759,340 research outputs found
Functional morphology of cephalopod gills
There is a wealth of literature dealing with fish gills
(Review, see Hoar & Randall, 1984), yet hardly anything is known about the gills of cephalopods. This is rather
surprising considering the commercial importance of the
cephalopods.
In view of the paucity of information available it was
necessary to start by establishing the morphology of the
gills. This is covered in the first section of this thesis.
Of all the cephalopods, Octopus vulgaris was singled out
for more detailed investigation (see chapters 2 & 3) as its
physiology is comparatively well understood (Wells, 1978).
The gills of cephalopods are the major sites for respiratory
gaseous exchange. It follows that their dimensions might be
expected to govern their potential for absorbing oxygen.
Section two deals with the morphometries of cephalopod gills, and predicted values are compared with physiological
measurements of oxygen uptake for four representative
The final section describes the physiological experiments I
performed on octopuses. These experiments were designed to
find out whether the animals could regulate the gills'
potential to take up oxygen through changes to the gills
themselves
Ro[u:]ting the interpretation of words
Word formation in Distributed Morphology (see Arad 2005, Marantz 2001, Embick 2008): 1. Language has atomic, non-decomposable, elements = roots. 2. Roots combine with the functional vocabulary and build larger elements. 3. Roots are category neutral. They are then categorized by combining with category defining functional heads
The impact of ocean acidification on the functional morphology of foraminifera
This work was supported by the NERC UK Ocean Acidification Research Programme grant NE/H017445/1. WENA acknowledges NERC support (NE/G018502/1). DMP received funding from the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland). MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions.Culturing experiments were performed on sediment samples from the Ythan Estuary, N. E. Scotland, to assess the impacts of ocean acidification on test surface ornamentation in the benthic foraminifer Haynesina germanica. Specimens were cultured for 36 weeks at either 380, 750 or 1000 ppm atmospheric CO2. Analysis of the test surface using SEM imaging reveals sensitivity of functionally important ornamentation associated with feeding to changing seawater CO2 levels. Specimens incubated at high CO2 levels displayed evidence of shell dissolution, a significant reduction and deformation of ornamentation. It is clear that these calcifying organisms are likely to be vulnerable to ocean acidification. A reduction in functionally important ornamentation could lead to a reduction in feeding efficiency with consequent impacts on this organism’s survival and fitness.Publisher PDFPeer reviewe
Saving the European eel : how morphological research can help in effective conservation management
The European eel (Anguilla anguilla) is a critically endangered species, whose recruitment stocks have declined to nearly 1% compared to the late 70s. An amalgam of factors is responsible for this, among them migration barriers, pollution, habitat loss, parasite infection, and overfishing. A lot of recent studies focus on aspects that can increase the mature silver eel escapement rate, such as identifying migration barriers and developing passageways or addressing the impact of pollution on the eel’s health. However, little attention is given to the eel’s morphology in function of management measures. Worryingly, less than 50% of the currently installed management plans reach their goals, strongly indicating that more information is needed about the eel’s ecology and behavior. Functional morphological studies provide insights on how species perform behaviors crucial for survival, such as feeding and locomotion, but also in how environmental changes can affect or limit such behaviors. Consequently, functional morphology represents an important biotic component that should be taken into account when making conservation decisions. Hence, here, we provide an overview of studies on the eel’s morphology that do not only demonstrate its relation with ecology and behavior, but also provide information for developing and installing proper and more specific management measures
Effect of riverbed morphology, stream order and season on the structural and functional attributes of caddisfly assemblages (Insecta: Trichoptera)
We tested the individual and joint effects of stream order, riverbed morphology (i.e. pool-riffle sequence), and season on the structural (i.e. species composition, density and richness) and functional (i.e. percent ratio of shredders, collectors, scrapers, and predators) properties of caddisfly assemblages in a closely natural headwater system (Börzsöny Mts., North Hungary). Each factor, both individually and in interaction had a significant effect on caddisfly assemblages as shown by MANOVA analyses. To clarify the effects of stream order, riverbed morphology and season on caddisflies, assemblage properties were also separately
studied by ANOVAs. Percent ratio of shredders and collectors were strongly affected by all factors, whereas other attributes were not always sensitive to stream order, season and riverbed morphology. In contrast, species compositions of the reaches differing in stream order and riverbed morphology were significantly different. Our findings on the contrasting differences in shredder composition between riffles and pools may suggest that not only riparian vegetation, but also instream habitat features could
shape the accumulation and retention of particulate organic matter (in streams with pool-riffle heterogeneity)
Agent, causer and instrument PPs in Greek : implications for verbal structure
In this paper we investigate the distribution of PPs related to external arguments (agent, causer, instrument, causing event) in Greek. We argue that their distribution supports an analysis, according to which agentive/instrument and causer PPs are licensed by distinct functional heads, respectively. We argue against a conceivable alternative analysis, which links agentivity and causation to the prepositions themselves. We furthermore identify a particular type of Voice head in Greek anticausative realised by non-active Voice morphology
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