摘要:

AbstractFollowing an extensive red‐tide induced mass mortality of the benthic macrofauna of a sandy intertidal habitat, the population dynamics of the polychaete species were studied. Detailed studies of the 12 most abundant species are presented. Data concerning total population levels, reproduction, recruitment, distribution within the intertidal zone, and gut content analyses are integrated in order to explain the observed spatial and temporal patterns of distribution and abundance. Potential competive interactions for food are considered to be the most important factor for explaining the observed ecological patterns. The polychaete species studied are divided into three trophic guilds: an omnivorous guild that feeds predaciously and as non‐selective deposit feeders, a surface feeding guild consisting of species usually considered to be selective surface deposit feeders, and a subsurface feeding guild usually considered as non‐selective infaunal deposit feeders. Within and between guild interactions are disc

ISSN:0020-9309    

DOI:10.1002/iroh.19800650402

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19800650403

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY

摘要:

AbstractThe aim of the investigation was to determine the phosphorus containing minerals present in Lake Balaton sediment. Chemical, electron microscope and X‐ray diffraction analysis succeeded in identifyinghydroxylapatite.No proof was found for the presence of other phosphorus mineral

ISSN:0020-9309    

DOI:10.1002/iroh.19800650404

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19800650405

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY

摘要:

AbstractSalt tolerance of the freshwater tubificidLimnodrilus hoffmeisterivaried from an LD 50 of 10 ppt to 10.5 ppt for mature and immature worms without sediment, 9.4 to 10.5 in sand, and 14.3 for immatures acclimated to 5 ppt.Ilyodrilus templetoniwas similarly intolerant to higher salinities. The estuarineTubificoides gabriellaetolerated salt water, but was susceptible to freshwater, with LD 50's of 2 and 3.5 when acclimated to 5 and 10 ppt sea water. It survived immersion in freshwater for 3 hours. The estuarine naididsParanais litoralisandfriciexperienced mortalities at both high and low salinities but showed a wide tolerance range. The coastal tubificidMonopylephorus irroratusshowed almost complete tolerance to the salinity range employed. The findings reflected field distributions especially when interstitial salinities were measured, but worms did not occupy the full range of habitats possible in terms of salinity alone.

ISSN:0020-9309    

DOI:10.1002/iroh.19800650406

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19800650407

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY

摘要:

AbstractSeasonal occurrence and vertical distribution of two sympatricBosminamorphs were investigated in two oligotrophic, deep fjord‐type lakes.Bosmina obtusirostrisandB. lacustrisdisplayed similar ecology, butB. obtusirostrisexhibited more eggs per clutch.B. obtusirostrisis probably the most viable of the two morphs when fish predation is relaxed, whileB. lacustrisexhibits an advantage with increasing fish and invertebrate predation. This has important consequences for habitat selection of the two morphs.B. obtusirostrisandB. lacustrisare most probably two phenotypes of a polymorphic specie

ISSN:0020-9309    

DOI:10.1002/iroh.19800650408

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY

摘要:

AbstractScale reduced populations of the Turkish speciesAphanius anatoliaeare usually found in biotopes containing magnesium and sodium sulphate. According to the hypothesis by Aksiray&Villwock (1962), there is a correlation between the adaptability to sulphate containing water and the scaly covering – a process which could be interpretedviapleiotropic gene effects. In laboratory experiments, the influence of sulphates on the ontogenetic development of the speciesA. anatoliae(5 populations),A. iberus, A. dispar, and A.mentowas investigated. No difference in the salt tolerance of scale reduced fish and normally scaled fish was observed. In addition, the number of scales in the central lateral row do not support the hypothesis either. The scale reductions are discussed to be a consequence of processes of regressive evolutio

ISSN:0020-9309    

DOI:10.1002/iroh.19800650409

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19800650411

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY

摘要:

AbstractDissolution of Triassic‐Jurassic, intrusive salt deposits within 150 m of the sea floor produces a hypersaline brine seep (∼200 0/00) at 71 m water depth on the East Flower Garden Bank. The anoxic, sulfide‐rich brine supports large populations of sulfur oxidizing bacteria. Toxic effects of the brine on surrounding epifauna, infauna and fishes are limited to the brine and a very narrow surrounding zone. Leafy algae, coralline algae, foraminifers, sponges, bryozoans, anemones, polychaetes, sipunculids, amphipods and pelecypods live on the hard substratum within 2 cm of the brine‐seawater interface. Sixty meters from the brine outflow, at dilutions of 50 to 1, the carbonate sand harbors polychaetes, ostracods, nematodes, amphipods, tanaidaceans, isopods, copepods, pelecypods and gastropods. Certain species of fish momentarily enter the brine and brine‐seawater

ISSN:0020-9309    

DOI:10.1002/iroh.19800650413

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY