摘要:

Abstract.The ingestion of carnivores and omnivores was determined during the investigation of higher trophic levels in a North Adriatic benthic community. The ingestion rate was calculated from respiration data using a respiration‐production equation and an assumed assimilation efficiency. In the case of the starfishAstropecten aranciacusthe ingestion rate obtained by this indirect method was in good agreement with the ingestion rate calculated directly from gut contents, taking the retaining period of food items in the gut into consideration. These results are compared to previously published ingestion rates. The influence of Aaranciacuson the community is briefly discusse

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1984.tb00303.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract.The relationship between a sponge,Callyspongia vaginalis,and an associated brittlestar,Ophiothrix lineata,was examined for mutualistic symbiotic interaction. Cinematography, feeding experiments, and analyses of stomach contents reveal thatO. lineata(unlike otherOphiothrixspecies) is a non‐selective deposit feeder. Its diet consists of detrital particles adhering to the sponge, which are too large to be utilized by the sponge as food. Thus, the brittlestar cleans the inhalent surface of the sponge as it feeds. Since siltation interferes with sponge pumping‐activity, it is suggested that the cleaning behavior ofO. lineatamay enhance the filtration capability ofC. vaginalis. In situelapsed‐time films show that brittlestars expose their arms when they feed, suggesting that they feed only at night because of a need to avoid diurnal predators. Manipulative experiments show that residence inC. vaginalisprotectsO. lineatafrom predatory fish. A comparison of the incidence of arm regeneration for brittlestars residing onC. vaginalis,and on a toxic sponge,Neofibularia nolitangere,indicates that factors other than sponge toxicity are involved in protecting sponge‐dwelling britt

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1984.tb00304.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract.The species composition and numbers of specimens of isopod crustaceans from the rubble of a Belizean reef crest were obtained. Four sets of 30 samples were taken from three rubble zones (rubble with algal turf, rubble betweenThalassiaplants, and pure rubble), in four different collecting periods. Twenty‐four species of isopods were identified, sexed and counted. By means of a Likelihood Ratio Chi‐square Contingency Table Analysis the presence of 13 species was shown to be positively correlated with habitat, 15 species with season, and nine species with habitat and season combined. From the spread of total numbers and of ovigerous females it is proposed that the isopods may be grouped into three patterns: a) those present and breeding in the reef crest rubble throughout the year,i. e.stress‐tolerant species; b) those showing a breeding peak in summer and a population decrease in winter‐spring,i. e.opportunist species; and c) those showing a breeding peak in the fall, and a second peak in spring, and a decrease or complete avoidance of the habitat, especially by ovigerous females, in the summer. The diversity of the Belizean reef crest isopod fauna is compared with the published report of the isopod fauna of a coral reef in Madagascar. Several similarities in composition are noted. The multiplicity of microhabitats is invoked as a possible explanation for the relatively high diversity of anthuridean isopods in cora

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1984.tb00305.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract.This paper is the quantitative description of the first month of colonization of rocky intertidal substrates. The results are discussed in the light of general ecological theory.The relationship between general ecological theory and recent findings on energy dissipation and structure of biological systems is examined. Some behavioural characteristics of the studied communities are compared with those described in systems with more than one month of growth after initial colonization.

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1984.tb00306.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract.Precious corals as a group consist of a variety of species which belong to several classes of Anthozoan corals. In general, all are long lived, slow growing and are characterized by slow rates of annual recruitment and adult mortality. In favorable environments, where large beds of commercial quantity exist, their life history parameters often approximate steady state. In such instances, fishery management models in which the assumption of steady state is explicit, can be applied to their management. In this paper, the history and ecology of precious corals are reviewed in light of modern attempts of resource management using fishery models. In Hawaii, the BEVERTON and HOLT model has been adapted for the management of black, pink and gold coral species. The application of this model as it applies to precious corals is described and an example is given illustrating that it can also be used for shallow water reef building corals which form discrete colonies.

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1984.tb00307.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract.The Philippines is generally accepted to be the center of the international trade of stony corals for ornamental use. Despite existing legal bans on the collection and export of stony corals in the Philippines, the coral trade continues to date, particularly in Cebu. This paper reports on the specific market demand for stony corals in Cebu and the effects of commercial collection based on the results of a quantitative study of two shallow coral reef areas subjected to large differences in collection effort. Comparison of the measured coral community parameters suggests selective population changes and reduced abundance of exploited coral populations as a result of commercial collection. Estimates of the natural mortality, fishing mortality and yield are presented for the two sampled populations ofPocillopora verrucosa, utilizing the method of GRIGG (1976). Based on the study results and a review of reported coral growth rates and coral colony size at reproductive maturity, the potential for resource management of stony corals on a sustainable yield basis is ‐ discusse

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1984.tb00308.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1984.tb00309.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY