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Hatcheries are frequently called upon to produce catchable-sized fish for stocking community fishing ponds. Desirable attributes of fish selected for stocking into community ponds are that they are easy to produce in a hatchery system to sizes anglers are interested in catching and they provide anglers with high catch rates once stocked. Hybrid sunfish [male Bluegill (Lepomis macrochirus) × female Green Sunfish (L. cyanellus)] have attributes that potentially make them attractive for use in community fishing ponds. We assessed initial angler catch rates of 100 stocked hybrid sunfish in a 0.12-ha hatchery pond and after being subjected to angling (four, 1-hr catch-and-release fishing events with five anglers). We also investigated whether catch rates would change following a supplemental stocking of an additional 100 hybrid sunfish (four, 1-hr catch-and-release fishing events with five anglers). The anal fin of each fish in the second stocking was hole punched to differentiate them from those of the first stocking and fish caught by anglers were hole punched in the caudal fin each time they were caught before being released back into the pond. Angler catch rates were highest during initial fishing events that followed stocking (9.2 fish/angler hr and 18.0 fish/angler hr) and substantially declined in subsequent events (≤3.4 fish/angler hr). Catches of the newly stocked fish and previously stocked fish contributed to the high catch following the supplemental stocking. Most (80 %) of the fish were caught in the first 30 min of each event and 45 % were caught during the first 10 min. Anglers were able to catch 88 % of the fish from the first stocking and 67 % from the second stocking at least once. No mortality occurred during the study as all fish were recovered when the pond was drained. Our results suggest that hybrid sunfish will potentially provide high initial catch rates following stocking into community ponds, but managers should expect reduced catch rates following initial fishing even without harvest. Additional stocking will be needed to provide periodic increases in angler catch rates even without harvest.

Conservation hatcheries designed to aid in recovery of imperiled fish population often implement atypical rearing and release strategies. We evaluated a conservation hatchery program for steelhead (Oncorhynchus mykiss) that hydraulically removed naturally spawned eggs and captively reared them in different freshwater hatcheries to the smolt stage and reared smolts in both fresh water and seawater to sexual maturity, before releasing the sexually maturing adults onto the spawning grounds. The adult steelhead added to the spawning population, accounting for most of the adults observed during snorkel observations. They produced 32% of the juvenile offspring sampled, and females were 2.9 times more successful than males. Reproductive success was positively correlated with female body size, which was influenced by pre-smolt and post-smolt rearing conditions and their effects on growth rate and age-at-maturity. Juvenile offspring of the released adults showed size and age differences from offspring of naturally returning steelhead, but exhibited very similar early marine survival rates.

Objective: The objective was to test additivity of digestible energy and nutrient concentrations in the hatchery byproduct mixture fed to nursery pigs.Methods: In the previous studies, energy, phosphorus, calcium, and amino acid digestibility of infertile eggs, unhatched eggs, culled chicks, and a mixture of 3 hatchery byproduct ingredients was determined in nursery pigs (initial body weight = 9.4 to 14.2 kg). An additivity test was conducted using these determined values.Results: No difference was observed between determined and predicted metabolizable energy values in the mixture (3,998 and 3,990 kcal/kg as-is basis, respectively). Measured standardized total tract digestible phosphorus in the mixture was less than the predicted value (4.5 vs 5.3 g/kg as-is basis, respectively; p

Ayu (Plecoglossus altivelis altivelis) is an important freshwater fisheries resource and popular recreational fishing species in Japan, lives for only one year, and has a single breeding season. To supplement increased recreational fishing demand for this species, huge numbers of wild-born landlocked juveniles have been translocated from Lake Biwa into most Japanese rivers for more than 100 generations. Hatchery-reared juveniles born from captive-reared parents for more than 30 generations have also been extensively released. Previous studies have reported that landlocked and amphidromous forms of Ayu easily hybridise, but survival of landlocked larvae could be very low in seawater, leading to a general consensus among scientists, hatchery managers, and commercial and recreational fishers that the reproductive success of landlocked Ayu is very low, or even 0 in translocated rivers. Despite this, limited information exists regarding the reproductive success of landlocked Ayu in translocated rivers, and no study has evaluated the effects of translocation on population structure. Demonstrating that hybridisation occurs between the two forms is central to future management and conservation of this specie. To address this issue, a comprehensive literature search was undertaken, and three published genetic data sets are analysed. Analyses provide strong evidence for very high gene flow between populations, but population structure has been retained in several regions, and several populations are nested. Allele frequencies are similar in amphidromous and landlocked forms. Genetic diversity is homogeneous in amphidromous populations. Bayesian admixture analysis infers widespread introgression in Japanese rivers, with a mean introgression proportion of 24 ± 8%. Maximum likelihood admixture graphs detect two migration events from Lake Biwa to anadromous populations. Analyses consistently indicate that hybridisation between translocated landlocked juveniles and native amphidromous Ayu occurs throughout Japanese rivers.

The development of effective vaccines is a critical step towards the domestication of emerging fish species for aquaculture. However, traditional vaccine delivery through intraperitoneal (i.p.) injection requires fish to reach a minimum size and age and therefore cannot provide protection at early developmental stages when infection may occur. This study investigated the effectiveness of immersion vaccination with respect to immunocompetence in a cleaner fish species (ballan wrasse, Labrus bergylta, Ascanius) used in Atlantic salmon farming as an alternative means to control sea lice. The species is susceptible to atypical strains of Aeromonas salmonicida (aAs) at early life stages (15 g), when i.p. vaccination is not applicable. While immersion vaccination is currently used in commercial hatcheries, the optimal fish size for vaccination, and efficacy of the vaccine delivered by this route has not yet been established. Importantly, efficacy depends on the capability of the species immune system to recognise antigens and process antigens to trigger and produce an adaptive immune response, (process known as immunocompetence). In this study, the efficacy of a polyvalent autogenous vaccine administered by immersion in juvenile ballan wrasse and the subsequent immune response induced was investigated after prime and booster vaccination regimes. In addition, temporal expression (0-150 days post hatch) of adaptive immune genes including major histocompatibility complex (MHC II CD74 molecule) and immunoglobulin M (IgM) was assessed using quantitative PCR (qPCR). Prime and/or boost vaccination by immersion of juvenile ballan wrasse (0.5 g and 1.5 g corresponding to 80 and 170 days post hatch (dph), respectively) did not provide significant protection against aAs vapA V after bath challenge under experimental conditions. Despite no evident protection80 dph, MHC II and IgM transcripts were first reported at 35 and 75 dph, respectively, suggesting a window of immunocompetence. The results provide important new information on the onset of adaptive immunity in ballan wrasse and highlight that immersion vaccination in the species for protection against aAs should be performed at later developmental stages (1.5 g) in the hatchery.

This cross-sectional study was conducted to determine the occurrence, risk factors, and characteristics of Salmonella isolates recovered from imported fertile broiler hatching eggs, hatcheries, and broiler farms in Trinidad and Tobago. Standard methods were used to isolate and characterize Salmonella isolates from two broiler hatcheries and 27 broiler farms in the country. The frequency of isolation of Salmonella was 0.0% for imported fertile hatching eggs (0 of 45 pools of 10 eggs each, i.e., 450 eggs), 7.6% for hatcheries (12 of 158 samples), and 2.8% for broiler farms (24 of 866 samples) (P = 0.006). Stillborn chicks at hatcheries had the highest prevalence of Salmonella (7 of 28 samples, 28.0%), whereas on broiler farms the cloacal swabs had the highest prevalence of Salmonella (15 of 675 samples, 2.2%). None of the 15 farm management and production practices investigated were significantly associated (P0.05) with the isolation of Salmonella. The predominant Salmonella serotypes were Kentucky (83.3%) and Infantis (62.5%) among hatchery and farm isolates, respectively. The disk diffusion method revealed frequencies of antimicrobial resistance (i.e., resistance to one or more agents) of 44.0% (11 of 25 isolates) and 87.5% (35 of 40 isolates) at hatcheries and broiler farms, respectively (P = 0.0002). Antimicrobial resistance among hatchery isolates was highest (28.0%) to doxycycline and kanamycin and was very high (65%) among farm isolates to sulfamethoxazole-trimethoprim, gentamicin, ceftriaxone, kanamycin, and doxycycline. Multidrug resistance (MDR; i.e., resistance to antimicrobial agents from three or more classes) was exhibited by 4.0 and 85.7% of Salmonella isolates recovered from several environmental and animal sources at the hatcheries and farms, respectively (P0.0001). The high level of antimicrobial resistance and the presence of MDR among Salmonella isolates from broiler farms highlight the therapeutic implications and the potential for MDR strains to enter the food chain.

Age of maturation in many salmonid species is phenotypically plastic and dependent on exceeding a genetically set threshold in growth, often described as a probabilistic maturation reaction norm (PMRN). Hatchery supplementation programs for Chinook salmon (Oncorhynchus tshawytscha) in the Pacific Northwest US have been developed to minimize differences between hatchery and wild fish by integrating natural-origin adults into broodstock, potentially affecting PMRNs. We raised fish from 10 Chinook salmon stocks with variable levels of natural-origin integration in a common garden environment to explore potential genetic variation in PMRNs for precocious male maturation as age 2 minijacks. Proportion minijacks varied ≈10-fold (0.043 to 0.443) and the PMRN WP50 (predicted weight at 50% maturation) varied by ≈18 g (24.1 to 41.7 g). The propensity for minijack maturation was generally higher in stocks with higher levels of natural-origin integration. These findings demonstrate the effect of genotype by environment interactions on life history of salmonids and the need for stock-specific tailoring of rearing regimes to regulate differences between hatchery and wild fish, when wild fish are used in broodstocks.

La Trobe University Faculty of Science, Technology and Engineering Murray Darling Freshwater Research CentreMDFRC item.Knowledge of the biology of native fishes of the Murray-Darling Basin is based largely on studies conducted under hatchery conditions and on a limited number of recreationally important species. From observations that increases in water level in aquaculture ponds initiate spawning in some species, and from limited studies of wild fishes and studies in overseas floodplain river systems, a perception has emerged of the importance of flooding and the flood plain in the life cycles of Murray-Darling fishes in general. However, there is little confirmatory evidence of the use of temporary floodplain habitats by larvae, juveniles or adults. The significance of in-channel habitats, especially for rearing, has received little attention. Murray-Darling fish species can be placed into three life history modes, based mainly on spawning style and time and developmental intervals of larvae at first feeding. Fish in each group may be able to take advantage of floods if the timing is right and prey are plentiful, however, the larvae of some species are able to recruit under non-flood conditions within the main river channel. This forms the basis of the low flow recruitment hypothesis, which attempts to explain why some species spawn during the warmest months and lowest flows and how they are able to recruit under these conditions. This hypothesis is then placed in the context of the current state of knowledge of the relationships between flow and the biology of Murray-Darling fishes, specifically cues for spawning, movement and recruitment. The lack of widespread evidence for floodplain use by any life history interval of fish may be due to a paucity of study, however, there are some fundamental factors, such as the predictability of timing and duration of high flow events as well as the lack of coincidence of high flows and high temperatures in some regions of the Basin, which may be important in determining the use of floodplain habitats by fish.

The release of captive‐bred plants and animals has increased worldwide to augment declining species. However, insufficient attention has been given to understanding how neutral and adaptive genetic variation are partitioned within and among proximal natural populations, and the patterns and drivers of gene flow over small spatial scales, which can be important for restoration success. A seascape genomics approach was used to investigate population structure, local adaptation, and the extent to which environmental gradients influence genetic variation among natural and restored populations of Chesapeake Bay eastern oysters Crassostrea virginica. We also investigated the impact of hatchery practices on neutral genetic diversity of restored reefs and quantified the broader genetic impacts of large‐scale hatchery‐based bivalve restoration. Restored reefs showed similar levels of diversity as natural reefs, and striking relationships were found between planting frequency and broodstock numbers and genetic diversity metrics (effective population size and relatedness), suggesting that hatchery practices can have a major impact on diversity. Despite long‐term restoration activities, haphazard historical translocations, and high dispersal potential of larvae that could homogenize allele frequencies among populations, moderate neutral population genetic structure was uncovered. Moreover, environmental factors, namely salinity, pH, and temperature, play a major role in the distribution of neutral and adaptive genetic variation. For marine invertebrates in heterogeneous seascapes, collecting broodstock from large populations experiencing similar environments to candidate sites may provide the most appropriate sources for restoration and ensure population resilience in the face of rapid environmental change. This is one of a few studies to demonstrate empirically that hatchery practices have a major impact on the retention of genetic diversity. Overall, these results contribute to the growing body of evidence for fine‐scale genetic structure and local adaptation in broadcast‐spawning marine species and provide novel information for the management of an important fisheries resource.

Freshwater fisheries represent important natural resources, yet a vast majority are threatened by anthropogenic stressors. Accurate baseline information on stock diversity, population history and hatchery representation are required for implementing effective conservation and management strategies for mitigating declines. Genetic tools have played key roles for informing fisheries management, including for kokanee, the freshwater resident form of sockeye salmon (Oncorhynchus nerka), particularly in the southern portion of its North American range. Here, we investigated stock diversity, population history and hatchery representation of kokanee at the northern extent of its range in Canada in Kluane National Park and Reserve (KNPR) in the Yukon that underwent a 12-year population crash followed by a rapid increase in numbers. Using restriction-site associated DNA sequencing, we genotyped individuals at 11,442 single nucleotide polymorphisms (SNPs) that were sampled from putative reproductive ecotypes spawning on the shore of Sockeye Lake (n = 26), within Sockeye Creek (n = 20) or near an outlet in between (n = 2), as well as broodstock from the Whitehorse Rapids Fish Hatchery (n = 29). We found no evidence of ecotype differentiation based on neutral SNPs nor outlier loci. Within-population genetic diversity and effective population size were substantially higher in the wild population relative to the hatchery and significant differentiation was detected, suggesting the hatchery population was not representative of wild stock diversity. Overall, our results indicate that separate management of kokanee in KNPR based on ecotype is not warranted at this time and that supplementation with the existing hatchery stock is not appropriate.

In the hatchery of white shrimp larvae, there are some problems, such as a decreased water quality and diseases caused by bacteria which cause a decrease in shrimp growth. The solution to reduce these problems is by applying synbiotics. This research aimed to make an innovative synbiotic formula for the absolute length growth and survival rate of white shrimp larvae (Litopenaeus vannamei) as well as the total number of bacteria and the number of Vibrio sp. In this study, there were four treatments, as follows: C-: negative control (without synbiotic application) C+: positive control (commercial synbiotic) P: probiotic 2.5 x 105 cfu/ml and prebiotic 1,5 ppm Q: probiotic 5 x 105 cfu/ml and prebiotic 1 ppm R: probiotic 7,5 x 105 cfu/ml and prebiotic 0,5 ppm S: probiotic 106 cfu/ml and prebiotic 2 ppm, each treatment with four repetitions. This research was set up in a completely randomized design experiment using twenty-four plastic tanks with 50 L total volume filled with 20 L sterile sea water and stocked with 4,000 nauplii in the PT. Citra Larva Cemerlang hatchery, Kalianda, Lampung. Variables observed in this research were survival rate, absolute length growth, total bacterial and Vibrio sp. counts, and water quality in the white shrimp larvae (Litopenaeus vannamei). The results showed that the best survival rate is in treatment S (probiotic 106 cfu/ml and prebiotic 2 ppm) (87.7%), the highest absolute length growth is in treatment P (3.8 mm), the highest total bacteria was in treatment S (11.1 log cfu/ml), and the best total Vibrio sp. is in treatment S (3.5 log cfu/ml). Water quality of the six treatments shows results that are still in normal conditions following Indonesian National Standard SNI 7311: 2009.

Carp (Cyprinus carpio) hatchery cultivation is one of the business activities carried out by the community in Ciparay District, Bandung Regency. This research aims to analyze the financial feasibility of carp hatchery cultivation in Ciparay District, Bandung Regency. This research was conducted using a case study method consisting of primary data and secondary data. Primary data obtained from interviews with respondents and secondary data obtained from related agencies. This research uses 38 respondents as samples based on the sampling method (purposive sampling). The analysis used in this research is descriptive quantitative. The results obtained from this research are carp hatchery cultivation in Ciparay District has a profit value of 164,225,000 IDR/year, Profitability of 217%, R/C of 3.2 and Payback Period of 33 days so it is feasible to run and develop. Carp hatchery cultivators in Ciparay District, Bandung Regency are indicated to be prosperous because they have a higher income than the Regional Minimum Wage of Bandung Regency.

Aceh Besar Regency has a relatively large freshwater fishery area. Based on the 2019 BPS, it was recorded that the area of aquaculture in the Jantho area at BBI was 32.10 Ha, while the People's Breeding Unit (UPR) had an area of 15.60 Ha. BBI Jantho produces freshwater fish, namely catfish, gourami, carp, and tilapia. However, every year there is a significant increase in production, namely tilapia with a percentage increase in production of 17%. This increase occurred due to the large demand for tilapia in the market but insufficient production. The problem is that the tilapia seed market is good but the production is lacking. The purpose of this study was to analyze the feasibility of Tilapia hatchery at BBI Jantho Aceh Besar. This research is a case study using primary and secondary data. The analytical tools used are market and marketing aspects, technical and technological aspects, income analysis, Cost Ratio (R/C), Break Event Point (BEP), Return On Investment (ROI). The results of this study indicate from all aspects that this business is profitable and feasible to work on. From the technical and technological aspects, all of them meet criteria such as the location of the tilapia hatchery, the scale of operation, production activities, pond layout and inputs. The market and marketing aspects have used 1 level distribution channels. From the economic aspect where the income is Rp.69,546.042, the R/C value is 2.81, the BEP Production value is 192,270 head 540,000, the BEP value Price is Rp.71/head Rp. 200/head. The ROI value is 181% which indicates that the rate of return on capital for Tilapia Hatchery is 81% greater.

The preparation process needs to be carried out in the treatment of hatchery waste. The objective of the study was to determine the mineral content and characterization of the eggshell waste after preparation. An experiment was arranged on a completely randomized design (CRD). Preparation treatment consisted of; T1: shell waste watered with distilled water; T2: shell waste soaked in distilled water for 12 h; T3: shell waste soaked in 0.5% NaOH for 720 min; and T4: shell waste boiled at 80°C for 15 min and soaked in 5% H3PO4 for 15 min. The data were analyzed using Analysis of Variance (ANOVA), and if any differences, a Duncan Multiple Range Test (DMRT) post hoc tests were carried out. Composition of proximate and mineral were detected by using X-Ray Fluorescence (XRF). Results indicated that proximate analysis of the dry matter content were T4: 98.98±0.01; T3: 98.58±0.04; T2: 98.75±0.08; and T1: 98.72±0.03. The calcium content of the treatment from the highest was T3: 24.22±0.31; T1: 22.80±0.57; T2: 22.77±0.71; and T4: 21.55±0.46. It may be inferred that the treatment technique had no major impact on the eggshells physical characteristics. However, boiling treatment at 80°C for 15 min and soaking in 5% H3PO4 reduced the eggshell waste's Mg, Si, and Ca content. The addition of 0.5% NaOH immersion did not degrade Mg, Ca, and Si of eggshell waste.

This paper reviewed the effects of lighted incubation (in ovo lighting) on incubation performance and chick quality in broilers. Globally, the broiler chicken industry is among the fastest growing commercial sectors. Chicken meat has the fastest growth rate compared to other common animal protein sources, and its demand will always increase due to increasing population growth worldwide. Therefore, a need for a proportional increase in hatchery efficacy is also increasing with this demand. Over the past decades, implementation of artificial light during incubation in broiler chickens has accelerated with key considerations such as light colour, light source, photoperiod, eggshell colour, pigmentation, light shape and light intensity. Photostimulation has a significant effect on embryo development during the last quarter (from 14 to 21 day of incubation). However, incubating eggs under light from day 1 to 18 improves embryo development and hatchability compared with lighting for 21 days. A photoperiod of 12 L:12 D improves hatchability, chick weight and leg health compared with 24 L and 24 D. High light intensity decreases hatching traits such as chick weight. While incubation under green light increases muscle growth and weight gain of chicks, lighted incubation with red and white light enhances hatchability compared with other wavelengths and darkness. In conclusion, it is important to continue studies on lighted incubation to identify the exact mechanisms of how other light colours impact embryogenesis and investigate the interaction or synergistic effects of a combination of two or more wavelengths.

Results of 4 salmon hatcheries operation in Primorye Region are overviewed. Dynamics of chum salmon producers return to the rivers is presented for 4 last years. Recent tendency of shifting the peak of return from middle October to late September — early October is noted both for the rivers flowing into Peter the Great Bay (Barabashevka) and for the rivers of central Primorye (Verbnaya and Milogradovka). High percentage of producers aged 2+ was observed in the hatchery rivers in some years (32.9 % in the Barabashevka in 2019, 31.0 % in the Verbnaya in 2020, 37.8 % in the Bezymyanny in 2020). Interannual fluctuations in the number of producers return are possibly caused by malfunctions of hatcheries. A problem of water supply to the hatcheries is considered. Expediency of temperature control at hatcheries is shown. Data on release of chum salmon juveniles in the last decade are presented for each hatchery: the number of juveniles released, the average weight of juveniles, and the timing of release. Total release to the Barabashevka River was 119.29 . 106 juveniles, to the Ryazanovka — 114.24 . 106 juveniles, to the Poyma — 49.43 . 106 juveniles, to the Narva — 6.02 . 106 juveniles, to the Brusya — 3.11 . 106 juveniles, to the Verbnaya — 69.66 . 106 juveniles, to the Milogradovka — 1.00 . 106 juveniles, to the Lidovka — 1.71 . 106 juveniles, to the Bezymyanny — 69.45 . 106 juveniles, and 2.00 . 106 juveniles each to the Kievka and Margaritovka Rivers.

Growth and survival rates of juveniles of pacific oyster Crassostrea gigas are estimated for the first time in conditions of Peter the Great Bay (Japan Sea). The data were collected at artificial hatchery in the Aquaculture Center located on Popov Island in 2019. The juveniles were settled and reared on two types of substrate: 1) perforated plastic plates with the diameter of 30 cm (area 7.1 dm2), and 2) scallop shells with the height about 10 cm (average area 0.8 dm2) mounted in the western Peter the Great Bay (Voevoda Bay) in September 2019. Before placing in this site, the average height of the juveniles’ shells did not exceed 7 mm. In July 2020, after the 9-month exposure of the collectors with spat in the Voevoda Bay, the height increased in 12–18 times and reached 55–90 mm on the substrate 1 and 25–65 mm on the substrate 2. Then the oysters reared on the substrate 1 were replaced from the plastic plates to the cage shelves and the cages were moved to the Stark Strait. Difference in the growth rate became more apparent in September 2020, when the height of shells settled on the plastic plates reached 67 mm, on average (73 % in the range 50–85 mm) and for the shells settled on the scallops — 32 mm, on average (72 % in the range 20–45 mm). The shell height increased to 76.6 and 52.4 mm, respectively, to the end of October 2020. Finally, about 59 % of the oysters reared on the substrate 1 and cage shelves and 9 % of the oysters reared on the substrate 2 reached the commercial size (80–100 mm). Their survival in the period from mid-October 2019 to July 2020 is estimated as 46.9 % (28.8–98.2 %) for the substrate 1 and 33.5 % (4.0–78.3 %) for the substrate 2. On the substrate 1, survival of the mollusks attached to lower surface of the plates was twice higher. The survival had a tendency to decrease with increasing of the juveniles density. The experiment showed good viability for artificially hatched juveniles of pacific oyster in conditions of Peter the Great Bay. Their growth in the Voevoda Bay and the Stark Strait, with necessary technological measures, as replacing, thinning, and substrate cleaning from fouling, allows to produce oysters with the commercial size.

State of blood cells is examined for juveniles of pink and chum salmon sampled from Lesnoy Pugachevsky, Taranaisky and Okhotsky hatcheries in Sakhalin in May-June of 2018 and 2019 and caught in the Ochepukha, Pugachevka and Taranay Rivers during their catadromous migration to the sea. Both hatchery and wild juveniles of both species were characterized by high adaptive capabilities evidenced with high content of young forms of erythrocytes in the blood (17.0–31.0 %), significant portion of lymphocytes (60.8–92.0 %), and small number of neutrophils. The high adaptive capabilities were confirmed in the experiment, when juveniles of pink salmon were placed in the seawater without preliminary acclimation, but noticeable changes in the state of blood cells were not revealed both for wild and hatchery-reared specimens. Proportion of different blood cells was highly variable for juveniles of both artificial and natural origin but was more similar between the fry hatched at the same hatcheries or in the same rivers. A case of increased number of neutrophils was noted in 2019 for certain groups of juveniles, with total increasing of platelets in the blood that was explained by an external influence on the juveniles.

One of the largest nesting colonies of the Vulnerable loggerhead sea turtle Caretta caretta is in Cabo Verde. Here we present the first comprehensive study of loggerhead turtle nesting on the island of Maio in Cabo Verde. During 2016–2019 we monitored 38 km of undeveloped sandy beaches that have minimal artificial lighting and where all nesting on Maio takes place. We counted 4,063 nests in 2016, 5,429 in 2017, 14,364 in 2018 and 7,937 in 2019. The estimated total number of females was 1,016, 1,357, 3,591 and 1,984 in each of these years, respectively. Our findings suggest there are more loggerhead turtles nesting in Cabo Verde than previously estimated, and that this could be the species’ largest nesting subpopulation (followed by Florida, USA and Oman). The inter-annual hatching success (the proportion of eggs producing hatchlings) was 29–38% for the whole island but varied between sites. Our study of 250 clutches showed that flooding affected 38–61% and predation by crabs 40–42%, with hatching success on different beaches in the range of 1–59%. Poaching of eggs was rare (< 2% of clutches), but dogs predated 68.4% of all clutches on the beach nearest the largest human settlement. We evaluated different nest management strategies at multiple sites and estimated productivity of hatchlings (the number of hatchlings that would reach the sea for each management strategy), finding that hatcheries are not always the best option for nest management. As the beaches on Maio are relatively undisturbed, and there is a high abundance and density of turtle nests, the island should be protected as a globally important site for the conservation of the loggerhead turtle, and of coastal biodiversity more broadly.

The influence of breed and storage period of hatching eggs on the duration and results of incubation and the development of quail was studied. It has been noted that in breeding quail farms, the collection period for hatching eggs can be as long as 2-3 weeks. Storage time has a negative effect on incubation time, embryo development, egg hatchability and hatchability of young chicks, which consequently reduces the economic efficiency of the poultry farm. The study was carried out on the eggs of the Pharaoh and Texas White quail breeds. It was found that storage of quail eggs for more than 7 days reduces the hatchability of eggs by 8.3-38.2% and the hatchability of young quail eggs by 15.7-41.4%. Reduced fertilization of eggs correlated with the loss of egg weight during storage (r = 0.974-0.995, p < 0.05). Extending the shelf life of quail eggs to 14-21 days increased the average incubation hour of the Pharaoh breed by 6.3-12.1 hours, and the Texas white breed by 2.5-9.7 hours, had a significant effect during the embryogenesis period on the live weight of day-old quails of both breeds, utilization of yolk sac nutrients and development of the heart, liver and gizzard (η2= 0.541-0.902, p

Common snook Centropomus undecimalis is an important estuarine-dependent predatory fish species. In Florida, the decline of wild stocks, due mainly to fishing pressure and loss of habitat, has led to increasingly restrictive management actions in the last 50 years. This has also promoted its culture for stock enhancement as one of many management actions. Stocking efforts indicate that survival of snook fingerlings can be poor and improvements could be achieved through prerelease conditioning. In this study we compared prey capture kinematics between naïve hatchery juvenile snook and wild conspecifics. Capture behavior, quantified with high-speed cameras, identified specific differences in prey capture of hatchery and wild snook. Naïve juvenile hatchery snook exposed to live prey made fewer attempts to feed, had longer delays in the time to strike, exhibited higher strike velocities and engulfed prey earlier in the gape cycle, and had less overall feeding success compared to wild fish. However, experience with repeated live prey feeding events quickly improved hatchery snook feeding success, similar to wild fish. Therefore, prerelease training via exposure to live prey could improve feeding performance and overall fate of snook released into the wild.

Ikan karper (Cyprinus carpio) merupakan komoditas perikanan air tawar yang saat ini mengalami perkembangan pesat dari waktu ke waktu. Perkembangan yang semakin pesat dan berkualitas tidak lepas dari peranan kegiatan pembenihan. Oleh sebab itu, diperlukan program yang tepat dalam usaha perbaikan kualitas benih ikan karper. Studi ini dilakukan untuk mengevaluasi proses pembenihan ikan karper (Cyprinus carpio) agar menghasilkan benih yang lebih optimal dengan mengkaji metode pembenihan secara alami. Metode kerja pada studi ini menggunakan metode deskriptif dengan teknik pengambilan data primer dan sekunder. Parameter yang diamati antara lain fekunditas, Fertilization Rate, Hatching Rate dan Survival Rate. Hasil studi menunjukkan nilai fekunditas sebanyak 240.000 butir dengan nilai FR sebesar 80%, nilai HR sebesar 95% dan nilai SR sebesar 36%.

In Manitoba, Canada, wild lake sturgeon (Acipenser fulvescens) populations exist along a latitudinal gradient and are reared in hatcheries to bolster threatened populations. We reared two populations of lake sturgeon, one from each of the northern and southern ends of Manitoba and examined the effects of typical hatchery temperatures (16°C) as well as 60-day acclimation to elevated rearing temperatures (20°C) on mortality, growth and condition throughout early development. Additionally, we examined the cold shock response, which may be induced during stocking, through the hepatic mRNA expression of genes involved in the response to cold stress and homeoviscous adaptation (HSP70, HSP90a, HSP90b, CIRP and SCD). Sturgeon were sampled after 1 day and 1 week following stocking into temperatures of 8, 6 and 4°C in a controlled laboratory environment. The southern population showed lower condition and higher mortality during early life than the northern population while increased rearing temperature impacted the growth and condition of developing northern sturgeon. During the cold shock, HSP70 and HSP90a mRNA expression increased in all sturgeon treatments as stocking temperature decreased, with higher expression observed in the southern population. Expression of HSP90b, CIRP and SCD increased as stocking temperature decreased in northern sturgeon with early acclimation to 20°C. Correlation analyses indicated the strongest molecular relationships were in the expression of HSP90b, CIRP and SCD, across all treatments, with a correlation between HSP90b and body condition in northern sturgeon with early acclimation to 20°C. Together, these observations highlight the importance of population and rearing environment throughout early development and on later cellular responses induced by cold stocking temperatures.

Burst swimming velocity (Uburst) was compared between wild and hatchery-reared chum salmon fry. In the hatchery-reared fry, Uburst was significantly correlated with the condition factor, but not with the body mass and fork length. In the wild-reared fry, on the other hand, Uburst ranged widely and did not correlate with condition factor. These suggest that well-balanced growth under satisfactory nutrient condition at the early developmental stage improves Uburst, and in the wild-reared fry, their cautiousness and various experiences may override the condition factor dependency of Uburst.

Genetic stock identification (GSI) is a major management tool of Pacific salmon (Oncorhynchus Spp.) that has provided rich genetic baseline data of allozymes, microsatellites, and single‐nucleotide polymorphisms (SNPs) across the Pacific Rim. Here, we analyzed published data sets for adult chum salmon (Oncorhynchus keta), namely 10 microsatellites, 53 SNPs, and a mitochondrial DNA locus (mtDNA3, control region, and NADH‐3 combined) in samples from 495 locations in the same distribution range (n = 61,813). TreeMix analysis of the microsatellite loci identified the greatest convergence toward Japanese/Korean populations and suggested two admixture events from Japan/Korea to Russia and the Alaskan Peninsula. The SNPs had been purposively collected from rapidly evolving genes to increase the power of GSI. The largest expected heterozygosity was observed in Japanese/Korean populations for microsatellites, whereas it was largest in Western Alaskan populations for SNPs, reflecting the SNP discovery process. A regression of SNP population structures on those of microsatellites indicated the selection of the SNP loci according to deviations from the predicted structures. Specifically, we matched the sampling locations of the SNPs with those of the microsatellites and performed regression analyses of SNP allele frequencies on a 2‐dimensional scaling (MDS) of matched locations obtained from microsatellite pairwise F ST values. The MDS first axis indicated a latitudinal cline in American and Russian populations, whereas the second axis showed differentiation of Japanese/Korean populations. The top five outlier SNPs included mtDNA3, U502241 (unknown), GnRH373, ras1362, and TCP178, which were identified by principal component analysis. We summarized the functions of 53 nuclear genes surrounding SNPs and the mtDNA3 locus by referring to a gene database system and propose how they may influence the fitness of chum salmon., By regressing the SNP population structures on those of the microsatellites, we estimated the selection on the SNP loci according to deviations from the predicted structures. The top five outlier SNPs were mtDNA3 (control region and NADH‐3 combined), U502241 (unknown), GnRH373, ras1362, and TCP178, which significantly differentiated in Japanese/Korean populations. The functions of the outlier SNPs related to fitness, namely endurance exercise training, oxygen consumption, reproduction, and growth.

