Day 2 :
Keynote Forum
S. M. Nurul Amin
University Putra Malaysia, Malaysia
Keynote: Biological characterization of planktonic Shrimp, Acetes spp. for stock management and aquaculture
Biography:
S M Nurul Amin has completed his BSc in Marine Science from University of Chittagong (CU), Bangladesh and PhD in Aquatic Biology from the Universiti Putra Malaysia (UPM), Malaysia. He is an Associate Professor in Department of Aquaculture, Faculty of Agriculture, UPM. He has 18 years of Teaching and Research experience in Aquaculture and Fisheries Biology.
Abstract:
Taxonomic characteristics, reproductive biology, food habits, population parameters like growth, mortality, exploitation status of the stock of planktonic shrimp Acetes spp, in coastal waters of Klebang Besar, Malacca, Malaysia were examined between February 2005 and March 2007. A total of three species of planktonic shrimp’s viz A. indicus, A. japonicus and A. intermedius were identified from the investigated area. It is found that sex ratio of A. indicus and A. japonicus was in favor of females. Gonadosomatic index (GSI) confirmed the continuously breeding of A. indicus and A. japonicus during the study period. Estimated mean fecundity of A. indicus was 1666.28 (±46.32) eggs. The mean monthly GSI of A. indicus proved positive significant (P<0.05) correlation with conductivity (r=0.67), salinity (r=0.65) and TSS (r=0.59)). Diverse compositions of food items in the gut contents revealed that the two shrimps were bottom feeder omnivore. Catch per unit effort (CPUE) of the estuarine push net (EPN) was found at 2.50 (±3.42) kg/fisherman/hr. Higher natural mortalities of male A. indicus and A. japonicus versus the fishing mortalities observed from the study indicated the unbalance position in the stock. Two major recruitment events per year where two cohorts were produced per year for A. indicus and A. japonicus populations. Estimated exploitation rate (E) based on the fishing mortality, indicates that the Acetes japonicus fishery is over exploited although A. indicus and A. intermedius fishery were slightly below the optimum level of exploitation. This implies that any further unrestrained increase in fishing effort might overshoot the level giving maximum sustainable yield, thus driving the stock down and leading to economic losses. Nowadays, Acetes wet tissue suspensions are being successfully used as food for all stages in the hatchery. It is also used as live food for brood stock management. Thus, Acetes as a food organism may play an important role in aquaculture.
- Fish Capture and Fishing Gears | Pelagic Fisheries | Deep Water & Demersal Fisheries | Shellfish Fisheries
Chair
Xinzhong Wu
Qinzhou University, China
Co-Chair
Sogbesan Olukayode Amos
Modibbo AdamaUniversityof Technology, Nigeria
Session Introduction
Xinzhong Wu
Qinzhou University, China
Title: Response of the oyster Crassostrea ariakensis environmental stress under experimental conditions
Biography:
Xinzhong Wu is currently a Professor at Qinzhou University and Dean of Ocean College, Qinzhou University China. He is a Scientific Researcher in Marine Mollusc Disease, and Mollusc and Fish Immunology. He has published about 46 papers in English reputed journals and more than 60 papers in Chinese. Now, he is the 11th council member of Asian Fisheries Society and the Chair of Workshops, Symposia and Training Committee of AFS, the Councilor of Federation of Asian Biotech Association, member of Steering Committee of the World Oyster Society, Councilor of the China Society of Fisheries and Councilor of the Chinese Society of Oceanography. He served as Editorial Board Member in several journals of China and international journals.
Abstract:
The oyster Crassostrea ariakensis is an important bivalve species cultured in southeastern China. In the year of 2004, farmed oyster C. ariakensis in Hailing Bay, GuangDong province of China had suffered from mass mortalities in autumn and winter. When analyzing the weather data of this area, we found it has been exposed to severe aridity. In this study, by pathological observation, the haemocytes in oyster were found present less than normal. By studying the haemocytes producing Reactive Oxygen Species (ROS) and percentage of haemocytes apoptosis of oyster cultured in higher temperature and salinity, it was found that the oysters in higher salinity and temperature could produce more ROS and present more haemocytes apoptosis than those cultivated in lower temperature and salinity. Subsequently, some cloned oyster innate immunity related genes and transcription level under different salinity and temperature were investigated by real-time PCR. It was found the gene galectin was extremely significantly up-regulated and met was very distinctly down-regulated from the oyster cultivated in higher salinity and temperature. It can be inferred that the higher temperature and salinity could induce oyster C. ariakensis producing more ROS, and then ROS could result in oyster haemocytes apoptosis and impairing the innate immunity and finally leading oysters to fatal death.
Tao Wang
Beihai Fengshun Aquaculture Company, China
Title: The design and application of the new anti-wave steel fish cage
Biography:
Tao Wang has completed his Bachelor of Landscape Architecture degree from Nanjing Agriculture University, China in 2010. This achievement led him to be able to transfer with two years of course credits to University of Adelaide, Australia in his Bachelor of Architectural Studies. He completed his Bachelor of Architectural degree and Master of Architecture degree from University of Adelaide in 2014. He is the Vice-President of Beihai Fengshun Aquaculture Company in Beihai, Guangxi, China. Currently, he works on “Developing new techniques for fish cages”.
Abstract:
The new innovative design of the anti-wave steel cage has the potential to supersede a large variety of currently used wooden cage for fish farming industry in Beihai, Guangxi, China. The key feature of the cage design is its square steel frame, as the use of the large tubular steel not only provides the sufficient buoyancy and structural support, but more importantly the space between two square units can create effective stable walkways for workers. Additionally, the new cage is equipped with a bait casting machine for feeding fish. From 2013 to 2015, we conducted Trachinotus ovatus farming experiments by using these new cages. During the test, the growth rate of Trachinotus ovatus greatly improved and equipped auto bait casting machines have saved both labor costs and feeding costs in comparison to traditional fish farming methods. In addition, these cages have undergone extreme weather conditions, including the typhoon rammasun in 2014. Typical wooden cages in the same area that were affected during the typhoon crisis suffered from various levels of damages, whereas the new steel cages remained rigid, unharmed and in working condition. This has proved that the advantages of using the new innovative steel cage have outstanding ability to withstand such extreme weather conditions in China’s south sea.
Fave Bulus Filli
Federal University Wukari, Taraba State, Nigeria
Title: Projection of table size fish prices in aquaculture business in Adamawa state, Nigeria
Biography:
Fave Bulus Filli has completed his PhD from Modibbo Adama University of Technology, Yola-Nigeria. He is the Director of Agricultural Economics and Teacher in his own field of specialization, having interest in Community Development and Research. He has published more than 10 papers in reputed journals and has been serving as an Editorial Board Member of repute.
Abstract:
The study was on projection of price of fish in Adamawa State, Nigeria. The objectives of the study were to determine the profitability of fish farming and examine the projected price to be received by fish farmers on a long-run equilibrium in Adamawa State, Nigeria. Data were collected using structured questionnaire administered to 150 fish farmers using snowball sampling techniques and were analyzed using descriptive statistics, net income analysis and Markov chain processes. The profitability analysis revealed a gross margin and net income of N155.81 and N135.22 per kg respectively, while N0.32 was gained for every naira spent. The projection showed that price above N500 will be received on every Kg of fish. It is concluded that fish farming is profitable with a higher price on table sized fish at the long run. The study recommends that youth and women should be engaged in fish farming, inputs should be supplied at subsidized rate and credits facilities should be provided to fish farmers to give a good platform to the farmers.
Adeosun Festus Idowu
Federal University of Agriculture, Abeokuta, Nigeria
Title: Fish species composition, distribution and abundance and gillnet fisheries in Ikere Gorge, Nigeria
Biography:
Adeosun Festus Idowu has completed his PhD from Federal University of Agriculture Abeokuta, Ogun State, Nigeria. He has held different offices within and outside the institution. He has served as Head of Department (HOD) in the absence of the HOD. He has also served in different capacity of the Academic Staff Union of the university as Vice to the Chairman and then as Chairman among others. He is currently a member of Community Based Farmers Society (COBFAS). He has published more than 25 papers in reputed journals.
Abstract:
Overfishing is a major problem in fisheries as fishermen without adequate knowledge of the composition, distribution and abundance of fish species continuously fish in water bodies using various fishing gears thereby depleting the stock. Here, we carried out the ecological study of Ikere Gorge between January 2004 and December 2005 to assess the fish resources of the Gorge and the gear commonly used by fish farmers in the Gorge. We collected data on fish composition, abundance and gear used from four sampling stations. 34 fish species belonging to 13 families were present in the Gorge. Our findings revealed that Bagridae (25.1%), Cichlidae (37.1%) and Mormyridae (14.5%) were most abundant families contributing 76.7% by number and 75% by weight of the total catch followed by Characidae (9.6%), Cyprinidae (7%) and Centropomidae (3%) constituting (19.6%) by number and 8.7% by weight. Schilbeidae (1.1%) Clarridae (0.8%), Hepsetidae (0.7%0, Mochokidae (0.6%), Channidae (0.5%), Icthyoboridae (0.2%) and Malapteruridae (0.1%) were least represented. We found that commonly used gears were cast net, traps, bamboo stems, spears, gura net and gillnet was the major fishing gears in used. Also, the gillnet fisheries showed the sensitivity of experimental gillnets mesh sizes to different fish species. 78.4 mm, 112 mm, 67.2 mm mesh sizes were efficient in catching Chrysichthys nigrodigitatus, Lates niloticus and the cichlids respectively. The study contributed to baseline data on the fish composition, distribution and gear selectivity on fish catch; thus, aiding fisheries policy makers in the management of this water body.
Biography:
Dipak Pandey has completed his Master’s degree in Chemistry Education from Tribhuvan University, Nepal and Master’s degree in Agriculture with major ‘Bio-resource production sciences’ specialized in Fisheries Research under supervision of Professor Takahiro Matsubara from Ehime University, Japan. Currently, he is pursuing his Doctoral degree at United Graduate School of Agricultural Sciences (UGAS), Ehime University, Japan.
Abstract:
Japanese anchovy (Engraulis japonica) is a very important marine species for commercial fisheries in addition to marine ecosystem. They are multiple spawning type species having oval-shaped pelagic eggs. However, little has been known about physiological and biochemical features on the process of their egg production. The aim of this study is to clarify morphological and biochemical changes of oocytes during final oocyte maturation (FOM), especially focused on proteolytic degradation of vitellogenin (Vg)-derived yolk proteins (YPs). The oocytes/eggs were collected from 1 pm to 10 pm coincide with the times of FOM and spawning in captive condition. Morphological observations showed that FOM was completed within 8 hours, and the processes were classified into five stages, including post-vitellogenic oocyte stage (St-I) to ovulated egg stage (St-V). Wet mass of oocytes increased from 69 µg (St-I) to 244 µg (St-V) due to high increases of water contents suggesting drastic hydration occurred during the FOM. Three types of Vgs were identified in the liver of Japanese anchovy, including Ja-VgAa, -VgAb and -VgC, and quantitative analysis of Ja-Vgs mRNA expression levels indicated that VgAa and VgAb were probably majors having important roles on yolk accumulation. The analyses of gel chromatography coupled with SDS-PAGE demonstrated proteolytic degradations of major YPs during the latter half of FOM. On the other hand, free amino acid (FAA) contents increased approximately 11 folds high during FOM. These results suggest that FAAs yielded from the proteolysis of YPs generate buoyancy of eggs involved with drastic hydration.
Sandip Bhatta
Nepal Agriculture Research Council, Nepal
Title: The endocrine function of germ cells directly regulate body composition in fish
Biography:
Sandip Bhatta has completed his Master’s degree and PhD in Agriculture Sciences from United Graduate School of Agriculture Sciences (UGAS), Ehime University, Japan with major ‘Bio-resource production sciences” specialized in Fisheries Research under supervision of honorable Professor Takeshi Miura. Currently, he is joining a Fisheries Research Program at Nepal Agriculture Research Council.
