Macrofauna Associated With Sponge Species of Different Morphology

Abstract. The macrofaunas associated with the three morphologically different North Aegean Sea sponge species Agelas oroides, Aplysina aerophoba , and Axinella cannabina were compared. The faunal abundance was not related to sponge surface area for any of the three species. Each sponge species supported a significantly different number of individuals per unit canal volume; A. aerophoba supported the most, A. oroides the least. A. aerophoba supported the highest species richness, A. cannabina the lowest. Canal volume was a good predictor of associated faunal abundance and species richness for two of the three sponge species. Faunal abundance was also directly related to sponge mean canal diameter. The species composition of associated fauna was similar on A. aerophoba and A. oroides and significantly different on A. cannabina .     

Efficient computation method for two-dimensional nonlinear waves

I~IOWNUmerics wave tank is a ~ tOOl by which variouS nonlinear wave - ac interactionpwhleln can be treated in time domain. As the face stage, we f~ our efforts on the devious of an effita saution tee~ of fully nofor waves. aam numtried of water - wavesconnected PwhlemS, es~ in a wave tank, is alwayS comas Of PartS: wave generation, P~ and a~. The effi~ Of a nUm~ wave tankdepends not Only on the qwhty Of the wave abotion tecboaue, which allowS the lOng times~ and keePS finite tank leng…     

Palaeogeographical influence on Late Eocene biosiliceous sponge-rich sedimentation, southern Western Australia

Late Eocene nearshore shallow-marine environments within the Bremer and western Eucla Basins of southern Western Australia were characterized by the thick deposition of spongolite and spiculite deposits. Epibenthic sponge communities dominated estuaries and topographically complex basin margin embayments-archipelagos, while cool-water carbonates with up to 10% sponges accumulated in open-shelf environments. The transition from a biosiliceous to calcareous epibenthos was related to the degree of palaeogeographical 'protection'. Within basement-protected embayments there was an offshore gradation from shoreface spongolite and pure spiculite to a muddy spiculite facies towards central embayment areas. Calcareous fossils are rare throughout embayment facies, but rapidly increase in more open outer archipelago areas. This depositional relationship occurred along 2000 km of the Late Eocene southern Australian coastline. Palaeogeographical protection from strong currents acted in concert with: (1) a planar, low-gradient inland topography with sluggish run-off, supplying fine-grained sediment, nutrients, and abundant dissolved silica; and (2) a microtidal setting, weak to moderate swells and opposing wind and Coriolis surface current forcing, which inhibited water exchange between embayments-estuaries and the open shelf. This situation led to an embayment water chemistry that encouraged prolific sponge growth. Calcareous spiculites record the mixing front between these embayment waters and normal open-shelf waters supporting cool-water carbonates.     

Preliminary paleolimnological study of rocha lagoon, SE Uruguay

Physical, chemical and biological data from a sedimentary profile of Rocha lagoon (Uruguay) are presented. Analyses of silica remains showed that opal phytoliths, diatoms, sponge spicules and chrysophyte cysts were the most important contributors to biogenic silica. Organic matter, total nitrogen and total phosphorus were used to infer past trophic development. Physical analysis of sediments allowed us to identify five lithological units related to sea level variation and climatic events.     

串管海绵一新属——新瓜达卢佩海绵属(Neoguadalupia),兼论塞巴加斯海绵科各属间的关系

本文论述了云南广南董那孟下二叠统生物礁内的串管海绵化石,提出塞巴加斯海绵科具有三个明显演化分枝,这是它们对不同生态环境长期适应的结果。文章讨论了新属Neoguadalupia与相关属的区别,确立了在串管海绵演化史上的地位,并详细描述和讨论了Neoguadalupia elegana gen.et sp.nov.     

海绵共附生微生物基因多态性的RAPD-PCR分析

采用传统分离手段对中国南海海域的细薄星芒海绵（Stelletta tenui（Lindgren,1897）1、皱皮软海绵（Halichondria rugosa（Ridley＆Dendy））、澳大利亚厚皮海绵（Craniella australiensis（Carter））、贪婪倔海绵（Dysidea avara（Schmidt））4种海绵体内的微生物进行了分离培养,随机挑选64株芽孢杆菌属细菌（每种海绵16株）进行了RAPD-PCR基因多态性分析。研究表明,一些海绵微生物是可以通过传统分离手段得到的,来自同一或者不同海绵的微生物均具有丰富的基因多态性。     

Temperature‐ and size‐associated differences in the skeletal structures and osculum cross‐sectional area influence the pumping rate of contractile sponge Cinachyrella cf. cavernosa

