共查询到20条相似文献，搜索用时 31 毫秒
1.
2.
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
3.
4.
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
5.
6.
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
7.
There is considerable interest in understanding the effect of the North Atlantic Oscillation (NAO) on recruitment to North Atlantic cod stocks. An earlier analysis of data for the North‐east Arctic cod stock showed that, while there is an empirical relationship between recruitment and the NAO over the period 1973–96, this relationship was absent over the period 1946–72. It has recently been suggested that the effect of the NAO on recruitment depends on the size of the spawning stock. Here, the possibility that this explains the earlier result for North‐east Arctic cod is tested and rejected. 相似文献
8.
Amano Masafumi Kubota Hisanori Kaneda Hideko Aoki Daisuke Yamamori Kunio 《Fisheries Science》2022,88(1):75-81
To clarify the mechanism of tetrodotoxin (TTX) accumulation in pufferfish, we compared the toxicity of two sets of wild juvenile “komonfugu” Takifugu flavipterus. The first set was sampled from Onisawa Fishing Port (FP) located in Okirai Bay, the Pacific Coast of Sanriku, Tohoku Area, Northern Japan. The second set was collected from the Onisawa FP and reared in an outdoor laboratory tank supplied with different seawater (Yoshihama Bay). The fish were sampled regularly and on the same days. The amount of TTX (mouse unit (MU)/fish) in the fish at Onisawa FP increased until 20 days and thereafter it did not change, while the amount of TTX in the fish in the laboratory tank remained low, and the TTX concentration (MU/g fish) decreased. Next, we compared the toxicity of wild juvenile T. flavipterus collected from Okirai Bay (Onisawa FP and Okirai FP) and Yoshihama Bay (Yoshihama FP). Large differences in TTX levels were observed among the fish from the three FPs. The amounts and concentrations of TTX in the fish at Onisawa FP were higher than those in the fish from the other two FPs. These results indicate that a large variation in toxic activity exists in the juvenile T. flavipterus in the bay of the Sanriku Coast.
相似文献9.
Yisheng Huang Xiaobo Wen Shengkang Li Wenjia Li Dashi Zhu 《Aquaculture International》2016,24(5):1229-1245
The present study aimed at determining the growth performance, feed utilization, body composition and antioxidant status of chu’s croaker (Nibea coibor) juveniles fed with increasing levels of dietary lipid: 6 % (D6), 9 % (D9), 12 % (D12) and 15 % (D15). Each diet was assigned to triplicate groups of fish in a total of 12 floating pens (300 fish, 25 fish per pen). After a 49-day growth trial, survival rate was not affected. D12 and D15 led to significantly higher specific growth rate (SGR). Fish fed D12 showed the highest protein efficiency ratio (PER), protein and lipid retention efficiencies (PER and LRE, respectively). The hepatosomatic and viscerosomatic indexes (HIS and VSI, respectively) increased, while feed conversion ratio (FCR) and feed intake (FI) decreased. Body protein, ash and muscle lipid contents were not significantly affected, but significantly higher body and liver lipid were noticed in fish fed with D15. Monounsaturated fatty acid (MUFA) was found to decrease compared to the experimental diets in muscle, while high unsaturated fatty acid (HUFA) was selectively accumulated in all treatments. Serum alanine transaminase (ALT, 14.13–22.53 U/L), aspartate transaminase (AST, 34.31–51.25 U/L), cholesterol (CHO, 2.02–3.03 mmol/L) and triglyceride (TG, 5.61–8.50 mmol/L) were correlated with increasing dietary lipids. Liver malate dehydrogenase (MDA, 3.32–6.67 mmol/L) and superoxide dismutase (SOD, 42.69–52.86 U/mg prot) increased with dietary lipids, while total antioxidant capacity (t-AOC, 1.08–3.50 U/mg prot) decreased. Polynomial regression analyses between SGR and dietary lipid levels showed that the optimal dietary lipid requirement of chu’s croaker is 12.9 % of dry matter. 相似文献
10.
The blue mussel, Mytilus edulis has been reared along the Normandy coast line since the 1960s. The gonadal cycle of this mussel species shows a sharp decrease in meat quality during the winter period after spawning. This decline in meat quality is so severe that sales have to be suspended from December to July. Another species of mussel, Mytilus galloprovincialis, which is reared in the lagoons along the French shore of the Mediterranean Sea has a different spawning cycle. An experiment was undertaken to study the meat quality of M. Galloprovincialis throughout the year after the spat were transferred from the Mediterranean Sea to the Normandy coast. This species showed an immediate adaptation to the gonadal cycle of M. edulis. Despite suggestions from researchers, no interest was expressed to consider such transfers of M. galloprovincialis in the future. 相似文献
11.
