10.+Arthropoda+-+arachnida

Arthropoda - Arachnida Merrick Tian

__**Specific species**__

Camaricus nigrotesselatus (spotted camaricus crab spiders) as seen in the image below.



=
Chelicerates with a body divided into two parts: a cephalothorax that bears six pears of appendages (four pairs of which are usually used as legs) and an abdomen that bears the genital opening. Familiar arachnids include spiders, scorpions, mites and ticks, and harvestmen. (1)=====

=
There are no segments on the abdomen. Eight simple eyes called ocelli are present on the cephalothorax. The primary reproductive structures, respiratory system, intestine, silk glands, and spinnerets (organs from which silk is spun) are contained in the abdomen. (6) They one of many species to show sexual dimorphism where females are larger than males. (8)=====

Spiders venom have beneficial uses like medicinal use and antimicrobial compounds. (17)
Because spider silk is the strongest and most elastic natural fiber, spider silk has also been implemented into a number of inventions such as parachutes, bullet-proof vests, and fishing nets. (22) Spiders help contain the population of pest insects. (22)

=
Arachnids utilize several tactics to avoid predators, including camouflage, feeding at times when their predators are sleeping (usually night), burrowing (e.g. trap door and wolf spider) and the use of their web to create shelter or as a means of escape. (4) In the case of crab spiders, they typically will change their body color to match the color of the flowers for they are living among where they catch their prey, most often white and pink flowers. This also serves as a way to hide from predators. (5) =====

=
Spiders are important terrestrial predators with hollow chelicerae, which they use to inject venom into their prey. Some have excellent vision that enables them to chase and seize their prey. Others spin elaborate webs made of protein threads in which they snare prey. (1) Most archnids feed on smaller insects; however, some can feed on bigger animals. (1)===== Unlike other most spiders, crab spiders don't make a web to catch their prey. Rather, they utilize their camouflage to wait prey to get close, and then, they use their front legs to grab and hold their prey as they inflict a poisonous bite that kills it. (24)

=
Most arachnids have a simple life cycle in which miniature adults hatch from internally fertilized eggs and begin independent lives almost immediately. Some retain their eggs during development and give birth to live young. (1)=====

Spiders also shed their skin through a process known as molting. While this process occurs, the spider is relatively defenseless, and cannot defend itself properly from attacks.
Hard exoskeleton made of a hard substance called chitin which is suspended in a protein matrix. It serves as a waterproof covering so that animal doesn't lose water in the body though evaporation. The colors founded on the spotted camaricus crab spider are a result of multiple small plates/ ridges on the outer skin layer that give it a metallic look. Integument is influenced heavily by ecdysone, a molting hormone that allows spiders to shed their outer shells and grow new ones when they are young, and into adult life as well. (20)

=
The placement of the reproductive organ in male arachnid in general presents an interesting case for external, appendage maintaining organisms. In contrast to the hectocotylus of male squid, a modified arm usually no shorter than the rest of its appendages, the male arachnid has evolved the pedipalps closer to the body. Perhaps by this comparison, the need to stay away from the female during insemination in squid can be determined not to be a problem at all in arachnid fertilization practice, rather safeguarding the organ itself by keeping it closer to the cephalothorax. =====

=
Arachnids have paired, jointed appendages, a part that is attached to the main body. (2) Spiders have eight legs, and they use their body fluid pressure from their blood to move. Arachnids have also been recorded to move by jumping, swimming, doing handsprings, or ballooning, which is also known as kiting and is when spiders use their silk to catch air currents to bring them from place to place. (21)=====

=
There are two appendages on the organisms front side; essentially, they look as though they are legs; however, they are used to sense the immediate environment that it is in. These"appendages" can be called pedipalps. (10)=====

=
Spiders rely on touch, vibrations, and taste to navigate and locate prey. They are able to sense light intensity, and some species have specialized eyes that can detect light on a more sensitive scale in order to hunt for prey at night. (23)=====

=
Arachnids perform gas exchange through book lungs, which are a compilation of flat, hollow plates that air circulates through. As hemolymph, the equivalent of blood for most invertebrates, flows through the plates, oxygen and carbon dioxide passively diffuse according to their concentration gradients and are exchanged. (3)=====

=
Arthropods have an exoskeleton made of chitin which protects them from predators and other environmental factors such as dry weather. In addition, they have compound eyes, meaning they have several lenses which gives them a wider range of vision. (16)=====

=
The circulatory system of arachnida are referred to as open systems, where the heart pumps blood through open cavities and bathes all the organs and tissues within the body with blood; they also have hemolymph circulating throughout their tissue sinuses. (10) =====

=
Arachnids have several major glands that produce chemicals: the digestive gland secretes enzymes and hormones to digest food; the silk glands secrete spider silk chemicals; the poison gland, which is found only in venomous spiders, secretes poison; and the ovaries or testes secrete hormones specific to the spider's sex. (14)=====

Other than walking, running, and climbing using it's silk, can spiders traverse and move across terrain in other ways? If so, what does it do?


 * //Depending on the species, they are also capable of swimming, jumping, doing handsprings, or ballooning.//**

Spiders are well known to have eight eyes, but they unable to "see" their surroundings like humans. If they can't "see" with them, how are spiders able to locate their prey, and what are their eyes able to do?


 * //Spiders rely on touch, vibrations, and taste to locate their prey. Additionally, their eyes are used to determine light intensity, and different species of spiders may different levels sensitivity.//**

Different species of spiders have their own unique method of hunting and avoiding predators. In the case of the spotted camaricus crab spider, how do they hunt and avoid predators?

//**They will change their body color to match color of the flower that it is living in, and because crab spiders don't use webbing to trap prey, they use their camouflage to hide and wait for prey to approach.**//

To many people spiders are terrifying creatures, but spiders also aid humans in several ways. List some of the ways that spiders help humans.


 * //They help regulate the population of pest insect, the venom has many medicinal uses, and the silk is used to create many products such as parachutes and nets.//**

(19) https://sciencing.com/difference-closed-open-circulatory-system-6594843.html
(20) https://www.britannica.com/science/integument/Arthropods (21) http://blogs.cornell.edu/naturalistoutreach/files/2013/09/How-Do-Spiders-Move-1bpzbvb.pdf (22) http://www.spiders.us/faq/how-are-spiders-helpful-to-people-and-the-planet/ (23) https://australianmuseum.net.au/how-spiders-see-the-world (24) https://ednieuw.home.xs4all.nl/australian/thomisidae/crabspiders.html