Sponges alter the proportion of structural and morphological components such as spicule skeleton and number of oscula in response to environment, development and growth. Such mechanisms indicate morphological and physiological variations within populations. We measured the pumping rate of different sized specimens of contractile sponge Cinachyrella cf. cavernosa present in the intertidal rock pools, during morning and afternoon low tides along the central west coast of India. Additionally, we measured the exhalant opening (oscular cross‐sectional area—OSA), tissue density, spicule skeleton weight and the abundance of choanocyte chambers to assess the morphological variations. Water temperature and sponge size showed a significant positive effect on pumping rate. OSA and the number of oscula increased with sponge size, but the sponge volume‐specific pumping rate did not increase (0.029 ± 0.020 ml/s ml^‐1). Histological sections showed the abundance of chaonocyte chambers increased marginally with the sponge size, but the contraction state affected the count. Both tissue density and spicule skeleton weight were positively correlated with sponge size, particularly the increase in the size and number of spicule bundles radiating from the centre indicated a denser core in larger specimens. The subcortical lacunae and the peripheral choanosome with high abundance of canals appear to be the major volume reduction zones during contraction events. Our results indicate that the size and number of spicule bundles increase with sponge volume and the variation in temperature, contraction state, and size and number of oscula influence the pumping rate of C. cf. cavernosa.     

一株抗硅藻附着的海绵附生菌的鉴定及发酵条件优化

为了从海绵共附生微生物中寻找天然高效抗污损活性物质,本文针对前期研究获取的4株具有显著抗硅藻附着的活性菌株进行活性验证和比较,选出其中最优菌株进行菌种鉴定及发酵条件优化.比较了活性菌株对小新月菱形藻(Nitzschia closterium)、咖啡双眉藻(Amphora coffeaeformis)、碎片菱形藻(Nitzschia frustulum)附着的抑制活性,确定菌株UST050418-715为最优菌株;通过16S r DNA的测序分析,结合平板的菌落形态和扫描电镜下菌体特征,鉴定活性菌株UST050418-715为短小芽孢杆菌(Bacillus pumilus).为优化该菌株的培养条件,选择了酵母粉、蛋白胨、Na Cl、p H值进行四因素三水平的正交实验,对菌株培养条件进行优化.发现选择的4个因素对应的菌株发酵产物对硅藻附着的抑制活性大小不同,影响显著性顺序是酵母粉蛋白胨Na Clp H值,综合菌株发酵产物活性、粗提物产量和菌株生长情况进行分析,确定菌株UST050418-715基于海洋2216E培养基的最佳发酵条件为:蛋白胨含量7.5 g/dm3,酵母粉含量3 g/dm3,Na Cl含量10.45 g/dm3,p H值9.5.     

Construction of a Metagenomic DNA Library of Sponge Symbionts and Screening of Antibacterial Metabolites

To study the bioactive metabolites produced by sponge-derived uncultured symbionts, a metagenomic DNA library of the symbionts of sponge Gelliodes gracilis was constructed. The average size of DNA inserts in the library was 20 kb. This library was screened for antibiotic activity using paper disc assaying. Two clones displayed the antibacterial activity against Micrococcus tetragenus. The metabolites of these two clones were analyzed through HPLC. The result showed that their metabolites were quite different from those of the host E. coli DH5α and the host containing vector pHZ132. This study may present a new approach to exploring bioactive metabolites of sponge symbionts.     

Biodiversity,ecological structure,and change in the sponge community of different geomorphological zones of the barrier fore reef at Carrie Bow Cay,Belize

Changes in the relative abundance of benthic groups on the barrier fore reef at Carrie Bow Cay, Belize, point to a significant reduction of corals and an expansion of the sponge community in 1995–2009. Fifty‐one species are now present in the four geomorphological zones of this reef: the low‐relief spur‐and‐groove zone, the inner reef slope, the outer ridge, and the fore‐reef slope (to a depth of 30 m). Five species are new additions to the sponge fauna reported for Belize, and six species account for 42.6% of the total assemblage: Niphates erecta (9.60%), Aiolochroia crassa (8.8%), Niphates digitalis (6.9%), Callyspongia plicifera (6.63%), Aplysina archeri (5.37%) and Xestospongia muta (5.37%). Species richness, average density, diversity and evenness indexes are statistically similar in these four zones but some species appear to be more dominant in certain areas. In the same 30 years, coral cover has decreased by more than 90%, while the octocoral cover has greatly increased (by as much as 10‐fold in the low‐relief spur‐and‐groove zone). Thus the Carrie Bow fore reef appears to be undergoing a transition from coral dominance in the late 1970s to algae dominance today, with other benthic groups such as sponges and octocorals showing signs of gradual recovery.