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1.
The parrotfish Sparisoma viride often grazes live coral from edges undermined by the Caribbean encrusting and excavating sponge Cliona tenuis. To test whether parrotfish biting action has an effect on the dynamics of the sponge–coral interaction, we manipulated access of parrotfishes to the sponge–coral border in two species of massive corals. When parrotfish had access to the border, C. tenuis advanced significantly more slowly into the coral Siderastrea siderea than into the coral Diploria strigosa. When fish bites were prevented, sponge spread into S. siderea was further slowed down but remained the same for D. strigosa. Additionally, a thinner layer of the outer coral skeleton was removed by bioerosion when fish were excluded, a condition more pronounced in D. strigosa than in S. siderea. Thus, the speed of sponge‐spread and the extent of bioerosion by parrotfish was coral species‐dependent. It is hypothesized that coral skeleton architecture is the main variable associated with such dependency. Cliona tenuis spread is slow when undermining live S. siderea owing to the coral’s compact skeleton. The coral’s smooth and hard surface promotes a wide and shallow parrotfish bite morphology, which allows the sponge to overgrow the denuded area and thus advance slightly faster. On the less compact skeleton of the brain coral, D. strigosa, sponge spread is more rapid. This coral’s rather uneven surface sustains narrower and deeper parrotfish bites which do not facilitate the already fast sponge progress. Parrotfish corallivory thus acts synergistically with C. tenuis to further harm corals whose skeletal architecture slows sponge lateral spread. In addition, C. tenuis also appears to mediate the predator–prey fish–coral interaction by attracting parrotfish biting. 相似文献
2.
Emma Cebrian 《Marine Ecology》2010,31(4):533-538
Although bioerosion is among the most destructive forces on coral reefs, indirect effects influencing the bioerosion dynamics are understudied. Here, I assess the hypothesis that coral reef grazers indirectly facilitate proliferation of bioeroding sponges by removing epibiotic fleshy seaweeds from the Great Barrier Reef. This study quantifies the degree of spatial correlation between the distribution of bioeroding sponges and the distribution of grazing pressure, as evidenced by the abundance of seaweed and parrotfish bite marks. While the sponge tissue area was negatively correlated with seaweed coverage, the number of parrotfish bite marks was associated with less algae and more sponge tissue. Several factors derived from grazing on seaweeds may facilitate sponge growth: increases in the availability of light may favor primary production by symbiotic zooxanthellae and thereby increase growth of bioeroding sponges; on the other hand, sponge settlement may be facilitated on grazed substrates. All these factors are likely related, and contribute to an increasing erosion of coral reefs. Similar processes have recently been described in Mediterranean ecosystems, suggesting that the interactions I document here, could be widespread. 相似文献
3.
Defense by association: Sponge‐eating fishes alter the small‐scale distribution of Caribbean reef sponges 
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下载免费PDF全文 Recent studies have demonstrated that sponge‐eating fishes alter the community of sponges on coral reefs across the Caribbean. Sponge species that lack chemical defenses but grow or reproduce faster than defended species are more abundant on reefs where sponge‐eating fishes have been removed by overfishing. Does predator‐removal have an effect on the distribution of sponges at smaller spatial scales? We conducted transect surveys of sponge species that are palatable to sponge predators in proximity to refuge organisms that are chemically or physically defended (fire coral, gorgonians, hard corals) on the heavily overfished reefs of Bocas del Toro, Panama, and a reef in the Florida Keys where sponge‐eating fishes are abundant. In Panama, palatable sponge species were not distributed in close association with refuge organisms, while in the Florida Keys, palatable sponge species were strongly associated with refuge organisms. The presence of fish predators alters the meter‐scale pattern of sponge distribution, and defense by association enhances biodiversity by allowing palatable sponges to persist on reefs where sponge‐eating fishes are abundant. 相似文献
4.
Yalan Chou Jiann Yuh Lou Chen-Tung Arthur Chen Li-Lian Liu 《Journal of Oceanography》2012,68(6):905-912
Biogenic silica (BSi) in marine sediments is an important indicator of siliceous organism distributions and paleoproductivities. Organisms that have BSi skeletons include diatoms, silicoflagellates, radiolarians and sponges. This study presents, for the first time, the distribution of biogenic siliceous fragments in shallow water sediments around Taiwan and the Sunda Shelf, which belong to this rarely studied region of the South China Sea (SCS). Thirty-one surface sediment samples were collected from intertidal to depths of 1,100?m. Only sponge spicules were found in this study and the abundance varied in the range of 3?C7,910?n?g?1 sediment. Combining previous studies with ours, from shallow to deep, it was observed that BSi composition in the surface sediment of this area changed from sponge spicules in the Sunda Shelf, followed by sponge spicules and radiolarians in the southwestern SCS, to sponge spicules, radiolarians and diatoms in the southern SCS. Based on this study, the abundance of sponge spicules correlated positively and negatively with water depth and sediment grain size when coral reef sites were excluded. The low spicule abundance in shallow waters may have resulted from local current conditions and the dilution effect through riverine input of terrestrial sediment. Other possible explanations for the varying spicule abundance among sites are the difference in local fauna, such as coral reefs which usually have high diversity and abundance of sponges. The findings provide additional information on the process of recent BSi deposition which may help future studies in sedimentology, paleogeography and paleoenvironments. 相似文献
5.
By the consumption of algae, parrotfishes open space for young coral settlement and growth, thus playing a central role on the maintenance of coral reefs. However, juvenile parrotfish ecology is often overlooked due to the difficulty discerning species during this phase. Herein, we present the first attempt to investigate changes in habitat use and diet that happen to juveniles of the Redeye parrotfish Sparisoma axillare, focusing on four zones within an algal‐dominated reef: the macroalgal beds, back reef, reef flat, and fore reef. Smaller S. axillare juveniles (<5 cm) preferred to inhabit the macroalgal beds and the reef flat, whereas juveniles larger than 5 cm were more abundant in the back and fore reefs due to distinct post‐settlement habitat conditions. Aggressive interactions with the territorial damselfish Stegastes fuscus were the primary driving factor of juvenile distribution and feeding rates. Attack rates increased with juvenile size and the lowest bite rates were observed in zones with higher densities of territorial damselfish. In previous studies, the persistence of parrotfish recruits in habitats dominated by damselfish was reduced, but newly settled parrotfish occurred more densely within the damselfish domain by behaving as a cryptic reef fish. As these juveniles grew, their bite rates increased, a change associated with a shift from cryptic to roving behavior. Feeding preferences were determined by substrate cover, where juveniles fed on available food sources in each habitat. Juveniles relied on jointed calcareous algae in habitats dominated by these algae, a pattern not observed for thick leathery algae. Filamentous algae were the preferred food for smaller fish; for individuals greater than 10 cm, a higher ingestion of sand was observed. Most studies evaluating the functional role of parrotfish do not consider species feeding preferences. However, the potential for a species to turn an impacted reef back to a coral‐dominated phase is influenced by their food selection, which is dependent on the algal species composition. 相似文献
6.
Despite the wide range of functional roles performed by marine sponges they are still poorly represented in many research, monitoring and conservation programmes. The aim of this review is to examine recent developments in our understanding of sponge functional roles in tropical, temperate and polar ecosystems. Functions have been categorised into three areas: (a) impacts on substrate (including bioerosion, reef creation, and substrate stabilisation, consolidation and regeneration); (b) bentho-pelagic coupling (including carbon cycling, silicon cycling, oxygen depletion and nitrogen cycling); and (c) associations with other organisms (facilitating primary production, secondary production, provision of microhabitat, enhanced predation protection, survival success, range expansions and camouflage though association with sponges, sponges as a settlement substrate, disrupting near-boundary and reef level flow regimes, sponges as agents of biological disturbance, sponges as releasers of chemicals and sponges as tools for other organisms). The importance of sponges on substrate, sponge bentho-pelagic coupling, and sponge interactions and associations is described. Although the scientific evidence strongly supports the significance and widespread nature of these functional roles sponges still remain underappreciated in marine systems. 相似文献
7.
Janie L. Wulff 《Marine Ecology》2008,29(2):193-204
Caribbean sponge species typical of coral reefs are generally inhibited from living in seagrass meadows by their vulnerability to predation by the large starfish Oreaster reticulatus (Linnaeus 1758). Although readily consumed by Oreaster , the conspicuous coral reef sponge species Lissodendoryx colombiensis Zea & van Soest, 1986 has expanded its habitat distribution to include a seagrass ( Thalassia testudinum Banks ex König, 1805) meadow in Belize, where individuals grow to volumes of nearly 7 l. By simple observation, L. colombiensis appears to be an inferior competitor in this system, because portions of many individuals are overgrown by seagrass sponge species. However, experimentally clustering seagrass sponges around L. colombiensis individuals deterred starfish from feeding on them, suggesting an advantage to being overgrown. Sizes of individual L. colombiensis can fluctuate widely over short time intervals, reflecting both a relatively fast growth rate and the high rate at which starfish consume this species. At the population level these fluctuations are not evident, as losses of L. colombiensis due to Oreaster are balanced by a combination of efficient recruitment, rapid regeneration and growth, and protection of portions of many individuals by the overgrowth of seagrass sponge species that are unpalatable to Oreaster . In turn, the seagrass sponges acquire stable perches on L. colombiensis individuals in this sediment-dominated habitat. Community ecology theory relating to diversity patterns in sessile organisms has focused on competition between space-requiring neighbors as the underlying process that inevitably decreases diversity unless curtailed. Sponges, with their propensity for engaging in beneficial interactions with neighbors, demand expansion of the theory to acknowledge how collaboration can increase abundance and species diversity within a community. 相似文献
8.
