摘要:

Abstract.The distribution pattern of corals and benthic space partitioning patterns on the fringing reefs of southern Taiwan were studied by the line‐transect method. The bathymetric distribution of corals in the study area was basically homogeneous except on the protected reef slopes and the exposed reef fronts and terraces. Corals on protected reef slopes are mainly foliaceous, includingMontipora foliosa, Merulina ampliata, Mycedium elephantotus, andPachyseris speciosa, but the dominant species on a reef slope vary from site to site. The formation of the foliaceous coral community is possibly related to a complex of environmental factors, chance, and biological interactions. The reef fronts and submarine terraces of exposed areas are dominated by alcyonacean corals. The most abundant species areSarcophyton trocheliophorum, S. crassocaule, andLobophytum sarcophytoides; their distributions are relatively homogeneous. The formation of alcyonacean‐dominated assemblages can be related to the special adaptive strategies of these corals. In regard to space partitioning patterns, the major space occupiers on those reefs exposed to storm disturbances are alcyonacean soft corals, scleractinian corals, and algae; on reefs protected from storms, scleractinian corals and algae dominate. Two conspicuous features of the study area are the high proportion of space occupied by algae and the abundant unoccupied space. The dense algal cover is possibly caused by sewage pollution and overfishing of the reef area. The unoccupied space is most likely related to the high frequency of typhoon disturban

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1993.tb00479.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract.Cladocora caespitosais a relatively common, colonial, symbiotic, scleractinian coral in the Mediterranean Sea. It inhabits a wide ecological range: hard and soft bottoms, shallow waters or depths to about 50m, calm water or sites exposed to strong currents and wave action. The present study compares the distribution of this coral at two sites, one shallow (3m — wave exposed) and one deeper (12m — soft bottom).Different parameters including dry weight, volume, and skeletal growth rates were investigated. The polyp biomass, carbon content, and overall area of fully expanded polyps were also measured. Equations are given for the relationship of skeleton diameter to polyp tissue dry weight as well as skeleton diameter to the possible filter area of fully expanded polyps.C. caespitosaharbors a rich community of vagile and sessile organisms within the skeleton. The cryptofauna was sorted to higher taxonomic levels and their biomass determined. Several highly significant linear relationship were found between skeleton dry weight, volume and cryptofauna biomass. Thus, the determination of colony volume allows the prediction of cryptofauna biomass.The interstitial space is dominated by sponges ‐ many of them borers ‐ which erode the corallites close to the living tissue until they break off from the colony. At the deeper sampling site, 26% of all colonies are smaller than 2 cm and 48% are smaller than 5 cm. The fragmentation process is discussed with respect to repro

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1993.tb00480.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract.The temperate, symbiotic coralCladocora caespitosaoccurs naturally with variable numbers of zooxanthellae. This allows us to study differences in the physiology of symbiotic and “non‐symbiotic” polyps and to correlate them with zooxanthellae activities.Zooxanthellae density in “dark” (normal‐colored) polyps was 50 times higher than in “white” (bleached) polyps.The chlorophyllacontent per zooxanthella was 3 times, and Chicwas 13 times higher in white polyps than in dark ones. O2‐flux experiments were conducted with coloniesin situand with single polyps ‐ dark and white ‐ under laboratory conditions. Two approaches were used to evaluate the contribution of zooxanthellae translocation products to animal respiration. Both revealed that the animal tissues derive a higher benefit from the zooxanthellae during periods of low water temperature tha

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1993.tb00481.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract.The population dynamics and life history characteristics ofCallinectes similisandC. sapidusin the Mobile Bay‐Mississippi Sound estuarine system of the northern Gulf of Mexico were studied. We report thatC. similisis numerically dominant in open‐bays, whileC. sapidusis more abundant in shallow salt marshes. JuvenileC. similisrecruit into both open‐bays and salt marshes, but juvenileC. sapidusprimarily recruit into shallow salt marshes. Sex ratios ofC. similisandC. sapiduswere generally skewed towards higher proportions of males than females.Callinectes similisappears to have a life cycle similar to that ofC. sapidus.Egg‐carryingC. similismigrate to higher salinity waters and presumably release larvae to nearshore shelf waters; following development, the larvae re‐invade estuaries as megalopae. JuvenileC. similisgrow more slowly thanC. sapidus.This may be attributable to reduced feeding rates. Marked differences in fecundity and reproductive effort were found between these species.Callinectes similisandC. sapidus, respectively, produced 2.4–5.5 times 105and 2.1–3.2 times 106eggs and invested 24–49 and 171–372 kJ per brood. Rhizocephalan barnacle infestation byLoxothylacus texanuswas encountered inC. sapidus, while sympatricC. similiswere free of this rhizo

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1993.tb00482.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Abstract.A population of sea‐bass, housed under semi‐natural and self‐feeding conditions, was presented with six different coloured levers. Their choices tended to favour more colour‐contrasted levers and were greatly affected by environmental conditions such as stress factors, circadian period, season, and thermal fluctuations. A correlation was observed between increases in instrumental acitivity, indicating an increase in energetic requirements, and a widening of choices in the exploitation of the coloured levers.Consequences of these behaviours were considered in relation to predator pressure that the fish imposes on potential prey populations in the natural environment, and in relation to the initiation of feeding activity when the fish are maintained in captivity and under self‐feeding c

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1993.tb00483.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1993.tb00484.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1993.tb00485.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY