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1.
Feeding responses of the tentaculate depositfeeding polychaeteEupolymnia nebulosa (Montagu) were studied by measuring rates of uptake of three different14C-labelled diatoms (unialgal cultures ofNavicula incerta Grunow,Nitzschia acicularis Wm Smith, andNitzschia sp.). Worms used during this study were collected in the harbor of Port-Vendre (Western Mediterranean) during August 1986 (immature worms) and December 1987 (mature worms). Uptake rates were affected both by the length of the experiments and by the nature of the food offered. The highest rate of uptake (2.98 10–4 mg ashfree dry wt of algae mg–1 dry wt of worms h–1) was obtained during short-term experiments (4 h) with the smallest diatom (Nitzschia sp.). The lowest rate of uptake (0.21 10–4 mg ash-free dry wt of algae mg–1 dry wt of worms h–1) was also obtained withNitzschia sp., but for a long-term (48 h) experiment. There was no significant difference between rates of uptake of immature and mature worms. 相似文献
2.
O. Barneah I. Brickner M. Hooge V. M. Weis T. C. LaJeunesse Y. Benayahu 《Marine Biology》2007,151(4):1215-1223
Epizoic worms were found to occur on certain coral colonies from reefs off the coast of Eilat (Red Sea). We identified 14
coral species infested by acoelomorph worms at a depth range of 2–50 m. The host corals were all zooxanthellate and included
both massive and branching stony corals and a soft coral. Worms from all hosts were identified as belonging to the genus Waminoa and contained two distinct algal symbionts differing in size. The smaller one was identified as Symbiodinium sp. and the larger one is presumed to belong to the genus Amphidinium. Worm-infested colonies of the soft coral, Stereonephthya cundabiluensis, lacked a mucus layer and exhibited distinct cell microvilli, a phenotype not present in colonies lacking Waminoa sp. In most cases, both cnidarian and Acoelomorph hosts displayed high specificity for genetically distinctive Symbiodinium spp. These observations show that the epizoic worms do not acquire their symbionts from the “host” coral. 相似文献
3.
Five Antarctic or south-temperate species of Spirorbiaae are centred in south-west Africa, whilst 6 tropical species extend round the south-east and another 4 are recorded from Mozambique. Of the three new species, Pileolaria (Pileolaria) annectans sp. n. has a rudimentary opercular plate surmounting a sort-walled sac of embryos, which somewhat resembles a thoracic brood pouch. Pileolaria (Pileolaria) dayi sp. n. has a helmet-like brood chamber, but this opens distally, like the brood cups found in the subgenus Duplicaria. Janua Pil-natalensis sp. n. has the dorsal collar folds usually separate, but partially fused in some juveniles. 相似文献
4.
D. A. Abdo 《Marine Biology》2007,152(4):845-854
The endofaunal assemblages associated with two species of sponge from the family Chalinidae (Haliclona sp. 1 and Haliclona sp. 2) were studied at four locations along the south west coast of Australia. The species have distinct morphologies and
inhabit similar microhabitats; there is also considerable scientific interest in Haliclona sp. 1 (green Haliclona) due to the unique bioactive compound it produces. A total of 948 and 287 endofaunal individuals were found associated with
16 specimens of both the green Haliclona and Haliclona sp. 2 (brown Haliclona), respectively. Twenty-four endofaunal taxa were found (from mysid shrimps to teleost fish), with the brown Haliclona having a greater density of endofaunal species and individuals than the green Haliclona. The endofaunal assemblages of both species of sponge were significantly different, but only the endofaunal assemblage within
the green Haliclona differed significantly among locations. Differences in the abundance and biomass of associated endofauna of each species
of sponge can be related to differences in their morphologies, size and internal structure. In the green Haliclona, differences in endofaunal assemblages among locations are unlikely to be due to environmental influences as taxa discriminating
each locations assemblage were common to both species of sponge. Numerous endofaunal individuals were found to be reproductively
active, and it is clear that the species of sponge provide important habitats for their associated endofauna. This provision
of habitat needs to be taken into account when harvesting green Haliclona biomass for supply of its target bioactive compound for further pharmaceutical development. 相似文献
5.
Jessica Haapkylä Adrian S. Seymour Orit Barneah Itzchak Brickner Sebastian Hennige David Suggett David Smith 《Marine Biology》2009,156(5):1021-1027
This is the first quantitative study on the prevalence of epizoic Waminoa sp. acoel worms and their association with corals in the Wakatobi Marine National Park (WMNP), South-East Sulawesi, Indonesia.
Three replicate transects were laid on the reef crest, flat and slope at six sites in 2006 and eight sites in 2007. Four of
the sites were common in both years. In total 69 transects were surveyed in 2006, and 87 transects in 2007. A total of 4.8%
of all observed hard corals were associated with acoel worms in 2006 and 2.6% of hard and soft corals in 2007. Acoels were
present on 16 and 21 of the coral taxa studied in 2006 and 2007 respectively. The worms were strongly associated with the
azooxanthellate coral Tubastrea spp. and were rare or absent on the most abundant coral genera Montipora and Porites. The mean number of corals having acoels was highest on reef slopes, whereas acoels were virtually absent on reef flats. Corals
that had a high and a medium cover of worms were more common in 2007 than in 2006. No significant trend in the adaptation
of the zooxanthellae of Waminoa sp. to different depths at different sites was revealed. The impact of the worm on the coral is unknown, but high numbers
may have a shading effect and a negative impact on the coral’s photophysiology. This acoel merits more study of its life cycle,
its photophysiology, and its impact on its host corals.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
6.
Two populations of Marenzelleria spp. from the North Sea and the Baltic Sea that had already been characterized by allozyme electrophoresis and found genetically
different in 1994 were again examined in 1997. The genetic identity (I = 1.0) examined in 1994 and 1997 shows that the structures of the populations of genetic Type I in the North Sea (Ringkobing
Fjord) and genetic Type II in the Baltic Sea (Darss–Zingst Bodden chain) are stable. Three diagnostic gene loci that were
determined additionally (citrate synthase, one locus; alanine aminotransferase, two loci) support the hypothesis of the existence
of two sibling species of the genus Marenzelleria in Europe. In addition, the activities of ten electrophoretically separated enzyme systems were measured in the worms immediately
after removal from their habitat and after they had been kept in the laboratory for 2 months. Under both conditions four enzymes
showed significant differences between genetic types. The higher activity of the alanine aminotransferase of the North Sea
worms (Type I) is discussed in the context of the different preferred salinities of the two Marenzelleria sibling species.
Received: 21 January 1999 / Accepted: 13 July 1999 相似文献
7.
The cosmopolitan polychaete Capitella capitata, known as a complex of opportunistic sibling species, usually dominates the macrobenthos of polluted or unpredictable environments.
A population of C. capitata, termed Capitella sp. M, was found in a shallow water hydrothermal vent area south of Milos (Greece). Here, this population occurs close to
vent outlets (termed the “transition zone”), an environment with steep gradients of temperature, salinity and pH and increased
sulphide concentrations of up to 710 μM. The field distribution of C. capitata in relation to sulphide concentrations around the vent outlets was investigated and sulphide tolerance experiments were conducted
on laboratory-cultured worms to elucidate possible adaptations of Capitella sp. M to these extreme environmental conditions. In order to investigate whether the population from the Milos hydrothermal
vent area can be considered a distinct sibling species within the C. capitata complex, crossbreeding experiments and analysis of general protein patterns were conducted with Capitella sp. M and three other C. capitata populations of different ecological ranges. Capitella sp. M showed high resistance (median survival time: 107 ± 38 h) to anoxia plus high sulphide concentrations of 740 μM. It seems that the ability to survive high-sulphide conditions in combination with reduced interspecific competition enables
the polychaete to maintain a continuous population in this rigorous habitat. From the extremely high tolerance to anoxia and
sulphide, shown in both the crossbreeding experiments and the analysis of total proteins, it can be concluded that Capitella sp. M from the Milos hydrothermal vent area represents a separate sibling species within the C. capitata complex.
Received: 3 March 1997 / Accepted: 12 September 1997 相似文献
8.
A total of 38 219 specimens representing 63 species of marine isopods (Crustacea) from deep and shallow Arctic waters were studied in a search for epizoic foraminifers (Protozoa). Foraminifers occurred on 21 species, and their frequency was generally low. A total of 290 foraminifer individuals were found, of which 289 belonged to Cibicides wuellerstorfi, C. refulgens and Cibicides spp. (juveniles) (Cibicidae), while only a single individual belonged to Cornuspira sp. (Cornuspiridae). The foraminifers were most frequent on species of the families Munnidae, Ischnomesidae (suborder Asellota) and on Gnathia stygia (suborder Gnathiidea), but were totally absent from the asellote families Janiridae, Haploniscidae, Nannoniscidae and from the suborder Epicaridea. The foraminifers were mainly located on the legs (Munna acanthifera), the anterior part of the body (Haplomesus quadrispinosus, heteromesus frigidus), or on the head (G. stygia adults). The epizoic foraminifers occur mainly on epibenthic isopods, which do not or only rarely clean themselves. The foraminifers are known to prefer elevated substrata, and in this the habitat of the isopods and the foraminifers coincide. The size of individual isopods was not related to the presence or absence of foraminifers. 相似文献
9.
Banu JR Logakanthi S Vijayalakshmi GS 《Journal of environmental biology / Academy of Environmental Biology, India》2001,22(3):181-185
Paper mills have severe problem in disposing effluent or semisolid sludge despite repeated recycling. It requires treatment prior to disposal of sludge. In recent years biological treatment methods received much attention and considered as efficient low-cost treatment. One such method is vermiculture treatment. The present study was carried out to dispose the paper mill sludge biologically using 2 exotic species (Eudrilus eugineae and Eiseniafoetida) and an indigenous species (Lampito mauritii) of earthworm. The paper mill sludge in various concentration 25%,50% and 75% were subjected to vermitub treatment for a period of 60 days. During the period of study data were collected on reproductive strategies of earthworm and chemical analysis of wastes before and after treatment. Results obtained indicate that 25% concentration of sludge was ideal and of the three worms used Eiseniafoetida proved to be the best worm for biomanagement. 相似文献
10.
Nuria Méndez Inez Linke-Gamenick Valery E. Forbes Donald J. Baird 《Marine Biology》2001,138(2):311-319
The effects of the widespread polycyclic aromatic hydrocarbon (PAH) fluoranthene on sediment-processing rates in the infaunal
polychaete Capitella spp. were investigated by comparing five populations of this deposit-feeding species complex: Capitella sp. I from New York, USA; Capitella sp. M from Milos, Greece; Capitella sp. S from Sylt, Germany; and two unidentified Capitella populations from salmon farm sediments –Capitella population K from Kilmelford, Scotland and Capitella population C from Cranford, Ireland. Replicate worms from each strain were exposed to 0, 10, and 95 μg (g dry wt sediment)−1 fluoranthene (=μg/g fluoranthene) for a period of 16 days. Initial and final wet and dry weights (mg) of worms and worm-specific
growth rates (WSGRs) were calculated. Sediment processing was measured as the sum of the total dry weight of pellets produced
during the experiment, and we estimated size-specific processing rates (SSPRs) as a measure of sediment processed per mg worm
dry weight per day. The five populations of Capitella spp. differed significantly in body size, WSGR, and sediment-processing rates. Capitella sp. I grew faster than all of the other populations. Capitella population C and Capitella population K from fish farm sediments, with the largest body lengths (up to 52.0 ± 27.2 mm), had the highest processing rates,
whereas the small Capitella sp. S (up to 17.1 ± 5.6 mm) had the lowest. There were also significant differences in SSPR among populations with Capitella sp. I having a higher SSPR (about 12 × body wt/day) than Capitella population C (about 5 × body wt/day) and Capitella population K (3 × body wt/day). The fluoranthene concentrations used in the present study, while representing moderately
to highly contaminated conditions, had only marginal effects on sediment-processing and growth rates of all of the Capitella populations examined. Processing of contaminated sediment by Capitella spp. may be important in the remediation of PAH-contaminated sediment.
Received: 16 January 2000 / Accepted: 28 August 2000 相似文献
11.
Metabolic studies on thiobiotic free-living nematodes and their symbiotic microorganisms 总被引:1,自引:0,他引:1
The marine, free-living Stilbonematinae (Nematoda: Desmodoridae) are remarkable for the ectosymbiotic, prokaryotic microorganisms that populate their entire body surface. These nematodes occur in sulfidic sediments in the microoxic zone just above the sulfide maximum. Several facts point to a chemolithotrophic, sulfide oxidizing nature of the microorganisms. The oxygen uptake of three species was measured with and without their microbial coat using Cartesian and Gradient Diver microrespirometry in February 1989 at Carrie Bow Cay (Belize Barrier Reef). Symbiont-free stilbonematids exhibited constant and uniform oxygen uptake rates over several hours; rates which are significantly lower than those of oxyphilic nematodes. Freshly extracted stilbonematids, with intact bacterial coats, consumed significantly more oxygen than symbiont-free worms in the first 3 h of measurement. While the rates of aposymbiotic worms were more or less constant over time, the rates of symbiont-carrying worms exhibited a conspicuous drop during prolonged respiration. InStilbonema sp., symbiont carrying individuals kept under oxygenated conditions for more than 12 h had a respiration rate similar to those of aposymbiotic specimens. When such worms were re-incubated in sulfide-enriched seawater the respiration rate was significantly elevated. The possibility of recharging the oxygenated symbiosis system via sulfide-uptake is seen as an indication that storage of reduced sulfur compounds, or reserve substances synthetized in the presence of sulfide, play a decisive role in the metabolisms of the symbiotic bacteria. Migration of nematodes between sulfidic and oxidized sediment-layers are, most likely, the key to understanding the success of this nematode-bacteria symbiosis.Please address all correspondence and requests for reprints to Professor J. Ott 相似文献
12.
Parthasarathi K Ranganathan LS Anandi V Zeyer J 《Journal of environmental biology / Academy of Environmental Biology, India》2007,28(1):87-97
The diversity of fungi, bacteria, yeast, actinomycetes and protozoa were analysed in the gut and casts of Eudrilus eugeniae, Lampito mauritii, Eisenia fetida and Perionyx excavatus, both qualitatively and quantitatively as influenced by different feed substrates like clay loam soil, cowdung and pressmud. While actinomycetes (Streptomyces albus, S. somaliensis, Nocardia asteroides, N. caviae and Saccharomonosporia) were not digested by any of these species of worms, protozoa (Amoeba proteus, A. terricola, Paramecium trichium, Euglena viridis, E. orientalis, Vorticella picta and Trichomonas hominis) and yeast (Candida tropicalis, C. krusei C. albicans and Cryptococcus neoformans) were totally digested. Certain species of fungi (Saksenae vasiformis, Mucor plumbeus, Cladosporium carrionii, C. herbacium, Alternaria sp., Cunninghamella echinulata, Mycetia sterila, Syncephalostrum racemosum, Curvalaria lunata, C. geniculata and Geotrichum candidum) and bacteria (Pseudomonas aeruginosa, Bacterium antitratum, Mima polymorpha, Enterobacter aerogenes, E. cloacae, Proteus vulgaris, P. mirabilis, P. rettgeri, Escherichia coli, Staphylococus citreus, Bacillus subtilis, B. cereus, Enterococci and Micrococci) were completely digested. Certain other species were not digested fungi like Aspergillus fumigatus, A. flavus, A. ochraceous, Trichoderma koningii (except by Eeugeniae), Fusarium moniliforme (except by E. eugeniae) and Rhizopus sp., and bacteria like Klebsiella pneumoniae and Morganella morganii) and these were multiplied during the transit of the organic residues through the gut of worms. The microbial proliferation was more in the casts, due to the environment prevailing--rich in nutrient supply and large surface area available for growth and reproduction of the microbes that lead to enhanced microbial activity and humic acid contents in the casts. 相似文献
13.
The feeding behavior of 8 species of sea basses (Serranidae) and 17 species of scorpionfish (Scorpaenidae) has been studied by quantitative analysis of their stomach contents. Most of the 459 specimens analysed were collected from the barrier reef of Tuléar (Madagascar). Examination of stomach contents revealed that in each species feeding behavior varies according to a nyctemeral rhythm, individual size of specimens, biotope and geographical area. Prey consumption by sea basses and scorpionfish on a reef tract is discussed in general terms. 相似文献
14.
Chromosomal nucleolar organizer region (NOR) phenotypes have been characterized in nine species of the genus Ophryotrocha (Polychaeta: Dorvilleidae), namely O. notoglandulata, O. sp. macrovifera, O. sp. labronica pacifica, O. labronica labronica, O. puerilis puerilis, O. diadema, O. sp. robusta, O. gracills and O. hartmanni. Irrespective of chromosome number and morphology, Ag positive regions were terminally located in all but one species, O. diadema, where the NORs were pericentromerical in a metacentric pair. The presence of a single chromosome pair bearing NOR in invertebrates is considered an ancestral trait. According to this assumption, O. sp. robusta, O. dialema, and perhaps O. p. puerilis appear to be more ancestral than the other species. On the contrary, O. notoglandulaia, O. sp. macrovifera, O. sp. labronica oacifica, with two chromosomal pairs bearing NOR sites, seem to represent examples of further evolution within the genus Ophryotrocha. 相似文献
15.
The phylum Gastrotricha includes about 750 species of meiobenthic marine and freshwater species that are often widely distributed.
The microscopic size, short life cycle, low motility of adults, and the absence of larval stages normally required for dispersal
raise doubts about the putative cosmopolitan distribution of many of gastrotrich species. The phenomenon of cosmopolitanism
is acknowledged for all major meiobenthic taxa (“the meiofauna paradox”) and can be explained, at least in part, with the
existence of sibling species, so far identified primarily by molecular analysis. In this paper, we report the discovery of
sibling species in the marine chaetonotidan Xenotrichula intermedia using confocal laser scanning microscopy (CLSM). A total of 40 specimens collected from two geographically separate populations,
the Mediterranean (Adriatic Sea) and the Arabian Gulf (Kuwait), were investigated. Fifteen specimens of each population were
studied in vivo with a contrast interference microscope (DIC) in order to obtain the main morphometric parameters; ten other
animals (five in each population) were fixed and marked with fluorescent phalloidin for the observation of their muscular
systems under CLSM. The metrics and meristic data of the two populations fall within the range of measures recognized for
the species. Pairwise comparisons (t-test) in general did not reveal statistically significant differences between the traits of specimens belonging to the two
populations; moreover, multivariate analyses (cluster- and MDS analysis) were unable to separate clearly the Mediterranean
from the Arabian specimens. In contrast, an examination of their muscular systems revealed clear dissimilarities between the
two geographic groups. In particular, while the Italian specimens possessed incomplete circular bands and dorsoventrally orientated
muscles that are partially inserted into the basal lamina of the cuticle, in both splanchnic- and somatic positions, their
Arabian counterparts showed partial dorsoventral bands and complete circular muscles that surround the entire body of the
animal in the same corresponding positions. Additional differences in the position of helicoidal bands (present in a more
anterior location in the Italian specimens) are noted between Mediterranean and Arabian specimens. Since the investigated
animals share a similar interstitial habitat, a working hypothesis connects the differences in the musculature to possible
differences in the reproductive modality of specimens between the two populations. 相似文献
16.
