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1.
采用在基础饲料中分别添加0、130和260 mg/kg的合成虾青素配制成3种粗蛋白和粗脂肪含量分别为42%和16%的等氮等脂的中华绒螯蟹(Eriocheir sinensis)育肥饲料(分别记为饲料1、2和3), 以中华绒螯蟹商业育肥饲料作为饲料4, 分别投喂4组雌蟹(每个饲料组3个重复水槽, 每个水槽中12只蟹), 进行为期60d的室内养殖实验, 以探讨添加合成虾青素对中华绒螯蟹成体雌蟹性腺发育、色泽及抗氧化能力的影响。结果显示: (1)实验进行到30d和60d, 在饲料中添加虾青素对雌体肝胰腺指数(HSI)和性腺指数(GSI)均无显著影响(P>0.05)。(2)性腺、肝胰腺和头胸甲中的总类胡萝卜素含量和红度值(a值)均以饲料3组最高, 性腺亮度值(L值)和黄度值(b值)以饲料1组最高(P<0.05); 饲料2组头胸甲的b值最高, 饲料1组最低(P<0.05)。(3) 饲料1组中华绒螯蟹血清过氧化物酶(POD)活性显著高于其他组, 饲料4组的过氧化氢酶(CAT)、谷胱甘肽还原酶(GR)、乳酸脱氢酶(LDH)、总抗氧化能力(T-AOC)、丙二醛(MDA)和乳酸(LD)含量最高(P<0.05); 肝胰腺中的SOD、T-AOC、GSH-Px和GR活性均以饲料1组最高, 饲料2组最低(P<0.05)。(4) 饲料2组血清酸性磷酸酶(ACP)活性和血蓝蛋白(Hc)含量显著高于其他组, 其余各组间差异不显著。血清中的碱性磷酸酶(ALP)和γ-谷氨酰转移酶(γ-GT)活性和一氧化氮(NO)含量均以饲料4组最高(P<0.05), 肝胰腺中的ACP、ALP和γ-GT活性以饲料1组最高。综上, 在育肥饲料中添加合成虾青素对成体雌蟹性腺发育无显著影响, 但可显著提高头胸甲、肝胰腺和卵巢中的类胡萝卜素总量、色泽和抗氧化能力, 建议雌蟹育肥饲料中合成虾青素的含量为90 mg/kg左右。  相似文献   

2.
为研究长期不同水体盐度对中华绒螯蟹(Eriocheir sinensis以下简称河蟹)成体雄蟹渗透压调节和生理代谢的影响, 在不同水体盐度条件下(0、6、12和18)对河蟹雄体进行为期60d的养殖实验, 并分别检测其渗透调节及生理代谢相关指标。结果显示: (1)血清渗透压、Na+、Mg2+和Cl-含量随水体盐度上升而显著上升(P0.05), K+和Ca2+含量有上升趋势, 但各盐度组差异不显著(P0.05); 无论何组雄蟹, 其血清渗透压均显著高于对应的水体渗透压; (2)0组雄蟹后鳃Na+/K+-ATP酶活性显著高于其他组(P0.05), 其他各组间差异不显著(P0.05); (3)就血清生理代谢指标而言, 12组雄蟹血清中甘油三酯(TG)含量显著高于其他组(P0.05), 而尿酸(UA)、葡萄糖(Glu)、丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性相对较低; 所有组尿素(Urea)、碱性磷酸酶(ALP)含量差异不显著(P0.05); (4)就肝胰腺生理代谢指标而言, 6组肝胰腺MDA含量和-谷氨酰转肽酶(-GT)活力最低, 12组酸性磷酸酶(ACP)和-GT活性显著高于其他盐度组(P0.05)。因此, 适当提高水体盐度可提高河蟹成体雄蟹的血清渗透压及其主要离子含量, 同时降低其后鳃中Na+/K+-ATP酶活性。肝胰腺和血清代谢指标暗示12盐度组雄体的代谢水平相对较低, 具有较强的免疫性能和抗氧化能力。  相似文献   

3.
实验以淡水(0.3‰)处理组为对照,研究了急性高渗胁迫(盐度16‰和30‰)对中华绒螯蟹(Eriocheirsinensis)雄蟹血淋巴和肝胰腺中可溶性蛋白质、血蓝蛋白、血糖及肝糖原含量的影响。结果显示,与对照组相比,进入16‰及30‰盐度后,蟹的血淋巴中可溶性蛋白质含量从6—48h显著降低(P<0.05),至72h时显著增加(P<0.05),而机体肝胰腺的可溶性蛋白质含量从12h开始至96h显著降低(P<0.05);血蓝蛋白含量在前24h显著降低(P<0.05),48h开始显著升高(P<0.05);肝糖原含量在6—96h与对照组相比有显著的降低(P<0.05);16‰盐度组蟹的血糖含量在24—48h时显著下降(P<0.05),到72h开始逐渐恢复(P>0.05),而30‰盐度组其血糖含量早在6—12h时就有显著的下降(P<0.05),到24h则开始逐渐升高。研究表明,在急性盐度胁迫下,糖类和蛋白质对中华绒螯蟹渗透压调节起重要的作用,其优先利用糖类的分解获得所需的能量,其中盐度越高,机体内葡萄糖的消耗越快,血糖水平的恢复也相应较快。对蛋白质的利用稍次之,机体可利用蛋白质的分解获得其渗透压调节的效应物游离氨基酸以维持渗透压平衡。  相似文献   

4.
湖泊放养长江水系中华绒螯蟹的性成熟规律研究   总被引:12,自引:1,他引:11  
于8-11月份,结合中华绒螯蟹捕捞期,即生死洄游期的到来,通过性腺发育的组织学和细胞学观察,重点观察了长江下游安徽杨赛湖等人工放养长江水系中华绒螯蟹的性成熟规律。结果表明:①在性成熟时期,性腺发育与肝脏变化极为密切,肝脏指数逐渐下降,而性腺指数逐渐上升;②雌、雄蟹的性成熟存在规律性差异,8-9月份,雄蟹的性腺指数和性/肝指数均高于雌蟹,而10-11月份,雌蟹的性腺指数和性/肝指数均高于雄蟹;③经性腺的组织学和细胞学观察,雄蟹的性腺发育略早于雌蟹;④洄游高峰期的出现是河蟹性细胞走向成熟的外在表现。作者建议把肝脏指数7.5作为捕捞长江水系河蟹最佳时机的指标。  相似文献   

5.
两种方式对红螯螯虾同步产卵影响的研究   总被引:1,自引:0,他引:1  
对红螯螯虾采取雌雄分养和烫伤雌虾单侧眼柄两种方法进行处理,研究其对红螯螯虾卵巢发育和产卵率的影响,进而判断对同步产卵的影响。结果显示,雌雄分开放养对雌虾性腺发育有促进作用,其性腺指数显著高于幼虾刚离体的雌虾和试验结束时未产卵的雌虾,而肝胰腺指数低于试验初的雌虾,但14 d的单放时间偏长;单养14 d组和烫伤单侧眼柄组的产卵率分别为35%和50%,小于对照组(75%);雌虾交配前不需要蜕壳;幼虾离体的雌虾不再次交配也可以产卵,但不一定能孵出苗。研究表明,雌雄分养和烫伤雌虾单侧眼柄对于刚理出的产空雌虾的同步产卵促进作用不明显,生产上对于幼虾离体后的雌虾应立即雌雄配组。  相似文献   

6.
中华绒螯蟹(Eridcheir sinensis)1龄性早熟是扣蟹养殖过程中的一个重要问题,尚不清楚1龄性早熟和2龄正常性成熟后代的生长发育规律是否存在差异,本研究通过构建1龄性早熟和正常性成熟中华绒螯蟹家系,综合比较了单养条件下两种家系子一代(以下简称早熟F1和正常F1)在扣蟹和成蟹阶段的生长蜕壳规律、雌蟹腹脐覆盖腹甲宽度比例、成熟后的性腺指数(GSI)和肝胰腺指数(HSI)。结果显示:(1)早熟F1雄体在第1、2次和第7、8次蜕壳后的体重显著大于正常F1雄体(P0.05);而早熟F1雌体在第1~5次和第7次蜕壳后的体重显著大于正常F1雌体(P0.05);(2)第1和2次蜕壳后早熟F1的增重率较高,正常F1在第3~8次蜕壳后的增重率略高于早熟F1,两群体在扣蟹阶段的特定生长率均呈下降趋势,且正常F1高于早熟F1,其中雌雄个体在第3~4次蜕壳后的特定生长率均存在显著差异(P0.05);(3)早熟F1在第1~5次蜕壳间隔较长,而第6~8次蜕壳间隔较短;两种家系在扣蟹养殖阶段蜕壳4~6次,成蟹养殖阶段蜕壳2~4次,其中早熟F1在扣蟹阶段的平均蜕壳次数低于正常F1,而在成蟹阶段的平均蜕壳次数高于正常F1;(4)早熟F1腹脐覆盖腹甲宽度比例一直高于正常F1,但二者无显著差异(P0.05);(5)无论雌体还是雄体,早熟F1和正常F1的性腺指数和肝胰腺指数均无显著差异,单养条件下性腺均可发育成熟(P0.05)。综上,单养条件下,中华绒螯蟹早熟F1和正常F1的生长模式存在显著差异,两者都可以完成生殖蜕壳和性腺发育成熟,这为今后深入研究中华绒螯蟹个体生物学提供了理论依据和参考资料。  相似文献   

7.
为研究育肥饲料中混合植物油替代鱼油对中华绒螯蟹(Eriocheir sinensis)成体雄蟹常规成分和脂肪酸组成的影响,采用豆油和菜籽油混合物替代鱼油制成5种不同鱼油替代水平(0%、25%、50%、75%和100%)的等氮等脂育肥饲料(分别记为1#~5#饲料组)饲喂雄蟹,测定5组雄蟹肝胰腺、肌肉和性腺中的常规成分和脂肪酸组成,并对实验数据进行方差分析。结果显示:(1)饲料1#组性腺灰分含量显著高于饲料4#和5#组(P0.05),但各组性腺中的水分、总脂和蛋白含量均无显著差异(P0.05);饲料1#组肝胰腺中的水分和灰分最高,但其总脂含量低于其他组,各组肝胰腺的蛋白含量无显著差异(P0.05);除1#饲料组外,肌肉中的总脂和灰分含量随鱼油替代水平的升高而显著上升(P0.05),而水分和蛋白含量均无显著差异(P0.05)。(2)各饲料组精巢中总饱和脂肪酸(∑SFA)、总多不饱和脂肪酸(∑PUFA)和总高度不饱和脂肪酸(∑HUFA)含量无显著差异(P0.05),其总n-6多不饱和脂肪酸(∑n-6PUFA)含量随鱼油替代水平升高而升高,而总n-3多不饱和脂肪酸(∑n-3PUFA)含量和∑n-3PUFA/∑n-6PUFA比值呈显著下降趋势(P0.05)。(3)肝胰腺中∑n-3PUFA和∑HUFA含量具有显著的组间差异,且均以饲料3#组最高。但各组的∑PUFA和∑n-6PUFA含量差异并不显著(P0.05)。(4)肌肉中大部分脂肪酸组成无显著差异,仅∑n-6PUFA含量随鱼油替代水平升高而升高。综上,中华绒螯蟹育肥饲料中植物油(豆油与菜籽油含量为1︰1)替代鱼油对成体雄蟹可食组织中水分和蛋白含量并无显著影响,但会对其脂肪酸组成造成显著的影响,50%的鱼油替代水平有利于雄蟹肝胰腺和肌肉中的脂肪沉积。  相似文献   

