Many people think that spiders and arachnids are synonyms with the same meaning and classifications. Through this piece, one will understand various differences and similarities between the two. Spiders are a member of the order, Araneae, class, Arachnids, and the phylum, Anthropods. Within the arachnid class lies much diversity and a few common traits. Spiders are grouped into this class as well as scorpions, ticks, mites, and many more organisms. The order, Araneae, is comprised of spiders. How do spiders and arachnids compare? While spiders and arachnids have many mutual traits, spiders differ in some key categories. All arachnids have similar anatomies, one of the most common traits being the number of appendages. Arachnids develop with eight legs. However, some species of arachnids appear to have only six legs because they are sometimes converted for use in their senses. Since all arachnids have eight legs, they are easily distinguishable from insects, which have six legs. Arachnids also possess two other pairs of appendages that have evolved to help their feeding, defense, and senses. The chelicerae, the first pair of appendages, serve in feeding and defense from predators. The next pair of appendages is named the pedipalps. These appendages have been adapted for such uses as eating and digestion, to move or travel, and for reproductive functions. However, there are slight differences between some types of arachnids. For example, the order Solifugae is a branch of arachnids and encompasses over 1,000 described species. The appendages of Solifugae appear leg-like and therefore these animals appear to have five pairs of legs. The larvae of mites and Ricinulei have only six legs; the fourth pair appears when the... ... middle of paper ... ...ds and Scorpions often fight despite they are similar organisms. The entire order has much in common with all arachnids but also differ in some key categories. Works Cited Beccaloni, J. (2009). Arachnids. Berkeley and Los Angeles, California: University of California Press. Evans, A.V. (2007). National Wildlife Federation Field Guide to Insects and Spiders & Related Species of North America (National Wildlife Field Guide). New York; Sterling. Foelix, R.F. (1996). Biology of Spiders, 2nd Edition (2 ed.). New York: Oxford University Press, USA. Frost Gordor, Pam. "Scientists Believe Ancient Arachnids May Have Spun Silk Like Modern Spiders." OSU Research News Index Page. N.p., n.d. Web. 1 Mar. 2010. . Hayashi, C. (2010, February 3). Researching spider silks (Lecture). Iolani School. Honolulu, HI.
There is no doubt that arthropods are an extremely successful group of animals, with an estimated 5-10 million species worldwide[1], and this can be attributed to having an exoskeleton; it provides many benefits, such as protection from parasitism and other threats. However, one major disadvantage of having an exoskeleton is the limitations that an inelastic cuticle can place on growth. The exoskeleton provides protection, but when freshly moulted the animal is soft and vulnerable, as well as having limited mobility and use of appendages; many seek shelter before moulting[2]. There are similarities and differences between the moult cycles of all the arthropods, however only crustaceans and insects will be discussed here.
In the phylum Mollusca, there are many organisms that have body parts that change as the environment around them change; such as the octopus. An octopus can camouflage to variety of objects in its environment. Each organism in the Mollusca phylum has a type of foot that stows mobility and they eat by a radula. The radula is strap like tongue that has very sharp teeth and they can change to be different shapes or sizes based on their prey. They have a pseudo coelomate body plan, meaning that they have a coelom that exists, but it is lined by mesoderm only on the body wall, not around the gut. This video enhanced my understanding standing of the phylum Mollu...
The experiment was conducted to test three different variables. These variables are an assessment of female aggressiveness, food deprivation, and staged male to female interactions. When testing the female aggressiveness, virgin females were run through a latency of attack assay to determine their aggressiveness. The spiders were given 30 seconds and a cricket was dropped in and a measurement was taken of how long interaction occurred between the cricket and the spider. When testing food deprivation, the number of days that female spiders went without food varied and was paired in groups of 1, 3, and 5 days for routine feeding. It was predicted that the longer female spiders went without food, the hungrier they would be. When testing staged male and female interactions, the males were placed in female containers with open lids as an escape route. Each pair interacted for six hours and all pairs resulted in successful copulation, sexual cannibalism, or the male abandons the female’s web. All instances of cannibalism were precopula and occurred shortly after males initiated their courtship sequence. After interaction, the remaining males were taken out the female web and females that cannibalized a male were given 24 hours to feed on the male before being given another male. A female never cannibalized two males consecutively. It was concluded that females that attacked prey more rapidly were more likely to cannibalize their first male mate. There is no detection of an association between cannibalism or food deprivation and female’s body mass. There is a positive association between the mass of egg cases and the number of offspring in females. The study proved that two factor are important in sexual cannibalism, female hunger state and female aggressiveness. There is also a source of fitness benefit for the female.
