多倍体贝类的繁殖生物学研究进展   总被引：2，自引：0，他引：2  

姜波  王昭萍  于瑞海  王如才 《海洋湖沼通报》2004,9(2):73-79

本文综述了国内外多倍体贝类繁殖生物学的研究现状。主要是从多倍体贝类的性腺发育、生殖细胞、减数分裂、繁殖力以及其性成熟年龄和性比等方面进行了论述。三倍体贝类的性腺虽然有一定程度的发育，但总体表现出高度的不育，而四倍体贝类的性腺发育正常；三倍体、四倍体贝类的生殖细胞明显大于同龄的二倍体的生殖细胞；多出的几套染色体使多倍体贝类减数分裂时染色体的分离形式复杂化；多倍体贝类的性成熟年龄与二倍体基本一致，三倍体贝类雌雄比例与二倍体有所不同，雌雄同体的比例增大。  相似文献   

Modelling the selective effects of fishing on reproductive potential and population structure of squid     

Murphy  E. J.; Rodhouse  P. G.; Nolan  C. P. 《ICES Journal of Marine Science》1994,51(3):299-313

  相似文献   

Episodic Mass Invasions of Juvenile Gadoids into the Wadden Sea and their Consequences for the Population Dynamics of Brown Shrimp (Crangon crangon)     

Rüdiger  Berghahn 《Marine Ecology》1996,17(1-3):251-260

Abstract. The brown shrimp Crangon crungon is considered to be a key species in the coastal waters of the North Sea and in particular in the Wadden Sea, since it occurs in masses and acts as both a highly efficient predator and important prey. The Wadden Sea is the nursery ground for brown shrimp. In 1990, a mass invasion of O-group whiting ( Merlangius merlangus ) reduced Crangon numbers to almost zero. Similar events, which had previously been reported in the 19th century, were observed in 1959 (whiting), 1970 (cod, Gadus morhua ), and 1983 (cod and whiting).
The 1990 invasion and the decline of the shrimp stock are documented on the basis of surveys that are compared with the years preceding and following. Consequences for the food web in the Wadden Sea and the reasons for the complete recovery of the shrimp stock in each case within one year after its collapse are discussed with regard to the Crangon crungon behaviour and reproductive potential. Sampling error and the impact of fisheries are also considered.  相似文献   

Feeding Ecology of three Populations of Blennius incognitus BATH 1968 (Pisces: Teleostei: Blenniidae) during the Reproduptive Period and under Human Influence     

Alfred  Goldschmid Kurt  Kotrschal 《Marine Ecology》1981,2(1):1-14

Abstract. Samples of Blennius incognitus from three differently polluted locations on the Istrian west coast (Adriatic Sea, Yugoslavia) were collected in early July during the spawning season. The gut content was analyzed employing the occurrence and point (relative volumetric) method. This fish grazes the surface of the rocky substratum. Inhabiting small benthic animals are ingested together with algae and detritus. The diet depends on the composition and condition of the covering phytal and its inhabiting fauna. A decrease of available animal food seems to intensify grazing on the substrate. A sexual dimorphism in the feeding habit during the reproductive period exists. Females feed more on animals; males feed more on substrate and in cases also on eggs of their own species.  相似文献   

Effect of changes in reproductive potential on perceived productivity of three Northwest Atlantic cod (Gadus morhua) stocks     

Morgan  M. Joanne; Brattey  John 《ICES Journal of Marine Science》2005,62(1):65-74

  相似文献   

Variation in the frequency of skipped spawning in Atlantic cod (Gadus morhua) off Newfoundland and Labrador     

Rideout  R.M.; Morgan  M.J.; Lilly  G.R. 《ICES Journal of Marine Science》2006,63(6):1101-1110

  相似文献   

热带雨林景观土壤测量采样深度与样品粒级试验研究——以加纳国雅卡锰金矿为例     

丁兆举 《地质与勘探》2021,57(3):554-562

加纳国雅卡锰金矿床位于著名的阿散蒂金矿带上。在该成矿带进行土壤测量采样深度、样品粒级试验以及方法技术的适应性和有效性研究,可为下一步开展大面积土壤地球化学测量提供技术依据,从而圈定可靠土壤地球化学异常。本文采用的工作方法为土壤垂向剖面法,选择有代表性的地段进行试验研究,结果显示在已知矿上方获得了明显的土壤地球化学异常。通过实验研究,选取土壤测量采样深度60～80 cm,截取样品粒级-4～+20目,获得了可靠、明显的土壤地球化学异常。研究证明该方法具有显著的地球化学找矿效果。  相似文献   

Reproductive resilience of ice‐dependent Antarctic silverfish in a rapidly changing system along the Western Antarctic Peninsula          下载免费PDF全文

Mario La Mesa  Emilio Riginella  Carlotta Mazzoldi  Julian Ashford 《Marine Ecology》2015,36(2):235-245

The Western Antarctic Peninsula (wAP) is globally one of the systems most heavily impacted by climate change, notably steep declines in sea ice extent. In forage species, reproductive resilience to change is particularly important because population fluctuations are rapidly communicated through the system via trophic interactions. The reproductive traits of the ice‐dependent forage species Antarctic silverfish (Pleuragramma antarctica) from different areas along the wAP and at the tip of the Antarctic Peninsula were investigated through macroscopic and histological analyses of gonads, with the aim to assess its reproductive potential and to test for spatial differences in fecundity and spawning season. Fish samples were collected in late summer off Charcot Island, in Marguerite Bay and off Joinville Island; no fish were caught in the central wAP. Samples from Charcot Island and Marguerite Bay consisted of adults in developing gonad stage, whereas those from Joinville consisted almost exclusively of juveniles. Mean GSI was relatively low (2–3%) and similar in both sexes, as specimens were still far from being actively reproducing. Developing females exhibited two discrete, though partially overlapping modes of oocytes of different size, with vitellogenic oocytes measuring 0.5–1.0 mm. Absolute and relative fecundity ranged between 3000 and 12,000 eggs per female and between 80 and 190 eggs·g^?1, with a strong relationship between absolute fecundity and body size. These results were consistent with a single population at Charcot Island and Marguerite Bay and indicated substantial reproductive potential, which may mitigate population isolation and reductions in habitat availability but cannot ultimately offset catastrophic loss of spawning habitat linked to sea‐ice retreat.  相似文献   

Invasive polychaete Boccardia proboscidea Hartman, 1940 (Polychaeta: Spionidae) in sewage‐impacted areas of the SW Atlantic coasts: morphological and reproductive patterns          下载免费PDF全文

María L. Jaubet  Griselda V. Garaffo  Eduardo A. Vallarino  Rodolfo Elías 《Marine Ecology》2015,36(3):611-622

  相似文献   

《测绘法》适应性浅析     

阮于洲 《东北测绘》2012,(3):219-220

分析了新时期测绘发展面临的新形势,对《中华人民共和国测绘法》规定的有关概念内涵、管理体制、运行机制、准入制度等的适应性进行了探讨,对进一步修订《中华人民共和国测绘法》提出了建议。  相似文献