摘要:

Substrata, plating densities and tissue culture media were compared for their effects on the proliferation and differentiation of myoblasts from skeletal muscle of rainbow trout. Mononuclear cells were isolated from the lateralis muscle of 4–11‐month‐old trout and plated on to glass coverslips coated with fibronectin, laminin or Matrigel. Cell proliferation was estimated by determining the density of nuclei on successive days in culture, and myoblast differentiation was detected by immunostaining cultures with the myosin‐specific monoclonal antibody MF20. Mononuclear cell proliferation was highest for cells cultured on fibronectin or laminin and lowest for cells cultured on Matrigel, but the total number of nuclei in myosin‐positive cells did not differ between substrata. The percentage of nuclei in myosin‐positive myocytes and myotubes was significantly higher for cells cultured on Matrigel. The proportion of cells adhering to Matrigel and undergoing differentiation increased with plating density. Of three media tested, Dulbecco's Modified Eagle Medium (DMEM), RPMI 1640 (RPMI), Leibovitz's L‐15 (L‐15) supplemented with 1 or 10% fetal bovine serum (FBS), a significantly greater proportion of the myoblasts differentiated when cells were cultured in L‐15+ 10% FBS. These results suggest that culturing trout muscle‐derived cells on a substratum of Matrigel at a high density and maintaining cells in L‐15+ 10% FBS provide the conditions that maximize the proportion of cells that actively synthesize muscle myosin and facilitate trout myoblast di

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1995.tb01597.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Lysozyme activity, haemolytic activity, total level of IgM, and levels of antibodies against A‐layer fromAeromonas salmonicidaand O‐antigen fromVibrio salmonicida, respectively, were determined in 77 full‐sib groups of Atlantic salmon in order to evaluate their possible use as immune parameters for indirect selection to improve disease resistance. Fish from parallel full‐sib groups had previously been challenged withAeromonas salmonicida(causing furunculosis),Renibacterium salmoninarum(causing bacterial kidney disease, BKD) andVibrio salmonicida(causing cold‐water vibriosis). Heritabilities were estimated for each of the immune parameters and correlations between the least square means of the full‐sib groups for the different immune parameters and survival rates in the parallel full‐sib groups were determined. A significant genetic variation in lysozyme activity was found, as well as an apparent genetic association between low lysozyme activity and high survival rates. Low heritabilities and low univariate correlations with survival in the full‐sib groups were estimated for all of the other immune parameters. An analysis of the multivariate associations between the full‐sib mean values of the complete set of immune parameters, and survival rates in the parallel full‐sib groups in each of the challenge tests, revealed that, at low levels of lysozyme activity and with low antibody titres againstV. salmonicidaO‐antigen, increased IgM levels seemed to increase survi

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1995.tb01598.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Laboratory feeding trials were conducted to determine how light intensity affects foraging success by the visual piscivore, the largemouth bass (Micropterus salmoides). Foraging success was greater than 95% at light levels ranging from low intensity daylight (2.43 × 102lx) to moonlight (3 × 10−3lx), but declined significantly to 62% at starlight (2 × 10−4lx) and near 0% in total darkness. Over a range of low to high water clarities (0.5, 2.0, and 4.0 m Secchi depth), estimated depth limits for feeding during the day ranged between 5.5 to 44 m and from 1.6 to 13 m at night during a full moon. At starlight, light intensity rapidly attenuated to a level below the feeding threshold within 0.5 m of the surface at all water clarities. The depth of the water column available for feeding in low clarity water (0.5 m Secchi) was 67 and 75% less than at moderate (2.0 m Secchi) and high (4.0 m Secchi) water clarities. The findings illustrate how differences in the light environment can have important ramifications for predator‐prey inte

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1995.tb01599.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

It is demonstrated that the rheophilic fish dace (Leuciscus leuciscus) is able to detect the direction of its movements in a water flow by perceiving and analysing positive and negative accelerations from 15 up to 50 cm s−2, by the use of labyrinth organs. Tests were conducted on fish with ‘switched off’ mechanoreceptors and labyrinth organs, under conditions which eliminated the use of visual orientation. It was also demonstrated that the values of linear accelerations which stimulated dace compensatory movements against water currents were comparable with the values of accelerations which could arise in river flows as a result of pulsation in current velocity. The results support the hypothesis that rheophilic fish are able to use inertial stimuli for their spatial orient

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1995.tb01600.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Haematological and haemorheological responses against a moderate management stress, applied for 2 weeks, have been studied in the gilthead seabream (Sparus aurata). The stress application leads to a significant reduction in circulating erythrocytes, which caused decreased blood viscosity. Although erythrocyte osmotic fragility showed a trend inversely related to the duration of management stress, no significant change in cell dimensions, aggregation and deformation indices was observed. Consequently, the decrease in oxygen transport capacity attributable to haematocrit reduction, is not compensated by a qualitative change in the microrheological behaviour of erythrocytes, since the blood viscosity decreases as a direct result of the decline in red blood cell number.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1995.tb01601.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

