共查询到18条相似文献，搜索用时 125 毫秒
1.
虾池长竹蛏肥满度的研究 总被引：2，自引：0，他引：2
本文作者于1997年4月至1998年3月期间，对幸福洋垦区虾池生长的长竹蛏进行了周年肥满度测定研究.结果表明长竹蛏5～9月份较肥，肥满度在60％～80％之间，11月至翌年4月份较瘦，肥满度在55％～47％之间；根据肥满度的测定，长竹蛏的繁殖期为6～8月份. 相似文献
2.
泥蚶的性腺发育和生殖周期 总被引：6，自引：0，他引：6
根据生殖细胞发育的宏观和组织切片观察以及各期生殖细胞在滤泡中所占的比例，泥蚶的生殖腺发育过程分为增殖期、生长期、成熟期、排放期和休止期五个阶段。按肥满度的变化并结合性腺组织切片确定，泥蚶的性晚发育在青岛海区一年一个周期。繁殖期在７月上旬至８月下旬，繁殖盛期在７月中旬至８月中旬。至少有二次集中排放过程。 相似文献
3.
欧氏六线鱼Hexagrammos otakii Jordan & Starks性腺发育的周年变化研究 总被引：1，自引：0，他引：1
根据对青岛附近水域欧氏六线鱼（已达性成熟年龄）性腺周年宏观和组织学观察，性腺发育可分为：①重复发育Ⅱ期；②开始成熟期；③接近成熟期；④临产期或产卵期；⑤产后期。按性腺指数变化并结合性腺组织切片确定，欧氏六线鱼性腺发育在青岛海区一年一个周期，繁殖期在１０月下旬至１２月，繁殖盛期是１１月下旬至１２月中旬。 相似文献
4.
3种蛏类线粒体16SrRNA和COI基因片段的序列比较及其系统学初步研究 总被引：15，自引：0，他引：15
对3种蛏类大竹蛏（Solen grandis），长竹蛏（Solen strictus）和小刀蛏（Cultellus attenuatus）的线粒体16SrRNA和COI基因片段序列进行了比较并对其系统学进行了初步研究。得到的序列总长度分别为472-481bp（16S）和658bp（COI）。3种蛏序列的碱基组成均显示出较高的A＋T比例（16SrRNA基因62．1％；COI基因62．8％）。对位排序比较表明，16SrRNA片段种内个体间变异较小，3种类间存在128个碱基变异位点（其中包括127个简约信息位点）和5个插入／缺失位点，总共12个碱基长；COI片段有200个碱基存在变异，其中包括191个简约信息位点，不存在任何插入／缺失位点。数据分析结果表明16SrRNA和COI基因片段大竹蛏与长竹蛏两片段的遗传距离分别为0．0856和0．1712，两竹蛏类与小刀蛏的遗传距离分别为0．3054，0．2798和0．2662，0．2933。作者认为小刀蛏与竹蛏之间的遗传距离已达到科之间的水平，结果支持将其提升为刀蛏科的分类观点。3种蛏类线粒体16SrRNA和COI基因在种间明显的多态性，证实了16SrRNA和COI基因序列均普遍适用于蛏类种及以上阶元的系统学分析。 相似文献
5.
沟竹蛏的繁殖季节与生长 总被引：2，自引：1，他引：2
根据性腺形态特征、组织切片观察和肥满度指数变化 ,报道沟竹蛏繁殖期为每年的6～8月份 ,分批放散精、卵 ,其两次生殖高峰分别出现于6月上、中旬和8月上、中旬。繁殖季节、肥满度指数与温度密切相关 ,其繁殖期适宜温度为25～29℃。沟竹蛏的壳长与壳高的关系呈直线正相关 ,L=4.304H -2.084 ,(r=0.9138) ;壳长与干肉重呈幂函数关系 ,W1(非繁殖季节 )=4.750×10-7×L3.53,(r=0.9196) ,W2(繁殖季节 )=3.942×10-7×L3.301,(r=0.9105)。 相似文献
6.
2005年1月至2007年12月,采用组织学和实验生态学方法对大竹蛏(Solen grandis Dunker)的性腺发育、生殖周期、肥满度、胚胎发育、幼虫发育及变态等进行了研究.结果表明,大竹蛏性腺发育过程分为增殖期、生长期、成熟期、排放期、休止期5个阶段;在浙南沿海大竹蛏繁殖期为4月下旬至5月中旬(水温21～24℃);肥满度最高出现在5月份,为31.2%;最低出现在2月份,为21.2%.大竹蛏卵径为85～95 μm;受精卵在水温22℃,经20～24 h孵化成D形幼虫;初孵D形幼虫平均大小为125 μm,浮游幼虫经5～6 d培养进入附着变态期,壳长为250 μm,发育变态为稚贝. 相似文献
7.
白沙湖四角蛤蜊的繁殖期及增养殖效果的研究 总被引：4，自引：0，他引：4
１９９４年１０月－１９９５年９月在汕尾市白沙湖进行了四角蛤蜊的肥满度及生长的周年观察研究，结果表明其肥满度在４．７３％－９．８４％之间，平均为７．０７％，最高值出现在１０月份，最低值在５月份；繁殖盛期主要为９－１２月，其闪为２－３月。其生长与水温及年龄均有密切关系，春夏季生长快，秋冬季生长慢；１－２龄贝生长快，３龄贝生长慢。 相似文献
8.
9.
利用透射电镜观察大竹蛏(Solen grandis Dunker)精子发生和精子的超微结构，描述了从精原细胞发育到成熟精子过程中超微结构的变化。大竹蛏精子发生历经精原细胞、初级精母细胞、次级精母细胞、精细胞和成熟精子5个阶段。成熟精子属典型的原生型，全长52—57 μm，由头部、中段和尾部三部分组成。头部由顶体和细胞核组成；中段由4—5个椭圆形线粒体和2个相互垂直的中心粒组成；尾部细长，为典型的“9+2”型结构。大竹蛏与同属的长竹蛏精子发生和精子超微结构存在差异。大竹蛏精细胞前顶体囊的高电子密度物质分布在周缘呈一个带缺口的弧形而不是圆形，而长竹蛏前顶体囊周缘的高电子密度物质呈一圆形分布；大竹蛏的前顶体囊是先内凹变形，然后一边变形一边移动，而长竹蛏的前顶体囊是在到达核前端后才开始变形。大竹蛏的顶体比长竹蛏的稍长；大竹蛏精子核形似子弹头而长竹蛏精子核形为圆球状；大竹蛏有卫星体结构而长竹蛏无卫星体结构；大竹蛏精子尾部鞭毛比长竹蛏的长。结果可以为竹蛏科相似种类的鉴定及亲缘关系的探讨提供参考依据。 相似文献
10.
11.
本文根据1987.12～1989.4对舟山朱家尖岛南沙沙滩逐月采集标本进行研究。结果表明,等边浅蛤Gomphina veneriformis的性腺发育可分为5期:增殖期、生长期、成熟期、排放期和休止期。在舟山海区,等边浅蛤一年中为一个繁殖周期,繁殖期为8月下旬至9月中旬。有雄性早熟现象。 相似文献
12.
13.
Aspects of the reproductive biology of the brown mussel Perna perna at the Iture rocky beach near Cape Coast, Ghana, were studied from September 2014 to August 2015. The current study was aimed at providing information useful for managing the mussel fishery in this locality and also that would form the basis for designing appropriate culture methods for the species. Microscopic examination of fresh smears of gonadal material, as well as histological preparations of the gonad, were used to study the sexuality and breeding pattern of the species. Monthly gonadal and condition indices were also determined. Perna perna exhibited gonochoristic sexuality with a sex ratio of approximately 1:1 throughout the study period. Sexes were identifiable at shell lengths of 15.0–19.9 mm. Five stages of gonadal development were identified in both sexes. Gametogenic activity was continuous throughout the year, with two major spawning activities, from April to June and from August to December. These periods coincided with the major and minor rainy seasons, respectively, as well as the major upwelling period in August. Condition indices suggest that the mussels were in better condition for harvesting in March and August prior to the major spawning events. 相似文献
14.
Charles B. Miller Bruce W. Frost Harold P. Batchelder Martha J. Clemons Richard E. Conway 《Progress in Oceanography》1984,13(2):201-243
Life histories for the dominant, larger copepods of the subartic Pacific have been constructed by sampling from weatherships patrolling Ocean Station P (50°N, 145°W) during 1980 and 1981. Neocalanus plumchrus reproduced at depths below 250 m from July through February. Copepodite stages were present in surface layers from October through August with a large peak in numbers and biomass in spring. Fifth copepodites prepared for diapuse in 38 days during spring and descended to depths below 250 m. They commenced immediately to mature, and the females reproduced without renewed feeding. This schedule contrasts with that of the population in the Strait of Georgia, which remains in diapause from July to January and matures exclusively in January and February. There appears to be a difference between the coastal and oceanic habitats in preparing the diapausing individuals for maturation.Maturation of the diapausing stock of N. plumchrus maintained constant adult populations, averaging 714 males m?2 from June through October and 1,434 females m?2 from August through January. This constancy, together with the exponential pattern of decline in the diapause stock from September through February, suggests that density of adults may regulate maturation of fifth copepodites. Offspring of individuals delaying maturation and, thus, reproduction would benefit from the resulting moderation of intraspecific competition, probably that among copepodites.Reproduction of Neocalanus cristatus also occurred below 250 m, and, while spawning was continuous through the year, there was a substantial peak in November. That resulted in a peak of abundance for early copepodite stages in mid-winter, and a peak for the fifth copepodite stage in June. Stocking of the population of fifth copepodites in diapause below 250 m occurred from July through October. Some fifth copepodites were present in surface layers through the entire summer, and some younger copepodites persisted through the summer in progressively declining abundance just below the mixed layer. In autumn 1980 resurgence of early copepodite populations was rapid, occurring during the course of a prolonged October storm. The storm may have improved the habitat either by cooling the mixed layer or by resupplying nutrients to the euphotic zone.Eucalanus bungii reproduced in the mixed layer in early May and in early July. The first event was a spawning by females that had previously spawned in 1979 and then had returned to diapause. The second, heavier spawning (more females, more eggs per female) was by newly matured females from stocks that had overwintered as fifth copepodites. Nauplii peaked sharply in abundance on 19 July, one week after the peak in spawning. First and second copepodites peaked on 1 August, and all had advanced to the third copepodite stage by September. The diapause stock was established by September, principally between 250 and 500 m, and consisted of copepodite stages from third to sixth. Duration of the E. bungii life cycle appears to be typically two years. New nauplii develop as far as the third or fourth copepodite stage during their first summer, then enter diapause. The second summer they advance to the fifth copepodite stage and reenter diapause. Fifth copepodites mature in their third summer at two years of age. The males remain at depth and mate without subsequent feeding. Females migrate at night to the mixed layer where spawning occurs. About 20% of females that had already spawned in 1980 reentered diapause. They would reproduce again in their fourth summer at three years of age. All aspects of the life cycle suggest low mortality rates for copepodite stages, particularly at depth in the habitat occupied during diapuse. There can be no premium on rapid reproduction for E. bungii in the subartic Pacific, and there must even be benefit from spreading reproduction between years. This iteroparity may amount to a “bet-hedging” tactic, the young from a given mother having more than one chance to find sustaining conditions. It also produces gene flow between the year classes of the biennial life cycle. 相似文献
15.
《海洋科学集刊》1976,(11):201-210
像其他海洋生物的生长一样,贻贝(Mytilus edulis L.)也是因海区或生境不同,养殖方法不同,季节不同,生长状况也不同。研究殆贝的生长规律,无疑对判断养殖效果、确立养殖程序等是十分重要的;同时在生态学研究中,对分析种群结构及推断某些生物学特点等,也是不可缺少的。
关于贻贝的生长过去虽有一些记载,但是较系统的材料,现在还不多见。随着生产发展及调查研究的需要,对这个问题我们必须做到胸中有数。为此,我们于1972-1973年结合人工育苗工作,对烟台沿岸的贻贝,自受精卵开始至成贝收获的全部生长过程,进行了较系统的调查研究。除贝壳生长的材料外,还测定了养成时期的肉质部生长的材料。对自然苗的生长情况也作了一些记录。关于春苗的幼虫期及幼苗期的生长情况,我们过去已较详细地报告过[1],此处不再赘述;仅对生产意义更大的人工秋苗的生长状沉予以论述。 相似文献
16.
对虾养殖池水域环境细菌的动态变化 总被引：49，自引：0，他引：49
于1990年6月下旬-10月初期间，每隔7－10d在大连市金州区董家沟镇养虾场突池定点采样一次，3h内带回实验室进行细菌培养计数，研究对虾养殖池水域环境中细菌的动态变化。结果表明，对虾养殖池水中异养菌和弧菌的数量变化与水温的变化趋势相同；6—7月末，细菌增长比较缓慢；8月初开始，细菌数量增长较快，8月中旬达到全年的最高值，异养菌为3．4×105cell／ml，弧菌为1．9×105cell／ml；而后随着水温的下降，水中细菌逐渐减少。底记泥浆中，细菌数量一直呈上升趋势，不受水温的影响；异养菌最高达6×107cell／ml，弧菌达1．5×106cell／ml。 相似文献
17.
18.
基于灰色系统西南大西洋阿根廷滑柔鱼资源丰度预测模型的构建 总被引：3，自引：0，他引：3
阿根廷滑柔鱼（Illex argentinus）是西南大西洋鱿钓渔业的主要作业鱼种，对资源丰度进行准确的预测可指导企业合理安排渔业生产。因此，本研究根据2000-2016年我国西南大西洋阿根廷滑柔鱼的生产数据，以单位捕捞努力量的渔获量（Catch per unit effort， CPUE）为阿根廷滑柔鱼资源丰度的指标，利用灰色绝对关联分析和灰色预测建模的方法（GM（0， N）），计算2001-2015年CPUE的时间序列值与产卵期（6-8月）产卵场海表面温度（Sea surface temperature， SST）时间序列值的灰色绝对关联度，选取产卵场海域中灰色绝对关联度大于0.90的海区SST建立资源丰度预测模型，并用2016年实际CPUE进行验证。灰色绝对关联分析表明，6-8月，30°~40°S，45°~60°W海域内存在若干海区的SST与次年对数CPUE时间序列呈现较强的关联度，可作为预报因子。GM（0， N）模型结果表明，以6-8月产卵场SST作为环境因子建立的模型4能较好地拟合出阿根廷滑柔鱼资源丰度变动趋势，与2016年真实值相比，相对误差为7%，该模型可较好地作为阿根廷滑柔鱼资源丰度的预测模型。相反，包含6月和7月SST的模型1效果优于不包含6月SST的模型2或不包含7月SST的模型3，拟合得到的2016年的数据与真实值相比，相对误差分别为128%和289%，这说明6月和7月是西南大西洋阿根廷滑柔鱼的主要产卵月份。 相似文献