人工养殖条件下真蛸的生物学特性及胚胎发育

对人工养殖条件下真蛸(Octopus vulgaris)的生物学特性和胚胎发育进行了初步研究.结果表明,真蛸喜栖息于阴暗的场所,隐居,主要捕食一些活体甲壳类和贝类,也能很好的适应死鱼、蟹和贝类等饵料,夜间或傍晚摄食较为活跃.繁殖季节,雌、雄个体间存在交配行为,临产时亲蛸(♀)藏入巢穴,受精卵分批产出,呈穗状悬挂于巢穴顶部或四壁,亲蛸(♀)具有护卵行为.人工养殖条件下亲蛸不能全部产出其所怀的卵,产卵量为7×104～20×104粒,单位体重产卵量为42～71粒·g-1.受精卵为盘状卵裂,经过肉眼可见的红珠期、黑珠期、胚胎的逆转,水温18.2～22.1℃时,真蛸幼体经过35～42 d孵化出膜;22.3～26.9℃时,真蛸幼体经过24～37 d孵化出膜;24.6～28.3℃时,真蛸幼体经过23～33 d孵化出膜.     

Effects of supplementation of decapod zoea to Artemia basal diet on fatty acid composition and digestive gland histology in common octopus (Octopus vulgaris) paralarvae

The present study aimed to evaluate the effect of the supplementation of different crab zoeas to enriched Artemia basal diet for Octopus vulgaris paralarvae during the first month of life. Paralarvae were fed using enriched Artemia nauplii alone and Artemia co‐fed either first zoea stages of Grapsus adscensionis or Plagusia depressa. The experiment was carried out over a period of 28 days, in 0.12 m³ tanks with a flow‐through rearing system. Growth in dry weight as well as mantle length and width were assessed weekly. Additionally, prey and paralarvae fatty acid composition and digestive gland (DG) histology were evaluated. Addition of low amounts of crab zoeas (approx. 100 indv. L^?1 day^?1) provided during critical life stages of O. vulgaris proved to be good enough to improve paralarvae growth and survival in comparison with those fed exclusively on enriched Artemia. These results were supported by the finding of a higher number of glycoprotein absorption vacuoles in the DG from paralarvae co‐fed crab zoeas, suggesting a higher feeding activity. In addition, fatty acid analysis of crab zoea showed that these are good sources of dietary arachidonic and eicosapentaenoic acids during the octopus planktonic life stage, whereas the low docosahexaenoic (DHA) content suggests the use of additional DHA sources or higher zoea densities to meet paralarvae nutritional demand to carry out a successful metamorphosis to benthic life.     

3种饵料对暂养长蛸生长的影响

用缢蛏、凡纳滨对虾、弧边招潮蟹投喂暂养长蛸,通过测量长蛸的摄食率、质量增加率、特定生长率、饵料转化率,分析3种饵料对长蛸生长的影响.试验结果表明,投喂弧边招潮蟹的长蛸摄食稳定,生长快,特定生长率及饵料转化率高,活动力强;投喂凡纳滨对虾的长蛸开始摄食量较大,生长较快,饵料转化率较高,一段时间后生长减慢,最后几乎停止生长;...     

Diet and trophic role of octopus on an abalone sea ranch

Gastric tract (crop and stomach) and stable isotope analyses (SIA) were used to evaluate the dietary composition of resident, commercially important Octopus aff. O. tetricus Gould, and its importance as a predator of Haliotis laevigata Donovan, on artificial abalone habitats. Taxonomic diversity and resolution of diet were higher in crops (13 taxa) than stomachs (10 taxa), with the latter dominated by unidentifiable material (%Volume = 74%). Crops contained mainly molluscs (~54%, including 31% abalone) and crustaceans (33%), suggesting octopus are important predators of abalone on the sea ranch. Dietary composition of crops did not differ with increasing octopus weight (<300 g, 300–999 g, ≥1,000 g wet weight), paralleling the findings of SIA and reflecting the high stocking densities of abalone that are able to be consumed by octopus of all sizes. The SIA also revealed that octopus occupy a mid‐trophic level, slightly below teleosts and loliginid squids.     

12种麻醉剂对长蛸的麻醉效果

本研究旨在探讨硫酸镁、乙醇、氯化镁、丁香酚、MS-222、氯化锰、利多卡因、盐酸普鲁卡因、乙二醇苯醚、薄荷醇、苯佐卡因和三氯叔丁醇对长蛸（Octopus minor）成体的麻醉效果。结果表明,在实验浓度下硫酸镁、丁香酚、MS-222、氯化锰、利多卡因、盐酸普鲁卡因、乙二醇苯醚、薄荷醇、苯佐卡因和三氯叔丁醇对长蛸无麻醉作用。在0.2~0.6 mL/L乙二醇苯醚、0.05 g/L和0.06 g/L薄荷醇、0.5 g/L苯佐卡因、40 μL/L丁香酚和50~500 mg/L MS-222浓度的溶液中,长蛸出现中毒现象。2 mL/L乙醇和2 g/L氯化镁溶液对长蛸无麻醉作用;6~40 mL/L的乙醇和6~35 g/L的氯化镁溶液中长蛸出现麻醉现象。根据长蛸在4~40 mL/L乙醇和4~40 g/L氯化镁溶液中的麻醉和复苏过程将麻醉程度分为5个时期,复苏过程分为4个时期。长蛸在15~35 g/L氯化镁和10~40 mL/L乙醇中能够达到第4期麻醉,此时期适于观察和操作。在4~35 mL/L乙醇溶液中,随着浓度的增加麻醉时间逐渐缩短,复苏时间逐渐增加,在40 mL/L时长蛸产生应激反应麻醉时间变长。3~35 g/L氯化镁溶液中,随着浓度的增加麻醉时间逐渐缩短,复苏时间逐渐增加。10 mL/L乙醇和20 g/L氯化镁对长蛸的麻醉和复苏总时间最短,分别为26 min和40 min。实验证明,乙醇和氯化镁均可作为长蛸的麻醉剂,在麻醉效率方面乙醇好于氯化镁。     

长蛸平衡囊的形态结构和神经支配模式

采用光镜、扫描电镜、透射电镜和同步辐射等方法对长蛸平衡囊的形态和神经支配进行了研究。平衡囊位于长蛸头后部两侧的软骨腔中,表面是近似椭圆形的膜质结构。平衡囊表面缠绕的大量纤维丝,与软骨壁粘联后使囊悬浮于腔内的淋巴液中。平衡囊中的感觉毛细胞分为感觉斑(macula)和感觉脊(crista)两个区域,其中感觉斑毛细胞区被包裹着胶质粘液层的耳石覆盖,毛细胞动纤毛顶端嵌入耳石底层钙质微晶体间隙中;感觉脊区毛细胞呈带状螺旋型排列,共分九节,其毛细胞均由胶质顶(cupula)覆盖。毛细胞仅含等长、9+2微管型动纤毛,无静纤毛,其周围细胞含微绒毛。平衡囊内的一软骨凸起结构,相对感觉脊(anticrista),其表面无感觉毛细胞。同步辐射结果表明:支配感觉斑区的神经仅一条,而感觉脊区却由两条神经束从脑部经囊表后分支进入各自支配的毛细胞节区。     

Effect of two fresh diets and sexual maturation on the proximate and fatty acid profile of several tissues in Octopus vulgaris: specific retention of arachidonic acid in the gonads

Most nutritional studies on Octopus vulgaris were based on males to avoid interaction with reproductive processes, focusing on muscle and digestive gland tissues. This study intends to evaluate the effect of two fresh diets, a fish diet (bogue Boops boops) and a mixed diet (600 g kg^?1 crab Portunus pelagicus and 400 g kg^?1 bogue), on the biochemical composition of muscle, digestive gland and gonad in males and females of O. vulgaris. Six octopuses per diet were selected (n = 3 per sex) after 60 days of rearing in floating cages. Weight increase was higher in males (3–3.2 kg) than in females (0.9 kg) regardless of diet associated with sexual maturation. Gondosomatic Index in females was 11.3–13.4%. High‐lipid content in fish (440 g kg^?1 dw) was reflected in digestive gland regardless of the diet, while muscle and testis showed a relatively stable composition. The increase in protein content in the ovary was related to sexual maturation. The low arachidonic content in bogue was reflected in all tissues, with no apparent negative effect on growth and welfare. However, specific retention of arachidonic in the gonads, related to high arachidonic content in crab, underlined the importance of this fatty acid in for gonad development in O. vulgaris.     

