Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Effects of environmental stressors on blood-glucose levels in sea hares, Aplysia dactylomela (1994)
    Springer
    Marine biology 118 (1994), S. 579-583 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Effects of natural stressors such as tidepool strandings, air exposure, and low salinity on blood-glucose levels were investigated in the sea hare Aplysia dactylomela from shallow areas of Discovery Bay, Jamaica. All treatments produced large and significant elevations in blood-glucose titre, 1.5-to 2.3-fold above baseline levels of 25 to 35 μg glucose ml-1. Response times were variable, with significant elevations being manifested within 30 to 120 min from initiation of the stressor. Recovery was swift, within an hour or two of restoration to pretreatment conditions, and often involved an undershoot to levels below control values. In two experiments involving tidepool strandings and associated high body-temperatures, excessively low blood-glucose titres were followed by death of all test individuals. When sea hares were exposed to 75 and 50% seawater (100%=33‰S) for 1 h, maximum elevation in blood-glucose concentrations occurred 1 to 2 h from onset of exposure, coincidental with maximum dilution of the body fluids of test individuals. The responsiveness of blood-glucose titres to relatively small temperature or salinity changes, or to short-duration air exposures, suggests that monitoring this physiological parameter may be a useful and sensitive means of diagnosing a wide variety of stressors in marine gastropods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00347504
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Feeding, food preference, and the uptake of food energy by the supralittoral isopod Ligia pallasii (1973)
    Springer
    Marine biology 18 (1973), S. 228-236 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Analyses of gut contents of freshly collected Ligia pallasii (Brandt) showed that the principal foods were encrusting diatoms, insect larvae, occasional members of the same species, and a variety of red and green seaweeds growing in the upper interiidal tidepool habitat. L. pallasii prefers to eat the green seaweed Ulva sp., and the brown alga Nereocystis luetkeana, when given a choice between several seaweeds, although neither of these forms is normally accessible to the isopods. The absorption (“assimilation”) of food-energy was 78% on a diet of Ulva and 55 to 76% on a diet of N. luetkeana—representative values for an algivorous invertebrate. A correlation analysis on the relationship of feeding preference of L. pallasii with calorific value of 7 potential seaweed foods suggested that feeding preference in this species is related to factors other than energy content of the food. Food preferences of invertebrates are discussed in relation to calorific value, accessibility, and to various nutritional factors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00367989
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Studies on the growth, reproduction, and life cycle of the supralittoral isopod Ligia pallasii (1973)
    Springer
    Marine biology 18 (1973), S. 302-311 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A two-year study on a field population of Ligia pallasii Brandt has shown that the isopods live for 1.5 to 2 years. Breeding occurs in the spring and early summer, with some females carrying winter broods of eggs. The mean length of breeding females is 22.5±2.2 mm (standard deviation) and the mean brood size is 48±11 eggs. Mature males are larger than mature females (900 and 300 mg live weight, respectively), and are disproportionately broader (31×17 mm and 22.5×9 mm, respectively). The larger size and breadth of the males is an adaptation for copulation, and may be atributed in some measure to slower growth of the female due to the extra energy demands of reproduction. The overall 1:1 ratio of males to females in the population represents the balance between an equal sex ratio in the immature stages, more females in the 18 to 24 mm length category, and more males in the larger length categories. This condition is attributed mainly to the faster growth of the males.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00347793
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Phagostimulatory properties of various chemical compounds to sea hares (Aplysia kurodai and A. dactylomela) (1982)
    Springer
    Marine biology 68 (1982), S. 207-215 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phagostimulatory properties of amino acids, carbohydrates, vitamins, fatty acids, and cholesterol were assessed for sea hares (Aplysia kurodai and A. dactylomela). A. kurodai were collected at Shirahama, Japan, during March-May 1979, and A. dactylomela were collected at Barbados, West Indies, during August-November 1978. Greatest phagostimulatory responses were elicited by starch, glutamic and aspartic acids, maltose, oleic acid, and certain combinations of vitamins. Combinations of nutrients resulted in negative synergistic or “masking” effects of the phagostimulatory properties of the component nutrients. The widespread sensitivity and responsiveness to glutamic and aspartic acids by marine invertebrates, and especially by sea hares, are discussed from the standpoint of possible use by marine herbivores as feeding cues.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00397608
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Mycosporine-like amino acids: possible UV protection in eggs of the sea hare Aplysia dactylomela (1998)
    Springer
    Marine biology 130 (1998), S. 389-396 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We investigated mycosporine amino acid (MAA) involvement as protective sunscreens in spawn of the sea hare Aplysia dactylomela to determine if adult diet and ultraviolet (UV) exposure affected the UV sensitivity of developing embryos. Adults were fed a red alga rich in MAAs (Acanthophora spicifera) or a green alga poor in MAAs (Ulva lactuca). Adults on each diet were exposed for 2 wk to ambient solar irradiance with two types of acrylic filters; one allowed exposure to wavelengths 〉275 nm (designated UV) and one to wavelengths only 〉410 nm (designated NOUV). Spawn from each adult group was likewise treated with UV or NOUV and monitored during development for differences in mortality and metabolic rate (measured as oxygen consumption: V˙ O2). Also recorded were number of eggs or embryos per capsule, times to hatching, hatching success, size at hatching, and V˙ O2 of adults. Spawn from adults eating red algae was almost twice as rich in MAAs as spawn from adults eating green algae, suggesting that MAA content is diet-related. Although overall quantities of MAAs in the spawn reflected MAA contents of the adult diet, specific MAAs were differentially sequestered in the spawn. Thus, porphyra-334, found in high concentration in Aplysia dactylomela's preferred red algal food, was present in only low concentration in the spawn. Conversely, mycosporine-glycine, in low concentration in red algal food, was the most abundant MAA in the spawn. UV treatment of adults had no effect on quantities of MAAs in the spawn. Adults exposed to UV had significantly higher V˙ O2s and spawned twice as often. The UV-treated adults produced spawn with significantly higher V˙ O2s and their embryos developed to hatching sooner. The only significant effect of UV exposure of the spawn was to reduce the percentage of veligers hatching from 71 to 50%. There was no significant effect on hatching time or size of the veligers at hatching, nor on number of eggs per capsule.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002270050259
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Hemolymph ion composition and volume changes in the supralittoral isopod Ligia pallasii Brandt, during molt (2000)
    Springer
    Journal of comparative physiology 170 (2000), S. 329-336 
    Details
    ISSN: 1432-136X
    Keywords: Key words Calcium ; Capillary electrophoresis ; Hemolymph volume ; Isopod ; Molting
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We analyzed ion composition and volume of the hemolymph of Ligia pallasii in four different stages of the molt cycle using capillary electrophoresis and 3H-inulin. The main ions in the hemolymph were Na+, K+, Mg2+, Ca2+, and Cl−. The Ca2+concentration increased significantly during the molt by 47% from intermolt to intramolt and by 37% from intermolt to postmolt, probably due to resorption of Ca2+ from the cuticle and sternal CaCO3 deposits. The K+ concentration increased significantly by 20% during molt. The hemolymph volume normalized to the dry mass of the animals decreased by 36% from intermolt to late premolt. This was due to a reduction in the hemolymph volume and to an increase in dry mass of the animals during premolt. A sudden increase in the hemolymph volume occurring between late premolt and intramolt served to expand the cuticle. Since the Na+, K+, Mg2+, and Cl− concentrations did not change significantly from late premolt to intramolt, the increase in hemolymph volume suggests an uptake of seawater rather than freshwater.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003600000108
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Haemolymph volume, changes in the biochemical composition of the blood, and cytological responses of the digestive cells inMytilus californianus Conrad, induced by nutritional, thermal and exposure stress (1978)
    Springer
    Journal of comparative physiology 127 (1978), S. 287-298 
    Details
    ISSN: 1432-136X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. The volume of the extracellular space inMytilus californianus is 46% of the wet weight of the tissues (excluding the shell). 2. Fluid lost through bleeding is replaced within four hours, and both the dissolved and the cellular components (haemocytes) of the haemolymph are quickly restored. 3. The level of ammonia in the plasma increases when starved mussels begin to feed. This is a result of the specific dynamic action (SDA) which is associated with protein metabolism during feeding. 4. Ammonia accumulates in the plasma when mussels are exposed to air, which indicates that catabolism of nitrogenous substrates continues when the animal is exposed at low tide. 5. There are few changes in plasma carbohydrate, lipid and protein levels which are attributable to exposure, ration or increased temperature, suggesting good short-term regulation. 6. Lysosomal intracellular digestion continues in the digestive cells of mussels exposed to air. During exposure, there is also an increase in the numbers of circulating haemocytes, which may be associated with the continuation of the digestion process. 7. At high ration and elevated temperature, the digestive epithelium thickens, and there is some evidence that the rate of lysosomal intracellular digestion increases. During periods of starvation the epithelium becomes thinner and there is a loss of cytoplasm, probably by autophagy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00738412
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...