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Wrote an article on Platycryptus undatus (Tan Jumping Spider)

Discussion in 'Other Spiders & Arachnids' started by TheJumperGuy, Jun 4, 2012.

  1. TheJumperGuy

    TheJumperGuy Arachnopeon

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    Please view this article in PDF format to preserve formatting.

    This is the first scientific paper I've ever written in the field of entomology and arachnology, since beginning personal/amateur study a couple months ago. I'm thinking of getting a degree in the field but I'm not sure if there's any work left, so I'm not sure what to do there.

    Anyways, let me know what you guys think and I really hope someone can find some use for this information. Let me know if there's anything at all that you think needs work on. I'm always 100% open to criticism! :geek:

    Also, as this is my first post on the board (although I've been reading quite a bit recently), I'd like to say hello to everyone! And a HUGE thanks to Debby for helping me with the issues I had during registration (sometimes 3G/4G services aren't all that great!). Response and resolution time where insanely fast, so seriously, I thank you!



    Enjoy!






    Behavior and Interactions Between Male and Female
    Platycryptus undatus


    ABSTRACT
    This paper dictates the approach I have taken in studying the general behavior and ecology of wild Platycryptus undatus jumping spiders maintained in captivity. One adult male P. undatus and one adult female P. undatus share living quarters inside of an one and one-half gallon, polycarbonate “Kritter Keeper®”. This paper will document the behavior and interactions of the two specimens, including any irregular habits or attempts at courtship and mating.

    DISCLAIMER
    I am performing this research independently, on my own time, with my own equipment and these are my own words. I am not affiliated with any cite-able researchers, laboratories, universities, or companies. The information contained in this document is for non-profit and educational use only and I am in no way responsible for anything that may arise from reading and applying this material. Although, if you find an error, big or small, please report it to me or if you're viewing this on an arachnid research website not moderated by me, alert the webmaster or mods to the correction(s) needed. Comments and experiences are more than welcome.

    If you publish any material contained in this document, please cite and give me credit for my time.

    TAXONOMY
    Phylum - Athropoda
    Class - Arachnida
    Order - Araneae
    Infra-order - Araneomorphae
    No Taxon - Entelegynes
    Family - Salticidae
    Subfamily - Marpissinae
    Genus - Platycryptus
    Species - undatus

    IDENTIFICATION
    Achieving an one hundred percent accurate identification of this species, as in any other arachnid, is best accomplished by examining the male and female reproductive organs under a microscope. These are the pedipalp in males, which are easily visible externally from the anterior of the cephalothorax, near the chelicera. Viewing the abdomen ventrally, females use the internal epigynum for reproduction. This of course would invariably lead to a dissection of the specimen for a positive ID, which in this case is not the result we are striving for. Given that we are studying the behavior and interactions of the species, we would of course need a healthy specimen.


    MIS-IDENTIFICATION
    The species californicus, also of the Platycryptus genus, appears remarkably similar to the undatus species when viewed externally from any angle. The only way to visually distinguish the two is the darker brown markings along the lateral edges of the carapace on the californicus. Given these conditions, it is often necessary to positively ID using the internal organs of the specimen.


    [Note: These two species are rarely found occupying the same areas of the US, thus referring to the location the specimen was collected, you can quite often tell with reasonable accuracy the species it belongs to.]

    GENERAL BEHAVIORAL TRAITS
    P. undatus tends to be very docile in nature and will only bite a human when handled improperly. Bites from this genus are extremely rare but will likely happen if you agitate the spider by squeezing or handling it much too rough. As with most Salticids they exhibit remarkable vision and can often be seen passively watching any humans in their visual range, which can be many feet away. Although, much like humans, individuals tend to have their own “personality” and habits that, while shared with others in the Salticidae family, can vary slightly from individual to individual. It is not uncommon for a particular spider to stalk and kill an insect just because it was in their habitat, versus others that will only kill in the sake of taking a meal. They can also calculate and time their jumps with amazing accuracy, getting over obstacles or tackling prey with grace and ease. Once transferred to a terrarium, they tend to spend many hours, quite literally, looking for a way out. They are likely to make several escape attempts if precautions are not taken. Being of the Salticidae family, they tend to spend most of their time on vertical surfaces, preferably man-made, in almost all environments. It is uncommon that they are seen on the ground.










    INFORMATION ON SPECIMENS COLLECTED FOR ANALYSIS

    FEMALE P. undatus

    Lat/Lon: 35.24°N -77.74°W
    Location: Found on the southern exterior wall of a wood frame structure, painted white, approx. 6 feet AGL and 268ft ASL.
    Time: ~1600 EST (Late May)
    Notes: Mature young adult female, rather on the skinny side.