8.
不同盐度条件下中华绒螯蟹亲蟹行为及血淋巴生理变化   总被引:5,自引:0,他引:5  
设定淡水对照组、盐度18适应组、盐度30骤变组(18→30)和盐度0骤变组(18→0),采用视频记录分析法研究了不同盐度条件下中华绒螯蟹雌性亲蟹的8项行为学指标变化,并测定了血淋巴渗透压及离子、血蓝蛋白含量。结果表明:中华绒螯蟹亲蟹封闭反应行为仅发生于盐度组(盐度18组和盐度30骤变组),且盐度30骤变组封闭反应时间显著高于盐度18组(P<0.05);腹部开合行为仅见于盐度0骤变组;盐度组第一触角回缩时间显著高于对照组(P<0.05);其他5项行为学指标活动频率均于盐度0骤变组最高。各实验组亲蟹血淋巴渗透压及离子浓度均高于外界实验水体,且均随盐度升高而增大。血蓝蛋白含量随盐度的降低而升高,盐度0骤变组血蓝蛋白含量显著高于盐度30骤变组(P<0.05)。分析认为,中华绒螯蟹亲蟹在0~30盐度范围内进行高渗透压调节,腹部开合行为是其在低盐度环境下暴露尾肠吸收水中离子的一种行为策略,封闭反应有助于机体减少高盐度坏境下水的吸收及扩散失盐。  相似文献   

9.
研究采用雨生红球藻(Haematococcus pluvialis)藻粉作为天然虾青素源, 配制4种不同虾青素含量(含量分别为0、26.60、41.62和81.37 mg/kg)的饲料(记为饲料1#—4#), 对三疣梭子蟹(Portunus trituberculatus)雌体进行为期45d的育肥实验, 研究其对雌蟹卵巢发育、色泽、抗氧化能力、免疫性能和生化组成的影响。结果表明: (1)育肥饲料中虾青素含量对雌蟹性腺指数(GSI)和肝胰腺指数(HSI)均无显著影响。(2)肝胰腺、卵巢和头胸甲中的总类胡萝卜素含量、红度(a*)值和黄度(b*)值均随饲料虾青素含量的升高而升高, 而3种组织的亮度(L*)值呈显著下降趋势(P<0.05)。(3)对抗氧化指标而言, 虾青素添加组(饲料2#—4#)血淋巴超氧化物歧化酶(SOD)和过氧化物酶(POD)活力均显著低于无虾青素组(饲料1#); 血淋巴中的总抗氧化能力(T-AOC)、谷胱甘肽过氧化物酶(GSH-Px)及肝胰腺中的SOD和T-AOC活力均随饲料中虾青素水平升高而上升, 而血淋巴和肝胰腺中的丙二醛(MDA)含量呈下降趋势。(4)对免疫指标而言, 血淋巴和肝胰腺中的酸性磷酸酶(ACP)活力均在饲料4#组最高, 而饲料1#组血淋巴中的血蓝蛋白(Hc)含量显著高于其他组(P<0.05)。(5)对生化组成而言, 肌肉和肝胰腺中的总脂、总碳水化合物及卵巢中总脂含量均随饲料中虾青素含量的升高呈上升趋势, 饲料2#组卵巢中的总碳水化合物含量最高(P<0.05)。综上所述, 三疣梭子蟹雌体育肥饲料中添加虾青素对其卵巢发育无显著影响, 但可改善色泽和提高其抗氧化能力及可食组织中的总脂和碳水化合物含量, 三疣梭子蟹雌体育肥饲料中虾青素适宜含量为50 mg/kg饲料左右。  相似文献   

10.
维生素C对中华绒螯蟹雄性生殖的影响   总被引:4,自引:1,他引:4  
采用不同Vc的人工配合饲料 ,研究了Vc对中华绒螯蟹雄性生殖的影响。实验分为 5组 ,其添加量分别为 0mg 1 0 0g饲料 (实验 1组 )、2 0 0mg 1 0 0g饲料 (实验 2组 )、40 0mg 1 0 0g饲料 (实验 3组 )、60 0mg 1 0 0g饲料 (实验 4组 )和 80 0mg 1 0 0g饲料 (实验 5组 ) ,实验为期 5 0d。结果如下 :1 )肝胰腺、精巢和副性腺中Vc的积累量以实验 3组最高 ,分别为 2 2 61 μg mgprot、1 0 2 1 7μg mgprot、7 661 μg mgprot;2 )肝体指数和性腺指数以实验 3组最高 ,分别为 0 0 5 2 3和 0 0 2 68;3 )增重率同样以实验 3组最高 ,实验 1组最低 ,分别为 3 1 3 3 %和 2 1 2 %;4)睾酮含量以实验 2组最高 ,为 1 2 5 7ng ml,但实验 3组的睾酮含量与实验 2组接近 ;5 )SOD酶活性与其Vc含量呈负相关 ,且精巢和副性腺的酶活性高于肝胰腺。结果表明 :适量添加Vc可促进雄蟹肝胰腺、精巢和副性腺对Vc的积累 ,同时可促进精巢的发育及睾酮的分泌 ,而过量添加可能会对精巢的发育产生不良影响 ;河蟹体内的抗氧化系统之间存在着相互的协调和平衡 ,生殖期性腺对其自身的抗氧化保护需求要高于其它组织  相似文献   

11.
The yellowfin seabream (Acanthopagrus latus) has a good potential for mariculture in Iran, so studies on various aspects of its culture has been carried out. In this study, the characteristic of reproduction in this species was investigated. The involvement of steroid hormones in the development of gonads was assayed by sampling blood and gonad tissue in 85 females of A. latus in fish caught from the Musa Creek, north-west Persian Gulf from October 2010 to May 2011. Gonadosomatic index (GSI) and hepatosomatic index (HSI) were recorded. Developmental stages were associated with changes in sex steroids, GSI and HSI. GSI and HSI began to increase in November (immature stage) and reached the highest value in March (ripe stage), decreasing sharply in April (spent stage). Plasma values of 17β-estradiol (E2) levels reached their highest levels in spawning females in March and then decreased in April. Progesterone levels were low through ovarian development, reached a maximum simultaneously with testosterone in February (mature stage) and then decreased in March (ripe stage). The seasonal changes observed in plasma steroid levels and GSI reflected the pattern of oocyte development and the spawning behavior of yellowfin seabream and were typical of the patterns described in most multiple spawners studied to date.  相似文献   

12.
Post-mating reduction in immune defence is common in female insects, and a trade-off between mating and immunity could affect the evolution of immunity. In this work, we tested the capacity of virgin and mated female Drosophila melanogaster to defend against infection by four bacterial pathogens. We found that female D. melanogaster suffer post-mating immunosuppression in a pathogen-dependent manner. The effect of mating was seen after infection with two bacterial pathogens (Providencia rettgeri and Providencia alcalifaciens), though not after infection with two other bacteria (Enterococcus faecalis and Pseudomonas aeruginosa). We then asked whether the evolution of post-mating immunosuppression is primarily a ‘female’ or ‘male’ trait by assaying for genetic variation among females for the degree of post-mating immune suppression they experience and among males for the level of post-mating immunosuppression they elicit in their mates. We also assayed for an interaction between male and female genotypes to test the specific hypothesis that the evolution of a trade-off between mating and immune defence in females might be being driven by sexual conflict. We found that females, but not males, harbour significant genetic variation for post-mating immunosuppression, and we did not detect an interaction between female and male genotypes. We thus conclude that post-mating immune depression is predominantly a ‘female’ trait, and find no evidence that it is evolving under sexual conflict.  相似文献   

13.
Information on migration patterns is critical to using no-take migratory corridors and marine reserves to protect the spawning stock of commercially exploited species. Both active and passive acoustic tracking methods quantified movement of commercially and ecologically important blue crabs in the White Oak River estuary, NC, USA. We targeted post-mating female crabs migrating down-estuary to oceanic spawning grounds. Crabs travelled approximately 14.1 km mainly in deeper channels and over 12–26 days from mating areas to spawning grounds. No crabs were detected migrating down-estuary in the autumn and only 30% were detected migrating down-estuary in spring. None of the crabs detected near spawning grounds were detected or recaptured back up-estuary, suggesting that they either (i) do not return to the estuary after a one to two week period in the spawning area or (ii) were captured by fishermen. The results from this study demonstrate that (1) acoustic transmitters coupled with passive acoustic receivers provided reliable and valuable data on migration patterns of mature female blue crabs and (2) mature female blue crabs are capable of migrating primarily within deep channels to spawning grounds shortly after insemination.  相似文献   

14.
A brackish water type ofPungitius pungitius (Gasterosteidae) is newly reported from Japan. Genetic differences, based on 13 loci of 6 enzymes and muscle protein, were examined between fresh and brackish water types in the Biwase River in the eastern part of Hokkaido. The alleles onGpd, Pgi andPgm were displaced between them, even though their distributions partially overlapped in the river. The brackish water type was also statistically different from the fresh water type on the basis of three morphological characters, such as number of dorsal spines, gill-rakers and vertebrae, although ranges overlapped. Segregation of spawning sites and differing nuptial colors of the male were found between fresh and brackish water types. These facts suggest that the brackish water type is reproductively isolated from the fresh water type and that both types should be regarded as independent species.  相似文献   

15.
Common torpedo Torpedo torpedo (Linnaeus, 1758) is widely distributed in the Mediterranean Sea, especially in southern and northern regions. The species is known throughout the Tunisian coast and entered brackish areas, such as the northeastern Lagoon of Bizerte, where it is commonly captured. Investigations conducted in this latter area showed that males and females sexually matured between 234–285 mm and 245–280 mm total length (TL), respectively. The largest male and female were 403 mm and 435 mm TL, respectively and weighed 721.5 and 1273.5 g, respectively. There was a not significant relationship total mass versus TL between males and females. Conversely, the relationship of liver mass versus TL significantly differed between sexes. The diameter of the largest yolky oocytes ranged between 43 and 47 mm (mean 45.08 ± 0.98)}, while the mass ranged between 29.5 and 37.4 g (mean 31.79 ± 2.20). Near term embryos ranged from 19.34 to 31.28 mm TL (mean: 24.60 ± 4.12) and weighed from 3.9 to 9.0 g (mean 5.97 ± 1.41). Ovarian fecundity ranged from 4 to 36 (mean = 11.60 ± 5.96). Uterine fecundity or litter size ranged from 3 to 13 (mean = 6.36 ± 2.67). Both fecundities showed a positive relationship with TL of females. A chemical balance of development based on mean dry masses of yolky oocytes and near-term embryos was 0.75 and suggested that T. torpedo could be considered as a pure lecithotrophic species. Hepatosomatic index (HSI) and gonadosomatic index (GSI) calculated for females presented significant higher values than those of males. HSI values of males significantly differed differences between juveniles, sub-adults and adults, and in females, HSI values were not significantly different between juveniles and sub-adults and significantly different between sub-adults and adults. The values of male GSI increased with TL of specimens; additionally, they showed significant differences between juveniles and subadults, but not between sub-adults and adults. Monthly mean values of adult male and female HSI significantly varied throughout the year. Monthly mean of females GSI showed significant changes especially from January to April, due to a high vitellogenic activity, GSI decreased from May to August, during this period all yolky oocytes were ovulated, then GSI increased progressively from September. The reproductive cycle lasted one year approximately and gestation period 4 months, while near-term females were captured in August. Vitellogenesis did not proceed in parallel with embryonic development: during ovarian vitellogenic activity, the uteri were empty and in an appearent resting phase, conversely during gestation, the ovaries did not exhibit an appearent activity, by contrast other specimens exhibited a vitellogenic activity during gestation. With special regard to the latter case, it remains difficult to state if these small yolky oocytes were not ovulated, or if they were new oocytes produced immediately after ovulation, both hypothesis remaining suitable.  相似文献   