The cytoplasm of Crassostrea angulata (collected from the Atlantic coast of Northern Spain, Galiza, between 1992 and 1993) spermatogonia contains a few proacrosomal dense vesicles and intermitochondrial round granulo-fibrillar dense bodies. In primary spermatocytes, large cytoplasmic spaces appear occupied by large round and more scattered granulo-fibrillar dense bodies which are intermingled with cord-like dense structures and are in close association with mitochondria and the rough endoplasmic reticulum. As a result of Golgian activity, the number of dense proacrosomal vesicles increases and a flagellum arises from the centrioles. During the second meiotic division, several round dense bodies surrounding cord-like dense structures as well as dense proacrosomal vesicles, were observed between chromosomes. During spermiogenesis, no Golgian activity was noticed, and only the rough endoplasmic reticulum was observed in close association with proacrosomal vesicles. Similar results were observed for Ostrea edulis (collected from the Atlantic coast of southern Portugal, Algarve, between 1992 and 1993). Spermatozoa of both species are of the aquasperm type, and although their ultrastructure is quite similar, silver and phosphotungstic acid-chromic acid stainings enabled us to clearly distinguish both species at the ultrastructural level. The different morphological aspects of spermatogenesis in the Pteriomorphia and the use of silver and PTA stainings in the Mollusca are reviewed and discussed. 相似文献
17.
G. A. Brenchley 《Marine Biology》1976,38(2):179-188
One strategy for predator avoidance involves the creation of a structural refuge. Onuphid polychaetes characteristically ornament above-sediment portions of their tubes (=tube-caps) with shell and algal debris. These species feed on the sediment surface through an opening in the tube-cap, and thus the ability to detect a surface predator while feeding would be advantageous. An investigation of the function of the ornamentation in Diopatra spp. suggests that ornamentation facilitates predator detection and avoidance. Three intensities of mechanical disturbance were applied directly to D. ornata tube-caps. When ornamented tube-caps were stimulated, the response of worms to the three intensities were significantly different, and increased in duration with greater intensities. In contrast, when no ornamentation was present, the responses were not significantly different, and were similar to the low-intensity response when ornamentation was present. This suggests that ornamentation should allow a worm to distinguish between harmful (high intensity due to mobile epifaunal predators) and profitable (low intensity due to drift algae) disturbances, and furthermore, worms with ornamented tube-caps should be more successful in escaping surface predators. Densities of intertidal populations of D. cuprea at Tom's Cove, Virginia, USA, correlated with the amount of tube ornamentation, consistent with this predator detection and avoidance hypothesis. Final tube-cap lengths of laboratory D. ornata and field D. cuprea were inversely related to the size of attached debris. When large debris was attached, cap formation ceased earlier and caps were shorter than when small debris or no debris was attached. Cryptic and food-catching functions would predict that highly ornamented tubes would be most advantageous, while only a few large debris would be required for disturbance transmission. Laboratory specimens showed no selectivity between 0.5 or 1.5 cm2 shell; or 1.0 cm2 or 3 to 8 cm2 algae, and utilized shell and algae when available and according to relative abundance. Tube-caps of field specimens also showed positive correlations between shell attached and shell abundance in the local sediment. While such lack of selectivity may enhance cryptic properties of the tube-cap, it is argued that conditions seldom exist which would permit selectivity of debris size or of specific material. These data are consistent with the hypothesis that ornamentation functions as a created refuge for predator detection and avoidance and further suggest that the availability of ornamental debris in the environment indirectly can affect these species' distributions and abundances. 相似文献
18.
