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31.
Commercially exploited tench, Tinca tinca, (L.) populations in 480 lakes in the northeastern Poland were analyzed on the basis of the fishery data from 1949 to 1994.
The long-term changes in tench catch were studied in four categories of lakes with respective proportions of littoral zones
(<30, 31–60, 61–90 and <90% of total lake area). The analyses were performed with using relative catch (kg ha−1 month−1) of tench. Mean relative catch of tench for 1949–1994 ranged from 0.36 kg ha−1 month−1 in lakes with smallest littoral zone (>30%) to 0.93 kg ha−1 month−1 in lakes with the largest littoral (<90%). Mean relative catch increased with increasing proportions of littoral zones in
lakes. However, long-term trends in mean relative catch of tench showed decreasing tendencies in all lakes. The beginning
of these tendencies was found about ten years earlier in lakes with smaller littoral (<60%) in comparison to lakes with larger
littoral zones (>60%). Mean stocking rates of tench (number of 1-year-old fish per ha of littoral) for 1949–1994 were not
significantly different in lakes of studied categories. However, lakes with proportionally less littoral zone had reduced
stocking efficiency estimated as number of stocked fish per ha of littoral to require 1 kg ha−1 month−1 of tench. 相似文献
32.
Evaluation of poultry by‐product meal as partial replacement of fish meal in practical diets for juvenile tench (Tinca tinca L.) 
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下载免费PDF全文 Álvaro González‐Rodríguez Jesús D Celada José M Carral María Sáez‐Royuela Vanesa García Juan B Fuertes 《Aquaculture Research》2016,47(5):1612-1621
The aim of this study was to evaluate different replacement levels of fish meal (FM) by poultry by‐product meal (PBM) on survival, growth performance and body composition of juvenile tench (Tinca tinca). A 90‐day experiment was conducted with 5 month‐old juveniles (31.95 mm total length, 0.396 g weight). Eight practical diets (50% crude protein) differing in the level of replacement of FM protein by PMB protein were tested: 0% (control), 25%, 31%, 37%, 43%, 49%, 55% and 61% corresponding to 0, 184.8, 229.2, 273.5, 317.8, 362.1, 406.5 or 450.8 g PBM kg?1 diet respectively. Significant differences were not found (P > 0.05) between 25% replacement of FM protein by PBM protein (184.8 g kg?1 PBM in diet) and control diet. At higher replacement levels, fish had significantly lower growth, higher feed conversion ratio and lower protein productive value (P < 0.05). Fish with externally visible deformities ranged from 1.1% to 3.3%. The relation among amino acid profiles of the diets, body composition, growth performance of juveniles and amino acid requirements of other fish species is discussed. Up to 184.8 g PBM kg?1 diet can be included in diets for juvenile tench without impairing growth performance. 相似文献
33.
中草药对丁鱥诱食效果的初步研究 总被引：8，自引：0，他引：8
对100尾平均体长为10．84cm、体重为22．8g的丁鱥进行了饲料诱食剂的初步研究。选用10种中草药（丁香、肉桂、八角、山萘、薄荷、黄连、黄柏、黄岑、枝子、胡椒）作为诱食剂,以2％的添加量分别加入到基础饵料中,用迷宫试验记录试验鱼进入诱鱼室和空白室的次数,以及试验鱼咬啄饵料球的次数,以分析不同中草药对丁鱥的诱食效果。试验期间水温为22-24℃。结果表明：丁香、薄荷、八角和黄连对丁鱥具较好的诱食效果（P〈0．05）。中草药的浓度不同,诱食效果也不同。其中：6％黄连、4％薄荷、2％八角对丁鱥的诱食效果最好;黄连与八角以1％的浓度添加在饲料中后对丁鱥的诱食效果最好。 相似文献
34.
Fertilizing capacity and motility of tench Tinca tinca (L., 1758) sperm following cryopreservation 下载免费PDF全文
下载免费PDF全文 Jelena Lujić Gergely Bernáth Zoran Marinović Nataša Radojković Vladica Simić Miroslav Ćirković Béla Urbányi Ákos Horváth 《Aquaculture Research》2017,48(1):102-110
Experiments were carried out to develop an optimal cryopreservation protocol for tench sperm by testing the fertilizing capacity and motility parameters including progressive motility, curvilinear velocity (VCL) and linearity (LIN) of cryopreserved sperm. Three experiments were designed to this aim: first experiment where we tested the effects of two extenders (sugar‐based Grayling and ion‐based Kurokura 180) and two cryoprotectants (DMSO and methanol) on fertilization and hatching success; second where we tested the effect of cryoprotectant type (methanol or DMSO) in different concentrations (5%, 10% and 15%) on fertilization and hatching success; and third where we tested the effect of two cryoprotectants (methanol and DMSO) on sperm motility parameters (progressive motility, VCL and LIN) after 4 h post‐thaw storage (4°C). Sperm prepared with the sugar‐based Grayling extender displayed better fertilization and hatching rates independently of the applied cryoprotectant most likely due to glucose present which acted as an external cryoprotectant. Concerning cryoprotectant concentrations, the use of 10% methanol yielded the highest fertilization (85 ± 15%) and hatching (80 ± 13%) rates, which were significantly higher than in all other groups. During the post‐thaw storage time, 5% methanol, 10% methanol and 5% DMSO groups had significantly higher motility parameters than other groups and we observed no significant decline in any of the parameters during the storage time. Overall, we found that a sugar‐based extender in combination with methanol as cryoprotectant is suitable for the cryopreservation of tench sperm and allows storage of cryopreserved sperm for up to 4 h post thaw. 相似文献
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36.
饥饿与温度对欧洲丁鱥幼鱼耗氧率的影响 总被引：1，自引：0，他引：1
用呼吸室法研究了不同饥饿时间及不同温度对欧洲丁（鱼岁）（Tinca tinca L）幼鱼（体重3．65～4．92g）耗氧率的影响。结果表明,随着饥饿时间的延长,欧洲丁（鱼岁）幼鱼的耗氧率呈下降趋势,饥饿前期的0d、3d、6d耗氧率下降差异显著（P〈0．05）,饥饿后期的9d、12d耗氧率下降变缓,差异不显著（P〉0．05）;其耗氧率呈昼夜节律性,自天平均耗氧率低于夜间平均耗氧率;在水温20℃、23℃、26℃和29℃时,欧洲丁（鱼岁）幼鱼的耗氧率与温度呈正相关,水温上升为32℃时,耗氧率出现下降。 相似文献
37.
运用统计分析方法研究了丁、川鲶个体的含肉率和可量性状之间的相关性。结果显示:1)丁的含肉率为64.04%,体长/体高的比值与丁的含肉率呈显著负相关性(Pearson系数分别为-0.783*,P0.05);体高/头长的比值分别与丁的含肉率显著正相关(Pearson系数分别为0.782*,P0.05)。2)川鲶的含肉率为68.47%,体重与川鲶的含肉率呈较高的负相关性(Pearson系数为-0.735,),其他指标相关性较低。结果表明,利用可量性状预测丁、川鲶的含肉率是可行的。 相似文献
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39.
Martin Flajshans Martin Kocour David Gela Veronika Piackova 《Aquaculture International》2004,12(1):103-118
Amphimictic diploid (2n), induced meiotic gynogenic (MeiG) and induced triploid (3n) siblings of tench, Tinca tinca L., were separately nursed, marked and kept in long-term communal testing in pond until sex maturation and natural spawning. Survival rates during the initial periods were lesser in 2n and 3n compared to MeiG population (65%). The first overwintering period showed decreased survival of 3n (62.67%) compared to MeiG (90.0%) and 2n populations (91.67%). Survival rates during the next seasons ranged in 70.50–90.97% similarly in both 3n and 2n while in MeiG population it dropped to 38%. Weight and length growth of all populations studied showed significantly higher growth of 3n females and of 3n in general, compared to 2n and MeiG populations (P < 0.001). Health examinations found metacercaria of Diplosthomus spathaceum in eyes of 2-year-old 3n specimens, weak polyparasitic infections of skin and gills by Dactylogyrus, Trichodina, Thrichophrya, Apiosoma and Chilodonella spp. in 3n and 2n specimens but medium strong to strong infections of 100% of MeiG fish which might contribute to their enhanced mortality. Ploidy analysis of progeny obtained from spontaneous spawning of the broodstock showed 100% diploidy, indicating the following possibilities: 2n population might spawn itself, 2n males might also mate to gynogens, or 3n males might also mate to 2n and/or MeiG females causing spontaneous gynogenesis. Further pedigree analyses will be focused to highlight these questions. 相似文献
40.
Various procedures for artificial insemination in tench, Tinca tinca (L.) were re-examined with evaluation of fecundity of males and females among different tench strains. The objectives of
this study were to enhance fertilization and hatching rates through optimization of the activation solution, the insemination
process, the activation of gametes, and the elimination of eggs stickiness. Sperm for all experiments was collected directly
into immobilization solution of modified Kurokura solution containing 180 mM of NaCl and stored at 2 °C for 2.5–5 h prior
to the experiment. When dechlorinated tap water was used for activation a gamete ratio of 1150 spermatozoa per egg showed
the best significant fertilisation and hatching rates. Optimal ratio between eggs (weight in g) and activation solution (in
cm3) was 1:1. Different concentrations of activation solutions such as NaCl from 0 to 68 mM (0–136 mOsmol kg−1) without buffer statistically decreased fertilization and hatching rates. The activation solution containing 17 mM of NaCl,
10 mM Tris–HCl, pH 8 and 9 significantly increased fertilization and hatching rates compared to dechlorinated tap water of
pH 7 or activation solution containing 17 mM of NaCl, 10 mM Tris–HCl, pH 6 and 7. Adhesiveness of the eggs was successfully
removed by incubation in Alcalase and activity: 3.16 Anson units per cm3. 相似文献