tended to be *** of DM and amylase-treated neutral detergent fiber remained *** on the results of this study,and discussed considerations,we recommend lowering the dietary sodium content for mid to late lactating cows in commercial herds to 0.52%of DM,in order to reduce sodium excretion to the environment via urine.

关键词： Mineral absorption Sodium Eating behavior Environmentally friendly dairy farm

A Study on Karyotypes and Ag-NORs of Odontobutis potamophila

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Agricultural Biotechnology 2018年第2期7卷 127-129页

作者： Haihua WANG Xiandong XU Wen QIU Bin WU Zhiying TAO Shugan ZHU Jiangxi fisheries Research Institute Nanchang 330039 fisheries Technology extension Center of Shangrao County Shangrao 334000China

In order to obtain cytogenetic data of Odontobutis potamophila,head-kidney cells were collected as experimental materials to prepare chromosome specimen. The karyotypes of O. potamophila and the distribution and amount of transcriptionally active nucleolar organizer regions on chromosomes were analyzed by Giemsa staining and Ag-NORs. The results showed that the number of diploid chromosomes of O. potamophila was 44; the genome of O. potamophila was composed of 44 telocentric chromosomes; the karyotype formula was 2 n = 44 t,NF = 44; Ag-NORs were found in the paracentromeric region of chromosome. The results may lay the foundation for revealing the genetic pattern and chromosomal evolution of O. potamophila and contribute to further genetic breeding of O. potamophila.

关键词： Odontobutis potamophila Karyotype Ag-NORsHomec

Intercrop movement of convergent lady beetle, Hippodamia convergens （Coleoptera： Coccinellidae）, between adjacent cotton and alfalfa

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Insect Science 2016年第1期23卷 145-156页

作者： Anup Bastola Megha N. Parajulee R. Patrick Porter Ram B. Shrestha Fa-Jun Chen Stanley C. Carroll Texas A&M UniversityAgriLife Research and extension Center Lubbock Texas USA department of Entomology Iowa State UniversityAmes Iowa USA department of Entomology Nanjing Agricultural University Nanjing China

A 2-year study was conducted to characterize the intercrop movement of conver- gent lady beetle, Hippodamia convergens Guerin-Meneville （Coleoptera： Coccinellidae） between adjacent cotton and alfalfa. A dual protein-marking method was used to assess the intercrop movement of the lady beetles in each crop. In turns field collected lady beetles in each crop were assayed by protein specific ELISA to quantify the movement of beetles between the crops. Results indicated that a high percentage of convergent lady beetles caught in cotton （46% in 2008; 56% in 2009） and alfalfa （46% in 2008; 71% in 2009） contained a protein mark, thus indicating that convergent lady beetle movement was largely bidirectional between the adjacent crops. Although at a much lower proportion, lady beetles also showed unidirectional movement from cotton to alfalfa （5% in 2008 and 6% in 2009） and from alfalfa to cotton （9% in 2008 and 14% in 2009）. The season-long bidirectional movement exhibited by the beetles was significantly higher in alfalfa than cotton during both years of the study. The total influx of lady beetles （bidirectional and unidirectional combined） was significantly higher in alfalfa compared with that in cotton for both years. While convergent lady beetles moved between adjacent cotton and alfalfa, they were more attracted to alfalfa when cotton was not flowering and/or when alfalfa of- fered more opportunities for prey. This study offers much needed information on intercrop movement of the convergent lady beetle that should facilitate integrated pest management decisions in cotton utilizing conservation biological control.

关键词： enzyme-linked irnrnunosorbent assay Hippodamia convergens markcapture protein marker

Age and sex specific timing, frequency, and spatial distribution of horseshoe crab spawning in Delaware Bay:Insights from a large-scale radio telemetry array

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Current Zoology 2010年第5期56卷 563-574页

作者： David R.SMITH Lorne J.BROUSSEAU Mary T. MANDT Michael J.MILLARD USGS Leetown Science Center Cornell University Cooperative extension U.S. Fish and Wildlife Service

To study horseshoe crab Limulus polyphemus spawning behavior and migration over a large-spatial extent （〉100 km）, we arrayed fixed station radio receivers throughout Delaware Bay and deployed radio transmitters and archival tags on adult horseshoe crabs prior to their spawning season. We tagged and released 160 females and 60 males in 2004 and 217 females in 2005. The array covered approximately 140 km of shoreline. Recapture rates were 〉70% with multi-year recaptures. We categorized adult age by carapace wear. Older females tended to spawn earlier in the season and more frequently than young females, but those tendencies were more apparent in 2004 when spawning overall occurred earlier than in 2005 when spawning was delayed possibly due to decreased water temperatures. Timing of initial spawning within a year was correlated with water temperature. After adjusting for day of first spring tide, the day of In＇st spawning was 4 days earlier for every 1 degree （℃） rise in mean daily water temperature in May. Seventy nine % of spawning occurred during nighttime high tides. Fifty five % of spawning occurred within 3 d of a spring tide, which was slightly higher than the 47% expected if spawning was uniformly distributed regardless of tidal cycle. Within the same spawning season, males and females were observed spawning or intertidally resting at more than one beach separated by 〉5 kin. Between years, most （77%） did not return to spawn at the same beach. Probability of stranding was strongly age dependent for males and females with older adults experiencing higher stranding rates. Horseshoe crabs staging in the shallow waters east of the channel spawned exclusively along the eastern （N J） shoreline, but those staging west of the channel spawned throughout the bay. Overall, several insights emerged from the use of radio telemetry, which advances our understanding of horseshoe crab ecology and will be useful in conserving the Delaware Bay horseshoe crab population and habita

关键词： Spawning behavior Marine arthropod Xiphosurid Limulus polyphemus Delaware Bay Radio telemetry

Effects of flow velocity on water quality and ammonia excretion in recirculating aquaculture system culturing juvenile largemouth bass(Micropterus salmoides)

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International Journal of Agricultural and Biological Engineering 2022年第5期15卷 213-218页

作者： Runguo Xiao Ganxiang Wang Zhenlei Chen Zhangying Ye Songming Zhu Xueyan Ding Fan Zhou Jianlin Guo Jian Zhao College of Biosystems Engineering and Food Science Zhejiang UniversityHangzhou 310058China Pinghu fisheries Technology Promotion Center Jiaxing 314200ZhejiangChina Ocean Academy Zhejiang UniversityZhoushan 316000ZhejiangChina Zhejiang fisheries Technical extension Center Hangzhou 310023China Key Laboratory of Healthy Freshwater Aquaculture Ministry of Agriculture and Rural AffairsKey Laboratory of Fish Health and Nutrition of Zhejiang Province/Zhejiang Institute of Freshwater FisheriesHuzhou 313001Zhejang Chna

Flow velocity plays an important role in recirculating aquaculture systems(RAS)and the growing practice of culturing juvenile largemouth bass(Micropterus salmoides).In this study,the effects of flow velocity on the water quality as well as the ammonia excretion were discussed from the perspective of actual production,and a polynomial model of ammonia nitrogen excretion was established,using the juvenile largemouth *** showed that the range of ammonia nitrogen and nitrite nitrogen decreased with flow velocity increasing,while the number and volume share of large particles *** to the polynomial model,compared with the medium flow velocity(11 cm/s,2.45 body length(bl)/s),the ammonia excretion of juvenile largemouth bass at high(18 cm/s,4.00 bl/s),and low(4 cm/s,0.90 bl/s)flow velocity changed faster with time,and the excretion rate peaked at the 6th hour after feeding,earlier than that under medium flow ***,it is suggested to increase the flow velocity at the 5th hour after feeding and then decreased it at the 10th hour,to ensure better water quality in RAS culturing juvenile largemouth bass.

关键词： flow velocity recirculating aquaculture system juvenile largemouth bass water quality ammonia excretion

Feeding ecology of hairtail Trichiurus margarites and largehead hairtail Trichiurus lepturus in the Beibu Gulf, the South China Sea

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Chinese Journal of Oceanology and Limnology 2011年第1期29卷 174-183页

作者：颜云榕侯刚陈骏岚卢伙胜金显仕 Institute of Oceanology Chinese Academy of Sciences College of fisheries and Center of South China Sea fisheries Resources Monitoring and Assessment Guangdong Ocean University Graduate University of Chinese Academy of Sciences Yellow Sea fisheries Research Institute Chinese Academy of Fisheries Sciences