16.
This study investigates sex steroids, gonadal histology and some biological indices of fall and spring spawning migrants of Caspian lamprey Caspiomyzon wagneri (Kessler, 1870). Blood and gonad samples were collected from 15 migrants during fall and spring. Serum sex steroid levels including testosterone (T), 17β-estradiol (E2) and progesterone (P) were determined with ELISA and gonadal development was studied using conventional histological methods. Our results showed serum E2 level in females were similar in the two seasons but in males, fall migrants had higher serum E2 concentrations. No differences were found in T levels in fall and spring migrants. Serum P concentration in fall migrant males were significantly higher than spring migrant males while spring migrant females had higher serum P levels compare to fall migrant females. Gonads in both fall and spring migrants were in the final stage of maturity. Fall and spring migrant males had similar HSI and GSI; fall migratory female had significantly higher HSI and GSI. Sex ratios were close to 1:1 in both seasons. There was a significant relationship between fecundity and length in both seasons. Comparison of fecundity and egg diameter between fall and spring seasons showed no significant difference. These results indicate that both fall and spring migrants Caspian lamprey were ready for spawning. Further studies are needed to clarify when spawning occurs in Caspian lamprey.  相似文献   

17.
为了解中华蛸(Octopus sinensis)繁殖行为特征,通过肉眼观察及水下摄像对其行为进行研究。结果表明,中华蛸在繁殖期有运动、捕食、求偶、交配、产卵和护卵行为。中华蛸运动依靠漏斗喷水的反作用力进行游泳和爬行;以突然袭击的方式捕食日本蟳(Charybdis japonica),繁殖后期不再进食;中华蛸具明显的求偶行为,雄性间为争夺交配对象会进行对峙搏斗:中华蛸是“距离式”交配,雄性和雌性亲体均可与不同异性多次交配,存在一只雌性与多只雄性同时交配的现象:雄性性腺成熟早于雌性,交配后雌性亲体并不立即产卵,而是继续发育,甚至交配后超过50d才产卵;卵径大小(2.5±0.2)mm×(1.1±0.1)mm,平均产卵量为83988粒:中华蛸雌性护卵行为明显,22.4~23.5℃水温时,在雌性保护下受精卵经21~24d孵出幼体,幼体全部孵出后雌性亲体最长存活34d。分析认为,中华蛸多次交配行为可以提高生殖成功率,雌性护卵行为有助于提高受精卵孵化率。  相似文献   

18.
Samples from a natural population of pike (Esox lucius L.) from the River Danube were used in a 12-month study to determine seasonal variations in biochemical parameters of pike blood sera, hepatosomatic index (HSI) and gonadosomatic index (GSI). The ranges of enzyme activities for sample means were: aspartate aminotransferase (ASAT) 252.0–583.8 U 1−1, alanine aminotransferase (ALAT) 4.9–11 -2 U1 and alkaline phosphatase (AP) 39.5–91.8 U1−1. The ranges of other parameters analysed in serum were total protein 27.7–40.1 g 1 1, urea 0.57–l.52 mmol 1 1 and creatinine 21.2–118.6 μmol 1 1. The range of sample means for HSI and GSI were 1.28–4.16 and 0.07–20.2 respectively. Temperature ranged from 4.5 to 23.5°C. The activity of serum AP was positively correlated to water temperature in males only, while urea and creatinine showed a positive correlation to water temperature in individuals of both sexes. GSI was correlated significantly with HSI in females. Total protein reached the lowest values during the spawning period, while creatinine levels depended on both the sex and season.  相似文献   

19.
Ovigerous blue crabs, Callinectes sapidus, are observed to undergo nocturnal ebb-tide transport (ETT) during their seaward spawning migration. A previous study found that females undergoing the spawning migration have a circatidal rhythm in vertical swimming, which serves as the biological basis for ETT. The present study asked three questions about this endogenous rhythm. First, does the rhythm occur in females with mature embryos regardless of whether they are undergoing ETT? Second, when exposed to a light/dark cycle in the laboratory, do ovigerous females only swim vertically at the time of ebb tide during the dark phase? Third, do attachments to the backs of ovigerous crabs affect the circatidal rhythm? The circatidal rhythm occurred in all crabs with mid-stage embryos that were prevented from undergoing ETT. The rhythm was unaffected by the light/dark cycle, which implies that migration can occur at lower light levels at depth during the day. Finally, attachments did not affect the rhythm, which suggests that tags and transmitters will not affect the spawning migration.  相似文献   

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