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31.
The present study focuses on the reproductive success of transplants of the bath sponge Spongia officinalis Linnaeus, 1759, with the aim of investigating the possibility of restocking this species, one of the most endangered organisms of the Mediterranean sessile zoobenthos. Transplants of S. officinalis, collected from a wild population along the Apulian coasts (Ionian Sea, Italy), have been moved into an area where the species was present in the past. The transplants consisted both of specimens in toto and of fragments of different sizes, obtained after having cut the mother sponge into pieces. All transplanted sponges showed complete cicatrisation of the cut surfaces within a month of the initial manipulation and had a survival rate of 100% throughout the 12 months of the study. From the present investigation, it has emerged that the reproductive effort and the larval release by the transplants do not differ significantly from those shown by the source population. This successful technical approach supports its application as a strategy for restocking the population of this endangered species.  相似文献   
32.
Very few coral reefs are located close enough to large cities to study the influence of large urban populations on reef assemblages. An exception is the Thousand Islands reef complex to the north of Jakarta, the capital city of Indonesia, and one of the largest conurbations in the world. Here we present data from a detailed survey where sponge assemblages were assessed at 30 patch reefs associated with islands in three coastal zones along an in-to-offshore gradient. Sponge assemblages are described at three taxonomic levels of detail (species, genus and family level). We recorded a total of 118 sponge species, 64 genera and 36 families, Aaptos suberitoides (Brønsted, 1934), Clathria (Thalysias) reinwardti (Vosmaer, 1880), Petrosia (Petrosia) nigricans (Lindgren, 1897) and Xestospongia testudinaria (Lamarck, 1813) were the most common species overall. There was a pronounced difference in composition among zones with the most distinct difference between the inshore zone and the other two zones. The inshore environment was characterised by very high turbidity and low live coral cover; the dominant substrate consisted of algal turf and sand. Environmental conditions improved and sponge diversity increased further offshore, although most areas appeared to have been affected by some form of disturbance. Ordinations were also largely congruent, at species, generic and family levels of taxonomic resolution. This indicates that variation in composition at higher taxonomic levels is a good indicator of variation at lower taxonomic levels, at least when there is a pronounced environmental gradient.  相似文献   
33.
陆刚  胡贵昂 《南方国土资源》2000,13(4):11-14,18
广西天峨老鹏礁发育于合山组下部,形成于晚二叠世吴家坪期.是在孤立碳酸盐岩台地内部生长的圆丘状点礁群,由菌藻类、串管海绵及一些纤维海绵、水螅、板海绵等造礁,发育有块状隐粘结岩、隐障积岩、潜障积岩等,从初期到后期具不同的发育模式.据其建造特征及海绵生物的造礁性能,说明了二叠纪台缘相发育的巨厚海绵灰岩是生物礁,菌藻类在礁的建造中起着关健作用.  相似文献   
34.
瓮安生物群中海绵化石的新证据   总被引:5,自引:0,他引:5  
曹芳  朱士兴 《地质学报》2001,75(3):289-291,T001,T002
近年来笔者依据现存的瓮安生物群中一些海绵及动物胚胎化石标本的研究,对那些可能的球形海绵体及有争议的海绵幼虫标本进行了简略的评述。本文提供的保存完好的具单轴骨针的球形海绵体化石及可能的海绵幼虫标本,对于陡山沱期出现海绵动物的推测提出了新的证据。  相似文献   
35.
36.
Hydrozoa (Cnidaria) symbiotic with Porifera: a review   总被引:1,自引:1,他引:1  
Many hydroids are symbiotic with other organisms. Sponges, because of their complex canal system and their filter‐feeding activity inducing a continuous water flow, are used by numerous species as either exclusive or facultative substrata. The associated hydroid fauna thriving on or inside sponges shows a wide range of relationships with their hosts. Hydroids may be simply epibiotic on sponges, their stolons running on the host surface. Alternatively, the stolons may grow inside the sponge body, the polyps emerging from the sponge surface, having also the possibility of retraction inside the sponge tissue. Finally, stolons and branches may develop deeply inside the sponge body, producing a skeletal network for sponge growth. This paper reviews the described relationships of hydrozoans symbiotic with sponges and reports new observations.  相似文献   
37.
Sponges Inhabiting a Mediterranean Red Coral Population   总被引:2,自引:0,他引:2  
Abstract. A coastal red coral [Corallium rubrum (L.)] population, whose age structure and demographic parameters have been previously analysed, harbours 10 species of endobiotic sponges. This sponge assemblage differs considerably from that inhabiting other calcareous substrata of the surrounding area, suggesting some selectivity for red coral. The two most common endobiotic species, Spiroxya heteroclita T opsent and Cliona sarai M elone , are described in detail. The percentage of infested coral colonies increases according with colony age, with a sharp increment at four years. An increase in coral colony mortality observed at this age may be related to the increment of endobiotic sponge infestation.  相似文献   
38.
The work is dedicated to multidisciplinary study of Upper Cretaceous deposits exposed at the day surface in a ravine near the village of Vishnevoe, the Petrovsk district of Saratov oblast. The exposed section includes deposits of the Bannovka, Mozzhevelovyi Ovrag, Mesino-Lapshinovka, Rybushka, Ardym, Lokh formations and of the Borisoglebsk sequence first distinguished in the Volga River basin. Age ranges of the formations studied are confirmed or defined more precisely (the Ardym and Lokh formations) based on fossil faunas of cephalopods, bivalves, radiolarians, planktonic and benthic foraminifers. The middle-upper Coniacian range of the Borisoglebsk sequence is substantiated. Distribution of brachiopods, sponges, radiolarians, ostracodes and calcareous nannoplankton in the section is established. Radiolarian assemblages are used to distinguish biostratigraphic subdivisions corresponding in rank to faunal beds. Based on nannofossil assemblages, zones and subzones of standard zonations after Perch-Nielsen (1985) and Burnett (1998) are established. Stratigraphic ranges of certain radiolarian, ostracode and calcareous nannoplankton taxa are verified.  相似文献   
39.
Sponges are one of the principal agents of bioerosion and sediment production in coral reefs. They generate small carbonate chips that can be found in the sediments, and we investigated whether these could provide a means for assessment of bioerosion applicable to reef monitoring. We tested this hypothesis on samples from 12 Mexican coral reefs distributed along the Pacific coast, where boring sponges were particularly abundant, and quantified the amount of chips in samples of superficial sediment in three grain‐size fractions: fine (<44 μm), medium (44–210 μm) and coarse (>210 μm). The grain‐size distribution varied among reefs, with the majority of the sediment of most reefs being composed of coarse sands, and the medium and fine fractions dominating only at La Entrega and Playa Blanca. All the reefs presented clear evidence of bioerosion by sponges, with the characteristic chips present in the sediment, although at most sites the percentage of chips was very low (from 1% to 3% of the total sediment). Only at La Entrega and Playa Blanca did they constitute a significant fraction of the total sediment (18% and 16%, respectively). While not statistically significant, there was an interesting trend between sponge chips versus sponge abundance that suggests that quantification of the chips in the sediment could be used as a proxy for sponge erosion of the entire community, which cannot be estimated in by laboratory experiments. However, while this methodology could provide an integrated approach to monitor sponge bioerosion, more studies are necessary due to the influence of environmental factors on the transport and deposition of these chips.  相似文献   
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