驼背鲈脑垂体显微和超微结构的观察

采用PAS、Mallory三色法和腺垂体不同细胞改良染色法3种组织学染色方法,以及透射电镜技术,对驼背鲈(Cromileptes altivelis)脑垂体的形态、组织结构和超微结构进行了研究。结果表明,驼背鲈脑垂体为圆球形实心腺体,位于间脑腹面,由神经垂体和腺垂体2部分组成。根据神经纤维中所含分泌颗粒形态和大小把神经分泌纤维分为A1、A2和B型。神经纤维中存在2种垂体细胞,即呈椭圆形的Ⅰ型垂体细胞和呈梭形的Ⅱ型垂体细胞。腺垂体由3部分组成:前外侧部(RPD)、中外侧部(PPD)和中间部(PI)。腺垂体部可以鉴别出6种内分泌细胞,其中RPD有2种内分泌细胞:促肾上腺皮质激素(ACTH)分泌细胞和催乳激素(PRL)分泌细胞;PPD有3种内分泌细胞:生长激素(GH)分泌细胞、促性腺激素(GTH)分泌细胞和促甲状腺激素(TSH)分泌细胞;PI只有1种内分泌细胞,即促黑激素(MSH)分泌细胞。此外,腺垂体还有1种非分泌细胞星状细胞(SC)。驼背鲈腺垂体中6种内分泌细胞的分布情况为:前外侧部分布有2种细胞,即嗜酸性的PRL分泌细胞和嗜碱性的ACTH分泌细胞;中外侧部有GH、GTH、TSH 3种分泌细胞;MSH分泌细胞分...     

驼背鲈血细胞的超微结构

利用电镜技术对驼背鲈（Cromileptes altivelis）外周血细胞的超微结构进行了研究。结果表明,电镜下可区分6种类型的细胞：红细胞、粒细胞、单核细胞、淋巴细胞、血栓细胞和浆细胞。红细胞呈圆形或椭圆形,可见线粒体、少数囊泡;根据细胞中的颗粒形态大小和细胞核的形态,可将粒细胞分为4种类型：I型粒细胞、II型粒细胞、III型粒细胞和IV型粒细胞。单核细胞圆形,表面较平整,偶有伪足伸出,空泡多见;淋巴细胞的胞质少,仅在细胞核边缘处形成薄薄的一层,细胞器少;血栓细胞异染色质丰富,沿核膜呈带状分布,胞质中有较多大小不等的空泡和少量的线粒体;浆细胞中粗面内质网成层分布包绕在核周围。此外可见到嗜曙红细胞吞噬红细胞、血栓细胞成群聚集分布的现象。     

驼背鲈肝脏结构的光镜和透射电镜观察

采用HE、Mallory氏三色法、Heidenhain氏Azan染色,PAS反应,组织块银浸染方法,对组织切片染色处理,应用光学显微镜和透射电镜对驼背鲈肝脏的显微和超微结构进行了观察,结果表明驼背鲈肝组织中肝细胞界限不明显,不存在双核现象,有暗细胞和亮细胞之分,胞质中细胞器丰富,有大量的线粒体、内质网和溶酶体,高尔基体很难观察到,仅在胆小管和狄氏间隙的附近发现。此外,在肝血窦的附近观察到成纤维细胞、枯否氏细胞和贮脂细胞。肝组织中胆管数量众多包括肝叶中央胆管、支胆管、小叶间胆管和小叶内胆管,并且在中央静脉附近偶见辐射状排列的肝细胞索。     

卵形鲳鲹肾脏的显微和超微结构观察

利用石蜡组织切片和透射电镜技术对卵形鲳鲹(Trachinotus ovatus)肾脏进行显微和超微结构观察研究。结果显示,根据卵形鲳鲹肾小管上皮细胞的结构特点,将其划分为颈段、第一近曲小管、第二近曲小管、远曲小管和集合小管5个部分。卵形鲳鲹肾小体长径平均70μm,短径平均40μm;比淡水鱼种类的肾小体直径要小。肾小管中第一近曲小管的上皮细胞游离端具有丰富的微绒毛,并含有丰富的线粒体,应为重吸收的主要场所。而第二近曲小管上皮细胞游离端微绒毛较少,远曲小管和集合管的内壁均没有微绒毛,但三者均可见有较多的线粒体,表明它们仍具有一定的重吸收功能。     

驼背鲈人工育苗技术初探

选取网箱驯养的野生驼背鲈亲鱼,经过强化培育,采用HCG催熟,网箱中自然产卵受精,采用池塘蓄水和室内玻璃钢水槽培育相结合的方法,成功繁育出驼背鲈3 cm左右鱼苗3万尾,繁育成功的关键技术是亲鱼的驯养和强化,控制好水质,提供适口、营养丰富的开口饵料生物.     

驼背鲈的染色体核型分析

研究利用植物血球凝集素(phytohemagglutinin,PHA)体内注射、肾细胞短期培养、空气干燥方法制备了驼背鲈染色体,并对其组型进行了分析。结果表明,驼背鲈的染色体组型公式是2n=48=48t,NF=48。结果显示,驼背鲈在鱼类系统演化上应属于高位类群,但在鲈形目中,其在进化上仍属相对原始的类型。     

驼背鲈的形态和生物学性状

观察并解剖３２尾活体驼背鲈,详细记录其形态特征和内部组织结构。驼背鲈的显著特征是身躯侧扁,头顶凹入,后头部突然隆起,体甚高,上下颚无犬齿,后鼻孔呈垂直长裂孔;背鳍１０棘,体褐色,体表布满黑色圆点。胃发达,卜型;肠管中等长,幽门盲囊１０～１３个;胆囊非常细长如线状,屈曲,其长为体长的２３％～２５％;生殖腺粗短,雌雄同体。     

驼背鲈消化系统组织学与组织化学研究

采用形态解剖、组织学及组织化学方法,分别用HE和AB-PAS染色法对驼背鲈(Cromileptes altivelis)的消化系统进行了研究。结果表明:驼背鲈食道内表面分布较多宽大的粘膜褶;胃分为贲门部、盲囊部和幽门部,贲门部胃小凹和胃腺最多,盲囊部厚度最大;前、中、后肠粘膜褶丰富,后肠粘液细胞密度最大;幽门与前肠交界处有幽门盲囊10~13个,结构与前肠相似。食道,胃,前、中、后肠及幽门盲囊均以分泌中性粘多糖的Ⅱ型粘液细胞为主。驼背鲈消化系统的结构表现出与其肉食性习性相适应的特点。     

驼背鲈的年龄与生长特征研究

鉴定和描述了驼背鲈鳞片的年龄及其年轮特征,采用4种生长模型来模拟其体长生长过程,通过比较分析得出最适的生长方程,并对其生长拐点以及生长指标等生长特征进行了相应的分析。实验结果表明,驼背鲈鳞片的年轮特征主要表现为疏密型,偶见副轮和生殖轮。von Bertalanffy 生长方程、Gompertz生长方程、Logistic生长方程以及三项式方程均可反映驼背鲈的体长生长过程,其生长特点属于均匀生长类型,其中Gompertz生长方程能更好地描述10龄以前的体长生长性状。体长体重的von Bertalanffy 生长方程为：Lt=566.0139[1-e-0.1549(t+1.0988)];Wt=4531.0076[1-e-0.1641(t+0.76635)]3.0245。体长与体重关系为 Wt＝2.3×10-5Lt3.0245。渐近体长Ｌ∞=566.0139mm,渐近体重Ｗ∞=4531.0076ｇ,体重生长拐点tr=5.98龄,此时的体长与体重分别为376.94mm和1346.26g。     

驼背鲈的年龄与生长特征

鉴定和描述了驼背鲈鳞片的年龄及其年轮特征,采用4种生长模型来模拟其体长生长过程,通过比较分析得出最适的生长方程,并对其生长拐点以及生长指标等生长特征进行了相应分析。实验结果表明,驼背鲈鳞片的年轮特征主要表现为疏密型,偶见副轮和生殖轮。vonBertalanffy生长方程、Gompertz生长方程、Log istic生长方程以及三项式方程均可反映驼背鲈的体长生长过程,其生长特点属于均匀生长类型,其中Gompertz生长方程能更好地描述10龄以前的体长生长性状。体长体重的von Bertalanffy生长方程为:Lt=566.0139[1-e-0.1549(t 1.0988)];Wt=4531.0076[1-e-0.1641(t 0.76635)]3.0245。体长与体重关系为Wt=2.3×10-5Lt3.0245。渐近体长L∞=566.0139 mm,渐近体重W∞=4531.0076 g,体重生长拐点tr=5.98龄,此时的体长与体重分别为376.94 mm和1 346.26 g。     

Polka-dot grouper, Cromileptes altivelis, can utilize dietary fat efficiently

Polka‐dot grouper, Cromileptes altivelis, a highly‐prized fish in Asian live fish markets, is a slow‐growing species. Long‐chain (LCF) or medium‐chain fatty acids (MCF) were fed to polka‐dot grouper (14 g initial weight) for 8 weeks to see if growth could be stimulated. Five dietary treatments were compared: a control diet with low fat (56 g kg^?1) or diets that contained either moderate (150 g kg^?1) or high (300 g kg^?1) supplements of fat that were added either as olive oil for the LCF or coconut oil for the MCF. Control fish performed well; they grew at 2.2 g week^?1, had a dry matter feed conversion ratio of 1.0 and deposited dietary protein and energy at efficiencies of 25 and 26%. Fish fed LCF at moderate levels performed better than controls but, when fed LCF at high levels or MCF at any level, their performance was inferior to controls. We conclude that dietary supplementation with 150 g kg^?1 of LCF stimulates growth and improves protein retention of polka‐dot grouper whereas higher levels, or the same or higher levels of MCF, depress performance.     

驼背鲈线粒体细胞色素b基因的序列分析

采用PCR—DNA测序技术,对驼背鲈线粒体DNA细胞色素b（Cytb）基因全序列进行分析。获得长度为1141bp的Cytb基因片段,序列碱基组成平均是T为29．1％,C为32．3％,A为23．2％,G为14．0％,A＋T的碱基百分比总体上略大于C＋G,平均值分别是52．3％和46．3％。与其它鱼类相同基因片段碱基序列含量相似。在由核苷酸推导的氨基酸中,亮氨酸（Leu）所占的比例最高,为16．03％。     

Oxidation of medium-chain and long-chain fatty acids by polka dot grouper Cromileptes altivelis

In this study we tested the hypotheses that higher fat diets will promote greater fat oxidation, and that medium‐chain fatty acids (MCFA) will be more readily oxidized than long‐chain fatty acids (LCFA). The oxidation of dietary MCFA (coconut oil labelled with ¹⁴C‐octanoic acid) and LCFA (olive oil labelled singly with ¹⁴C‐palmitic acid and ¹⁴C‐oleic acid) was measured in a metabolic chamber. MCFA and LCFA were included in the respective diets at 150 and 300 g kg^?1. Polka dot grouper fed diets containing MCFA had a significantly higher (P < 0.05) respiration rate [2.4 mmol CO₂ BW (kg)^?0.79 h^?1] and proportion of radioactivity in the respired CO₂ (49.5%) than those fed diets containing LCFA [1.2 mmol CO₂ BW (kg)^?0.79 h^?1 and 12.8%, respectively]. The amount of dietary fat did not significantly affect either of these two response attributes. The radioactivity in faeces and regurgitated material was low with diets containing MCFA, but was significantly higher with diets containing LCFA, and increased with increasing LCFA content, suggesting a decrease in digestibility. These results show that MCFA provide this species with a more readily utilizable source of energy than LCFA. Moreover, raising the amount of lipid in the diet above 150 g kg^?1 did not increase the oxidation of fatty acids for energy.     

An established kidney cell line from humpback grouper (Cromileptes altivelis) and its susceptibility to bacteria and heavy metals

Fish Physiology and Biochemistry - Humpback grouper (Cromileptes altivelis), one kind of commercial fish with considerable economic value, has been recognized as a promising candidate for...     

Polka dot grouper Cromileptes altivelis fingerlings require high protein and moderate lipid diets for optimal growth and nutrient retention

An 8‐week comparative slaughter experiment was carried out to determine the effect of dietary protein and lipid on growth, apparent digestibility (AD) and nutrient retention of polka dot grouper Cromileptes altivelis. Fingerlings were fed diets that varied in crude protein (CP) at 55 g kg^?1 increments between 410 and 630 g kg^?1 dry matter (DM) and at either a moderate (150 g kg^?1 DM) or high (240 g kg^?1DM) lipid concentration. Each diet was fed to satiety twice daily to four replicate tanks (110 L) of fish. One replicate block of tanks comprised 150 fish of mean (±SD) initial weight of 9.6 ± 0.29 g, which were distributed equally to 10 tanks. The other three replicate blocks of tanks comprised 300 fish of 12.6 ± 0.45 g, which were distributed equally to 30 tanks. Tanks were provided with filtered and heated (29 ± 0.5 °C) seawater in a flow‐through system within a laboratory where photoperiod was maintained at 12 : 12 h light–dark cycle. Voluntary food intake was not significantly affected by either the CP or lipid concentration of the diet (mean ± SD of 1.93 ± 0.146 g week^?1) but there was a trend for intake to be higher on the moderate compared with the high lipid diets (mean ± SEM of 1.97 versus 1.89 ± 0.033 gweek^?1, respectively). Daily growth coefficient (DGC) and food conversion ratio (FCR) improved linearly (P < 0.01) with increasing dietary CP (from 0.94 to 1.35% day^?1 for DGC and 1.58 to 1.00 g DM g^?1 wet gain for FCR) and these responses were almost coincident for each of the lipid series. The AD of CP increased linearly with increasing dietary CP (from 46.8 to 74.1%) and was independent of dietary lipid. Apparent digestibility of energy increased curvilinearly with increasing dietary CP, with the quadratic component being more prominent for the high‐lipid series. Increasing the amount of lipid in the diet markedly increased the lipid content of the fish from an initial composition (mean ± SD) of 173 ± 7.3 g kg^?1 to a final composition (mean ± SEM) of either 217 or 250 ± 5.9 g kg^?1 for moderate and high‐lipid series, respectively. Total body lipid content tended to increase linearly with increasing dietary CP for the high‐lipid series but with an opposite effect for the moderate‐lipid series. The retention of digestible nitrogen decreased linearly with increasing dietary CP but at a steeper rate for the moderate, compared with the high, lipid series (from 62.7 to 35.7%, slope ?0.115 for moderate‐lipid and 54.6 to 41.9%, slope ?0.050 for high‐lipid). A quadratic function of dietary CP concentration best explained the retention of digestible energy with the curvilinearity being more marked for the high, compared with the moderate, lipid diet series. While there was some indication that ingested lipid spared dietary protein, the results showed a far greater propensity of polka dot grouper fingerlings to use protein as the prime dietary energy source. Diets for juvenile polka dot grouper should contain not less than 440 g digestible protein kg^?1 DM and at least 150 g lipid kg^?1 DM.