The objectives of this work were (1) to assess the influence of zooplankton biomass on activity and consumption rates of young‐of‐the‐year brook trout (Salvelinus fontinalis) and (2) to validate anin situenclosure approach to quantify energy allocation patterns in fish. These objectives were attained by directly estimating fish growth, consumption and activity rates on 10 occasions characterized by different levels of zooplankton biomass (0.005 to 0.100 mg dry weight 1−1). One enclosure was used to estimate growth and activity rates and five additional enclosures were used to estimate consumption rates. Among‐experiment variations of activity rates (sum for five trout = 2.4 to 33.5 calories day−1) were proportionally more important than variations of consumption rates (sum for five trout = 59.5 to 112.7 calories day−1). The results support the existence of a significant positive relationship between fish activity rates and zooplankton biomass. No significant relationship was found between consumption rates and prey biomass. Final size of fish inside the enclosure was within 7.6% of the value estimated using experimentally derived activity and consumption rates. This situation, together with the stability of among‐enclosure activity and feeding schedules, suggested that the experimental design was appropriate to estimate fish energy allocation patterns. Combination of our observations with those of a previously published work indicated that small variations of fish size or zooplankton biomass can cause a two‐fold variation of fi

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1995.tb01602.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Surgically implanted activity‐circuit radio transmitters (40 MHz) were used to study the seasonal activities of 21 adult (males: 23 to 35 cmf.l.and females 38 to 55 cmf.l.)Barbus barbus(Pisces, Cyprinidae) in the River Ourthe (Southern Belgium) in 1989–1991. During the autumnal thermal transition (water temperature 9 to 10° C), the typical dusk and dawn pattern observed in summer turned to a trimodal pattern with the emergence of a diurnal phase. The auroral then crepuscular and finally diurnal activity periods progressively vanished as water temperature decreased down to the thermal limit for activity (4.0° C), when barbel entered a dormancy period. An opposite progressive shift was observed during the spring thermal transition. Daily activity budgets ranged from 0 to 720 min—on the annual cycle and were significantly (r2=0.686,P<0.05, d.f. = 36) dependent on water temperature and on morphodynamic unit size, while fish size was non‐significant. Although the dusk and dawn rhythm pattern was consistent throughout summer, water temperature significantly (P<0.05) interfered with the respective duration of crepuscular and auroral activities (r2=0.586, d.f. = 57 andr2=0.692, d.f. = 55). The precise timing of activities was also thermal‐related and the activities of small male barbel were proportionally more nocturnal than those of large female barbel (ANCOVA,F=80.61, d.f. = 31 andF=4.s5, d.f. = 23, at dusk and dawn respectively), possibly due to predation pressure on small fish. It is concluded that the seasonal variations of activity budgets, rhythm patterns and timings inB. barbuscorrespond to a form of time‐budgeting partly to achieve thermal homeostasis in a variabl

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1995.tb01603.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Seven published extenders, three thawing media and two thawing temperatures were tested in order to determine their suitability for cryopreservation of northern pike (Esox luciusL.) sperm. Sperm motility during successive steps of cryopreservation was evaluated. Erdahl and Graham's extender with the addition of egg yolk proved to be the most efficient (maximum hatching rate of 74.5%) when semen was thawed in 120 mmNaCl solution warmed up to 30° C. No correlations between motility of sperm (diluted in extenders or diluted in extenders and then activated with thawing solution) and the subsequent hatching success were observed. The relationship between motility of thawed sperm and its fertilization ability was considerable, but correlation was not significant. Spermatozoa frozen in some extenders were frequently motile after thawing but they were not able to fertilize the eggs, this resulted in a poor hatching rate. Depending on the extender, the addition of yolk induced either positive or detrimental effects on fertilization success

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1995.tb01604.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Rates of oxygen consumption were measured in the geothermal, hot spring fish,Oreochromis alcalicus grahamiby stopped flow respirometry. At 37° C, routine oxygen consumption followed the allometric relationship:Vo2=0.738M0.75, whereVo2is ml O2h−1andMis body mass (g). This represents a routine metabolic rate for a 10 g fish at 37° C of 0.415 ml O2g−1h−1(16.4 μmol O2g−1h−1). Acutely increasing the temperature from 37 to 42° C significantly elevated the rate of O2consumption from 0.739 to 0.970 ml O2g−1h−1(Q10=l.72). In the field,O. a. grahamiwas observed to be ‘gulping’ air from the surface of the water especially in hot springs that exceeded 40° C.O. a. grahamimay utilize aerial respiration when O

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1995.tb01605.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

The quantitative electron transport system (ETS)‐assay based on tetrazolium reduction has been adapted for determining the terminal ETS activity during embryonic development of the subtropical teleost fishOryzias latipes, medaka. Homogenization with a glass potter for 1–2 min was required for the complete extraction of the ETS. Additional sonication and centrifugation had a degradatory effect on the ETS activity. The main substrate of the ETS of fish embryos was NADH. NADPH also donated electrons for the ETS but with much less intensity. The impacts of the NADH and the NADPH on the enzyme activity was not additive. Succinate was ineffective as a substrate for the ETS. NADH (1.7 mM) and NADPH (0.25 mM) in combination with 0.8 mM of the artificial electron acceptor, 2‐(p‐iodophenyl)‐3‐(p‐nitrophenyl)‐5‐phenyl tetrazolium chloride (INT), ensured aVmaxfor the ETS if the reaction mixture contained 400 μg wet weight egg ml−1of cell‐free homogenate. The pH‐optimum of the ETS was between pH 8.0 and 8.6. The enzyme reaction at 24°C was linear during 40 min incubation. The ETS activity increased exponentially during embryonic development. The assay could be a useful tool for detecting the effect of pollutants on the development of the respiratory enzyme system in

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1995.tb01606.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY