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Aquaculture International - Seafood has important health benefits, and the growing demand for aquatic products has stimulated rapid trade development. Using 2000–2018 data from the UN... 相似文献
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The sex ratio of the feral Southern catfish was reported to be about 1:1, while the fish obtained by artificial fertilization
were always female. Hence, we examined the possible influence of the micro-environment during artificial insemination (pH
of the ovarian fluid and concentration of the semen) and early development (feed, hatching temperature, and water) on the
sex ratio of Southern catfish fry. In order to examine the possibility of the occurrence of gynogenesis during artificial
propagation, cytological observations on the insemination processes and the artificial induction of gynogenesis were also
performed. However, no male fish were obtained even in these experiments, excluding the possibilities of these micro-environmental
changes on catfish sex ratio and the occurrence of gynogenesis during artificial propagation. Female-to-male sex reversal
was achieved by treatment with fadrozole (an aromatase inhibitor) and tamoxifen (an estrogen receptor antagonist). Histological
analyses on the gonadal development of both female and induced male fish were subsequently performed. Moreover, several genes
involved in sex differentiation, such as dmrt1, foxl2, and cyp19, and three subunits of gonadotropin (gth), i.e., gthα, lhβ, and fshβ, were isolated. Their expression patterns were studied under normal gonadal development and sex reversal conditions. The
results revealed that dmrt1, foxl2, and cyp19a were closely related to catfish sex differentiation, and the gth subunits were possibly related to ovarian differentiation and oocyte development. Taken together, we hypothesized that estrogen
was highly responsible for the ovarian differentiation and feminization of catfish fry under artificial propagation, although
the mechanism involved remains elusive. 相似文献
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If Arctic charr Salvelinus alpinus is ‘the most diverse vertebrate’, what is the lake charr Salvelinus namaycush? 
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下载免费PDF全文 Andrew Michael Muir Michael Jay Hansen Charles Richard Bronte Charles Conrad Krueger 《Fish and Fisheries》2016,17(4):1194-1207
Teleost fishes are prominent vertebrate models of evolution, illustrated among old‐world radiations by the Cichlidae of East African Great Lakes and new‐world radiations by the circumpolar Arctic charr Salvelinus alpinus. Herein, we describe variation in lake charr S. namaycush morphology, life history, physiology and ecology, as another example of radiation. The lake charr is restricted to northern North America, where it originated from glacial refugia and diversified in large lakes. Shallow and deepwater morphs arose in multiple lakes, with a large‐bodied shallow‐water ‘lean’ morph in shallow inshore depths, a small‐bodied mid‐water ‘humper’ morph on offshore shoals or banks, a robust, large‐bodied moderate to deep‐water ‘redfin’; morph and a large‐bodied deep‐water ‘siscowet’ morph at depths > 100 m. Eye position, gape size, and gillraker length and spacing adapted for feeding on different‐sized prey, with piscivorous morphs (leans, siscowets and presumably redfins) reaching larger asymptotic size than invertivorous morphs (humpers). Lean morphs are light in colour, whereas deepwater morphs are drab and dark, although the pattern is reversed in dark tannic lakes. Morphs shift from benthic to pelagic feeding at a length of 400–490 mm. Phenotypic differences in locomotion, buoyancy and lipid metabolism evolved into different mechanisms for buoyancy regulation, with lean morphs relying on hydrodynamic lift and siscowet morphs relying on hydrostatic lift. We suggest that the Salvelinus genus, rather than the species S. alpinus, is a diverse genus that should be the subject of comparative studies of processes causing divergence and adaptation among member species that may lead to a more complete evolutionary conceptual model. 相似文献
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Imtiaz Ahmed 《Fish physiology and biochemistry》2010,36(4):1133-1143
An 8-week growth study was conducted to determine the effect of ration level, energy, and protein maintenance requirement
of catfish, Heteropneustes fossilis–Bloch, fingerling (7.90 ± 0.55 cm; 3.10 ± 0.28 g) by feeding casein–gelatin-based purified diet (40% CP; 3.61 kcal g-1 GE)
at six ration levels 1–6% of BW/day, at 0800 and 1700 h, in triplicate, with 20 fish per trough fitted with water flow-through
system of volume 55 L. Maximum live weight gain, best feed conversion ratio (FCR), best specific growth rate (SGR), and highest
protein efficiency ratio (PER) were evident for ration levels of 4–5% body weight. However, second-degree polynomial regression
analysis for weight gain, FCR, PER, protein, and energy retention data indicated that the break-points occurred at 5.08, 4.18,
4.05, 4.16, and 4.17% BW/day, respectively. Significantly (P < 0.05) higher body protein content was recorded at 4 and 5% rations. While a linear increase in body fat content with inverse
relationship in moisture content was evident with increasing rations. Ash content remained insignificantly (P > 0.05) low at higher rations. Protein and energy retention values also produced significant (P < 0.05) differences. Based on the results obtained, it is recommended that feeding in the range of 4 to 4.5% BW/day, corresponding
to 1.60–1.80 g protein and 14.46–16.27 kcal energy g100 g−1 of the diet/day is optimum for the growth and efficient feed utilization of H. fossilis, while 2–3% ration levels (0.80–1.20 g protein and 7.23–10.84 kcal energy) suggest that these amounts approximate to the maintenance
requirement of this fish. 相似文献
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Al-Salahy MB 《Fish physiology and biochemistry》2011,37(3):373-385
Female catfish, Clarias gariepinus, were collected from the Nile River at Assiut region, were divided into 7 groups. The first group was left as control, and
the second was treated with mercuric chloride (MC) for 3 weeks following by normal water for 1 week. The third, fourth and
fifth groups were provided by MC (150 μg/ l of water). This treatment was continued for 3 weeks. Then, the fish were received
CN instead of MC, for 1 week, with 15 and 25 mg CN/100 g wet food. The fifth fish group received diet supplemented with vit
E (α-tocopherol) (100 mg/kg wet diet), for 1 week, instead of MC treatment. Vitamin E was used as standard antioxidant drug.
Following 3 weeks of normal ambient water, the sixth and seventh aquaria received only CN for 1 week, with 15 and 25 mg CN
respectively/100 g wet food, respectively. At the end of the experiment, Samples of liver, kidneys (posterior part), gills
(right gills) and ovary were excised. The measurement included the oxidative stress parameters: carbonyl protein and total
peroxide and the antioxidant enzyme activities superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST)
in all selected organs. MC treatment induced harmful effect in fish, probably due to its enhancing effect on reactive oxygen
species (ROS) production in fish organs especially the respiratory and osmoregulatory organs namely gills. The result suggests
that this gill damage may exert hypoxic case, anoxia for different organs and some Cu excretion resulting in a magnification
of ROS overproduction. Also, the observed oxidative stress in ovary tissue of MC-treated fish may affect fish fertility. The
addition of CN in fish diets could protect the fish C. gariepinus against MC-induced oxidative damage showing recovery of fish organs. It could suggest that the detoxifying mechanism of action
of CN is mainly due to its scavenging activity of free radicals rather than tissue healing. 相似文献
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There has been much recent discussion about the idea that large whales are potential competitors with fisheries for available marine resources. Based on this idea, often referred to as the ‘whales eat fish’ conflict, culling whales has been proposed as a way to increase resources available for human consumption and thereby ensuring global food security. However, the scientific basis for such arguments remains unclear, especially in the Caribbean waters where baleen whales generally do not feed. In this article, we (i) develop an ecosystem model describing the trophic interactions between whales, fish and fisheries in the Caribbean waters, (ii) calculate the level of overlap between cetaceans and fisheries for food resources, and (iii) simulate the removal of cetaceans from the Caribbean waters in order to quantify the potential increase in available biomass of commercially important fish. Ten groups of cetaceans are considered in the model, including baleen whales, toothed whales and small cetaceans. Our results suggest that baleen whales are not a threat to fisheries in Caribbean waters, while toothed cetaceans seem to be more impacted by fisheries than they actually impacting them. Whales target different types of food resources and consume significantly less than what is taken by fisheries. Moreover, simulated reductions in large whale abundance do not produce any appreciable increase in biomass of the commercially important fish species. In some cases, the presence of some whales actually improves fishery yield as a result of indirect predation effects. 相似文献
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Takeshi Ito Yudai Iino Shizuko Nakai Shiro Itoi Haruo Sugita Noriyuki Takai 《Fisheries Science》2018,84(4):627-640
The early life history of girellid fishes in Japanese waters is unclear, and little is known about their species-specific reproductive strategies. We examined seasonal changes of distribution patterns for settlement-stage juveniles of Girella punctata and Girella leonina on the rocky shore in the regions of Kanto and Izu, Japan, to infer the influence of the Kuroshio Current on their reproduction. We collected 813 settlement-stage juveniles mainly in Sagami Bay and genetically identified the species. The juveniles of G. punctata were collected on the rocky shore in Sagami Bay during April to August, with the abundant catch in May and June. Thus, we infer that juvenile G. punctata ubiquitously inhabit the rocky shore in the area in spring and summer. By contrast, juveniles of G. leonina were rarely collected in Sagami Bay, with a total catch of only 66. Notably, no juveniles were collected during the wintertime in Sagami Bay, although an abundant catch of G. leonina had been previously reported for Sagami Nada off Sagami Bay during January to March. This clear-cut difference between the areas likely reflects the difference in proximity to the path of the Kuroshio Current. We expect that the Kuroshio Current strongly influences the reproductive success of G. leonina. 相似文献
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Are hatchery‐reared abalone naïve of predators? Comparing the behaviours of wild and hatchery‐reared northern abalone,Haliotis kamtschatkana (Jonas, 1845) 下载免费PDF全文
下载免费PDF全文 Abalone populations have declined worldwide, generating interest in enhancement using hatchery‐reared individuals. In many cases, such restoration efforts have met with limited success due to high predator‐induced mortality rates. Furthermore, the mortality rates of outplanted hatchery abalone are often considerably higher than for wild individuals. This study uses northern abalone (Haliotis kamtschatkana) as a case study to determine whether hatchery‐reared abalone behave differently than their wild counterparts. In the field, outplanted hatchery‐reared abalone were significantly less responsive than wild abalone, in terms of number of abalone responding and intensity of response, to nearby movement and to physical contact with an inert probe. Also, when encountering a cue to which all abalone responded (a seastar predator), hatchery‐reared individuals remained subdued. Anti‐predator behavioural deficits in hatchery‐reared abalone were more pronounced in 4‐year‐old individuals than in 1‐year‐old individuals, suggesting an influence of either age or amount of time spent in the hatchery environment. These behavioural differences are expected to increase the vulnerability of hatchery‐reared abalone to predators, and are likely a major cause of their elevated predator‐induced mortality when outplanted. 相似文献
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Does the wild‐caught Chinese mitten crab megalopae perform better than the hatchery‐produced seed during the juvenile culture? 下载免费PDF全文
下载免费PDF全文 Xugan Wu Jie He Xiaodong Jiang Qing Liu Feng Gao Yongxu Cheng 《Aquaculture Research》2018,49(5):2042-2050
Although wild Yangtze Eriocheir sinensis juveniles (coin‐sized seed) have better culture performance than the pond‐reared juveniles during the adult crab culture stage, the culture performance of wild‐caught megalopae (WC) remains unknown. Therefore, this study was designed to compare the growth, survival rate, crab yield, feed conversion rate (FCR), precocity, final weight and size distribution between WC and hatchery‐produced megalopae (HP) during the juvenile culture stage. Wild‐caught megalopae had significantly higher body weight, weight gain rate (WGR) and specific growth rate (SGR) during 0–4 weeks but lower WGR and SGR than HP during 4–8 weeks (p < .05). Although WC had a significantly lower survival rate and yield of normal juvenile crabs than HP, total yields of normal juveniles and precocious crabs were similar. Wild‐caught megalopae had a significantly higher precocious rate and yield of precocious crabs than HP (p < .05). Regardless of sex, no significant differences were found in the gonadosomatic index (GSI), hepatosomatic index (HSI) and final weight of normal juveniles and precocious crabs between WC and HP. As for the size distribution of normal crabs, WC had a higher percentage of small female juveniles (<3 g) but a lower proportion of middle size ranges (3–5.99 g and 6–8.99 g) than HP for females (p < .05), and there was no significant difference for males. In conclusion, wild megalopae of the Yangtze E. sinensis had worse culture performance than the hatchery‐produced seeds; therefore, wild megalopae would not be recommended for commercially juvenile culture of E. sinensis. 相似文献
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Ruilong Wang Yun Gao Lihong Zhang Yike Zhang Zhanqiang Fang Jianguo He Weimin Zhang Guangzhi Ma 《Fish physiology and biochemistry》2010,36(2):157-164
Vitellogenins (Vtgs), the precursors for the yolk proteins, are very important for the embryonic development of teleosts,
and have also been studied extensively as biomarkers for environmental estrogenic mimics. The cDNA for a Vtg was isolated
from the liver of the female white cloud mountain minnow (Tanichthys albonubes) by 3′- and 5′-RACE methods. It is 4,171 bp in full length, and encodes a putative protein of 1,326 amino acids. This putative
Vtg, designated as wcmmVtg, contains complete portions of LVI and PV, but lacks the C-terminal half of LVII and thus belongs
to type I vitellogenin. In addition to the liver of the female fish, wcmmVtg was also shown to be expressed in the ovary.
