Stock delineation of pink snapper and tailor from Western Australia by analysis of stable isotope and strontium/calcium ratios in otolith carbonate

The ¹⁸O/¹⁶O and ¹³C/¹²C ratios in the otolith carbonate of pink snapper Pagrus auratus and tailor (bluefish) Pomatomus saltatrix, from several locations along the Western Australian coast, indicated that pink snapper stocks are location specific but that tailor stocks are less so. The hypersaline Shark Bay, on the coast of Western Australia, generated strongly characteristic isotopic signatures which serve as natural tags. Otolith carbonate from pink snapper from normal oceanic waters just north of Shark Bay showed no evidence that the fish had been in hypersaline water. Similarly, pink snapper from the hypersaline bay showed no evidence of having spent time at normal oceanic salinity. By contrast, some tailor from oceanic waters showed evidence of having spent considerable time in the bay, and some fish from the bay had oceanic signatures. This suggested that tailor were more migratory than snapper. The similarity in the distribution of the isotopic signatures (from oceanic to hypersaline) in otolith carbonate from tailor from oceanic waters north of Shark Bay (Koks Island), and from those within Shark Bay, indicated a single stock in this region (in contrast to pink snapper). Moreover, tailor from coastal south-western Australia and from the Shark Bay area could be considered seperately for some management purposes. For pink snapper stocks from oceanic waters, oxygen isotope signatures were clearly related to water temperature although the temperature relationship was obscured for fish within Shark Bay because of the strength of the signal generated by the hypersaline water. For tailor the temperature relationship was not obvious, probably because migrations of tailor smeared the temperature effect, and the hypersaline Shark Bay waters dominated, and, possibly, at the southern extemity of the range, the freshwater in some estuaries influenced the isotopic signatures of the otolith carbonate. Strontium/calcium ratios in pink snapper otoliths also indicated a separation of stocks, but for tailor overlap of signatures again suggested migratory behaviour.     

葡萄糖和维生素C对普安银鲫卵黄囊仔鱼ACC、FAS及CPTⅠ活性的影响

本试验旨在探究普安银鲫(Carassius auratus )卵黄囊仔鱼发育过程中ACC、FAS及CPT I活性变化及葡萄糖和维生素C溶液分别浸泡对它们的影响。采用酶学方法研究了普安银鲫卵黄囊仔鱼过程中ACC、FAS及CPT I活性变化的变化特点。结果显示：在卵黄囊仔鱼发育过程中,对照组与维生素C组中ACC和FAS活性呈上升趋势,CPT I活性呈“下降-上升”变化趋势,而葡萄糖组ACC、FAS及CPT I活性均呈上升趋势,且3种酶的活性均显著高于对照组(P<0.05)。维生素C组ACC活性在内源营养期显著高于对照组,FAS活性在混合营养期和外源营养期显著高于对照组,CPT I活性在内源营养期和外源营养期显著高于对照组(P<0.05)。研究表明：ACC、FAS及CPT I在维持普安银鲫卵黄囊仔鱼发育中脂质代谢的动态平衡起着重要作用,15g/L的葡萄糖溶液可通过调节仔鱼体内脂质代谢酶的活性而形成新的脂质代谢水平,以满足仔鱼生长发育需要;而30mg/L的维生素C对维持仔鱼发育中体内正常的脂质代谢具有重要作用。     

云南高背鲫鱼不同组织同工酶分析

采用聚丙烯酰胺凝胶电泳技术,分析了滇池中云南高背鲫鱼(Carassius auratus)的脑、眼睛、肝脏、心脏、肌肉5种组织中的酯酶(EST)、超氧化物歧化酶(SOD)和乳酸脱氢酶(LDH)3种同工酶的表达模式,并对各种酶的同工酶酶谱表型进行了分析。结果表明,云南高背鲫鱼的同工酶系统具有明显的组织特异性,且同工酶的种类与活性变化与其功能相适应。     

3种肟类化合物对中毒乙酰胆碱酯酶的重活化能力比较

3种肟类化合物(TMB4、LUH6和2-PAM-Cl)对辛硫磷抑制的鲫鱼、蟑螂和家蝇的乙酰胆碱酯酶(AChE)均具有重活化作用。初步比较研究了3种肟类化合物对中毒AChE的重活化能力,发现它们对被抑制的蟑螂和家蝇的AChE重活化能力差异不显著;但是对被抑制的鲫鱼的AChE来说,TMB4和L H6的重活化能力明显比2-PAM-Cl强。推测这3种肟类化合物对蟑螂、家蝇和鲫鱼的中毒AChE的活化能力的差异可能是由脊椎动物与无脊椎动物AChE本身的差异性造成的。     

The presence of Couch's goby in the Mediterranean Sea

Known distribution of Couch's goby, Gobius couchi Miller & El-Tawil, 1974 formerly limited to the British Isles, appears now to be extended to the Mediterranean. A new specimen collected at the island of Ischia, near Naples, Italy, is described.     

