Chondrichthyes vs Arthropod :: essays papers

Chondrichthyes vs ArthropodThe ignominious widow is closely easily recognized by the hourglass marking on the underside of its abdomen. When bitten, a neurotoxin is released that butt joint cause dull pain and cramping in muscles, that cannister be accompanied by sweating and vomiting. Less than 1% of grue nigh widow bites result in death.Black widow bird of passages are normally not aggressive. If disturbed, they will retreat to a corner of their web. These spiders are more(prenominal) aggressive if they are protecting an egg sac. The natural habitat of a unappeasable widow is outdoors, under rocks, brush or piles of debris. Indoors, these spiders can usually be found behind furniture, in storage boxes, and so forth A black widows eyes are on top and approximate the front of its head. They take on 8 eyes, arranged in 2 rows of 4 each. Some spiders have better vision than others. For example, hunting spiders have honorable eyesight at short distances. Their eyesight enab les them to form images of their prey and mate. Web-building spiders (the black widow) have poor eyesight. Their eyes are used for detecting changes in light. A black widows spill the beans opening is bellow its eyes. It does not have chewing mouth parts, and they eat only liquids. Various appendages around the mouth opening form a short straw through which the spider sucks the body fluid of its victim. The black widow can eat some of the solid tissue of its prey by predigesting it. To do this, the spider sprays digestive juices on the tissue. Chelicerae are a pair of appendages that the spider uses to seize and blot out its prey. The chelicerae are above the mouth opening and just below the spiders eyes. severally chelicera ends in a hard, hollow, exhibited claw, and these claws are the spiders fangs. An opening in the tip of the fang connects with the envenom glands. When the black widow stabs an insect with its chelicerae, poison flows into the wound and paralyzes or kills the victim. The fangs of tarantulas point straight down from the head, and the poison glands are in the chelicerae. In the black widow, the fangs point crosswise, and the poison glands extend back into the cephalothorax. They also crush thier prey with their chelicerae. Pedipalpi are a pair of appendages that look like blue legs. One pedipalp is attached to each side of the spiders mouth, and they form the sides of the mouth.