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1.
James D Salierno Steve Rebach Mary C Christman 《Journal of experimental marine biology and ecology》2003,287(2):249-260
The effects of competitor pressure and prey odor on foraging behavior of the rock crab, Cancer irroratus (Say), were investigated. The Jonah crab, Cancer borealis (Stimpson), was chosen as the interspecific competitor because it shares resources with C. irroratus. Four treatments were tested for their effect on foraging: the presence or absence of a competitor and two types of prey odor; body odor (living mussel) and tissue extract (dead mussel tissue). The presence of Jonah crabs did not influence location time, search time, prey size selected, or handling time of the rock crabs. However, rock crabs responded differently to the presence of body odor and tissue extract cues. The presence of extract odor decreased the time to locate prey while increasing the number of prey manipulated and prey size selected. When prey body odor was present, rock crabs displayed less investigative behaviors than in the presence of extract odor, illustrated by reduced location time. Extract odor provided a stronger and more attractive cue than body odor, but increased prey manipulation and search time. Extract odor induced increases in manipulation and searching for prey but canceled out the benefits of decreased location time, resulting in crabs from both treatments displaying similar search times. These elevated behaviors may be associated with foraging for injured and cracked prey or may indicate an area of conspecific feeding. 相似文献
2.
Vera MF da Silva Anthony M Carter Carlos E Ambrosio Ana F Carvalho Marina Bonatelli Marcelo C Lima Angelica Maria Miglino 《Reproductive biology and endocrinology : RB&E》2007,5(1):26-6
A recent reassessment of the phylogenetic affinities of cetaceans makes it timely to compare their placentation with that
of the artiodactyls. We studied the placentae of two sympatric species of dolphin from the Amazon River Basin, representing
two distinct families. The umbilical cord branched to supply a bilobed allantoic sac. Small blood vessels and smooth muscle
bundles were found within the stroma of the cord. Foci of squamous metaplasia occurred in the allanto-amnion and allantochorion.
The interhemal membrane of the placenta was of the epitheliochorial type. Two different types of trophoblastic epithelium
were seen. Most was of the simple columnar type and indented by fetal capillaries. However, there were also areolar regions
with tall columnar trophoblast and these were more sparsely supplied with capillaries. The endometrium was well vascularised
and richly supplied with actively secreting glands. These findings are consistent with the current view that Cetacea are nested
within Artiodactyla as sister group to the hippopotamids. 相似文献
3.
C. W. Kuhar L. J. Miller J. Lehnhardt J. Christman J. D. Mellen T. L. Bettinger 《Zoo biology》2010,29(1):68-79
With the growing trend in zoos to build complex, naturalistic exhibits comes the potential for exhibits to be so densely vegetated or complex that animals are not easily seen by zoo visitors. This can negatively impact the visitor's visiting experience and the zoo's ability to communicate conservation and education messages. Over the past 9 years, Disney's Animal Kingdom® has developed a process for monitoring and improving the visibility of animals on display to the public. This animal visibility process utilizes a data collection system whereby systematic observations are collected each week. The percentage of observations where at least one animal was visible is recorded for each species and compared to an 80% visibility criterion. Species that do not reach this criterion for 4 consecutive weeks are discussed at animal management meetings. If the problems associated with animal visibility cannot be easily solved, the animal‐care teams partner with the research team to conduct a second process, called the Visibility Issues Process. This process provides additional information for the animal‐care team to utilize in developing a plan to improve visibility. Although the processes described here are specific to the infrastructure at Disney's Animal Kingdom®, the basic concepts of (1) a formalized visibility data collection process, (2) a visibility criterion to which managers of species are held accountable, and (3) a process for planning to improve animal visibility without negatively impacting animal welfare are fundamental concepts that can be developed at individual institutions and incorporated into that zoo's existing infrastructure. Zoo Biol 29:68–79, 2010. © 2009 Wiley‐Liss, Inc. 相似文献
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For several species of lepidoptera, most of the approximately 350-bp
mitochondrial control-region sequences were determined. Six of these
species are in one genus, Jalmenus; are closely related; and are believed
to have undergone recent rapid speciation. Recent speciation was supported
by the observation of low interspecific sequence divergence. Thus, no
useful phylogeny could be constructed for the genus. Despite a surprising
conservation of control-region length, there was little conservation of
primary sequences either among the three lepidopteran genera or between
lepidoptera and Drosophila. Analysis of secondary structure indicated only
one possible feature in common--inferred stem loops with higher-than-random
folding energies-- although the positions of the structures in different
species were unrelated to regions of primary sequence similarity. We
suggest that the conserved, short length of control regions is related to
the observed lack of heteroplasmy in lepidopteran mitochondrial genomes. In
addition, determination of flanking sequences for one Jalmenus species
indicated (i) only weak support for the available model of insect 12S rRNA
structure and (ii) that tRNA translocation is a frequent event in the
evolution of insect mitochondrial genomes.
相似文献
9.
Vinpocetine is a potent antioxidant and free radical scavenger. We investigated the effects of vinpocetine on torsion/detorsion (T/D) induced testicular damage, HSP-70 expression and germ cell apoptosis in rats. Sixty Wistar albino adult male rats were divided into five groups of 12. The groups comprised a control group, a sham treated group, a T/D group, a vinpocetine treated group, and a T/D plus vinpocetine treated group. The left testis of each rat was subjected to unilateral torsion followed by detorsion after 2 h. Vinpocetine was administered intraperitoneally immediately and for 10 days following detorsion. At the end of the study, the rats were sacrificed and their testes removed and processed. HSP-70 expression, apoptosis and histopathological damage scores were determined for each group. Testicular T/D caused significant increases in apoptosis and HSP-70 expression, and a significant decrease in Johnsen’s testicular biopsy scores and mean seminiferous tubule diameter. Vinpocetine ameliorated testicular histopathology and HSP-70 expression in the T/D + vinpocetine group. Consequently, vinpocetine may prevent testicular injury following testicular torsion owing to its antioxidant effects. 相似文献
10.
A Yay D Akkuş H Yapıslar E Balcıoglu MF Sonmez S Ozdamar 《Biotechnic & histochemistry》2014,89(8):552-557
Nitric oxide (NO) plays a significant role in the development of diabetic nephropathy. We investigated the effects of an antioxidant, carnosine, on streptozotocin (STZ)-induced renal injury in diabetic rats. We used four groups of eight rats: group 1, control; group 2, carnosine treated; group 3, untreated diabetic; group 4, carnosine treated diabetic. Kidneys were removed and processed, and sections were stained with periodic acid-Schiff (PAS) and subjected to eNOS immunohistochemistry. Examination by light microscopy revealed degenerated glomeruli, thickened basement membrane and glycogen accumulation in the tubules of diabetic kidneys. Carnosine treatment prevented the renal morphological damage caused by diabetes. Moreover, administration of carnosine decreased somewhat the oxidative damage of diabetic nephropathy. Appropriate doses of carnosine might be a useful therapeutic option to reduce oxidative stress and associated renal injury in diabetes mellitus. 相似文献