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91.
根据1997-2000年东海区底拖网渔、№资源调查资料,以Beverton—Holt模型的单位补充量渔获最方程估算东海区18种主要经济鱼类的最适开捕年龄。运用von Bertalanffy,丰长方程估算最适开捕体长。结合鱼类生长的拐点年龄、临界年龄和初届性成熟年龄的体长,以及各鱼种实测最小性成熟体长,确定开捕规格。结果表明,目前东海区产量较高的带鱼(Trichiurus japonicus)和小黄鱼(Larimichthys polyactis)的建议开捕规格分别应为体长230mm和170mm。调整后的开捕规格与旧开捕规格相比,带鱼、短尾大眼鲷(Priacanthus macracanthus)、灰鲳(Pampus cinereus)、自姑鱼(Argyrosomus argentatus)均有所增大,小黄鱼、银鲳(Pampus argenteus)的开捕规格有所减小,变化较小的有蓝点马鲛(Scomberomorus niphonius)、日本鲭(Somber japonicus)、慌圆鲹(Decapterus maruadsi)等。建议以这18种主要经济鱼类为指标种类,制定新的法定开捕体长和幼鱼比例检查措施,实现东海区渔业资源的可持续利用。 相似文献
92.
T. Morato P. Afonso P. Lourinho J. P. Barreiros R. S. Santos R. D. M. Nash 《Fisheries Research》2001,50(3):297-302
Length–weight relationships were estimated for 21 coastal fish species of the Azores, namely Abudefduf luridus, Bothus podas, Chromis limbata, Coris julis, Diplodus sargus, Echiichthys vipera, Gaidropsarus guttatus, Labrus bergylta, Mullus surmuletus, Phycis phycis, Pomatomus saltator, Sarda sarda, Scorpaena maderensis, Scorpaena notata, Seriola rivoliana, Serranus atricauda, Sparisoma cretense, Sphyraena viridensis, Synodus saurus, Thalassoma pavo and Trachinotus ovatus. Significant length–weight relationships were found for all species. Sexual dimorphism did not affect the length–weight relationships, except in the cases of S. cretense and C. julis. Length–length equations for converting size measurements (standard length (SL) and fork length (FL) to total length (TL)) are also presented for all fish species. 相似文献
93.
The presence of neuroendocrine hormones in extant agnathan fishes suggests that a method of control involving these hormones
was operating 500–600 million years ago in emerging vertebrates. Data on a limited number of species show that several members
of the GnRH family of peptides may have arisen in non-teleost fishes. Lamprey (Petromyzon marinus) GnRH has a unique composition and has not been detected in other vertebrates. It is not yet clear whether the chicken II
GnRH-like molecule arose in cartilaginous fishes, but a chromatographically and immunologically similar molecule is found
in dogfish (Squalus acanthias) and ratfish (Hydrolagus colliei). Finally, a mammalian GnRH-like molecule is detected in three primitive bony fish: sturgeon (Acipenser transmontanus), reed fish (Calamoichthys calabaricus), and alligator gar (Lepidosteus spatula). Minor forms are also present, but are not yet characterized. Clearly, the basic structure of GnRH peptides was established
in primitive fish. In contrast, at least three other identified forms of GnRH have been detected in teleosts or tetrapods:
Salmon I, catfish I, and chicken I GnRH. Evidence for the presence of members of the GnRH family and the neurohypophysial
hormone family in primitive fishes argues for the importance of neuroendocrine control throughout the history of vertebrates. 相似文献
94.
鱼类热忍耐温度研究进展 总被引:25,自引:1,他引:25
The paper is a review of the studies on the temperature of the thermal tolerance in fishes. It was described from four aspect: (1) The key parameters of temperature of thermal tolerance in fishes; (2) The influence factors of temperature of thermal tolerance in fishes; (3) The research methods of thermal effect of fishes; (4) The evaluation of effects of thermal pollution on fishes, especially, with the coastal power station will be‘built in China recent years, the effects of thermal discharge water on the marine fisheries resource wered iscussed. 相似文献
95.
一、研究和保护鱼类种质资源的意义和迫切性 (一)从保护生物多样性谈起 为什么我国西北一些地区原来“风吹草低见牛羊”的大草原如今变成了土地贫瘠、经济落后的黄土高原?为什么原来郁郁葱葱、生意盎然的北非大森林如今变成了偶尔只闻驼铃声的撒哈拉大沙漠?为什么历史上盛产脍炙人口的大白鱼(翘嘴红鲌)的太湖如今变成了肉少刺多的毛鲚鱼的天下?这些都同生物多样性的破坏有关。 相似文献
96.
南沙群岛西南部陆架海区主要经济鱼类渔业生物学的初步研究 总被引:10,自引:1,他引:10
本文根据1992-1993年南沙群岛西南部陆架海区底拖网渔业资源调查资料,分析了 17种主要经济鱼类的渔业生物学特性,并应用体长方法估计了 von Bertalanffy生长参数(L和K)、总死亡系数、自然死亡系数、捕捞死亡系数和开发率,讨论了资源的开发状况。 相似文献
97.
T. K. Banerjee 《Fish physiology and biochemistry》2007,33(4):441-454
Air-breathing fishes have evolved bimodal respiratory mechanisms for exploitation of water (through gills and highly vascularized
skin) as well as atmospheric air (through aerial respiratory organs, ABO). Mucous cells in these respiratory organs of variously
stressed fishes exhibit periodic fluctuations in their density and staining properties. The main types of damage in the gills
include congestion of blood capillaries (BLCs), periodic lifting and sloughing of respiratory epithelia of the secondary lamellae
causing haemorrhage, extensive fusion of secondary lamellae and hyperplasia of the respiratory epithelia due to uncontrolled
regeneration leading to asphyxiation, altered excretion, and death of the fish. Haemolysis has also been observed following
lead exposure. The damage in the ABO of Heteropneustes fossilis includes sloughing of the epithelial cells, leading to haemorrhage causing decreased red blood corpuscles density and degeneration
of the secondary gill lamellae with reduced respiratory area. Subsequent hyperplasia of the respiratory epithelia and fusion
of gill lamellae increase the respiratory barrier distance. The BLCs often bulge out and protrude into the lumen, bringing
blood nearer to air. The ladder-like pillar cell (PLC)-BLC components of the gill lamellae frequently collapse. Damage to
the ABO of Channa striata is less severe. Often haemorrhaging due to bursting of extensively stretched BLCs causes aerial respiratory failure. Chloride
cells of the ABOs also show hyperplasia. While the highly mucogenic epidermis of C. striata shows less damage, the epidermis of Clarias batrachus and H. fossilis shows severe wear and tear, sloughing, and haemorrhage. Side-by-side regeneration continues, causing altered histomorphology
of the epidermis. The different gland cells also show periodic fluctuations in their density and staining. The dermis also
shows severe damage with loosening of their connective tissue fibres. These fibres give stronger reactions for sulfated mucin
that not only retain additional water molecules for continuance of skin breathing, but also bind the toxic ambient pollutants. 相似文献
98.
99.
用富含A蛋白的金黄色葡萄球菌国际标准株(cowanl),分别标记16株淡水鱼类致病菌高兔血清,制备SPA诊断液,建立了检测这16株致病菌的SPA-CoA。将待检病料经分离培养16~18h进行检测,3min内可判定结果,比玻片凝集试验的敏感性高25~50倍。经交叉和重复性试验表明,其特异性强、重复性好、操作简便,快速,无需特殊仪器。适用于基层鱼场对淡水鱼类主要病原菌的快速鉴定和流行病调查。并将16株致病菌用11种药物作药敏试验,为防治上述致病菌引起的鱼病提供依据 相似文献
100.
E O Wiley 《Fish and Fisheries》2002,3(3):161-170
The nature of species and the processes in which they participate are subjects of continuing debate among evolutionary biologists. I begin by examining how ichthyologists treat species empirically. Such treatments provide a pattern of species and their relationships over time and space. I suggest that this empirical record points to a predominant mode of speciation: vicariant, Model I, allopatric speciation. I also suggest that species are real and that they are individuals. There is a single species concept, the evolutionary species concept (ESC), that best captures the way we think about fish species. This concept is also well integrated with the manner in which species are treated in Phylogenetic Systematics and with the philosophical concept that species are particulars rather than universals. 相似文献