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

Info iconThis 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
Background image of page 1

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

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

This note was uploaded on 07/29/2008 for the course BIO 206L taught by Professor Unknown during the Spring '08 term at University of Texas.

Page1 / 3

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

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online