(Tables 1-15) Morphometric characteristics of the genus Hinia (Nassariidae, Gastropoda) in the Tertiary of northwest Germany

The genus Hinia is divided in 4 subgenera; other subgenera are not represented in the area studied. It was possible to find criteria for a better discrimination of the highly variable species H. (Hinia) schlotheimi and H. (Hinia) turbinella. The species "fuchsi" has been placed in the synonymy of H. (Hinia) turbinella. The species H. (Hinia) schlotheimi (BEYRICH) and H. (Telasco) schroederi (KAUTSKY) have been united under the name H. (Hinia) schlotheimi. The easily distinguishable species H. (Tritonella) tenuistriata and H. (Hinia) sulcata belong to two different genera. H. (Tritonella) cimbrica andersoni of the Viol- and Katzheide-Beds (Reinbek-stage) is separable from the population found in the Hemmoor-stage, it turned out to be a valuable guide subspecies for the Reinbek-stage. The species H. (Tritonella) serraticosta, H. (Tritonella) catulli, H. (Hinia) holsatica, and H. (Telasco) syltensis are all similar in respect to shape and ornamentation. Criteria have been found for a better discrimination of these species. The species contabulata, effusa and seminodifera described by SPEYER (1864), turned out to be contogenetic stages of H. (Tritonella) pygmaea. H. (Tritonella) cavata, previously described from the Tertiary of the North sea area, was proven to be absent from the area investigated. The forms described under that name, belong to H. (Tritonella) woodwardi.

Molecular differentiation by PCR-RFLP technique shows that Antarctic fishes of the genus Notothenia, claimed to be two species, are phenotypic varieties with the same genetic pattern (Table 1)

The taxonomy of Antarctic fishes has been predominantly based on morphological characteristics rather than on genetic criteria. A typical example is the Notothenia group, which includes N. coriiceps Richardson, 1844, N. neglecta Nybelin, 1951 and N. rossii Richardson, 1844. The Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP) technique was used to determine whether N. coriiceps Richardson, 1844 and N. neglecta Nybelin, 1951 are different or whether they are the same species with morphological, physiological and behavioural variability. N. rossii was used as control. Mitochondrial DNA (mtDNA) was isolated from muscle specimens of N. coriiceps Richardson, 1844, N. neglecta Nybelin, 1951 and N. rossii, which were collected in Admiralty Bay, King George Island. The DNA was used to amplify a fragment (690 base pairs) of the mitochondrial gene coding region of NADH dehydrogenase subunit 2. Further, the amplicon was digested with the following restriction enzymes: DdeI, HindIII and RsaI. The results showed a variation of the digestion pattern of the fragment amplified between N. rossii, and N. coriiceps Richardson, 1844 or N. neglecta Nybelin, 1951. However, no differences were found between N. coriiceps Richardson, 1844 and N. neglecta Nybelin, 1951, on the grounds of the same genetic pattern shown by the two fish.

Distribution of the planktonic foraminifer genus Streptochilus in Neogene sediments

Study of four species of the biserial planktonic foraminifer Streptochitus from Deep Sea Drilling Project cores of the Eauripik Rise, western equatorial Pacific, and Ninety-east Ridge, Indian Ocean, shows that both the stratigraphic distribution of species and their frequency patterns (though not actual frequencies or abundances) are correlative in the two areas, supporting their use as stratigraphic and paleoecologic index fossils. Their distributional trends are linked to eustatic sea level changes and to changes in the mixing of surface waters; low frequencies and species turnovers occur during regressive phases when strong circulation of oxygenated waters could lead to the subsequent decline of their oxygen-minimum habitat. The species S. subglobigerum. S. latum. S. globigerum, and S. globulosum succeed one another at intervals averaging 2,5 my from late middle Miocene Zone N15 through Quaternary Zone N23. The new species, Streptochilus suhglobigerum, is described for what was formerly thought to be a stratiraphically lower, disjunct part of the range of S. globigerum. These four species most likely belong to a single phylogenetic lineage as evidenced by some transitional morphologies.

Biostratigraphic significance of the calcareous nannofossil genus Reticulofenestra in the Upper Pliocene of the North Atlantic

We demonstrate size fluctuations of the calcareous nannofossil genus Reticulofenestra in Upper Pliocene sediments from the North Atlantic Ocean and clarify a characteristic evolutionary trend of this genus. Four bioevents, which are based on abrupt decreases in maximum size and on changes of morphologic features of Reticulofenestra specimens, are detected in the sediments. They are the disappearance of R. minutula var. A, the termination of Acme Zone II of R. minutula var. C, the disappearance of R. minutula var. B, and the termination of Acme Zone I of R. minutula var. C, in ascending order. These are nearly synchronous and traceable events.

Meiofauna densities, nematode biomass, nematode genus diversity, sediment grain size, organic matter, and pigments for the surface layers of two sites in summer (November 2009) and winter (august 2010)

The meiobenthic community of Potter Cove (King George Island, west Antarctic Peninsula) was investigated, focusing on responses to summer/winter conditions in two study sites contrasting in terms of organic matter inputs. Meiofaunal densities were found to be higher in summer and lower in winter, although this result was not significantly related to the in situ availability of organic matter in each season. The combination of food quality and competition for food amongst higher trophic levels may have played a role in determining the standing stocks at the two sites. Meiobenthic winter abundances were sufficiently high to infer that energy sources were not limiting during winter, supporting observations from other studies for both shallow water and continental shelf Antarctic ecosystems. Recruitment within meiofaunal communities was coupled to the seasonal input of fresh detritus for harpacticoid copepods but not for nematodes, suggesting that species-specific life history or trophic features form an important element of the responses observed.

Nutrition of species of the genus Amphiophiura in the Pacific and Indian Oceans

Nutrition of 6 deep-sea ophiuroid species of the genus Amphiophiura in the Pacific and Indian Oceans has been studied. One species is a detritus-feeder while the others are carnivorous. All 6 are widespread in deep-sea eutrophic regions of both oceans. Carnivorous species are also necrophagous, feeding on dead fish, surface pteropods, and crustaceans. Fishes are consumed mainly in the Indian Ocean, pteropods in the Pacific. Thus, as shown by carnivorous Amphtophiura, the rain of dead surface pelagic organisms is one of the most important sources of food for a number of deep-sea bottom-dwelling invertebrates.