Abstract:
This study evaluates the interactions between body composition and reproduction between male and female tilapia ((Oreochromis mossambicus). Reproductive organs are known to be important organs for somatic growth, but direct evidence for their role is not available elsewhere. Here, using a fish model, we report direct evidence that gonads are endocrine organs equal to the pituitary in controlling body growth. Gonadal loss of function, gain of function and rescue of growth were investigated. Gonadectomy significantly retarded body composition; however, this retardation was rescued by the implantation of extirpated gonads in the body cavity. GH is classically associated with pituitary and IGF-1 is the liver. This study clearly exhibit that both hormones are expressed as mRNA and protein in the testis and ovary. GH was expressed in the sertoli cells of testis and in the granulose and fibroblast (thecal) cells of ovary. Real time-PCR and enzyme linked immunosorbent assays (ELISA) were used to measure changes in the rate of synthesis growth hormone (GH), insulin like growth factor-1 (IGF-1) and sex steroids in sham operation, gonadectomy and ectopic transplanted fish. After the 50 days post-surgery, gonadectomized fish had significant lower body weight then sham-operated fish. The gonadectomized fish did not exhibit advancement of spermatogenesis and oogenesis; thus prevention of sexual maturation by gonad removal was accompanied by retarded body growth. Measurement of sex steroid hormones 11-ketotestosterone (11-KT) in males and es-tradiol-17β (E2) in females decreased significantly in gonadectomized fish and concentrations in fish with ectopically transplanted gonads recovered to the same level as those in sham operated fish. Gonadal GH, sex steroids and advancement of spermatogenesis and oogenesis at the auto-transplanted site suggests that in addition to pituitary, gonads are major participants in the regulation body growth in tilapia.
Ha Thi Thu Bui
Curtin University, Australia
Title: Technical feasibility of cultivating Sargassum podacanthum and Sargassum linearifolium in inland saline water in Western Australia
Biography:
Ha Thi Thu Bui is pursuing her PhD in Aquaculture at Curtin University, Australia. She has been a Researcher at Research Institute for Aquaculture in Vietnam since 1998, after graduating in Aquaculture Engineering with excellent grades, working on socio-economic studies in Fisheries sector. She completed her Master of Aquaculture at Nha Trang Fisheries University in Vietnam in 2001 with first class-excellent grade. She completed her Master of Natural Resource Management from University of Western Australia in 2011. She has been pursuing her PhD since 2012 sponsored by Vietnamese Government and Curtin International Post-graduate Research Scholarship. Topic of her PhD research is on “Growing seaweed species in inland saline waters in Western Australia”.
Abstract:
Aquaculture using salt-affected land is considered as an additional resource for mariculture in Australia, India and USA. However, the deficiency of potassium in ISW is the major constraint in cultivating marine aquatic species. The aim of this research was to investigate the technical feasibility of cultivating Sargassum spp. in inland saline water (ISW) in Western Australia by conducting a three-phased research. The first phase was aimed to determine the suitable seaweed species which can survive in ISW. Sargassum linearifolium and S. podacanthum were selected out of seven trialled species. The second phase focused on investigating the optimum potassium concentration to grow Sargassum spp. in ISW by testing the different levels of potassium fortification in ISW (33%, 66% and 100% of potassium concentration equivalent to potassium concentration in ocean water) under both indoor and outdoor conditions. The results showed that 100% fortification of potassium by potassium chloride or sulphate of potash can sustain the growth of Sargassum spp. in ISW. The relationship between the fresh biomass of S. linearifolium and cultivation time was correlated (R2>0.7) in all potassium fortified ISW. The third phase attempted to improve the productivity of both Sargassum spp. by enriching nutrients to 100% potassium-fortified ISW. Only S. podacanthum showed the highest dry biomass at a nutrient mix of 160 mg l-1 of ammonium and 16 mg l-1 phosphate in potassium-fortified ISW. After 84 days of cultivation, the biomass of both species was significantly (P<0.05) affected by the nutrient levels. It is technically feasible to cultivate S. linearifolium and S. podacanthum in 100% potassium-fortified ISW.
Bingyuan Yang
Chinese Academy of Sciences, China
Title: Repeated handling compromises the immune suppression and improves the disease resistance in overwintering channel catfish (Ictalurus punctatus)
Biography:
Bingyuan Yang is pursuing his Doctorate degree at Institute of Hydrobiology, Chinese Academy of Sciences. He is working on Fisheries and Fish Nutrition. He has published three papers in reputed journals and won the national scholarship of CSC in 2015.
Abstract:
In winter, fish have suppressed immune functions and are susceptible to bacteria or virus which may lead to a high mortality. It is necessary to improve the immune response and disease resistance for overwintering fish. The present study tested the hypothesis that appropriate repeated handling could compromise the immune depression and increase the disease resistance in channel catfish over winter. Before the experiment, 35 fish randomly assigned to one of six cages. Three cages were designed as the control group and did not receive any interfere. Fish in the other three cages received a weekly repeated handling of an air exposure for 5 minutes. Fish were not fed over winter. At the end of the trial, fish were challenged with Aeromonas hydrophila. Plasma cortisol levels in the control fish were induced at 6 h post challenge and then declined to the normal levels. However, plasma cortisol levels in the repeated handled fish did not show any significant change after bacteria challenge. The reduced inducement of HSP70 expression by repeated handling was observed in fish post bacterial challenge. After overwintering, repeated handled fish exhibited increased CAT activities and reduced MDA contents. TAOC, CAT and SOD activities of channel catfish were enhanced by repeated handling post bacterial challenge. The enhanced up-regulation of IL8, IL1β-a, IL1β-b together with the immune related genes of TLR2, TLR3, NOD1and NOD2 by repeated handling was found in catfish after bacterial challenge.
Biography:
Kiran Bhatta has completed his Master’s and PhD from United Graduate School of Agricultural Sciences (UGAS), Ehime University, Japan with major in Bio-resource Production Sciences specialized in fisheries conservation and management since 2006 -2012 AD. Currently he works for World Vision Advocacy Forum (WVAF) at the National NGO of Nepal. His current research and working area is primarily involved in fisheries conservation and management. This program is designed to provide training in ecological principles, field research techniques, and the application of these tools for the management and conservation of fisheries resources. The program responds to the research needs of the fisheries pocket area of Nepal and research based organizations.
Abstract:
In teleost fishes, growth hormone (GH) and sex steroids appears to play an important regulatory role in several physiological events, including reproduction, growth and development. GH secretion is regulated by hypothalamic neuroendocrine factors that either act directly on the somatotrophic cells in the pituitary gland, or modulate the secretion or activity of other neuroendocrine factors. In addition, the degree of the neuroendocrine influence on GH release is influenced by the nutritional and reproductive state of the fish. Thus, the neuroendocrine control of GH secretion in fishes is complex, and still poorly understood. In this study, we clearly state that sex steroids 11-ketotestosterone (11-KT) levels peaked during the transition from spermatogenesis to spermiogenesis at 90 daf, and estradiol-17b (E2) levels increased during transition from the previtellogenic to mature vitellogenic stages at 75 daf. The maturation inducing hormone 17a-20b-dihydroxy-4-pregnen-3-one (DHP) involved final gametes maturation increased during reproductive maturation in both male and female. A consistent positive relationship between body growth, gonadal GH, sex steroids and advancement of spermatogenesis and oogenesis clearly indicate that these factors are essential in the reproductive endocrine axis to stimulate overall body growth regulation of developing juvenile fish.
Sirirat Chatvijitkul
Auburn University, USA
Title: Pollution potential indicators for feed-based fish and shrimp culture
Biography:
Sirirat Chatvijitkul has completed her PhD and MS from School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University. Her expertise is in “Nutrition in aquatic species”. She has conducted research focused on “Alternative protein sources in feeds, exogenous enzymes improving digestibility and nutrient retention in aquatic animals, sustainability and environmental issue in feed-based aquaculture”. She is currently working at Auburn Research Station in Gulf Shores, AL. She is responsible for developing feed formulations, producing experimental feeds, conducting experiments in RAS systems, culturing white shrimp in small-scale farming.
Abstract:
Biochemical oxygen demand, acidification potential and elemental waste loads from feed were determined for production of channel catfish Ictalurus punctatus, tilapia Oreochromis spp. Atlantic salmon Salmo salar, rainbow trout Oncorhynchus mykiss, and white leg shrimp Litopenaeus vannamei. Loads of these variables in culture systems (system loads) at typical FCRs ranged from 1090-1500 kg t-1 for biochemical oxygen demand, 270-440 kg t-1 for acidification potential, 1186-1885 kg t-1 for carbon dioxide, 35.9-63.5 kg t-1 for nitrogen, and 6.1-15.9 kg t-1 for phosphorus. Using these estimates as representative of feed-based aquaculture and literature data on the proportions of system waste loads typically discharged to the environment (environmental loads), the approximate amounts of waste generated globally by feed-based aquaculture were estimated small in comparison to approximate estimates of global anthropogenic waste. Nevertheless, aquaculture should lessen its environmental waste load and reducing waste load by improving FCR will be discussed.
