Viaje a las profundidades del Océano (VIDEO) + Extrañas criaturas marinas (FOTOS)

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  Pero, ¿qué es un Océano? U n océano es una enorme masa de agua salada que representa un importante ecosistema para el equilibrio ecológico de la Tierra y que constituye el  71% de la superficie terrestre , gracias a los 360,132,000 km² de su extensión. Y,  ¿cuántos océanos existen? Lo que cubre gran parte de la superficie de la Tierra, es en sí, un solo océano. Es decir, una sola masa de agua. Para un mejor estudio, el hombre dividió esta enorme masa en 5 partes de acuerdo a su ubicación geográfica. Por ello, la expresión “los océanos”, es correcta. Importancia de los océanos *Absorben entre un 25 y 30% del dióxido de carbono emitido a la atmósfera, por lo que Equilibran el clima de toda la Tierra. *Representan numerosos ecosistemas para diversas formas de vida animal, vegetal, bacteriana, protista y fúngica. *Son hogar para miles de especies, conocidas y aún desconocidas. Existen aproximadamente 250,000 especies conocidas, pero se cree que puedan haber 750,000 más. *Proveen fuentes

Dogs Can Go Temporarily Nuts When Kenneled

Dogs in kennels not only may bark incessantly, but they may also show other signs of extreme distress that are often associated with mental illness.
A new study, published in the latest issue of the journal Physiology & Behavior, examined the behavior of 30 kenneled dogs. These canines were even more socialized than most home pets, since all were male German shepherd trained police dogs. (Often researchers will focus on a specific grouping like this to avoid other influencing factors, such as differences between breed temperaments, size, sex, age and so on.)
Police dogs also sometimes spend time in kennels after their work shifts. This particular kennel, located in the U.K., had accommodation for 40 dogs, a run area and an enclosed resting area.
None of the dogs included in the study were on any prescription medications.
Lead author Hamish Denham of the University of Bristol’s Anthrozoology Institute and his
colleagues videotaped the dogs and noted the following repetitive behaviors:
*Bouncing off the walls — literally: The researchers described this as “jumping at a wall and rebounding from it or jumping on the spot either all four legs leaving the floor or hind legs continuously in contact with floor and forelegs only leaving the floor.” The dogs would do this over and over again.
*Spinning: This involved “turning in a tight circle pivoting about (the) hind legs.”
*Circles: Dogs were seen “walking or trotting around perimeter of pen” in repetitive circles.
*Paces: The researchers observed the dogs “walking or trotting back and forth along a boundary or imaginary line.”
The dogs would also combine the behaviors and frequently after various triggers, such as when human caretakers were around at feeding times.
Such repetitive, obsessive behavior is associated with numerous mental health problems. Scientists are not sure what’s behind such behaviors. In humans, they propose that the people live in a world of sensory confusion, or are trying to block out painful stimulation with focused behaviors. Another theory is that the behaviors are linked to senses that are not functioning properly.
In the dog study, it’s interesting to note that a large proportion of the test subjects — 93 percent — performed some repetitive behavior. It was more evident in certain dogs than others.
The researchers explained that “some dogs may find isolation from humans particularly aversive, hence affecting their reactions both to being left in a kennel and to being taken to the veterinary surgeon.”
They added that some dogs might also experience “chronic stress” related to overstimulation of their adrenal glands.
Surprisingly, some of the dogs that looked like they were going bonkers did not show exceptionally high levels of cortisol, a stress hormone. The researchers think that certain dogs might use repetitive behaviors as a “coping mechanism.”
The researchers have called for further studies to better determine if repetitive behaviors performed by kenneled dogs compromise their welfare.
Source: news.discovery.com

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