JCRlab4 - J Colton Riley Lab 4 Results and analysis Monday...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
J. Colton Riley Monday, July 21, 2008 Lab 4 Results and analysis 1. The functional external structures of the crayfish that I identified in class are the cephalothorax, abdomen, exoskeleton, carapace, rostrum, compound eyes, antennules, antennae, nephridiopore, mandibles, mouth, maxillae, maxillipeds, walking legs, chelipeds, swimmerets, genital pores (both male and female), seminal receptacle (female only), uropods, telson and anus. The cephalothorax (head and thorax), abdomen, carapace, and rostrum are all part of the exoskeleton that is composed of a nitrogen- containing carbohydrate called chitin that is hardened with minerals. This tough exterior is the crayfish’s ultimate line of defense because it is the last thing a predator would have to get through in order to feed on the crayfish. The compound eyes, antennules, and antennae are sensory organs used in both the avoidance of predators and the acquisition of food. The mandibles, mouth, maxillae, and maxillipeds are all used in the acquisition of food. The walking legs, chelipeds, and swimmerets are used in locomotion and in the case of the chelipeds for defense against predators. The genital pores and the seminal receptacle are used in sexual reproduction. The uropods and telson are both used in locomotion. Finally, the anus and nephridiopore are both used as means for different types of waste excretion. 2. The pathway of a crayfish’s meal and its digested nutrients begin in the mouth and travel down the esophagus into the stomach. The anterior and larger part of the stomach is called the cardiac stomach. Here food is ground up in the gastric mill and digested by enzymes from the digestive glands. The pyloric stomach is the smaller part of the
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern