Monday, February 22, 2016

Invertebrate anatomy sketches

All of these sketches are based off of either models or digital dissections. Click to enlarge.

Monday, February 15, 2016

Analysis of Plastic Varieties of Arthropoda

Okay, this is my observations and classification of toy bugs and other arthropods. But after this foreword, I'm going to write it like it's an actual paper about actual living animals. Try not to laugh. Actually, go ahead and laugh.
A typical colony of plastic arthropods.
The image above shows a set of toy "insects". But are they really insects? Not most of them. Contained in this set of "insects" are a millipede, a scorpion, and a spider, none of which are insects! In fact, when I observed cheap plastic insects in the wild (Dollar Tree), I noticed that many colonies of these insects contained many impostors. One colony was even mostly spiders with only the occasional actual insect. But I had a purpose! I wanted to see which orders were most commonly found in this Dollar Tree environment. Therefore, I captured some specimens and brought them into the wild.

The native species proceeded to prey on our specimens, hindering the research.
Our findings were quite surprising surrounding the most common orders of Arthropoda in these plastic colonies. The species in Heteroptera, a suborder of Hemiptera, were poorly represented in these colonies, with only one individual in the entire order. By contrast, Hymenoptera was well-represented, with eight fine specimens in the plastic colonies we collected. Diptera was also well-represented, with six individuals. Blattodea had four individuals, surprisingly few. In contrast, Mantodea had three individuals total. Orthoptera had four respectively, and Odonata had three representatives. Coleoptera, despite having more individual species than any other orders represented, had only four individuals. Lepidopterans, despite being common in popular culture, especially for young human females, only had two representatives in these plastic colonies. Phthinaptera (no, I can't pronounce it either), had two individuals.
Our classification. Click to enlarge.
As I discussed earlier, other arthropods are much more common in these colonies that are falsely labeled as "insects". Chilipodae had three individuals, more than many insect orders. Acori had two representatives, and Scorpiones had three. But even more surprising is the domination of Araneae and Ophilones. (Note:Ophilones in these plastic colonies were probably manufactured intended to be Araneae, but morphologically did not live up to the part.) Ophilones had sixteen individuals, more than any of the insect orders. Aranea, shockingly had twenty individuals.
Classification of other arthropods.
 There are some creatures in these colonies that aren't actually arthropods. This complicated the study, so I am personally glad that the only non-arthropod creature in these colonies was a single Cestoda worm.

The study may have been skewed due to the fact that due to having such colonies such as the Parasite Pals and Giant Microbes, we probably have more individuals than most typical colonies.

Monday, February 8, 2016

Hiding preferences and analysis of pillbugs

Hiding preferences and analysis of pillbugs

Alli Metler

The main analysis portion of the project was observing color preferences for hiding spots in our pillbug specimens. As we found, there seemed to be absolutely no preference for color. However, any unknown specimens were probably actually on the green piece of paper because the green piece was folded and our specimens had the ability to go inside the paper. In many cases, the specimens simply preferred to go underneath any paper in the tank, regardless of paper color or type. The specimens behaved normally during the analysis, however, at the 8:00 time, two specimens were observed chasing each other. The reason for this behavior is unknown, but my personal theory is that this is a behavior for dominance. Interestingly, unlike the Madagascar Hissing Cockroaches, these specimens did not try to climb the wall of the tank. This is possibly due to their fossorial preferences, or simply that they may not have strong enough legs to be able to.

Table of behavior over time for our specimens. Click to enlarge.

At the beginning of the analysis, I answered some questions asked by the research questions about general characteristics of the specimens. As I observed, to sense the environment around them, the specimens mainly used their antennae. Unlike previous specimens I have observed, namely arachnids and insects, these crustaceans had 14 legs rather than 8 or 6. They all seemed to be the same species, given that the specimens were collected in the same place and they all coiled into protective balls when threatened. When they come out of their protective balls and flipped over, they rolled and moved their legs to right themselves. They move very quickly for their size, probably an adaptation due to their placement in the food chain. When I observed them first, they did not seem to exhibit dominance behaviors, but later in the experiment, this was proven false. The specimens sought hiding places, especially underneath objects. When an object was placed in their path, the specimens would go around it and otherwise ignore it.

Sketches. Click to enlarge.