Project Results

      I am excited to announce that my research on the hard bodied tick exoskeleton has finally been concluded. According to my findings, these three species of tick (Deer, American dog, and Lone star) only have low amounts of Chlorine (Cl), Calcium (Ca), and Sodium (Na) in addition to their chitinous elements: carbon (C), hydrogen (H), oxygen (O), and nitrogen (N). It turns out that these species of Ixodidae do not utilize transition metals as other arachnids do (Schofield 2001, Gallant and Hochberg 2017), and in fact only have small amounts of Ca (alkaline earth metal) throughout their exoskeleton with the highest amounts in their outer cheliceral digits. The amounts of Na (alkali metal) present were very low and dispersed unevenly throughout the exoskeleton. This suggests that more research has to be done in order to be sure that it is actually present and not a result of contamination or noise. Chlorine was found in amounts higher than Ca and Na throughout the exoskeleton. Chlorine is commonly found in arachnid exoskeleton coupled with zinc (Zn) (Schofield 2001). These high amounts of Cl in the absence of Zn suggest that Cl may be adding strength to the exoskeleton similar to how transition metals are proposed to. An article representing this work will soon be published in the Journal of Parasitology.

Literature Cited:

Gallant, J. and Hochberg, R. (2017). Elemental characterization of the exoskeleton in  the whipscorpions Mastigoproctus giganteus and Typopeltis dalyi (Arachnida: Thelyphonida). Invertebrate Biology 136(3): 345-359.

Schofield, R. (2001). Metals in cuticular structures Scorpion  biology and research Brownell, P. and G. A. Polis. New York Oxford University Press: 235-256.           

About This Project

To “show one's metal” is to reveal one’s strength of character. Ticks may have tiny character, but I propose they do have metal! As blood sucking parasites, ticks must penetrate thick animal skin to obtain food. I propose that ticks enrich their appendages with metals to strengthen them for penetration. I intend to use electron microscopy to quantify the chemical elements in the appendages of deer, dog, and lone star ticks to observe their composition and determine if ticks employ metals.

Ask the Scientists

What is the context of this research?

Ticks are well known parasites of mammals, but despite being infamous for the diseases they carry, there is little knowledge about why they are such successful parasites. One reason might be in the chemical makeup of their biting appendages. Ticks are arachnids like spiders, and many spiders have metals (Zn, Mn) in their fangs to add strength. As spiders use their fangs for biting, ticks use their appendages for cutting and anchoring in skin. As ticks grow and molt, they prey on successively larger hosts (mouse -> dog -> deer), which might necessitate stronger appendages. To understand this, I will try and answer 3 questions: 1) Are metals incorporated into tick appendages? 2) Does the quantity of metals change throughout a tick's life? 3) Do different ticks use different metals?

What is the significance of this project?

Those who have removed ticks from pets, or themselves been bit by a tick, understand the unsettling feeling, which is quickly followed by disgust and fear of disease. However, as a scientist, these feelings are often followed by surprise and fascination for how such a tiny animal can perform such a remarkable task. This fascination has led me to use EDS to examine 3 species of ticks and determine if they rely on metals like zinc and/or calcium to strengthen their tiny biting parts. Surprisingly, this type of research has never been performed on ticks, so it is unknown if they enrich their appendages (chelicerae, hypostome) with metals. Such knowledge may prove useful in developing strategies to prevent tick bites and thereby tick-borne diseases.

What are the goals of the project?

The main goal of this experiment is to quantify all the chemical elements in the cuticles of 3 species of tick. I will use a well known method called energy dispersive x-ray spectroscopy (EDS) to quantify all chemical elements in preserved specimens of all life stages. I will analyze the claws, chelicerae, hypostome, scutum and alloscutum. This elemental data will will not only help us understand why ticks are such successful parasites, but may provide insights why ticks (like other arachnids) rely on some chemical elements and not others for strengthening their cuticles. This research will be used for my MS thesis and the data will be posted here, published in scientific journals, and presented at the American Arachnological Society.