Intertidal community composition along rocky shores in South-west Greenland: a quantitative approach

The intertidal communities on rocky shores are directly subjected to climatic changes in air and water temperatures and to derived effects of climate change, such as changes in freshwater run-off and ice dynamics. Global warming occurs at elevated rates in Greenland and results in changing species distributions with range expansions to the north and new species entering terrestrial habitats from the south. There is, however, no quantitative knowledge of past or present species distribution in the littoral zone of Southern Greenland, an area which represents an important gateway for northern range expansions of temperate species. This study provides baseline information on abundances of macroorganisms in the eulittoral Southern Greenland. This knowledge will pave the way for future studies on the impact of climate change and anthropogenic activities on these communities. Nine sites, situated at different exposure levels, were investigated. A total of 22 taxa were recorded, suggesting low species richness. Patellid limpets and predators such as dogwhelks, starfish and crabs were absent. Total standing stock ranged from 0 to 31,898 g m^?2. Species composition and biomasses were related to locally generated wave exposure, oceanic swells and ice scouring. The high standing stock at sheltered sites indicated that neither light, temperature nor nutrients, constrained buildup of biomass in this environment. Inshore seasonal measurements of water and air temperatures were recorded for the first time in the region, displaying low water temperatures and high variation in air temperatures, indicating lack of insulating stable sea ice in the area. Possible impacts of ongoing temperature changes are discussed based on recorded temperatures and meteorological data from the past 30 years.     

In vitro bioassay for the brain allatotropic hormone of Galleria mellonella (Lepidoptera).

An in vitro sensitive bioassay for the Galleria mellonella brain allatotropic hormone (ATTH) was developed. This assay measures the rate of juvenile hormone (JH) synthesis in corpora cardiacacorpora allata complex (CC-CA) stimulated in vitro by ATTH released from the brain during short-term in vitro incubation, or by ATTH extracted from the tissue with methanol. CC-CA of the late VIth instar (VI3) larvae were used for assessment of ATTH. The maximum activation of test CC-CA by ATTH occurred at a concentration of 2 brain equivalents (per 100 ul medium). The highest ATTH activity was exhibited by the brains of chilled VII1 larvae: ATTH extracted from freshly dissected brains, or ATTH released from these brains during 6 h in vitro incubation, activated JH synthesis in the CC-CA nearly five or four times, respectively. The brain of VII1 hydroprenetreated larvae were ATTH inactive.