We evaluated the feeding ecology of largehead hairtail (Trichiurus lepturus) and hairtail (T. margarites). We collected specimens from fishing ports in the Beibu Gulf (Gulf of Tonkin) from October 2008 to September 2009 and analyzed their gut contents. We collected 857 T. lepturus and 666 T. margarites samples. The number of stomachs examined in this study was sufficient to describe the monthly and ontogenetic diet shifts for the two species, as indicated by the trophic diversity curves. T. lepturus was a general omnivore, feeding primarily on Bregmaceros rarisquamosu, Decapterus maruadsi, and Acetes chinensis. Conversely, T. margarites preyed primarily on D. maruadsi, B. rarisquamosus, B. nectabanus, and A. chinensis. Both species exhibited distinct ontogenetic diet shifts. Although the two hairtail specie fed on similar sources in the same habitat, the diet overlap was relatively low. Our results suggest that hairtail play an important role in controlling small pelagic and benthic fish populations in the gulf. This trophic correlation shall be used for developing a marine ecosystem model for the Beibu Gulf.

关键词： feeding ecology Trichiurus margarites Trichiurus lepturus ontogenetic diet shift the Beibu Gulf South China Sea

An evaluation of the engineering suitability of extensive brackishwater ponds in Barru, South Sulawesi Province, Indonesia

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Aquaculture and fisheries 2023年第6期8卷 644-653页

作者： Tarunamulia Jesmond Sammut Research Institute for Coastal Aquaculture and fisheries extension(RICAFE) Ministry of Marine Affairs and FisheriesJl.Makmur Daeng Sitakka No.129Maros South Sulawesi90512Indonesia Centre for Ecosystem Science School of BiologicalEarth and Environmental SciencesThe University of New South Wales(UNSW)Kensington NSWSydney2052Australia

In brackishwater aquaculture, pond engineering is essential to meet the cultured species’ bio-physical requirements and potentially minimizing social and environmental impacts. This study evaluated the suitability of pond engineering designs and pond, dyke, and canal construction at family-run, extensive brackishwater aquaculture farms in Barru regency of South Sulawesi, Indonesia. Soil properties, topography, hydrological data, field surveys, and high resolution (0.6 m) Quickbird imagery were used to assess the suitability of local pond engineering designs and the efficiency of canals. The study shows that in 752 of the evaluated pond units (430 ha), about 70% of pond beds were not constructed at the optimal pond elevation. Basic engineering requirements for pond layout and dyke and canal designs were not addressed in more than 70% of the pond units. Cease-to-flow conditions commonly occur due to the sedimentation of canals. Flows are also attenuated due to collapsed dykes. Farmers disregarded soil limitations and the impacts of tidal conditions and wave regimes. It is unlikely that shrimp and fish production in the region can increase without significant improvements in pond engineering. The problems identified by the study are not unique to Barru;they also occur in other extensive aquaculture areas in Indonesia and the region. Increased awareness of the need for improved pond engineering techniques is urgently needed to safeguard the economic and environmental sustainability of Indonesia’s valuable aquaculture industry.

关键词： Brackishwater aquaculture GIS Pond engineering

Compensatory growth response of rainbow trout Oncorhynchus mykiss Walbaum following short starvation periods

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Chinese Journal of Oceanology and Limnology 2015年第4期33卷 928-933页

作者： Maryam AZODI Eisa EBRAHIMI Omidvar FARHADIAN Nasrollah MAHBOOBI-SOOFIANI Vahid MORSHEDI department of fisheries Faculty of Natural Resources Isfahan University of Technology Young Researchers Club of Ilam Azad University

This sixty-day study was performed to determine the effects of short-term starvation and refeeding cycles on growth, feeding performances and body composition of rainbow trout （Oncorhynchus mykiss）. Three hundred trout fingerlings with an average initial weight of 17.54-0.06 g were randomly distributed in 15 circular fiberglass tanks. The fish were exposed to 5 different feeding regimes; control： continuously fed twice daily to apparent satiation; T1： starved for 1 day and re-fed for 2 days; T2： starved for 1 day and re-fed for 4 days; T3： starved for 3 days and re-fed for 12 days; T4： starved for 4 days and re-fed for 16 days. At the end of the experiment, growth performance, feed utilization, whole body ash and moisture contents were not significantly （P〉0.05） different among the treatments. However, whole body protein content in T3 was significantly higher than other treatments （P〈0.05）. A significant difference in whole body fat content was observed between T3 and the control group at the end of the experiment （P〈0.05）. In conclusion this experiment suggests that feeding schedules involving starvation （1-4 days） and re-feeding cycles are a promising feed management tool for rainbow trout culture.

关键词： Oncorhynchus mykiss compensatory growth growth performance body composition