Evaluation of relationship between Chilean octopus (Octopus mimus Gould, 1852) egg health condition and the egg bacterial community

The objective of this study was to evaluate how bacterial community associated with Chilean octopus (Octopus mimus) egg was related to egg health condition using a culture dependent method and PCR‐DGGE fingerprinting technique. Total heterotrophic bacterial number of fresh egg was much lower than infected egg. However, biodiversity of culturable bacterial community associated with the fresh egg exhibited a higher diversity than the infected egg. Result of a culture dependent method showed that Roseobacter clade was predominant in the fresh egg, while predominant species in the infected egg was γ‐proteobacteria. DGGE fingerprinting technique showed that fresh egg associated unculturable bacterial community was constituted of Roseobacter clade and Bacteroidetes, whereas Bacteroidetes was predominant bacteria in the infected egg. These results suggest that there might be some sort of relationship between octopus eggs associated bacterial community and egg health condition. Moreover, Roseobacter clade and Bacteroidetes might be potential symbiotic bacteria associated with the octopus egg, and some γ‐proteobacteria might be involved in octopus egg disease. In particular, Roseobacter clade may play an important role in octopus egg health and it raises the possibility that this clade can be utilized as potential probiotics for octopus aquaculture.     

Enrichment of Artemia metanauplii in phospholipids and essential fatty acids as a diet for common octopus (Octopus vulgaris) paralarvae

Highly unsaturated fatty acids (HUFA), like the eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids and polar lipids (essentially phospholipids, PL) have been identified as essential nutrients for common octopus (Octopus vulgaris) paralarvae. However, they are not available in sufficient amounts in live preys as Artemia, making necessary a supplementation of these nutrients previous use. A commercial emulsion, soya liposomes, and marine and soya lecithins were used to supply HUFA and PL to Artemia metanauplii, those being regarded as suitable size preys for octopus paralarvae. Our results prove that a simultaneous enrichment in HUFA and PL is possible using enrichment diets combining HUFA‐ and PL‐rich products in short‐term (4 h) incubations. Particularly interesting was the enrichment efficiency shown by the marine lecithin, which enabled the enhancement of the PL fraction of Artemia metanauplii and, importantly, also their HUFA with a remarkable 13% DHA of total fatty acids. Marine lecithin arises as a novel enrichment diet for Artemia and more effective than some commercial products currently used in hatcheries worldwide.     

Growth,food intake,protein retention and fatty acid profile in Octopus vulgaris (Cuvier, 1797) fed agglutinated moist diets containing fresh and dry raw materials based on aquaculture by‐products

The lack of specific compound diets for cephalopods is limiting the industrial development of some species. In this study, four agglutinated moist diets were tested in individually reared Octopus vulgaris (979 ± 151 g) for 8 weeks. All diets were based on bogue Boops boops, accidentally reared in fish farms (aquaculture by‐product), and agglutinated with alginate and calcium. One diet was based exclusively on bogue fillets, two on bogue fillets complemented with meat from two crab species (Portunus pelagicus, Grapsus grapsus) and the last one on bogue and G. grapsus meals. As a control diet, bogue and P. pelagicus were supplied fresh on alternate days. All diets induced similar feed intake (2.1–2.6% day^?1). However, the meal‐based diet induced negative growth in comparison with the control and the other agglutinated diets (0.80–0.85% day^?1). Higher lipid content in agglutinated diets (28–30% dw) in comparison with the control diet (16% dw) led to higher protein retention in muscle. These results underline the inadequacy of traditional meals in diets for cephalopods and that the inclusion of crab meat did not increase feeding rates and growth in O. vulgaris. The dietary fatty acid, with high levels of oleic and linoleic acid and low levels of ARA, clearly reflected in digestive gland, while only decreasing ARA and increasing EPA levels were observed in muscle, with no apparent negative effect on growth.