During ovarian development, the mRNA expression of wcmmVtg in both the liver and ovary was continuously increased from the
previtellogenic to late vitellogenic stages, but then decreased significantly at post-spawning stage. In the male fish, expression
of wcmmVtg mRNA was induced in the liver by treatment with E2 (10 and 100 ng/l) for 14 days. These results suggest that the Vtg originated from the ovary of the white cloud mountain minnow
may also contribute to the accumulation of yolk proteins during oocyte growth, and that the male white cloud mountain minnow
is sensitive to the estrogenic treatment in terms of Vtg mRNA expression, which could also be applied to monitor the environmental
estrogenic mimics. 相似文献
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D. V. Garina V. A. Nepomnyashchikh A. A. Mekhtiev 《Fish physiology and biochemistry》2016,42(4):1137-1141
Serotonin-modulating anticonsolidation protein (SMAP) can impair the formation of memory traces in mammals and fish. We have studied the influence of SMAP on behavioral lateralization of juvenile carps Cyprinus carpio in a T-maze without food reinforcement in three experimental groups (n = 8 each): (1) negative control (intact animals); (2) experimental group (fish injected ICV with SMAP; 2 μl, 1.2 mg ml?1) and (3) active control group (fish injected ICV with inactivated SMAP). The behavioral lateralization of carps was observed on the 1st, 2nd, 3rd and 6th days after the injections. In each observation session, a fish was placed five times in a start chamber of the T-maze. The direction of the turn upon leaving the start chamber, as well as the latency from the opening of start chamber flap to the fish’s turn was registered. The number of right turns (of all five turns observed during the session) was a criterion of lateralization. It was found that carps have no inherent preference for turning left or right. The SMAP injection did not influence the choice of turning direction, but increases latency values insignificantly. The results are important for the correct interpretation and clarification of data reporting the role of SMAP in training and formation of spatial memory of fish in a maze. 相似文献
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F. Chu-Koo R. Dugué M. Alván Aguilar A. Casanova Daza F. Alcántara Bocanegra C. Chávez Veintemilla F. Duponchelle J.-F. Renno Salvador Tello J. Nuñez 《Fish physiology and biochemistry》2009,35(1):125-136
Arapaima gigas is an air-breathing giant fish of Amazonian rivers. Given its great economic and cultural importance, the aquaculture development
of this species represents an evident solution to face the decline of wild populations. In captivity, reproduction occurs
generally in large earthen ponds where stocks of a few tens of brooders are maintained together at the beginning of the rainy
season (December–March in the Peruvian Amazon). Fry production relies on the spontaneous formation of male and female pairs,
which build a nest, delimit a territory and guard the offspring for at least 20 days from other congeners and predators. However,
as sex determination of A. gigas is not possible by morphological criteria, it is very difficult to optimize reproduction conditions and fry production in
each pond, which seriously hampers the culture of this species. This situation prompted us to develop sexing methodologies
based on (1) the detection of female specific plasma Vitellogenin (Vtg) using an enzyme immuno assay (EIA), and (2) the determination
of plasma 17β-estradiol and 11-ketotestosterone levels for immature specimens. The Vtg purification was performed by electro-elution
after polyacrilamide gel electrophoresis (PAGE) from plasma of 17β-estradiol treated A. gigas juveniles. Two different Vtg molecules were isolated, (Vtg1 and Vtg2) with 184 and 112 kDa apparent molecular masses, respectively, and two antibodies were raised in rabbits for each Vtg molecule.
Adult fish were 100% accurately sexed by Vtg EIA, while 100% of immature fish and 95% of adults were accurately sexed by 17β-Estradiol
and 11-Ketestosterone ratios. We also observed different color pattern development in male and female adult fish (6-year-olds)
around the reproductive period. 相似文献
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Masashi Sekino 《Fisheries Science》2009,75(4):819-831
A cornerstone in conserving wildlife is to resolve taxonomic uncertainties over organisms so that conservationists can define
the entity that should be conserved. This is the case for two closely related Crassostrea oysters inhabiting the Ariake Sea (Kyushu, Japan) in sympatry, the kumamoto oyster C. sikamea and Pacific oyster C. gigas, where molecular markers have shed light on their taxonomic separation and species diagnosis. In the past, there was a concern
that Kumamoto oysters may be at risk of extinction. However, several field surveys equipped with species-diagnosis molecular
markers have provided solid evidence that this perception is incorrect. Nevertheless, previous studies have sometimes given
conflicting results, throwing us into confusion about the resource status. Research on natural Kumamoto oysters that the author
hopes could help to enhance our understanding of the conservation of this invaluable oyster is reviewed here.
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| Masashi SekinoEmail: |
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Arun M. Chilke 《Fish physiology and biochemistry》2010,36(4):1145-1149
Liver is the metabolic factory and contains several valuable enzymes that catalyze biochemical reactions. β-glucuronidase is one of the well-known lysozymes that participates in the carbohydrate metabolism in the tissues of various vertebrates. In the present study, an attempt was made to study the kinetic properties of hepatic β-glucuronidase of the Indian major carp (IMC), Labeo rohita. It was observed that the enzyme activity increased largely at pH 5 (0.1 M acetate buffer) when exposed to 38°C. However, the maximum activity was noticed at 52°C and later it started declined up to 70°C. It was also observed that with time the enzyme activity increased until substrate was completely used up. It has been concluded that it is a heat stable enzyme and cannot be destroyed at room temperature. Enzyme activity was observed to increase in response to increase in enzyme and substrate concentrations. The reaction velocity maxima (Vmax) and Michaelis constant (Km) were recorded using Lineweaver–Burk plot that was 18.182 μg/h and 2.907 mM, respectively. 相似文献
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Natascha Wosnick Hugo Bornatowski Carolina Ferraz André Afonso Bianca Sousa Rangel Fábio Hissa Vieira Hazin Carolina Arruda Freire 《Fish physiology and biochemistry》2017,43(1):165-178
Sharks are very sensitive to stress and prone to a high mortality rate after capture. Since approximately 50 million of sharks are caught as bycatch every year, and current recommendations to reduce the impact of commercial fishing strongly support immediate release, it is imperative to better understand post-release mortality caused by the stress of capture and handling. Blood samples allow the assessment of stress levels which are valuable tools to reduce mortality in commercial, recreational and scientific fishing, being essential for the improvement in those conservation measures. Biochemical analyses are widely used for sharks as stress indicators, with secondary plasma parameters (lactate, glucose and ions) being the most often employed assays. However, it is virtually impossible to determine baseline plasma parameters in free-ranging sharks, since blood withdrawal involves animal capture and restrain, which are stressful procedures. This study aims at analyzing secondary parameters of five healthy tiger sharks captured with circular hooks and handlines in Fernando de Noronha (Northeastern Brazil) and comparing them with secondary parameters of three dead tiger sharks caught off Recife (also Northeastern Brazil). The results showed that the analysis of some plasma constituents in dead animals may be an efficient tool to assess stress and lethality. However, traditional parameters such as glucose and calcium, need to be used with caution. The results also demonstrated the extreme importance of urea and phosphorus for assessing stress response and mortality in tiger sharks, both parameters frequently neglected and of utmost importance for shark’s homeostasis. 相似文献
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Misako Urabe Kentaro Nakai Daigo Nakamura Masaharu Tanaka Toshio Nakatsugawa Kazuo Ogawa 《Fisheries Science》2009,75(1):63-70
An introduced pathogenic fish trematode, Parabucephalopsis parasiluri Wang, 1985 (Digenea: Bucephalidae), was studied to determine the seasonal fluctuation in its metacercariae abundance. The
timing of the recruitment period of the metacercariae and the relationship between yearly fluctuation in metacercarial abundance
and some environmental factors were also examined to develop an effective plan for disease control. Monthly changes in metacercarial
abundance in the caudal fin of pale chub (Zacco platypus) and of the prevalence of the first intermediate host (golden mussel Limnoperna fortunei) suggest that P. parasiluri generally has an annual life cycle. The metacercarial abundance in chub increased when the water temperature fell below 7°C
in winter, but the rapidity of the increase varied between 2007 and 2008. The fluctuations in the abundance of metacercariae
in winter from 2001 to 2008 showed that mean flow rate and mean water level in January were negatively related to the infection
level each year, and positively related to the mean water temperature. Based on these results, we propose a control plan for
parabucephalopsiosis involving discharge control; that is, more than 50 m3/s (corresponding to 150 m3/s in the Yodo River) of water should be flushed from upstream dams for a period of at least one week starting on the day
when the water temperature falls below 7°C. 相似文献