Response of the Lateglacial fauna to climatic change

This study deals with faunal finds from the Swiss Paleolithic, especially from the Late Glacial. Faunal assemblages from archeological sites as well as off-site finds dated by scientific means are included. In the middle of the Oldest Dryas the large glacial species – mammoth, rhinoceros, cave bear, musk ox – become extinct. During the Early Bølling the last arctic species disappear, and are succeeded by animals like red deer and elk, preferring a moderate climate. From the middle of the Allerød, species typical of a denser forest (roe deer and wild boar) are very frequent.

Distribution and Efficiency of Bacteriolysis in the Gut of Arenicola Marina and Three Additional Deposit Feeders

A simple technique was developed to measure the bacteriolytic activities of the digestive fluids of the deposit-feeding polychaete Arenicola marina. Lysis of a cultured environmental isolate, incubated with extracts of gut luminal contents, was monitored spectrophotometrically. Concurrent direct counts were used to verify cell lysis. The ability of extracts from 8 longitudinal sections of the gut to lyse the bacterium was monitored. The digestive ceca, anterior stomach, and posterior stomach regions exhibited high lytic activities, whereas bacteriolytic activities in all other regions of the gut were negligible. Similarly, extracts of surface sediments and fecal castings showed negligible lytic capabilities. The sharply limited distribution of lytic activity implicates the ceca as the source of bacteriolytic agent and suggests a true plug-flow system, with little axial mixing. Questions regarding the fate of lytic agents, which disappear abruptly posterior to the stomach, remain unanswered. Localization of lysis in the gut coupled with estimates of gut residence time permit the calculation that ingested bacteria are exposed to strong lytic activity for approximately 20 min. Incubation of in situ sediment samples with gut fluids corroborates the distributional findings of the in vitro work although the efficiency of lysis is much reduced, possibly due to exopolymer capsules and slimes of natural sedimentary bacteria. Cross-phyletic comparisons of bacteriolytic activities reveal both qualitative and quantitative differences. Much less demarcation of lytic activity is observed in the guts of a holothuroid (Caudina arenata) and a hemichordate (Stereobalanus canadensis), with a pattern more similar to that of A. marina observed in another polychaete, Amphitrite johnstoni. Quantitatively, the polychaetes showed higher levels of activity with rates in A. marina exceeding those of the hemichordate and holothuroid by more than 10-fold.

Structures and Concentrations of Surfactants in Gut Fluid of the Marine Polychaete Arenicola Marina

Marine invertebrate deposit feeders secrete surfactants into their gut fluid in concentrations sufficient to induce micelle formation, enhancing solubilization of sedimentary lipids. We isolated and identified 3 related surfactant molecules from the deposit-feeding polychaete lugworm Arenicola marina. Surfactants were isolated and separated by a combination of solvent extraction and thin-layer and gas chromatography. Identification was performed using mass and infrared spectrometry, coupled to various derivatization and hydrolysis reactions. A. marina produces a mixture of related yet distinct anionic surfactants composed of branched, C9, saturated and unsaturated fatty acids that are amide linked to leucine or glycine residues, showing some similarity to crustacean surfactants. The critical micelle concentration of the mixture of these surfactants in gut fluid was about 2 mM, and total concentrations ranged from 5.5 to 19.5 mM. The hydrophilic amide linkage helps to explain previous observations that gut surfactants do not adsorb onto sediment transiting the gut.

Patterns of the Remnant Cichlid Fauna in Southern Lake Victoria. Patrones de la Fauna de Ciclidos Remanentes en el Sur del Lago Victoria

During the years 1984–1987 Lake Victoria in East Africa experienced what is probably the largest mass extinction of contemporary vertebrates. Within a decade about 200 endemic species of haplochromine cichlids disappeared. The extinctions that occurred in the 1980s have been documented predominantly on species of offshore and sub-littoral waters in the Mwanza Gulf of southern Lake Victoria. Although the littoral fauna of southern Lake Victoria had not been examined in detail, their diversity seemed less affected by the changes in the ecosystem. We give results of the first comprehensive inventory of the littoral cichlid fauna in southern Lake Victoria and discuss its conservation status. We also report on new developments in the sub-littoral fauna after 1990. More than 50 littoral and 15 sub-littoral stations were sampled between the years 1991 to 1995. Of the littoral stations, 34 were sampled for the first time. One hundred sixty three species of haplochromines were collected. Of these, 102 species were previously unknown. About two thirds of them live in rocky areas that were sampled for the first time. Littoral rocky habitats harbored the highest diversity. Since 1990, however, 13 more species disappeared from established sampling stations in littoral habitats. Fishing practices, spreading of exotic fishes, water hyacinth, and eutrophication are considered important threats to the littoral fauna. Also in the upper sub-littoral the number of species declined further. On deeper sub-littoral mud bottoms individual and species numbers increased again, although they are nowhere close to those found before the Nile perch (Lates niloticus) upsurge. This fauna differs from the well studied pre-Nile perch fauna. At well-established sampling stations, the sub-littoral zone is dominated by previously unknown species, and some known species have performed dramatic habitat shifts.

Seasonal Variability in the Bacteriolytic Capacity of the Deposit Feeder Arenicola Marina: Environmental Correlates

Although deposit-feeding macrofauna consume and digest sedimentary bacteria, it is unclear whether feeding rates and digestion efficiencies are high enough to significantly impact the composition and abundance of bacteria in marine sediments. It is likely that both feeding rates and efficiency of digestion vary markedly through space and time. We used a turbidimetric assay to compare the rate of bacteriolysis by digestive fluids collected seasonally from the deposit-feeding polychaete Arenicola marina. Under standardized, experimental conditions, bacteriolytic rates represent concentrations of lytic agents. This concentration was found to vary significantly throughout the year (p = 0.001), showing greater than a 2x range. Lytic agent concentration was positively correlated with bioavailable amino acid concentrations in the surface sediment (r = 0.85, p = 0.03) but showed no apparent relationship to other proxies for food resources (e.g, chl a), sediment temperature, or gut throughput time. In vitro, temperature has been shown to have a strong positive influence on bacteriolytic rate. Temperature has no influence, however, on the in situ concentration of lytic agent in gut fluids, thus it appears that compensation for this temperature dependence is unimportant. These findings, combined with previous kinetics studies with A. marina gut fluids, predict that the quantitative influence of deposit feeding on the microbial ecology of sediments will exhibit clear seasonal variation.

Zur biblischen Fauna und Flora : ein nachträglicher Beitrag zur Festnummer für I. Löw

Felix Perles

Der Badeschwamm : Ein Kapitel aus der Fauna der Juden

Immanuel Löw

Zur Kenntnis der Copeognathen-Fauna Westpreußens

Von Dr. Günther Enderlein

Zweiter Beitrag zur Kenntnis der westpreußischen Geradflüglerfauna (Orthoptera). Gliederung der Fauna nach Lebensgemeinschaften

Von Dr. Wolfgang La Baume

Die einheimische Wirbelthier-Fauna

Von Dr. Conwentz

Beiträge zur Fauna der Tucheler Heide

Von Dr. Willy Wolterstorff

V. Die einheimische Wirbelthier-Fauna

Von H. Conwentz

Fauna und Flora des Golfes von Neapel und der angrenzenden Meeres-Abschnitte

hrsg. von der Zoologischen Station zu Neapel

Diebesrätsel aus der sibirischen Fauna

Von Dr. Wilh. Gross