The impact of an introduced predator on a threatened galaxiid fish is reduced by the availability of complex habitats

1. The availability of complex habitats such as macrophytes may be vital in determining the outcomes of interactions between introduced predators and native prey. Introduced brown trout (Salmo trutta) have impacted numerous small native freshwater fishes in the southern hemisphere, but the potential role of complex habitats in determining the direct outcomes of brown trout – native fish interactions has not been experimentally evaluated. 2. An in‐lake enclosure experiment was used to evaluate the importance of structurally complex habitats in affecting the direct impacts of brown trout on a threatened galaxiid fish. Five Galaxias auratus and a single brown trout were added to enclosures containing one of three different habitat types (artificial macrophytes, rocks and bare silt substrate). The experiment also had control enclosures without brown trout. Habitat‐dependence of predation risk was assessed by analysis of G. auratus losses to predation, and stomach contents of remaining fish were analysed to determine if brown trout directly affect the feeding of G. auratus and whether this is also habitat‐dependent. 3. Predation risk of G. auratus differed significantly between habitat types, with the highest mortality in enclosures with only bare silt substrate and the lowest in enclosures containing artificial macrophytes. This result highlights the importance of availability of complex habitats for trout – native fish interactions and suggests that increasing habitat degradation and loss in fresh waters may exacerbate the direct impacts of introduced predators. 4. Stomach contents analyses were restricted to fish in enclosures with artificial macrophytes and rocks, as most fish were consumed in enclosures with brown trout and only bare silt substrate. These analyses suggest that brown trout do not directly affect the feeding of G. auratus in complex habitats, but it is still unknown whether its feeding is reduced if complex habitats are unavailable.     

Developmental changes in intestinal globule leukocytes of normal rats

Among vertebrates, telencephalo-pontine systems exist only in birds and mammals. However, three nuclei in the diencephalon and mesencephalon of teleost fishes have been indicated — analogous to the pons — to represent relay stations between telencephalon and cerebellum. Since two of these nuclei (dorsal preglomerular nucleus, dorsal tegmental nucleus) have only been described in the highly derived, electrosensory mormyrids, we investigated telencephalic connections in two nonelectrosensory teleosts, the goldfish Carassius auratus and the freshwater butterflyfish Pantodon buchholzi, and cerebellar connections only in the latter species, since for C. auratus these connections are already established. Horseradish peroxidase tracing reveals that C. auratus has a dorsal tegmental nucleus and a paracommissural nucleus both of which are telencephalo-recipient and project to the cerebellum, and that P. buchholzi has a dorsal preglomerular nucleus with such connections. These results extend our knowlegde of the distribution and, therefore, the phylogeny of telencephalo-cerebellar systems in teleosts. Similar to tetrapods, teleosts appear to have developed telencephalo-cerebellar systems several times independently.     

鲫鱼雌性有关蛋白的研究

本文利用聚丙烯酰胺、SDS、超薄平板等电聚焦等多种电泳方法,对不同性别鲫鱼的血清分析后,发现了两种与雌性有关的特异血清蛋白,FSSP-Ⅰ及FSSP-Ⅱ。分离提纯了含量较多的FSSP-Ⅱ,其分子量、等电点、氨基酸组成分析的结果证明,它是一类与已报道过的鱼类雌性蛋白极不相同的、与性别有关的蛋白。为性别问题的研究提供了有意义的资料。     

Thermosensitivity of the preoptic region and the spinal cord in the golden hamster

1. 1.|The effects of thermal stimulation of the preoptic region (POAH) and the spinal cord on non-shivering thermogenesis (NST) and shivering were studied in euthermic golden hamsters.

2. 2.|Shivering intensity is suppressed by heating the POAH but is independent of spinal cord temperature. Therefore, NST in the interscapular brown adipose tissue does not suppress shivering.

3. 3.|NST is inhibited by heating of the POAH as well as of spinal cord. It is discussed that the control of NST by two different central thermosensitive areas is significant for thermoregulation during exercise.

银鲫肌酸激酶M3-CK cDNA的克隆及其表达特征

用抑制性差减杂交结合SMART cDNA合成和RACE—PCR技术克隆到雌核发育银鲫(Carassius auratus gibelio)肌酸激酶M3-CK基因的全长cDNA。银鲫M3-CK cDNA全长1551bp，编码380个氨基酸，与普通鲤鱼(cyprinus carpio)M3-CK的氨基酸序列同源性高达95％。种系分析表明，银鲫M3-CK与其它脊椎动物的肌肉型肌酸激酶聚为较近的一支，与鲤鱼的M3-CK聚在一起，与脑特异型肌酸激酶及线粒体型肌酸激酶分歧较大。虚拟Northern杂交显示银鲫M3-CK基因在胚胎发育中差异表达。RT—PCR表明，银鲫M3-CK基因在成熟卵母细胞和胚胎发育早期可检测到少量的转录产物，在胚胎发育期间从肌肉效应期开始转录，并一直持续表达。组织RT—PCR表明，银鲫M3-CK基因只在心脏和肌肉表达。