Fish Squid Lab Report

Our lab manual states that dissecting a fish/squid gives anyone who has not experienced one "a chance to see just exactly what makes an organism tick on the inside and how they compare to human internal anatomy" (Mertz, Garrison and Baker 164). What is meant by this is, by becoming familiar with the essential organs and body parts of vertebrate organisms such as a fish or rat, along with those of invertebrates like a squid or crab, one can have an idea of what to expect with the anatomy of humans. While humans are not exactly the same as the said animals—particularly the fish or squid—one should at least be able to understand that since fishes are vertebrates, they are much closer to humans than squids, which lack any bones. By looking at the bones of any fish, such as the ribs or the spine of a mackerel, their structural similarities to the bones of humans and other mammals can be quite noticeable.

Identifying the organism of examination or research is essential for marine scientists, even if it may not be the easiest task to carry out since there are “literally thousands of possibilities” on what the organism could be (Mertz, Garrison and Baker 163).

Throughout time, of course, marine biologists have created methods—or “techniques” (163)—that allow such a task to become more straightforward. The method which mainly comes to mind involves close observation of the organism, and noting as much of its minor and major characteristics while attempting to identify it. By recording such details as the organism’s symmetry, general shape, colors, external appearance, internal structure, and measurement, marine scientists can refer back to identification guides to figure out what specific classification their organism fits in, or whether they have the right taxonomy in mind or not (Mertz, Garrison and Baker 163-164). Upon confirming the organism’s identity with the noted characteristics, finding extra information about it becomes much easier

(164).

Dissections are often a revealing task for marine scientists in that they discover several details about their organisms that they may have not known before. As noted in our lab manual, they can further learn about the organism's ecology, identify their certain body parts and organs and even the "diseases, injuries, infections, and infestations" that may have killed or harmed them to a certain degree (Mertz, Garrison and Baker 164). In the case of further learning about the organism’s ecology, one can become more familiar with their lifestyle this way. One example given in the lab manual being what food they typically consume (164), while some other examples can relate to their defensive or predatory behavior, swimming speed, neutral buoyancy, or where their body parts are, such as their mouth or eyes. Being aware of such details as the squid lacking a swim bladder that most vertebrate fish have, in addition to how squids have an ink sac available for defensive use, can give crucial hints to how the organism lives its life, let alone what taxonomy it best fits in.