Mumdoh Elhassan Abdalla Elhassan
University of Khartoum, Sudan
Title: Assessment of biological treatment of Red Sea water contaminated by organic phosphate using Aquatic Seashells
Biography:
Mumdoh Elhassan Abdalla Elhassan has completed his MSc at Gezira University. Currently, he is pursuing his PhD at Institute of Endemic Disease, University of Khartoum.
Abstract:
The most dangerous threaten to marine environment is the sea water contamination. This study assessed the biological treatment of contamination in Dongonab in red sea using aquatic seashells. In this study, the seashells were bred (pearl oyster) and kept in a closed basin in a managed natural reserve for a period of six months. The concentration of chemical contaminants (organic phosphates) in water was measured, and seashells samples were collected from the area (before and after the experiment). 60 samples of sea water were collected from the farm from the depth of the 220 cm because they may contain the largest amount of pollutants. Chemical measurements were conducted in a laboratory in the reserve. This study is done to assess the capabilities of seashells for the filtration of these chemical contaminates, The study found a decrease in phosphate concentration from an average of (32.95 mg/L) to (1.75 mg/L) and within a period of 36 hours from the filtration and an increase in ammonium concentration from an average of 4.51 mg/L in the contaminated water to an average of 20.87 mg/L, and therefore, a significant increase of planktons (the basic material of the biodiversity). The study concluded that marine seashells farms can contribute naturally and effectively in reducing the spread of chemical contaminants (especially organic phosphate) and thus, can contribute to increase the biodiversity. This research recommends studying the bioremediation and natural treatment of chemical pollution by using the seashells in open sea or in the farm of the seashells.
Olorunfemi Momodu F
Rhodes University, South Africa
Title: Detection of Aspergillus Section Flavi and aflatoxins in locally formulated fish feeds from South-Western Nigeria
Biography:
Olorunfemi Momodu F is pursuing her PhD at University of Ibadan in Nigeria. Her research interests includes “The study of moulds, mycotoxins research, foods and feeds safety and finding methods for extending shelf life of agricultural produce”. She is an awardee of Organization for Women in Science for the Developing World (OWSD) in Italy and has published nine papers on subjects in her research field. Currently, she is on a research visit to Chemistry Department of Rhodes University, South Africa where she is developing tools to help in ameliorating multi-mycotoxins in fish feeds.
Abstract:
Aspergillus section flavi (ASF) is a group of molds associated with aflatoxin production. They are responsible for aflatoxicoses in humans and animals through the feed-animal-food-human chain. Aflatoxins are potent carcinogenic secondary metabolites produced by the Aspergillus spp. Their presence in fish feeds reduce feed quality and feeding inefficiencies leading to low productivity, poor growth and untimely deaths. Detection of ASF and aflatoxins were carried out on 94 randomly collected fish feed samples from different fish farms in South-Western Nigeria. ASF were detected in all samples with 1873 ASF isolated. Aspergillus flavus, Aspergillus parasiticus, unnamed taxon and Aspergillus tamari isolated was 1806 (96.40%), 12 (0.64%), 3 (0.16%) and 52 (2.78%) respectively. Aflatoxin B1 was detected in 92% of samples followed by aflatoxin G1 (85%), aflatoxin B2 (81%), aflatoxin M1 (75%) and aflatoxin G2 (36%). Highest aflatoxin concentration was 550.8 µg/kg for aflatoxin B1 while highest total aflatoxin concentration recorded was 826.9761 µg/kg. Percentage of samples having total aflatoxin concentration higher than the Maximum Allowable Limit (MAL) in animal feeds as recommended by USFDA (20 µg/kg) was 79.79%. Considering the high incidence of ASF and aflatoxin contamination of sampled fish feeds, the fish industries in South-western Nigeria may be at risk of economic losses due to aflatoxicoses in the fish species.