Marco Bertolino Barbara Calcinai Riccardo Cattaneo‐Vietti Carlo Cerrano Anna Lafratta Maurizio Pansini Daniela Pica Giorgio Bavestrello 《Marine Ecology》2014,35(2):149-158
The Mediterranean coralligenous substratum is a hard bottom of biogenic origin, mainly composed of calcareous algae, growing in dim light conditions. Sponges are among of the most representative taxa of the coralligenous assemblages, with more than 300 recorded species of different habits: massive, erect, boring and insinuating. When sponges die, their siliceous spicules remain trapped in the biogenic concretion, offering the opportunity to describe the coralligenous spongofauna over a very long span of time, virtually dating back to a large part of the Holocene period. The data reported here were obtained from core samples collected from four coralligenous concretions. Each block was collected in a different locality of the Ligurian Sea: Santo Stefano Shoals, Bogliasco, Punta del Faro (Portofino Promontory) and Punta Manara. Radiocarbon age determinations indicate for these conglomerates a maximal age between 1600 and 3100 years. The spicules trapped in the cores show deep dissolution marks in the form of circular holes on their surface or present an enlargement of the axial canal. However, their original shape, generally intact, suggests the absence of mechanical injuries and allows a tentative identification at the species level. The analysis of these old spicules reveals an ancient sponge assemblage composed of 30 recognisable species. This indicates that almost one half of the sponge community today settled on coralligenous substrata has been present in the conglomerates for their entire existence. 相似文献
9.
Sven Zea 《Marine Ecology》2011,32(2):162-173
The Caribbean sponge Cliona delitrix is among the strongest reef space competitors; it is able to overpower entire coral heads by undermining coral polyps. It has become abundant in reefs exposed to organic pollution, such as San Andrés Island, Colombia, SW Caribbean. Forty‐four sponge‐colonized coral colonies were followed‐up for 13 months to establish the circumstances and the speed at which this sponge advances laterally into live coral tissue and the coral tissue retreats. Cliona delitrix presence and abundance was recorded at seven stations to interpret current reef space and coral species colonization trends. The spread of C. delitrix on a coral colony was preceded by a band of dead coral a few millimeters to several centimeters wide. However, the sponge was directly responsible for coral death only when live coral tissue was within about 2 cm distance; coral death became sponge advance‐independent at greater distances, being indirectly dependent on other conditions that tend to accelerate its retreat. Cliona delitrix advanced fastest into recently killed clean coral calices; however, sponge spread slowed down when these became colonized by algae. The lateral advance of C. delitrix was slower than other Cliona spp. encrusting excavating sponges, probably owing to the greater depth of its excavation into the substratum. Cliona delitrix prefers elevated portions of massive corals, apparently settling on recently dead areas. It currently inhabits 6–9% of colonies in reefs bordering San Andrés. It was found more frequently in Siderastrea siderea (the most abundant local massive coral), which is apparently more susceptible to tissue mortality than other corals. Current massive coral mortality caused by C. delitrix could initially change the relative proportions of coral species and in the long‐term favor foliose and branching corals. 相似文献
10.
Current trends of space occupation by encrusting excavating sponges on Colombian coral reefs 总被引：1，自引：0，他引：1
Some sponges of the genus Cliona (Porifera, Hadromerida, Clionidae) simultaneously excavate and encrust calcareous substratum, competing aggressively for illuminated space with corals and other organisms. To interpret current trends of reef space occupation, the patterns of distribution and size of three Caribbean species were examined at San Andrés Island and Islas del Rosario in Colombia. While Cliona aprica was ubiquitous, C. caribbaea (= C. langae) preferred deep and protected reef zones, and C. tenuis shallow and wave‐exposed settings. In contrast to the effect on other excavating sponges, chronic exposure to raw sewage did not significantly increase the abundance of the studied sponges. Substratum occupation/availability ratios showed a positive tendency of the sponges toward certain coral skeletons, and a negative or neutral tendency toward calcareous rock, indicating that establishment may be easier on clean, recently dead coral than on older, heavily incrusted substratum. High relief generally limits sponge size to that of the illuminated portions of the substratum. A generally lower proportion of small individuals than of larger ones indicates currently low recruitment rates and low subsequent mortality. Successful events of higher recruitment seem to have occurred for C. tenuis. These are related to the massive acroporid coral die‐off in the early 1980s and to asexual dispersion during storms, resulting in a current 10% substratum cover. Reefs with high coral mortality were and/or are thus more susceptible to colonization and subsequent space occupation by these sponges, although relief may prevent space monopolization. 相似文献