Lukas Schärer Dagmar Knoflach Dita B. Vizoso Gunde Rieger Ursula Peintner 《Marine Biology》2007,152(5):1095-1104
The Labyrinthulomycota are a relatively poorly studied group of heterotrophic unicellular eukaryotes. They comprise three
lineages, labyrinthulids, thraustochytrids, and aplanochytrids, which are all primarily marine organisms and considered to
be important components of marine microbial communities. Recently a number of Labyrinthulomycota have been implicated as parasites
of marine (but also terrestrial) plants and marine molluscs. Here we describe a new species of thraustochytrid, Thraustochytrium caudivorum sp. nov. that we have isolated from laboratory cultures of Macrostomum lignano (Rhabditophora, Macrostomorpha), a marine free-living flatworm. In these worms T. caudivorum can cause lesions, which start at the tip of the tail plate and which can lead to the dissolution of the posterior part of
the animal. Although the worms can frequently cure these lesions and regenerate the lost parts, the lesions can also result
in the complete dissolution of the animal. We describe this thraustochytrid based on pure agar cultures and infestations in
the worm cultures. Moreover, we describe its pathological effects on the worms and its morphology using both light and electron
microscopy. In addition, we report a phylogenetic analysis using a partial 18S rDNA sequence that allows us to place this
new species within the thraustochytrids. Finally, we outline a protocol that allows to permanently remove the parasites from
infested worm cultures. We conclude that thraustochytrids represent a novel group of parasites of free-living flatworms.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
19.
Growth rates of juvenile Capitella sp. I were determined on different rations of six food types: Gerber's mixed cereal, TetraMin fish flakes, benthic diatoms, Ulva sp., spring detritus, and summer detritus. A simple growth model estimated maximum growth rate and maintenance ration for each food. There were differences in the growth response among foods relative to nitrogen content. As juveniles increased in size, differences in growth between foods became more pronounced. For all juveniles, growth rates were correlated with levels of the amino acids histidine, phenylalanine, threonine, and valine, and the polyunsaturated fatty acid 20:5w3; correlations with histidine and phenylalanine levels were the most significant. Regressions of growth rates as a function of these two amino acids suggest a daily maintenance ration of 300 pg histidine and phenylalanine mg-1 nitrogen biomass. Juvenile worms grew on spring detritus but not on summer detritus, indicating the probable importance of micronutrients (polyunsaturated fatty acids, amino acids) for growth of juvenile Capitella sp. I in the field. 相似文献
20.
Recovery of benthic communities at Macquarie Island (sub-Antarctic) following a small oil spill 总被引:5,自引:0,他引:5
Intertidal communities at Macquarie Island (sub-Antarctic) were re-evaluated seven years after a small oil spill resulting
from the grounding of the “Nella Dan”, and six years after the first assessment of biological impact. Sampling was conducted
to evaluate community structure in three zones of the exposed rocky shore (upper red, kelp, and lower red) and in samples
of Durvillaea antarctica holdfasts. There were no significant differences between the community structure in oiled and control locations in any of
the three shore zones, but holdfast macrofaunal communities at oiled sites still showed evidence of impact. Holdfast community-structure
in samples from heavily oiled sites showed moderate levels of recovery, with increased abundances of species which were considered
sensitive to the oiling in the first post-impact studies and decreased abundances of opportunistic polychaete and oligochaete
worms. In contrast, samples collected from the moderately oiled location at Secluded Bay showed little evidence of recovery.
Holdfasts at this site were filled with sediment containing traces of diesel oil, and the macrofaunal community was dominated
by opportunistic worms. This study clearly indicates that even small incidents of anthropogenic perturbation can have long-lasting
consequences for marine communities at Macquarie Island.
Received: 23 July 1997 / Accepted: 5 February 1998 相似文献