Crustaceans belong to the Arthropoda Phylum, which includes critters like ants, spiders, and centipedes. I know! Crazy to think that a delicious crab is in the same group as a spider! But they share similar characteristics. For starters, members of the Arthropoda Phylum do not have a backbone like you and me, so they are called __invertebrates__. And, as mentioned earlier, their skeleton is external, which is referred to as an __exoskeleton__.
With the ever-increasing problem of pest control, it is clear that some form biological must be implemented in order to help farmers. This biological control must be able to effectively control the pest population, this means not killing them but rather never letting the pest populations get too large. Through computer-simulated programs the Spider Division of Frankenstein, Inc. was able to genetically create a spider that genetically perfect for biological control. This paper will discuss the methods that were taken as well as the results of the Spider Divisions experiment.
Liubicich, D.M., et al. 2009. Knockdown of Parhyale Ultrabithorax recapitulates evolutionary changes in crustacean appendage morphology. PNAS 106 (33): 13892-13896
Fox, R. 2001. Invertebrate Anatomy OnLine: Artemia Franciscana. Lander University. http://webs.lander.edu/rsfox/invertebrates/artemia.html, retrieved February 13, 2011.
There are nearly one million species of insects known. Insects are defined by having six legs and a body divided into three segments: head, thorax, and abdomen. Chitin is an organic material that makes up an insects exoskeleton. There are three life cycles of insects, ametabolous or incomplete and paurometabolous or gradual, and homotabolous or complete metamorphosis. These life cycles are important in the aging of insects for aiding in legal investigations, (Houck and Siegel. Entomology).
Cerci: a pair of small appendages at the end of an insects abdomen or other arthropods
What are the differences between alligators and crocodiles? Aren’t they the same animal though, with different names? Well, actually one would be surprised by how different these two creatures actually are. Alligators and crocodiles are two of the most commonly confused animals out there. Their two families split from a common ancestor around 100 million years ago, thus forming two new families, known as the Alligatoridae and the crocodilian. This split caused them to adapt and live in different environments. The environment then played a major role in distinguishing their features and the appearance of their size, as well as their aggression levels towards humans and other animals. Learning more about these two creatures may actually open up your eyes and make you think about other objects that you see as one and may even change your attitude towards them. Alligators and crocodiles are very different in various aspects due to several factors involving their behavior and the environment surrounding them.
Arachnida is a subphylum of Arthropoda, consisting of over 100 000 species, many of them being parasites which can carry disease. They are found in all environments, and mostly have eight legs, which is a feature, together with the fact that they do not have wings or antennae, often used to distinguish them from the other subphyla, though there are exceptions. They include spiders, scorpions, ticks and mites. Their bodies are divided up into three parts: the cephalothorax, the opisthosoma and the thorax, and use a type of lung for gas exchange. Most Arachnids are carnivorous, and eat pre-digested insects and other small animals. They reproduce using internal reproduction usually lay eggs, except for the scorpion which bears living young. The word ‘Arachnid’ comes from the Greek word ‘Arachne’ meaning ‘spider’.
One of the largest issues in animal sexual reproduction is the conflict of interests between the female and the male of the species. For example, multiple mating has been shown to greatly increase the fertilization rate for the male, but recent studies have shown that multiple mating also benefits the female.
If I were Gary Anderson, I would not accept to take up the position of a project manager after the director stated that this project would be his baby all the way (Dawn, 2010). This statement shows that the director will overshadow the project and potentially become a hindrance to ultimate outcome of the project. There is a possibility of conflict of interest developing.
Insect, small, air-breathing animal characterized by a segmented body with three main parts—head, thorax, and abdomen. In their adult forms, insects typically have three pairs of legs, one pair of antennae, and in most instances, two pairs of wings. Insects rank among the most successful animals on Earth. About one million species of insects have been identified so far, which is about half of all the animals known to science. That is why for every pound of human on the earth there are 10 pounds of insects. So that is why there are many reasons why insects are so successful, their exoskeleton, their size, their body function, the way they reproduce, and their development of metamorphosis.
I find ants to be such a unique insect because of the fact that they can pick 50 times their own body weight, not even the buffest men can do that. Also for each human there are about 1.5 million ants which mean their reproducing system is very high and fast. Ants provide a huge amou...