Hippocampus
The Genus Hippocampus belongs to the family Syngnathidae, order Syngnathiformes, class Osteichthyes, phylum Chordata, and kingdom Animalia. The genus Hippocampus is made up of more than twenty different species of seahorses (Beltran). They live preferably in the coral reefs or sea grasses where they can easily camouflage to avoid predators. They are found mostly in the tropical or temperate shallow water areas of the oceans around the world. Seahorses are most closely related to sea dragons, pipefishes, and the flagtailed pipefishes (Seahorses). Although seahorses are similar to their relatives, they do have many different characteristics that the relatives do not have. Seahorses are distinctive species that possesses the most unique characteristics among all the marine fish.
One of seahorses’ differences from other fish is their appearance. Seahorses have a body of bony plates that arranged in rings and covered with thin skin all the way to their tails, which curl up and toward their bodies. Their heads look like horse head with long tube-shape snout and large eyes. At the end of their snout are their mouths, which they use to get their food. On top of their head is a coronet that is unique for each individual. Lastly, only male seahorses have a pouch in front of their stomach. Although all the species of seahorses share the same basic morphological characteristics that are not shared by other marine fish, they are different in sizes, number of rings on their bodies, and their colors (Seahorses).
Seahorses also behave in ways that are unique to themselves. One of their uniqueness is their vision. Unlike other sea animals, seahorses’ eyes move independently from each other, which help them aware of their surroundi...
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... Marsden, Karl L. Evans, Laila M. Sadler. “Temporal and Spatial Opportunities for Polygamy in a Monogamous Seahorse, Hippocampus whitei.” Brill. Behaviour, Vol. 141, No. 2 (Feb, 2004), pp. 141-156. 20 March 2011. < http://www.jstor.org/stable/4536118.>
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These scientists reviewed the natural space-use patterns and hippocampal size in kangaroo rats after undergoing evolution by natural selection. The size of the hippocampus, a forebrain structure that processes spatial information, correlates with the need to relocate food caches by passerine birds and with sex-specific patterns of space use in microtine rodents. The influences on hippocampal anatomy of sexual selection within species, and natural selection between species, have not yet been studied in concert, however. Here we report that natural space-use patterns predict hippocampal size within and between two species of kangaroo rats (Dipodomys). Differences in foraging behavior suggest that Merriam''s kangaroo rats (D. merriami) require better spatial abilities than bannertail kangaroo rats (D. spectabilis). Sex-specific differences in mating strategy suggest that males of both species require more spatial ability than females. As predicted, hippocampal size (relative to brain size) is larger in Merriam''s than in bannertail kangaroo rats, and males have larger hippocampi than females in both species. Males of a third species (D. ordii) also have smaller hippocampi than Merriam’s kangaroo rat males, despite being similar to Merriam''s in brain and body size. These results suggest that both natural and sexual selection affect the relative size and perhaps function of mammalian hippocampus. They also reassert that measures of functional subunits of the brain reveal more about brain evolution than measures of total brain
The Northern White-tailed deer have a polygynous mating system (fcps.edu, nd). Most white tails mate in their second year but it is possible for females to become sexually active after only seven months. The male species are polygamous but may develop an attachment to a doe for several days or weeks. The female species come into heat in November for only twenty-four hours. If the female is not mated she will have a second heat...
Deborah L. Duffy, Yuying Hsu, James A. Serpell ,Applied Animal Behavior Science - 1 December 2008 (Vol. 114, Issue 3, Pages 441-460, DOI: 10.1016/j.applanim.2008.04.006)
What is the role of the hippocampus and associated areas such as the entorhinal cortex and medial septum in spatial navigation: Do theta oscillations have a significant effect on spatial navigation and could this shed light on the underlying neural mechanisms ?
Actually monogamy had developed long before religion became interested. According to Fisher’s estimate, nearly every human society has been monogamous to some degree (69), and she claims that human beings have a biologically natural preference for mo...
Vision plays a huge role in the lives of non-human primates. Non-human primates have exceptional binocular vision, due to forward-facing eyes with overlapping visual fields (Prescott). This binocular stereoscopic color vision allows primates to see the world in terms of height, width, and depth, also known as three-dimensional vision (Haviland et al. 2010). Highly developed vision allows the later arboreal primates to judge depth, distance, and location when moving at speed from branch to branch (Haviland et al. 2010). This bino...
Striped dolphins, Stenella coeruleoalba, are some of the most abundant and well-known dolphins in the world. These dolphins can reach the length of about 9 ft (2.7 m). The males weigh up to 350 lbs (160 kg). The females weigh 330 lbs (150 kg). Striped dolphins have a slender body shape combined with a long beak, which is separated from their forehead, and they also have a curved dorsal fin. The beak, tapered flipper, tail, and back, or cape, are dark blue/gray. The name “Stenella coeruleoalba” refers to the pattern of blue and white stripes along the lateral and dorsal fins of their body. Their underbelly (ventral) is usually white. Their primary feature is a black stripe that runs along their full length and to their flippers. There is also a dark blue patch around the eyes. Calves and juveniles may have more muted colorations and patterns.
Through studies performed on sleep-deprived rats, experimental results have shown a decrease in cellular activity in the hippocampus. The hippocampus is responsible for most of the brain’s memory processing. When entering into sleep deprivation, the brain will experience consequences such as a failure for the hippocampus to encode, consolidate, or retrieve signals powering memory processing. As a result, researchers are looking for cellular characteristics that could lead to further details into the relationship between sleep deprivation and memory impairment. There are several different ways memory can be disrupted, one suggested in being an imbalance of neurotransmitters in the hippocampal region of the brain. Both hormonal and oxidative stress are also factors that are observed to play major roles of memory impairment in the hippocampus. These
This paper will look at why monogamy is important, the reason it’s dying, and why it needs to be placed back in the spotlight. Besides the social stigma of polygamy, monogamy has many benefits for the human race. Although some may argue, as humans, we aren’t exactly designed to be a perfectly monogamist species, it is my personal opinion that we have the adept skills to make monogamy work and be a valuable way of life. Of the about 4,000 mammal species on Earth, only a few dozen form lifelong monogamous pair bonds (Jeffries). That equates to approximately 3% of all mammals participating in monogamous activities....
The evolution of horses over the last 50 million years, is remarkable really. Horses used to look so different back then, its amazing to look at the difference now. Because there’s so much information on each and every type of horse that the modern horse started off as and a lot of researchers have put the information on timelines and graphs for people to view. It kinda resembles a tree if you look at the picture. It has so many different branches. To make this easy to understand this paper will go over a view of the many different forms of horse, including how old they are and what they looked like.
World Archaeology, 31:3:329-350. Mitani, J.C. et al 1996 Sexual Dimorphism, the Operational Sex Ratio, and the Intensity of Male Competition in Polygamous Primates. The American Naturalist, 147:6:966-980. Rogers, Alan R. and Arindam Mukherjee 1992 Quantitative Genetics of Sexual Dimorphism in Human Body Size.
Sea lions may look like sea creatures, but they also behave like terrestrial animals. Unlike whales, mammals that spend their entire lives in water, sea lions inhabit both the water and land throughout their lives. This aquatic land animal prefers the water for food, fun, and safety; while preferring the land for socializing, territory, and procreation. Being mammals, they share many behaviors common to humans and other mammals. Like mammals, they are born with the ability to walk on land shortly after birth. Surprisingly, they are not born with the ability to swim from birth, but need to be taught by their mothers. Like other mammals, they love to stay in social groups. During their reproductive season, females are dominated by aggressive males, that establish harems on the beaches. The relationship between females and their pups is characterized by affection, protection, nourishment, and instruction. In contrast to their limited terrestrial mobility, they can swim much better than they can walk. Unlike other land mammals, they have the ability to sleep in water . The most interesting thing is that they can sleep in water by using one part of their brain, while the other part of their brain is asleep ("Birds sleep with one eye open, half awake, study finds"). Clearly, sea lions have adapted well to a both an aquatic and land life.
when in water. They're thick fur makes there body seem much thicker on land, than how it looks
Within the eye wall, the winds are the strongest. They move around so fast that it is difficult to hear, see, and even breathe. While over the ocean, these winds can create waves that are talle...
" Society & Animals 18.2 (2010): 183-203. Academic Search Premier -. EBSCO. Web. The Web. The Web.