Population genetic structure of cultured fish species is vital for improving the fisheries management and stock enhancement programs. The genetic variability and population genetic structure at fourteen microsatellite loci of a total 210 individuals of Cyprinus carpio from six selected hatcheries were analyzed. The data obtained through microsatellite markers showed a low- to-moderate level of genetic diversity in terms of allele numbers (Na), allelic richness (Ar), effective allele numbers (Nae) and observed heterozygosity (Ho) in all the populations. At the examined loci, 32 out of 84 possible tests were observed to be significantly (P

In Cameroon, wild strains of Clarias gariepinus (Burchell, 1822) are often used for artificial reproduction in hatchery facilities, but there is insufficient information on their reproductive capacity and progeny performance. The reproductive capacity of two strains of C. gariepinus from the Mezam and Mungo Rivers and the performance of their F1 larvae obtained following hybridization were assessed. Reproduction was carried out with four crosses as follows: Mezam (♂) x Mezam (♀) (T1), Mezam (♂) x Mungo (♀) (T2), Mungo (♂) x Mezam (♀) (T3) and Mungo (♂) x Mungo (♀) (T4). Thereafter, three days old larvae obtained following reproduction were subjected to a 30 day experimental trial with standard feeds. The performance of larvae obtained from T4 was not assessed since larvae obtained were too few for the experiment. Although the broodstock of the different strains did not differ significantly in size, Mezam stock had significantly (p = 0.00) bigger eggs when compared to Mungo stock. Fecundity of 52480 was recorded for Mezam stock compared to 32985 for Mungo stock. Fertilization and hatchability rates differed significantly (p < 0.05) among the crosses, with the highest (82.28 and 81.31%, respectively) in T1, followed by T3 (65.96 and 61.28%, respectively), and the least (38.61 and 2.81%, respectively) in T4. The best larval survival was recorded in T1 (37.17%) and the least in T2 (15.67%), meanwhile T3 recorded best growth after 30 days. In terms of fertilization and hatchability, T1 was more suitable for artificial reproduction, but T3 is more encouraged for aquaculture based on its reproductive capacity and larval performance.

Mortality in Norwegian salmonid aquaculture has a major influence on fish welfare and represents economic losses for producers. We reviewed the estimated monthly mortality for freshwater farms with Atlantic salmon and rainbow trout between 2011 and 2019. We built a regression model for mortality which included the variables year, weight group, season, region and farm. Additionally, we distributed questionnaires to farmers to gather information regarding potential causes of mortalities. The analysis of data for Atlantic salmon showed that median monthly mortality increased from 0.15% in 2011 (interquartile range [IQR]: 0.06-0.39) to 0.25% (IQR: 0.1-0.67) in 2019. Mortality was highest in the North (0.27%, IQR: 0.11-0.72) and lowest in the Southwest region (0.16%, IQR: 0.07-0.4). The season with highest mortality was summer (0.24%, IQR: 0.1-0.64), while winter had the lowest (0.12%, IQR: 0.05-0.35). The smallest fish (3-12 g) showed highest mortality (0.31%, IQR: 0.14-0.69) compared to heavier fish. Results from the questionnaire showed that infectious or non-infectious diseases were the most commonly reported causes of mortality. The mortality patterns described in this study identifies several important risk factors. Highlighting causal links is an important step to reducing mortality and improving welfare in the freshwater production phase of salmonids in Norway.

This study was carried out to reveal bacterial contamination and antibiotic resistance profiles of isolated bacteria in the hatchery systems of trout farms located in the Eastern Black Sea region of Turkey. Inlet water, egg, alevin and fry samples of 11 different trout farms were examined in terms of bacterial contamination in four different basins. After sampling, isolated bacteria were identified by making phenotypic and genotypic analyses. The majority of a total of 43 strains belongs to the genera Aeromonas and Pseudomonas, but also Lelliottia sp., Bacillus sp. and Lactococcus lactis were isolated from hatchery systems. Considering all basins, except for the 2nd basin, the highest antibiotic resistance of bacteria was against Ampicillin. The lowest antibiotic resistance percentages were determined against gentamicin and enrofloxacin. As a result of the research, the detection of different bacteria in the samples taken from the inlet water of fish farms showed presence of different bacteria contaminating the hatchery water. It thereby stressed the need for improved hygiene measures in these farms Bu çalışma, Türkiye'nin Doğu Karadeniz bölgesinde bulunan alabalık çiftliklerinin kuluçkahane sistemlerinden izole edilen bakterilerin kontaminasyonu ve antibiyotik direnç profillerini ortaya çıkarmak için yapılmıştır. 11 farklı alabalık çiftliğinin giriş suyu, yumurta, alevin ve yavru örnekleri, dört farklı havzada bakteriyel kontaminasyon açısından incelenmiştir. Örneklemeden sonra izole edilen bakteriler fenotipik ve genotipik analizler yapılarak teşhis edilmiştir. Toplam 43 suşun çoğunluğu Aeromonas ve Pseudomonas cinsinlerine aittir, fakat aynı zamanda Lelliottia sp., Bacillus sp. ve Lactococcus lactis, kuluçka sistemlerinden izole edilmiştir. 2. havza hariç tüm havzalara bakıldığında bakterilerin en yüksek antibiyotik direnci Ampisiline karşı olmuştur. En düşük antibiyotik direnç yüzdeleri gentamisin ve enrofloksasine karşı belirlenmiştir. Araştırma sonucunda, balık çiftliklerinin giriş sularından alınan örneklerde farklı bakterilerin tespiti, kuluçkahane suyunu farklı bakterilerin kontamine ettiğini göstermiştir. Böylelikle bu çiftliklerde hijyen önlemlerinin iyileştirilmesi ihtiyacı belirlenmiştir.

