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John C. Town 《新西兰海洋与淡水研究杂志》2013,47(4):427-435
Dietary composition in Astrostole scabra was ascertained by regular sampling at four geographically separated locations on the Kaikoura coast between January 1976 and January 1977. A. scabra is a food generalist and scavenger with a diet composed mainly of molluscs and crustaceans belonging to more than 60 genera. The diet was dominated numerically by chitons and trochid molluscs. Several site‐specific differences in dietary composition were apparent. Only Ischnochiton maorianus was a numerically important prey species at all study sites. Dietary diversity and evenness were more or less constant and comparable both seasonally and geographically. The proportion of intertidal seastars feeding fluctuated during the study from a peak of 42% in January to 23.7% in June 1976. Prey species were consumed in proportions independent of their abundance. In the laboratory, A. scabra, free of ingestive conditioning, discriminated between different prey species and preferentially consumed I. maorianus. There were strong prey preferences at the specific, but not at the familial, level. 相似文献
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黑海参(Holothuria atra)是热带珊瑚礁大型底栖动物群落中的代表种类之一,其摄食活动对珊瑚礁生境底质有机物的循环再利用具有重要作用。本文研究了三亚蜈支洲岛典型热带珊瑚礁海域野生黑海参的沉积物选择特征及其触手和消化系统结构功能的适应性。结果表明,黑海参摄取的沉积物颗粒相对较粗,其中粒径0.25mm部分占到了总重量的96.67%。触手上3—6个乳突形成乳突簇[直径(283.00±40.94)μm],适宜摄取大颗粒沉积物。黑海参胃内含物有机物含量显著高于环境沉积物,证实其对有机物含量的选择性;粒径0.25mm部分有机物含量占摄入总有机物量的75%,与环境沉积物中相同粒度的有机物总量占比接近(76%),表明黑海参选择的沉积物粒径范围有效保证了其高效摄入有机质。黑海参前肠的脂肪酶、淀粉酶、纤维素酶、胰蛋白酶活性最高,同时绝大部分的有机质(98.33%)在前肠被吸收。组织学定量分析表明,黑海参前肠黏膜层厚度最大,占总厚度的56.33%,这与其高效吸收有机质的功能相适应;后肠的肠壁总厚度和黏膜下层、肌层厚度均显著高于前肠和中肠,表明其具有相对更好的弹性和收缩能力,适合于大颗粒有机质的高效输送与排出。研究结果证实,黑海参摄食器官和消化道独特的结构与功能保证了其在珊瑚砂粗颗粒生境中高效摄取有机物。 相似文献
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为了解糙海参(Holothuria scabra)精子发生的过程及其形态结构,作者于2013年11月~2014年4月每月采集2头海南岛的野生雄性糙海参,取精巢组织固定后分别制作投射电镜、扫描电镜切片和石蜡包埋切片,在电镜和光镜下连续观察。观察结果表明,糙海参精子发生经历了精原细胞、初级精母细胞、次级精母细胞、精细胞和成熟精子5个阶段。精细胞分化过程可分为3个时期,早期:细胞核前端出现前顶体囊;中期:顶体腔内出现围顶体物质;后期:胞质往尾部方向收缩,形成精子中部。糙海参成熟精子全长约60μm,由头部、中部和尾部3部分组成,为典型的鞭毛型精子。精子头部呈球形,精子核中顶体形态为"U"型内陷囊状体,围顶体物质呈"月牙"形,核染色质凝集成团块状。精子中部由一个巨大的线粒体和中心粒复合体融合而成。精子尾部鞭毛横切面为典型的"9+2"微管结构。本研究可为糙海参的繁殖生物学和人工育苗提供理论参考。 相似文献
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West versus East Mediterranean Sea: origin and genetic differentiation of the sea cucumber Holothuria polii 
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下载免费PDF全文 We studied the genetic structure of the sea cucumber Holothuria (Roweothuria) polii (Delle Chiaje 1823) by analysing the mitochondrial DNA variation in two fragments of cytochrome oxidase I (COI) and 16S genes. Individuals were collected in seven locations along the Mediterranean Sea, which cover a wide range of the species distribution. We found high haplotype diversity for COI and moderate diversity for 16S, and low nucleotide diversity for both genes. Our results for the COI gene showed many recent and exclusive haplotypes with few mutational changes, suggesting recent or ongoing population expansion. The Western and Eastern Mediterranean populations exhibited slight but significant genetic differentiation (COI gene) with higher genetic diversity in the East. The most ancient haplotype was not present in the westernmost sampling location (SE Spain). The oldest expansion time was observed in Turkey, corresponding to mid‐Pleistocene. Turkey had also the highest genetic diversity (number of total and exclusive haplotypes, polymorphisms, haplotype and nucleotide diversity). This suggests that this region could be the origin of the subsequent colonizations through the Mediterranean Sea, a hypothesis that should be assessed with nuclear markers in future research. 相似文献
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沉积食性海参通过大量摄取沉积物在热带珊瑚礁生态系统中发挥重要的生态功能,但其食物来源组成尚不清楚。本文研究了海南三亚近岸典型珊瑚礁海域红腹海参(Holothuria edulis)及绿刺参(Stichopus chloronotus)脂肪酸组成,利用脂肪酸标志法探讨了夏季和冬季两种海参的食物来源异同。结果表明,红腹海参与绿刺参的脂肪酸组成存在显著种间和季节差异。7月份时,鞭毛藻及原生动物是绿刺参的重要食物来源,而12月份绿刺参的食物来源较为广泛,涵盖鞭毛藻及原生动物、异养细菌褐藻和红藻等。红腹海参7月份的主要食物来源包括褐藻和红藻等,12月份异养细菌和绿藻在红腹海参的食物组成中比例相对较高。研究结果可为揭示红腹海参及绿刺参摄食活动的生态功能提供数据支持。 相似文献
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黑海参(Holothuria atra)体壁经Folch 法提取总脂, 用HCl-甲醇进行甲酯化处理, 以气相色谱/质谱法分析总脂中的脂肪酸组成。从黑海参中共分析出28 种化合物, 包括25 种脂肪酸甲酯和3 种脂肪醛二甲基缩醛。黑海参体壁中的饱和脂肪酸含量为22.93%, 以C16:0(5.49%)和C18:0(4.38%)为主; 不饱和脂肪酸含量为65.19%, 其中单不饱和脂肪酸33.86%, 主要为C20:1(n-9)(15.90%); 多不饱和脂肪酸为31.33%, 主要为C20:4(n-6)(19.57%)和C20:5(n-3)(5.86%)。脂肪醛二甲基缩醛含量为7.28%, 表明黑海参体壁总脂中含有较丰富的缩醛型甘油酯。 相似文献
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To elucidate which environmental factors affect lagoonal‐scale sea cucumber distributions in Ishigaki Island, Okinawa, Japan, intertidal and subtidal areas of three coral reef lagoons were classified into several ground divisions by bottom characteristics, and sea cucumber densities therein were compared with the composition of sediment cover, grain size and organic content, and coverage of macroalgae, seagrass, and massive corals. Holothuria atra, Holothuria leucospilota, Stichopus chloronotus, and Synapta maculata had highest densities in the nearshore areas but were rare in reef flats, probably because of wave disturbance and low areal cover of sand sediment as potential feeding environments. No relationship was observed between sea cucumber densities and sediment organic content or grain size. Thus, even if these sea cucumbers have selectivity for habitats with a high sediment organic content, the effect of such selectivity on the distribution seems to be limited to relatively small areas. The sea cucumber distributions can be classified by bottom sediment/biota composition into bedrock (H. leucospilota), sand (H. atra), and lagoonal types (St. chloronotus and Sy. maculata). These habitat selections were possibly related to various aspects of sea cucumber ecology such as refuge from predators or turbulence, or settlement and nursery place, which have implications for importance of the complexity of lagoonal‐scale topography and sediment/biota conditions for the coexistence of various holothurian species. 相似文献
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为了研究微塑料对黑海参(Holothuria atra)免疫及消化生理的影响,将体重为(47.61±6.97) g的黑海参暴露于添加了不同浓度(0、10~2、10~4、10~6粒/L)聚苯乙烯微塑料的海水中,分析了黑海参的免疫和消化生理指标的变化情况。结果表明,海水中的微塑料浓度对黑海参体腔细胞的数量和吞噬活性,体腔液中酸性磷酸酶(ACP)、溶菌酶(LZM)和超氧化物歧化酶(SOD)活性均有显著影响(P0.05),而对碱性磷酸酶(AKP)活性没有显著影响。随着微塑料浓度升高,黑海参的体腔细胞数量以及体腔液中ACP、LZM和SOD活性呈先持续增加后降低的趋势,体腔细胞数量、体腔液中ACP活性均在104粒/L浓度达到峰值,体腔液中LZM和SOD活性则在10~2粒/L浓度达到峰值;而体腔细胞的吞噬活性随着微塑料浓度的增加而持续增加。黑海参消化道内的淀粉酶受海水中的微塑料浓度的影响显著(P0.05),胰蛋白酶活性和脂肪酶活性没有显著变化。随着微塑料浓度升高,黑海参肠道淀粉酶活性呈先持续增加,在10~4粒/L浓度达到峰值,而后又降低;胰蛋白酶活性随着微塑料浓度的增加持续增加;而三种微塑料浓度下黑海参的脂肪酶活性均低于空白组。由此可见,海水中添加微塑料后,黑海参体内产生了免疫防御反应,并倾向于优先消化淀粉和蛋白质以快速获取能量从而适应周围环境的改变;海水中高浓度的微塑料可能对黑海参的体腔细胞结构产生损伤,导致其免疫防御能力下降,影响其正常生理活动。 相似文献
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本研究测定了壳寡糖对海南热带糙海参(Holothuria scabra)体腔液和体壁组织中免疫相关因子,酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、溶菌酶(LSZ)和溶血素活性的影响。结果表明,投喂0.5%壳寡糖对糙海参体腔液中AKP、ACP、LSZ和溶血素活性均有明显增强作用(P0.05),其中对ACP和LSZ活力有极显著的影响(P0.01),且投喂6 d内活性均持续增强;0.5%壳寡糖对体壁组织匀浆液中AKP、ACP活性明显增强(P0.05),但随着时间延长,对体壁组织中LSZ和溶血素作用不明显。壳寡糖可以提高海南热带糙海参(Holothuria scabra)的非特异性免疫力。 相似文献