    MALE P. undatus

    Lat/Lon: 35.24°N -77.74°W
    Location: Found on the southern exterior wall of a wood frame structure, painted white, approx. 6 feet AGL and 268ft ASL. Same location as female.
    Time: ~1700 EST the following evening. (Late May)
    Notes: Mature young adult male, optimum weight.











    ENVIRONMENT
    The two P. undatus specimens share a living environment inside of a one and one-half gallon, polycarbonate “Kritter Keeper®”. For experimentation purposes, the substrate was taken from the ground directly below the location the spiders were collected, versus using the “paper towel” method. Three unidentified dried leaves serve as “leaf litter” in the event that one of the spiders would like a location for camouflage, nesting and/or retreat. Also introduced to the environment is a small patch of moss, also for experimentation. A small bottle cap (16 oz. Bottle) serves as a watering area for both spiders. The sides of the enclosure are also slightly misted every other day to further ensure adequate watering of the specimens. The temperature is regulated between 70°F and 85°F. They receive both indirect natural sunlight during the day, along with further periodic illumination with a florescent light source throughout the natural daylight hours, mostly to aid myself in seeing small details inside their environment.

    FOOD SOURCES
    Specimens are given the opportunity to feed upon a variety of local insects, specifically “Forage Looper Moths” (C. erechtea) and small house flies (Fannia spp.).

    REACTION TO INSECTS
    The reaction to various insects is nearly the same with both specimens, although the female has three traits or habits that I find intriguing and rather different than the male.

    She is very likely to kill an insect simply because it has gotten too close and/or has agitated her by making subsequent close passes. She will pounce, inflict a lethal bite and hold the prey until it is thoroughly dead and then discard the corpse.
    She tends to be behave more aggressively, in general, toward any insects in the environment but she has not been observed approaching the small male P. undatus for any reason.
    She has put on nearly twice the weight as her male counterpart. This is likely due to her aggressively seeking a meal when the opportunity presents itself.
    GENERAL HEALTH AND WELL-BEING
    The female has nearly doubled in size during her time in captivity, whilst the male has lost half of his weight. Observations that may be the cause:

    The female more aggressively seeks prey
    The male is more opportunistic
    The female is larger, thus more dominate in the environment
    Possibly stress and/or chemical imbalance on the male's behalf

    The male was noted stalking, killing and eating for the first time in nearly 5 days. Even with a variety of insects to prey upon, he would sit passively on the wall and watch them from a distance. Today, after 5 days of fasting, he caught a C. erechtea that got too close and has begun slowly eating it.

    INTERACTIONS BETWEEN MALE AND FEMALE
    As previously noted, the male and female P. undatus are 100% aware of each other in their environment, although they do not make any effort to copulate or “trespass” on one another. They have given each other “plenty” of room since being housed together, usually taking up positions on the walls opposite of one another. It can also be noted that a recent study found that female spiders from the Salticidae family were more likely to mate with “larger, more aggressive” males for their first year as adults. This is a risk to the female, for she may be eaten if the male is inclined for an easy meal. Although it may be worth the risk since it is theorized that this behavior increases the chances of the female giving birth to stronger offspring as a young adult. However, this behavior soon stops and the females go after the smaller and less aggressive males their second time around, thus increasing the likelihood of her not getting eaten but still furthering her species and genetics.

    This is one plausible explanation for this specimen's distaste for our male, as they both are young adults and he is considerably smaller and weaker than she.


    “ODD” BEHAVIOR
    It has been noted that the now much larger female P. undatus has began facing down while resting on her wall, whereas prior to collection, she was found facing up. The male on the other hand has began doing the opposite. He was located and collected facing down and has now begun spending nearly all of his time facing up. Note, he has lost a significant amount of weight since being collected.

    One plausible theory to explain this behavior is that the female is spending more of her time focusing on the ground/substrate due to her being more aggressive and more likely to take prey, either ground dwelling or airborne. While her male counterpart has begun looking up toward the lid of the enclosure, in the hopes of finding a way out, quite possibly to search for food or likely a mate.

    CONCLUSION
    I will be updating this paper/article periodically, with any new findings and information. If you have any thing that you would like to add or have any questions, feel free to contact me.



    John Mullen
    Independent Entomological Research
    (919) 480-1230
    jmullentech@gmail.com
    http://www.jmserver.dyndns-ip.com/entomology
     

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