The increasing demand for simultaneous hatching of a large number of chicks has led to the need for refrigerated egg storage often over 7 days. This results in low embryo viability, low hatchabilit...

The authors greatly appreciate SEAFDEC Aquaculture Department for funding the study (Study Code: FS-02-M2020T); the Abalone Hatchery staff for providing the abalone juveniles used in the study; the Feed Mill Plant staff for producing the feeds to the desired formulation and forms; Mr. Silverio Tibudan for his assistance in the conduct of the experiment; Mr. Manny Librodo for his assistance in improving the resolution of the figures; and the anonymous journal reviewers for painstakingly reviewing the manuscript.

Alaska Sea Grant, University of Alaska Fairbanks, Grant/Award Number: NA18OAR4170078; Blue Evolution

In the present study, the white shrimp, Litopenaeus vannamei, was supplemented with the probiotic Bacillus subtilis IS02 in order to improve the larval survival rate. Various experimental groups including control (no probiotic in the rearing water), 106, 107, and 108 CFU mL–1 of the probiotic supplemented samples were added to the salt water once every 3 days during the 21 days of breeding. The stress tolerance and immune status were then evaluated. It was shown that the larval development stages and survival rate were significantly improved following application of the 108 CFU mL−1 of the probiotic. Total bacterial and presumptive Vibrio counts were numerically reduced. The stress test revealed a considerable increase in the postlarvae vitality. Moreover, a significant decrease in the cumulative mortality of postlarvae exposed to the probiotic at the level of 108 CFU mL−1 was recorded after a sudden transfer to 300 mg L−1 nitrite-N, compared to that of the control. The analysis of immune-related gene expressions showed the overexpression of the genes prophenoloxidase (proPO) and peroxinectin (PE) in the shrimp fed with water containing 108 CFU mL−1 of probiotic. These findings demonstrate the effects of the administration of B. subtilis IS02 on improving growth and enhancing the immune response, thus increasing resistance to bacterial pathogens.

Environmental conditions strongly affect antipredator behaviors; however, it is less known how migrating prey adjust antipredator behavior in migration corridors, in part, because active migrants are difficult to observe and study. Migrants are vulnerable and encounter many predators in the corridor, and their propensity to travel towards their destination ties antipredator behavior with movement. We evaluated how environmental risk cues in the migration corridor including in-water habitat structure (present, absent) and overhead shade (sun, shade), and salmon origin (hatchery, wild) affected how juvenile Chinook salmon (Oncorhynchus tshawytscha) reacted to a live predator. We measured how salmon react to predation risk as the difference in time to swim downstream through a 9.1-m long field enclosure with or without a live predatory largemouth bass (Micropterus salmoides). Shade significantly modified the reaction to the predator, and it did so in two ways. First, the magnitude of antipredator behavior was larger in shade compared to direct sun, which suggests salmon perceived shade to be a riskier environment than sun. Second, the escape tactic also varied; salmon slowed down to be cautious in shade and sped up in sun. Structure did not significantly affect behavior and hatchery and wild salmon behaved similarly. Our study suggests that environmental risk cues can shape the magnitude and tactics of how migrants react to predation risk and illustrates how these responses relate to movement with potential to scale up and affect migration patterns.

The objective of this research was to study the potential of cherry leaf extract as natural sanitizer agent for Alabio eggshell in hatching process. A number of 533 of Alabio hatching eggs were used in this study. Hatching eggs produced from College of Vacational Studies IPB University, were collected three times a day. Three hundred thirty-three hatching eggs were divided into five treatment groups. The first group was considered as control, the second was dipping into commercial disinfection, and the third and the fifth gruop were dipping into cherry leaf extract 250 ppm, 500 ppm, and 750 ppm respectively. The results showed cherry leaf extract has secondary metabolite compounds : alkaloids, flavonoids and tannins. All of these secondary metabolite compounds have a role as antibacterial agent. cherry leaf extract 750 ppm shows the same potential as commercial disinfectants in reducing the microbial population in eggshells. The dipping treatment of 750 ppm cherry leaf extract in alabio duck hatching eggs resulted in the lowest embryo mortality rate compared to other treatments (9.3%). Key words: Alabio duck, cherry leaf extract, hatchery, total plate count of eggshell

The study was carried out for six (6) weeks at the Department of Fisheries Teaching and Research farm, Modibbo Adama University, Yola, to compare the reproductive performance of Clarias gariepinus using synthetic (ovaprim) and natural (C. gariepinus pituitary extract) hormones . At the end of the feeding trial, the fecundity, percentage fertilization, hatchability, and survival rates of the hatchlings were estimated using standard procedure. The hatchlings were further raised for six weeks and the increase in weight was determined. The results showed that female broodstock injected with C. gariepinus pituitary extract (CgPE) had a higher fecundity (124,000) while the female injected with Ovaprim had 65,000 eggs. The weight of the testes significantly differed (p