海洋沉积物中生物扰动对微生物降解石油烃的影响

室内试验研究小头虫的生物扰动作用对沉积物油污降解的影响。实验在混加定量20~#柴油的小生境中进行6个月。期间对氧化还原电位不连续展(RPD)深度,Eh,烃类氧化菌菌量以及油浓度等参数做了连续测定。结果表明,小头虫的生物扰动作用通过改善沉积物次表层氧含量水平而促进了烃类氧化菌的生长,并因此使得沉积物中油污的生物降解提高了15％。     

多毛类18S rDNA和GOⅠ基因序列片段及其分子系统发育研究

应用分子系统发育学的方法,以多毛类18S rDNA和线粒体细胞色素C氧化酶亚单位Ⅰ(CO Ⅰ)基因序列片段为分子标记,结合形态学特征对它们的分类地位进行了探讨.结果显示,四索沙蚕-梯斑海毛虫分枝的遗传距离为0.044,(四索沙蚕-梯斑海毛虫)-小头虫分枝的遗传距离为0.072,四索沙蚕分枝与岩虫分枝的遗传距离比较大,为0.091.分析结果显示18S系统发育树将仙女虫科定位为矶沙蚕目的内群分类单元,100%的Bootstrap值进一步表明仙女虫科和索沙蚕科的姐妹群关系;分析结果还显示了小头虫目与矶沙蚕目的亲缘关系密切.     

深圳湾福田红树林潮滩大型底栖动物的垂直分布

2002年1月对深圳湾福田红树林潮滩0～10、10～20、20～30cm层的大型底栖动物的垂直分布进行了研究．结果表明，羽须鳃沙蚕主要分布在10～20cm层，奇异稚齿虫、德氏狭口螺、尖刺樱虫、寡鳃齿吻沙蚕、莫顿长尾虾、沼蚓和小头虫主要分布在0～10cm层．大型底栖动物在0～10cm层呈高密度分布是各种类型潮间带生物分布的共性，其原因是沉积物越深含氧量越低、食物越少．大型底栖动物个体的分布深度与其种类有关．     

多毛类小头虫卵子发生过程中亚微结构的变化

本文在亚微结构水平上介绍了多毛类小头虫Capitella Capitata(Fabricius)卵子发生的形态学,包括卵母细胞和滤泡细胞中内质网、线粒体和高氏体的变化,胞内腔隙和细胞表面陷窝的形成以及卵黄的自体和异体合成等。此外本文还就卵母细胞和滤泡细胞线粒体、内质网及高氏体参与卵黄合成和卵黄前体物质运输问题进行了分析。     

镉、三价铬和六价铬对小头虫Capitella capitata幼虫的效应

本文将镉、三价铬和六价铬对不同营养状态(喂食和不喂食)和不同年龄组小头虫幼虫的效应进行了观察,不喂食的幼虫对三种重金属的抗性逐渐下降,但它们的抗性随着幼虫的发育而增加。因此,我们认为,研究海洋污染时,必需考虑实验动物的年龄和营养状态。     

青岛湾有机质污染带小型底栖生物群落的研究

本文是1990年6月至10月,对青岛湾东侧有机质污染潮间带的小型底栖动物群落的研究结果。结果指出海洋线虫与多毛类小头虫的数量消长完全一致,它们保持着共栖或互利的共生关系。共鉴定出海洋线虫20种,其中6种占总丰度的90％。依据种类组成计算的Simpsion和Shannon-Wiener多样性指数,以及线虫与桡足类、小头虫与其他多毛类的数量比值指明,该有机质污染带正向着半污染带过渡。     

外来物种沙筛贝对厦门马銮湾大型底栖动物的影响

沙筛贝(Mytilopsis sallei)属于软体动物门(Mollusca)双壳纲(Bivalvia)帘蛤目(Veneroida)饰贝科(Dreissenidae),也称萨氏仿贻贝.20世纪90年代初作为鱼虾饵料被引到厦门马銮湾,逐渐成为附着生物的优势种,严重影响贝类养殖.在厦门马銮湾水域设计挂板实验和采集沉积物中大型底栖动物,获得了外来物种沙筛贝与其他大型底栖动物的时空分布数据.SPSS统计软件回归分析表明,沙筛贝与网纹藤壶(Balanus reticulatus)在挂板的垂直分布上呈负相关,沙筛贝高密度(大于105个/m2)时能导致网纹藤壶死亡,其主要原因是沙筛贝附着在网纹藤壶壳壁上,抢夺网纹藤壶食物而导致其饿死.无论是在挂板上还是在沉积物中,小头虫(Capitella capitata)、凿贝才女虫(Polydoraciliata)的数量有随沙筛贝数量增加而增加的趋势,这是因为成团的沙筛贝有利于小头虫和凿贝才女虫的栖息.     

多毛类18S rDNA和CO Ⅰ基因序列片段及其分子系统发育研究

应用分子系统发育学的方法，以多毛类18S rDNA和线粒体细胞色素C氧化酶亚单位Ⅰ（COⅠ）基因序列片段为分子标记，结合形态学特征对它们的分类地位进行了探讨．结果显示，四索沙蚕-梯斑海毛虫分枝的遗传距离为0．044，（四索沙蚕-梯斑海毛虫）-小头虫分枝的遗传距离为0．072，四索沙蚕分枝与岩虫分枝的遗传距离比较大，为0．091．分析结果显示18S系统发育树将仙女虫科定位为矾沙蚕目的内群分类单元，100％的Bootstrap值进一步表明仙女虫科和索沙蚕科的姐妹群关系；分析结果还显示了小头虫目与矶沙蚕目的亲缘关系密切．     

底栖生物生物量周年变化动态模型

大型底栖动物生态的研究主要集中在底栖动物的种类组成、分布、有机物含量和多样性指数等方面(刘瑞玉等，1992；余日清，1995；李荣冠等，1995)。大型底栖动物有些种类具有重要经济价值，如虾蟹类；有些种类是经济类动物的主要饵料，如多毛类的沙蚕；有些种类是环境的指示生物，如小头虫等。因此，研究底栖生物生物量与环境因子之间的定量关系，以及底栖生物生物量变化的数学模型的建立，对海洋水产增养殖和海洋环境学具有重要意义。     

底栖生物生物量周年变化动态模型

大型底栖动物生态的研究主要集中在底栖动物的种类组成、分布、有机物含量和多样性指数等方面(刘瑞玉等,1992;余日清,1995;李荣冠等,1995)。大型底栖动物有些种类具有重要经济价值,如虾蟹类;有些种类是经济类动物的主要饵料,如多毛类的沙蚕;有些种类是环境的指示生物,如小头虫等。因此,研究底栖生物生物量与环境因子之间的定量关系,以及底栖生物生物量变化的数学模型的建立,对海洋水产增养殖和海洋环境学具有重要意义。一、基本原理与理论推导摆动差分模型是建立在邓聚龙(1985)静态GM(0,N)模型基础上的,GM(0,N)模型表达式为:X1(1)=b1X2(…     

Coral Associations, Biocorrosion, and Space Competition in Pedum spondyloideum (Gmelin) (Pectinacea, Bivalvia)

Abstract. In the northern Red Sea several genera of sclcractinian corals arc used as hosts by Pedum spondyloideum. High population densities lead to space competition. The bivalves use chemical means to interact with each other and with their host corals. Due to dorsal attachment and predominantly ventral growth - to keep pace with coral growth - biocorrosion is less obvious, than in Lilhophuga.     

Biogeography, Taxonomical Status and Ecology of Alcyonium (Parerythropodium) coralloides (PALLAS, 1766)

Abstract. Ecology and morphology of Alcyonium (Parerythropodium) coralloides were studied in different sites of the Eastern Atlantic and the Mediterranean. The species is extremely variable in size, colony shape and colour. In the Mediterranean population, encrusting red colonies are mostly encountered, although lobate colonies also exist. White and pink colonies are considered mutants, which tolerate the stable environment of deeper habitats better than the conditions encountered in shallow biotopes. Mediterranean colonies are dioecious and reproduce sexually. In the Eastern Atlantic, lobate pink colonies are the most common form, and show little variability. These (at least partly) parthenogenic populations are considered offspring from stray larvae from more southern regions. This explains the rather patchy distribution of the Atlantic populations, as compared to the widespread distribution throughout the entire Western Basin of the Mediterranean and the Adriatic Sea. A study of the most important systematic characters of the species (growth form, sclerites and solenial network) leads to the conclusion that coralloides belongs to the genus Alcyonium. As a result, coralloides being its type-species, the genus Parerythropodium will have to be suppressed.     

Reproductive biology of Parazoanthus axinellae (Schmidt, 1862) and Savalia savaglia (Bertoloni, 1819) (Cnidaria,Zoantharia) from the NW Mediterranean coast

Despite the wide distribution of zoanthids, little is known about their pattern of reproduction. Here we investigate the reproductive biology of two Mediterranean species, the common Parazoanthus axinellae (Schmidt) and the rare Savalia savaglia (Bertoloni). For both species, samples were collected during an annual cycle, from January to December 2005, in the Western Mediterranean (Ligurian Sea, Italy). Both species are gonochoric. In P. axinellae the sex‐ratio (n colonies = 30) showed a slight predominance of male colonies (M/F = 1.35), whereas in the population of S. savaglia (n colonies = 15) a predominance of females was found (M/F = 0.3). In P. axinellae the first gametocytes were visible in March, whereas in S. savaglia they became visible in May. Both species reproduce at the end of autumn when seawater temperature begins to decrease. Parazoanthus axinellae (10 m depth) spawns eggs and sperms in November, whereas S. savaglia (67 m depth) spawns in December. In P. axinellae sexes were segregated on a rocky wall, with males occurring deeper, whereas male and female colonies of S. savaglia were irregularly dispersed in the population. The maximum number of oocytes differed between the species, being higher in P. axinellae than in S. savaglia.     

The Biology of Upogebia pusilla (PETAGNA) (Decapoda, Thalassinidea)

Abstract. Populations of the thalassinidean shrimp Upogebia pusilla were studied on tidal flats in the Northern Adriatic Sea. Biometric analysis showed a sexual dimorphism, especially in propodus size. Size frequency distributions revealed the presence of large animals during all seasons; recruitment by juveniles occurred in autumn. Moult intervals and moult increments were determined in the laboratory and used to generate growth curves which were compared with those calculated from size frequency distributions. The life span of U, pusilla is over 5 years. Ovigerous females occurred between March and September. Egg numbers were high in spring, lower in summer and increased with body size. The incubation time of embryos was 35 days; a female produces an estimated number of three egg batches during the breeding season. A total annual production of 994 kJ was estimated for a theoretical population of 100 animals; 13.5 % is spent for somatic growth, 31 % for egg production of females, and 55.2% is lost as exuviae. The population structures, growth and breeding patterns, as well as embryonic and larval development within the Upogebiidae and Callianassidae are discussed.     

The Biology of Upogebia pusilla (PETAGNA) (Decapoda, Thalassinidea)

Abstract. The distribution of the thalassinidean shrimp Upogebia pusilla was studied at four sites in the North Adriatic Sea: 1) a tidal flat in the lagoon of Grado, 2) a tidal flat at Lido di Staranzano near the mouth of the Isonzo, 3) a mud flat seawards of a salt marsh in a protected bay north of Rovinj, and 4) a sublittoral station in 6m depth near Aurisina. Information on grain size distribution, organic content, amount of debris, redox profiles and pH of sediment as well as temperature and salinity is given. Density, as determined by hole counts and a hole: burrow relationship derived from resin casting, generally increased with increasing water depth in the intertidal. The upper limits ranged between +10cm (Rovinj) and -20cm (Grado); densities between mean water and low water level varied strongly due to microtopography and macrophyte cover. Maximum densities in the intertidal ranged from 189 (Grado) to 2420 (Rovinj, juveniles) animals m². Shrimp density at the sublittoral station ranged between 80 and 230 m"². The zonation of the Upogebiidae and Callianassidae with respect to environmental parameters is discussed.     

Ibla cumingi (Crustacea, Cirripedia) -A Gonochoristic Species (Anatomy, Dwarfing and Systematic Implications)

Abstract. Ibla cumingi (Crustacea, Cirripedia) is a gonochoristic species with dwarf males. The anatomy of both sexes is described and compared with that of other Cirripedia s. str. Systematic implications on the basis of anatomy and biology are given. The degree of dwarfing in the male and the possible cause and way of reduction are discussed.     

Polymorphic Zooids in Deitaic Species Populations of Conopeum seurati (CANU, 1928) (Bryozoa, Cheilostomata)

Abstract. Deltaic populations of Conopeum seurati from diverse environmental settings have variable phenotypes related to strong competitive regimes and to dissolved oxygen minima. Under extremely stressful conditions, the poorly canalized phenotype of C. seurati displays new additional features such as kleistozooids ( kleistós = closed) and chaotic celleporoid layers. Kleistozooids are clearly distinguishable polymorphs characterized by the presence of a compact, imperforate frontal membrane and by a strongly reduced lumen of the "opesium". They commonly aggregate in clusters of regularly-arranged individuals that store a large quantity of proteic material. The inferred function of these cell-like structures is to supply nutrients for basic colony activities. Celleporoid layers are, possibly, a developmental relaxation of the colony of C. seurati for a more efficient use of space in competitive interactions.
Both celleporoid layers and kleistozooids reveal the magnitude of intracolony variability of a widespread opportunistic bryozoan species.     

Larval shell development of the toheroa,Paphies ventricosa (Gray, 1843) (Mactracea: Mesodesmatidae)

The larval shells of Paphies ventricosa, reared to settlement in the hatchery, are similar in longitudinal profile to shells of some other mactracean larvae; the umbo‐stage larval shells are nearly round with the anterior margin less broadly curved than the posterior margin, the anterior end is longer than the posterior end, and the umbo is broadly rounded. Straight‐hinge larvae had total lengths up to 149 μm, and total heights up to 126 μm, and umbo larvae had total lengths up to 320 μm, and total heights up to 282 μm. The larvae settled in about 22 days at a size of about 270 μm. The larval hinge structure bears some similarities to those of other mactracean larvae.     

Comparison of the biology, dynamics, and secondary production of Talorchestia brito (Amphipoda, Talitridae) in Atlantic (Portugal) and Mediterranean (Tunisia) populations

The biology, population dynamics, and production of Talorchestia brito were studied at two sandy beaches located on the Atlantic (Portugal) and on the Mediterranean (Tunisia) coasts, respectively. The seasonal variation in abundance and the overall densities were similar in both populations. Reproduction occurred from February to September in the Atlantic, and from March to early November in the Mediterranean. The sex ratio was male biased in the Atlantic, and female biased in the Mediterranean. Based on data from the Atlantic population, both abundance and the proportion of reproductive females were positively correlated with temperature, while the proportion of juveniles in the population was positively correlated with temperature and sediment moisture. On average, individuals from the Atlantic were larger than the ones from the Mediterranean. Life span was estimated at six to nine months in the Atlantic, and five to eight months in the Mediterranean. Talorchestia brito was shown to be a semiannual species, with iteroparous females producing two broods per year, and exhibited a bivoltine life cycle. The minimum age required for males' and females' sexual differentiation and for female sexual maturation was shorter in the Mediterranean. Growth production (P) was estimated at 0.19 g m⁻² y⁻¹ ash free dry weight (AFDW; 4.3 kJ m⁻² y⁻¹) in the Atlantic population, and 0.217 g m⁻² y⁻¹ AFDW (4.9 kJ m⁻² y⁻¹) in the Mediterranean one. Elimination production (E) was estimated at 0.35 g m⁻² y⁻¹ AFDW (7.9 kJ m⁻² y⁻¹) in the Atlantic, and 0.28 g m⁻² y⁻¹ AFDW (6.3 kJ m⁻² y⁻¹) in the Mediterranean. The average annual biomass ( ) (standing stock) was estimated at 0.032 g m⁻² in the Atlantic beach, and 0.029 g m⁻² in the Mediterranean one, resulting, respectively, in ratios of 5.9 and 7.5 and ratios of 10.8 and 9.6. Like other talitrids, T. brito exhibited geographic variation in morphometrical characteristics, sex ratio, growth rates, life span, and reproduction period, with the Atlantic population presenting a slower life history.