Paiboon Panase Bunyanuch Kamee Sakditad Moungmor Prameda Tipdacho Jaturong Matidtor Nantaporn Sutthi 《Fisheries Science》2018,84(6):1025-1036
This study was conducted to evaluate the effects of Euphorbia hirta leaf extract on the growth performance, hematological and organosomatic indices of hybrid catfish, Clarias macrocephalus?×?C. gariepinus. The fish were treated with 0 (control), 300, 500 and 800 mg/kg (ppm) for 90 days. The weight gain, average daily growth rate, and specific growth rate were at significantly higher levels in fish from all the treatment groups on days 75 and 90, while the feed efficiency and protein efficiency ratio were consistently higher in fish from all the treatment groups from day 60 up until day 90. The feed conversion rate significantly decreased from day 60 until day 90 in all treatment groups when compared with the control group, and the survival rate was significantly different from day 30 until day 90; a consistently higher rate was observed in fish fed 800 mg/kg. The highest viscerosomatic index and intraperitoneal fat were observed in the group fed 500 mg/kg (p?<?0.05). The hepatosomatic index was significantly increased alongside increasing levels of E. hirta extract. The total white blood cell count in the control group was significantly higher on day 30, but on day 90 all the treatment groups showed higher levels. Hematocrit percentage was significantly different on days 30 and 90. Lymphocyte, eosinophil and thrombocyte levels were shown to be significantly different (p?<?0.05) when different groups of fish were compared. In conclusion, 300 mg/kg of E. hirta leaf extract could improve growth performance, hematological and some organosomatic indices in hybrid catfish. 相似文献
12.
1. Long‐term data sets on macro‐algae, sediment invertebrates, shorebirds and physical parameters are explored for the Ythan estuary, Scotland. 2. Coverage by macro‐algal mats has increased over the last 40 years with significant impacts on the distribution and abundance of benthic invertebrates and their shorebird consumers. Areas of the estuary worst affected by the mats now support fewer Corophium volutator, whilst the abundance of this and other species has increased in areas less affected by mats, possibly through enrichment by non‐local macro‐algal detritus. 3. Shorebird abundance increased between the early 1960s and the 1980s, possibly in response to enhanced invertebrate abundance in unaffected areas, but has declined since, as algal mats continue to spread. 4. The cause of the increased biomass of macro‐algae is contentious, but the present analysis shows that the increase is unlikely to be related to changes in the physical characteristics of the estuary, which appear to have remained fairly constant over at least the last 30 years. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
13.
14.
Junming Deng Kun Wang Kangsen Mai Liqiao Chen Lu Zhang Haifeng Mi 《Fish physiology and biochemistry》2017,43(4):941-954
A feeding trial was conducted to evaluate the effects of replacing fish meal with rubber seed meal (RSM) on growth, nutrient utilization, and cholesterol metabolism of tilapia (Oreochromis niloticus × Oreochromis aureus). Five experimental diets were formulated with 0, 150, 300, 450, and 600 g kg?1 RSM replacing graded levels of fish meal, respectively. Each diet was randomly assigned to triplicate groups of 25 fish (initial average weight 65.3 g) per aquarium in a rearing system maintained at 29 ± 1 °C for 8 weeks. Dietary 150 g kg?1 RSM inclusion did not affect the weight gain and daily growth coefficient, whereas these were depressed by a further inclusion. Additionally, feed efficiency ratio and protein efficiency ratio were not affected by dietary RSM inclusion regardless of inclusion level. However, the inclusion of 450 and 600 g kg?1 RSM decreased the mid-intestinal trypsin, lipase, and amylase activities; the hepatic acyl-CoA/cholesterol acyl transferase; low-density lipoprotein receptor; and 3-hydroxy-3-methyl-glutaryl-CoA reductase activities. Similarly, dietary 600 g kg?1 RSM inclusion inhibited the plasma catalase and hepatic glutathione peroxidase activities. These results indicated that 150 g kg?1 RSM can be included in tilapia diets, whereas higher inclusion of RSM inhibited the growth rate, digestive enzyme activity, antioxidant capacity, and cholesterol metabolism. 相似文献
15.
16.
Isao Tsutsui Poonmanee Kanjanaworakul Prapansak Srisapoome Dusit Aue-umneoy Kaoru Hamano 《Aquaculture International》2010,18(4):545-553
Growth of juvenile giant tiger prawn, Penaeus monodon Fabricius, was evaluated at an aquarium-scale in co-culture with a discarded filamentous seaweed, Chaetomorpha ligustica (Kützing) Kützing. Juveniles at different ages in days were examined, designated as J 16, J 44, J 58, J 93 and J 128, where
a 1-day-old juvenile (J 1) is equivalent to a 20-day-old post-larva (PL 20)). Juveniles at every age group grazed directly
on live C. ligustica, even those fed an artificial shrimp diet to satiation. Mean specific growth rate (SGR: % day−1) was higher in early age juveniles. Compared to mono-culture, significant differences in growth were observed at J 16 (4.44% day−1) and J 44 (1.60% day−1); however, no significant differences were recorded at J 58 (1.16% day−1), J 93 (0.75% day−1) or J 128 (0.45% day−1). It was concluded that co-culture of giant tiger prawn with C. ligustica has a dietary advantage, especially in early age juveniles. 相似文献
17.
18.
The use of biomarkers as early-warning signals to assess the impact of pollutants and other environmental stressors in coastal
habitats has been internationally recognized as a useful tool in marine coastal monitoring. We propose a similar approach
to verify the welfare of edible shellfish, Ruditapes philippinarum, thus exploiting its possible application as an effective tool to verify the origin of fishing/aquaculture products. A selected
battery of biomarkers was chosen and applied to organisms from two different habitats in the Lagoon of Venice (a farming site
and a natural area where fishing is currently banned, because of pollution problems) and from a local market. Biological responses
were evaluated physiologically (survival in air test and condition index), behaviourally (reburrowing rate), and histochemically
(quantification of neutral lipids and lipofuscin). Micropollutants (heavy metals, PCBs, and PAHs) were also determined in
the soft tissues. Results indicated clams from the farming site were in the best condition with regard to both chemical and
biological measurements. In contrast, the market sample contained the highest concentrations of PAHs. PCBs and heavy metals
varied slightly and quite irregularly among the three samples. The worst values of the biomarkers were observed for clams
collected at the polluted site, where, in particular, the lowest physiological and behavioural indexes and the highest accumulation
of lipofuscin in the digestive tissue were recorded. 相似文献
19.
Srijaya Thekkeparambil Chandrabose Pradeep Padmaja Jayaprasad Hassan Anuar Chatterji Anil Shaharom Faizah Jeffs Andrew 《International Aquatic Research》2014,6(1):1-13
A set of feeding trials was carried out for different microalgal species and processed diets for the culture of the New Zealand pipi, Paphies australis. Five microalgal species (Isochrysis galbana clone T-ISO, Pavlova lutheri, Tetraselmis suecica, Chaetoceros muelleri, and Thalassiora pseudonana clone 3H) and three formulated diets (baker's yeast, wheat flour, and corn flour) were fed to spat, juvenile, and adult pipi for 21 days. Unfed pipi were used in the control group. The spat and juvenile pipi showed a major shell increase with I. galbana while the greatest wet weight increase was obtained with P. lutheri. The shells of adult pipi grew better with corn flour, and the P. lutheri-fed group obtained the greatest wet weight. Results of proximate analysis in adult pipi revealed that proteins and lipids were accumulated in the tissue for all fed groups, while carbohydrate levels were depleted in all treatments including the control group. It is suggested that the gonads have developed during the experiment. 相似文献
20.
Rhoda Mae C. Simora Shangjia Li Nermeen Y. Abass Jeffery S. Terhune Rex A. Dunham 《Journal of fish diseases》2020,43(12):1553-1562
Cathelicidins are a class of antimicrobial peptides (AMPs) known to possess rapid and direct antimicrobial activities against a variety of microorganisms. Recently identified cathelicidins derived from alligator and sea snake were found to be more effective in inhibiting microbial growth than other AMPs previously characterized. The ability of these two cathelicidins along with the peptides, cecropin and pleurocidin, to protect channel catfish (Ictalurus punctatus, Rafinesque) and hybrid catfish (I. punctatus ♀ × blue catfish, Ictalurus furcatus, Valenciennes ♂) against Edwardsiella ictaluri, one of the most prevalent pathogens affecting commercial catfish industry, was investigated. Cathelicidin-injected fish (50 µg ml−1 fish−1) that were simultaneously challenged with E. ictaluri through bath immersion at a concentration of ~1 × 106 CFU/ml had increased survival rates compared with other peptide treatments and the infected control. Bacterial numbers were also reduced in the liver and kidney of channel catfish and hybrid catfish in the cathelicidin treatments 24 hr post-infection. After 8 days of challenge, serum was collected to determine immune-related parameters such as bactericidal activity, lysozyme, serum protein, albumin and globulin. These immune-related parameters were significantly elevated in fish injected with the two cathelicidins as compared to other peptide treatments. These results indicate that cathelicidins derived from alligator and sea snake can stimulate immunity and enhance the resistance to E. ictaluri infection in channel catfish and hybrid catfish. 相似文献