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991.
Todd David Sink Sathyanand Kumaran Rebecca T. Lochmann 《Fish physiology and biochemistry》2007,33(3):189-193
Baitfish such as golden shiners are subjected to stress during harvesting, grading, and transport. Their small size makes
it difficult to measure the stress response with the biological indicator cortisol using conventional assay methods for plasma.
This paper examines the development and validation of methods for whole-body cortisol extraction from individual baitfish.
Three types of extracts were tested: (1) an ethyl ether unaltered extract (UA); (2) an extract reconstituted in phosphate
buffered saline (PBS); (3) an extract that had been increased in volume by the addition of food-grade vegetable oil (VO).
These extracts were evaluated using validation tests with radioimmunoassays (RIA) and enzyme-linked immunosorbent assays (ELISA).
The UA extract produced inadequate volumes of extract for multiple assays and could not be used for the determination of cortisol
in a single fish. The PBS reconstitution method failed the precision recovery of serial dilutions (62.3%), linearity (R
2: 0.7864), and parallelism validation tests. The VO volume-boosting method passed all validation tests [intra-assay coefficent
of variation (%CV): 16.3 for ELISA and 5.9 for RIA; inter-assay %CV: 10.3; spiked recovery: 102.0%; dilution recovery: 93.0%;
linearity R
2: 0.9435; log of serial dilutions was parallel] and provided enough extract for multiple assays from an individual baitfish.
Based on these results, we conclude that the VO volume-boosting method presents a means for determining cortisol from individual
baitfish using either RIA or ELISA assays. 相似文献
992.
Increased abundances of a number of seabird species have been found in areas of mussel longline aquaculture (compared to control
sites) in a recent study at Bantry Bay, southwest Ireland. The aim of this study was to investigate whether this form of mussel
aquaculture also affects the activity budgets and foraging behaviour of these seabirds. Scan-sampling was used to compare
seabird activity budgets between three areas of mussel longline aquaculture and three control sites. Foraging activities of
Great-Northern Divers Gavia immer, an Annex 1 species under the Euopean Union's Birds Directive, were also compared between sites using focal sampling. The
behaviour of gulls (Larus sp.), Cormorants Phalacrocorax carbo, Shags Phalacrocorax aristotelis and Great-Northern Divers (but not auks, Alcidae) differed significantly between areas of mussel aquaculture and control
sites in this study. Mussel suspension buoys were heavily utilized by gulls, cormorants and shags as safe perching platforms
for preening activities. Gulls also fed extensively on epifauna attached to the buoys. Great-Northern Divers spent more time
snorkelling (head submerged in search of food) in mussel sites than in the control sites, however dive duration and visible
foraging success rates did not differ significantly between sites. Overall, the environmental impact of mussel suspension
culture appears to be positive or neutral on marine bird species occurring at this study site. 相似文献
993.
H. Qi X. P. Dong L. N. Cong Y. Gao L. Liu T. Mikiro B. W. Zhu 《Fish physiology and biochemistry》2007,33(2):181-188
The sea cucumber (Stichopus japonicus) is able to undergo autolysis in response to a variety of environmental and mechanical cues. Within the framework of a long-term
study of this phenomenon we have purified a protease from the body wall of the sea cucumber by means of ion-exchange chromatography
with DE-52 cellulose and gel filtration chromatography with Sephadex G-100. The final enzyme preparation was nearly homogeneous
on polyacrylamide gel electrophoresis, and its molecular weight was estimated to be approximately 35.5 kDa. The purified enzyme
exhibited a maximum activity for the hydrolysis of casein at pH 7.0 and 50°C and a remarkable stability at pH 4.0–7.0 and
40–60°C. Based on the inhibition and activation profiles obtained with numerous specific protease inhibitors and an activator,
the protease purified from the body wall of the sea cucumber was defined to be a cysteine-like protease. 相似文献
994.
Shogo Moriya Shunpei Sato Moongeun Yoon Tomonori Azumaya Shigehiko Urawa Akihisa Urano Syuiti Abe 《Fisheries Science》2009,75(2):359-367
More than 1,000 age-identified chum salmon Oncorhynchus keta collected at 23 stations in the Bering Sea and the North Pacific Ocean in June to July 2003 were used to estimate their origin
of stocks using a DNA microarray developed for analyzing the mitochondrial (mt)DNA haplotypes. The observed haplotype distribution
was nearly the same as that reported previously for fish collected in September 2002 and 2003 in the present surveyed areas.
A conditional maximum-likelihood method for estimation of stock compositions indicated that the Japanese stocks mainly distributed
in north central Bering Sea, whereas the Russian stocks were mainly in western Bering Sea. The North American stocks were
abundant in eastern Bering Sea and around the Aleutian Islands. Such an area-specific stock composition was not significantly
different between mature and immature fish. Thus, the combined results of 2 years suggest that the distribution of chum salmon
is nonrandom in the surveyed areas in summer and autumn, and that fish of the same origin migrate together to the same area
irrespective of age. 相似文献
995.
The spawning grounds of the chub mackerel (Scomber japonicus) and spotted mackerel (Scomber australasicus) in the East China Sea were estimated based on catch statistics of the Japanese large- and medium-type purse seine fishery
from 1992 to 2006. Biometric data were obtained from specimens caught by purse seiners in the East China Sea from 1998 to
2006. Gonadosomatic index (GSI) at 50% sexual maturity of chub mackerel and spotted mackerel females was 2.5 and 2.6, respectively.
Using this criterion for GSI, chub mackerel larger than 275 mm and spotted mackerel larger than 310 mm in fork length were
considered to be mature. Mature chub mackerel was observed in the area of 15–22°C sea surface temperature (SST), and mature
spotted mackerel was observed in the area of 17–25°C SST. The spawning period of chub mackerel ranged from February to June,
and that of spotted mackerel ranged from February to May in the East China Sea. The spawning grounds were estimated from the
distributions of catch per unit effort (CPUE) of spawners and SST. As a result, the spawning ground of chub mackerel was estimated
to be in the central and southern part of the East China Sea and the area west of Kyushu in February, March, and April, and
in the central part of the East China Sea, the area west of Kyushu and Tsushima Straight in May, and in Tsushima Straight
and western part of the Sea of Japan in June. The spawning ground of spotted mackerel was estimated to be in the central and
southern part of the East China Sea and southern coastal area of Kyushu in February, March, and April, and the central and
southern part of the East China Sea and the area west of Kyushu in May. 相似文献
996.
We examined the ability of salmon growth hormone (sGH) in sodium alginate (SA) gel to accelerate the somatic growth of juvenile
abalone, Haliotis discus hannai, by feeding. After the feeding of sGH at 50 μg or 100 μg in 350 mg SA gel, immunoreactivity to sGH in body fluid was maximal
after 12 h, and was still detectable at 24 h. No immunoreactivity was observed in the control group. Following the feeding
of sGH at 0.5 mg or 5 mg/8 g of SA gel at 7- and 14-day intervals, there was a greater increase in shell length and body weight
than in the control. In abalone, sGH can be transported from food into the circulatory system and subsequently improve somatic
growth. 相似文献
997.
998.
This study was carried out to investigate the influences of feeding frequency of extruded pellet and moist pellet on growth
and body composition of juvenile flounder (initial mean weight 6.3 g) in sub optimal water temperatures. A 2 (diets: extruded
pellet and moist pellet)×2 (feeding frequencies: two and three times daily)×2 (water temperatures: 12 and 17°C) factorial
design with three replications was used. After 60 days of feeding, the feeding frequency did not significantly affect growth
performance of fish. Weight gain, daily feed intake, feed efficiency and protein efficiency ratio were significantly (P<0.05) higher for fish reared at the higher water temperature. At the same water temperature, weight gain, feed efficiency,
and protein efficiency ratio were significantly (P<0.05) higher for fish fed the extruded pellet than moist pellet. The results of this study indicate that feeding frequency
of two times daily is sufficient for optimal growth of juvenile flounder when reared in suboptimal water temperatures, and
an increase in water temperature from 12 to 17°C improved growth and feed efficiency. 相似文献
999.
ABSTRACT: The thermal stability of carp G-actin was investigated by monitoring loss of actin polymerization ability. To determine the amount of native actin remaining after heat treatment, actin was labeled with a fluorescence reagent, N-(1-pyrene)iodoacetamide. The loss of polymerization ability of carp actin during heat treatment, at between 45 and 55°C, occurred faster than that of chicken actin. The inactivation rate was influenced by concentrations of ATP and Ca2+ in solution. With the increase of Ca2+ concentration, the inactivation of carp actin was markedly suppressed. Furthermore, the activation energy of the inactivation of carp actin obtained from an Arrhenius plot was similar to that of chicken actin. These results indicated that the thermal instability of carp G-actin was due to the low affinites of ATP and Ca2+ for carp actin described in a previous report. 相似文献
1000.
Bigeye tuna (Thunnus obesus) vertical movements in the Azores Islands determined with pop-up satellite archival tags 总被引:2,自引:0,他引:2
H. ARRIZABALAGA J. G. PEREIRA F. ROYER B. GALUARDI N. GOÑI I. ARTETXE I. ARREGI M. LUTCAVAGE 《Fisheries Oceanography》2008,17(2):74-83
Movement patterns of 17 bigeye tuna (Thunnus obesus) near the Azores Islands were analyzed between April and May 2001 and 2002 using pop‐up satellite archival tags. Despite short attachment durations (1 to 21 days, 8.2 days on average), their vertical movements revealed much shallower distribution of bigeye tuna in comparison with previous studies in the tropical Pacific and tropical Atlantic. Depth and temperature histograms were unimodal, although overall depth distribution during the day was deeper than during the night due to daily incursions in deeper waters. Although generalized additive models showed significant non‐linear relationships with weight of the fish and sea level anomaly (as a proxy for variability of thermocline depth), the effect of these variables on bigeye depth appeared minor, suggesting that vertical movements of bigeye in the Azores during the spring migration may be influenced by food availability in upper water layers. 相似文献