Biology108
It was hypothesised that P. lurca is an osmoconformer with a soft-body while U. coarctata is an osmoregulator and has a thick cuticle. This was predicted due to the fact that both species inhabit local salt water creeks and salinity levels fluctuate throughout the year. Osmoconformity occurs within an animal if the osmotic concentration of the body fluids equals that of the medium (Miller & Harley, 2005). However, an animal that maintains its internal concentrations different to that of its surrounding environment is an osmoregulator. In order to find P. lurca and U. coarctata and their means of osmoregulatory ability, the specific gravity of the animal’s extracellular fluid (ceolomic fluid) needs to be found....
Sipunculans are worm-like animals ranging from 2 to 720 millimeters (0.079 to 28 in) in length, with most species being less than 10 centimeters (3.9 in). The sipunculan body is divided into an unsegment trunk and a narrower, retractable anterior section, called the "introvert". Sipunculans have a body wall somewhat similar to that of annelids (though unsegment) in that it consists of a non-ciliated epidermis overlain by a cuticle, an outer layer of circular and an inner layer of longitudinal musculature.
Subphylum Crustacean (the Crustaceans) comprises a large group of arthropods. The group contains familiar popular marine food animals such as lobsters, crabs, and shrimp. While mainly found in salt and freshwater environments, there are also terrestrial Crustacean such as woodlice and isopods. Crustaceans have three distinct body parts: head, thorax, and abdomen (also called a pleon).
Excretion is the removal of toxic (nitrogenous) waste products of metabolism from the body. The waste end products of catabolism contain carbon, hydrogen, oxygen and nitrogen.
Osmoregulation is based largely on controlled movement of solutes between internal fluids and the external environment.
Osmoregulation and excretion are intimately related; these process
Sipunculans are worm-like animals ranging from 2 to 720 millimeters (0.079 to 28 in) in length, with most species being less than 10 centimeters (3.9 in). The sipunculan body is divided into an unsegment trunk and a narrower, retractable anterior section, called the "introvert". Sipunculans have a body wall somewhat similar to that of annelids (though unsegment) in that it consists of a non-ciliated epidermis overlain by a cuticle, an outer layer of circular and an inner layer of longitudinal musculature.
Subphylum Crustacean (the Crustaceans) comprises a large group of arthropods. The group contains familiar popular marine food animals such as lobsters, crabs, and shrimp. While mainly found in salt and freshwater environments, there are also terrestrial Crustacean such as woodlice and isopods. Crustaceans have three distinct body parts: head, thorax, and abdomen (also called a pleon).
Excretion is the removal of toxic (nitrogenous) waste products of metabolism from the body. The waste end products of catabolism contain carbon, hydrogen, oxygen and nitrogen.
Osmoregulation is based largely on controlled movement of solutes between internal fluids and the external environment.
Osmoregulation and excretion are intimately related; these process