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1.
在常温静水条件下,选用4种中草药对金鱼进行急性毒性试验。根据96hTLm来判断药物对金鱼的毒性大小。结果表明:这4种中草药的毒性大小顺序为:贯众〉苦楝〉青蒿〉鱼腥草;高浓度中草药水提液和CuSO4同时使用时毒性较大;置金鱼于中草药水提液中药浴后进行CuSO4毒性试验,除鱼腥草外,药浴72小时以内可降低其死亡率。  相似文献   
2.
A cDNA encoding the subunit of thyrotropin (TSH) was isolated from a goldfish (Carassius auratus) pituitary gland cDNA library. By comparing the sequence with other teleost TSHs, a signal peptide of 19 amino acids and a mature hormone of 131 amino acids were predicted for goldfish TSH subunits. The resulting putative mature hormone of 131 amino acids had well-conserved cysteine positions and a putative N-linked glycosylation site; homology was 51–67% with TSHs from other teleosts, 38–43% with tetrapod TSHs, but only 27 and 29% with goldfish GTH-I and -II, respectively. We also examined the effects of thyroid hormones (TH) and thiourea (TU, an inhibitor of TH production) treatments on TSH and GTH subunit gene expressions in the goldfish pituitary gland. After thyroxine (T4) treatment, circulating T4 concentration increased and TSH mRNA level decreased. Supressing the amount of circulating T4 and triiodothyronine (T3) by TU treatment increased the TSH mRNA level. Moreover, T4 replacement therapy (simultaneous treatment of both TU and T4) caused a high level of circulating T4 and a low level of circulating T3, and a decrease in the TSH mRNA level. Thus, changing levels of circulating TH exert a negative feedback on the level of TSH subunit mRNA in goldfish in vivo. On the other hand, GTH subunit mRNA levels were not affected by changes in the levels of circulating TH.  相似文献   
3.
A bioassay for insulin-like growth factor (IGF), based on the in vitro incorporation of [35S]-sulfate into gill arch tissue was used to study the hormonal regulation of proteoglycan synthesis in the goldfish (Carassius auratus). [35S]-sulfate incorporation into gill arch tissue was found to be time-dependent with maximal uptake occurring by 48h, suggesting that proteoglycan synthesis in this tissue was maintained for at least 48h in vitro. The addition of human recombinant IGF-I (IGF-I) to the incubation medium was found to significantly stimulate [35S]-sulfate uptake into the gill arches, whereas bovine growth hormone (GH) was without effect. Porcine insulin was also stimulatory, but results indicate that the effects of porcine insulin and IGF-I may be mediated by a single receptor system. Finally, arches from hypophysectomized fish were significantly less responsive to IGF-I than were arches from sham-operated fish. Furthermore, administration of ovine GH in vivo appeared to increase subsequent responsiveness in vitro. Together, these results provide evidence that the growth-promoting actions of GH in the goldfish may be mediated, at least in part, by a peptide related in structure to mammalian IGF-I.  相似文献   
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Intensive grow‐out of goldfish, Carassius auratus (L.), larvae and juveniles in closed systems requires the control of environmental conditions and feeding. This study investigates the use of different types of live food and combinations of live food and dry food in a series of four rearing experiments. Juvenile goldfish can be weaned from Artemia onto live food at about 24 days after the onset of feeding without causing a reduction in growth and survival. The replacement of Artemia by Daphnia at day 10 appears feasible, as growth and survival were not significantly affected. Fish fed decapsulated Artemia cysts grew better than fish fed live Artemia. Within the first 14 days, goldfish juveniles should be fed at least 155 cysts per fish per day to achieve fast growth and to minimize size variation.  相似文献   
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Activin (AA, AB and BB) is a dimeric protein that belongs to the transforming growth factor- (TGF-) superfamily of growth factors and is involved in the regulation of many physiological and developmental processes. Recently, we have demonstrated that porcine activin stimulated goldfish gonadotropin-II (GTH-II) and growth hormone (GH) secretion from dispersed pituitary cells in static culture and pituitary fragments in perifusion. The action of activin in the goldfish is unique in that it has an acute stimulatory effect on the secretion of GTH-II and GH, whereas in mammals activin usually exhibits long-term stimulatory actions on FSH secretion. The action mechanism of activin is different from that of gonadotropin-releasing hormone (GnRH). Using domain-specific antibodies against mammalian activin subunits, we subsequently demonstrated the existence of immunoreactive activin subunits (A and B) in the goldfish ovary, testis, pituitary and brain, suggesting endocrine, paracrine and autocrine roles for activin in the regulation of goldfish reproduction. Both activin A and B subunits have been cloned from goldfish genome by polymerase chain reaction (PCR). Using the PCR fragments as probes, we have cloned a full length cDNA coding for activin B subunit from the goldfish ovary. Both activin A and B subunits show high homology to those of other vertebrates with the B subunit much more conserved (93 and 98% identity with human and zebrafish B subunit, respectively). The identity of the cloned B subunit was further confirmed by expression in the Chinese hamster ovary (CHO) cells and detection of the specific activity of activin in the culture medium. The messenger RNA of activin B subunit is expressed in a variety of goldfish tissues including ovary, testis, brain, pituitary, kidney and liver, suggesting a wide range of physiological roles for activin in the goldfish. We have also cloned a full length cDNA coding for the activin Type IIB receptor from the goldfish ovary, suggesting that activin may have paracrine or autocrine actions on the ovarian functions. The identity of the cloned receptor was confirmed by specific binding of125 I-activin on COS-1 cells transfected with the cloned Type IIB receptor.  相似文献   
8.
Recording cerebellar neuron activities in swimming goldfish   总被引:1,自引:0,他引:1  
ABSTRACT:   Neuronal activities were investigated in the cerebellum of immobilized and swimming goldfish Carassius auratus . Extracellularly recorded neural activities of the cerebellum in immobilized goldfish were characterized and classified into five types. Based on the waveforms and recording depths, these five neural activity types were estimated to originate from three identified classes of cerebellar neurons: Purkinje cells, eurydendroid cells, and granule cells. Chronic recording of cerebellar neuron activities in unrestrained goldfish was performed for more than 100 h. During the chronic recordings, a submersible amplifier attached to the goldfish head, and a multielectrode array developed for the present study were used. Neuronal activities in the cerebellum of free-swimming fish could also be classified into five types as in the immobilized condition. Firing patterns of two neurons identified as Purkinje cells and eurydendroid cells were analyzed during turning movements of the goldfish. The firing patterns of these neurons changed in relation to turning movements. Although some improvements are required, the chronic recording method developed in the present study can be applied to further investigations concerning the direct relationship between brain neural activities and certain behavior.  相似文献   
9.
Testes from spermiating goldfish were incubated with [3H]17-hydroxyprogesterone. The major products in the unconjugated fraction were identified as androstenedione, androstenetrione, 11-β-hydroxyandrostenedione, 11-ketotestosterone, 17,20α-dihydroxy-4-pregnen-3-one (17,20αP) and 11-deoxycortisol. Testosterone was present predominantly in the glucuronide fraction, but yields were low (1–3%). The major components of the sulfate fraction were 17,20αP and 11-deoxycortisol. The identification of cortisone in low yield (< 2.5010) in both the free and sulfate fractions is the first report of corticosteroid biosynthesis by a teleost testis. The high yields of 17,20αP and 11-deoxycortisol and their sulphates suggests that their possible role in spermiation of the goldfish should be further investigated.  相似文献   
10.
To compare the effect of polyculture against conventional monoculture on ornamental carp production, investigations on food selection and growth performance of koi carp (K), Cyprinus carpio L. and goldfish (G), Carassius auratus (L.) were conducted in a 11‐week rearing experiment in two monoculture (100% K and 100% G) and five polyculture (90% K–10% G, 70% K–30% G, 50% K–50% G, 30% K–70% G and 10% K–90% G) conditions in tropical ponds. There were three replicates for each treatment. Environmental conditions and food availability were similar in all the treatments. Ivlev's electivity index showed that both fish species avoided phytoplankton and preferred cladocerans to other zooplankton groups (copepods and rotifers) in monotypic conditions. However, in the polyculture treatments, the positive electivity of goldfish towards cladocerans reduced significantly (P<0.05), while the percentage of copepods, rotifers and phytoplankton in the gut content increased. No significant differences in weight gain, specific growth rate and deformities were recorded at harvest for koi carp between the different treatments (P>0.05). Even the survival rate of koi carp recorded above 90% in all the treatments. However, the goldfish recorded significantly better weight gain, specific growth rate and survival in monoculture (100% G), compared with the polyculture treatments (P<0.05). Goldfish deformities were lowest (P<0.05) in the monoculture treatment (2.42%). The number of marketable fish above a set size limit of 4 g total weight was significantly higher in the two monoculture treatments, compared with the five polyculture treatments (P<0.05). Keeping in view of the dietary similarities of koi carp and goldfish, and the aggressive nature of koi carp in polyculture, it is suggested to refrain from polyculture of goldfish and koi carp until further documentations relating to optimum stocking density and management of polyculture of ornamental carps are available.  相似文献   
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