Title

The tubuliform glands of the black widow spider (Latrodectus Hesperus)

Poster Number

27

Format

Poster Presentation

Abstract/Artist Statement

Two forms of tubuliform glands (white and orange) are present within the abdominal cavity of the black widow spider (Latrodectus Hesperus). It is believed that these glands produce silk used in the production of egg cases. This study was performed to determine if the two different forms produced two different types of silk. The spiders were immobilized using carbon dioxide gas, followed by a microdissection of the abdominal cavity. This procedure was performed repeatedly on both male and female black widow spiders. White tubuliform glands were found in nearly every male and female spider dissected. Orange tubuliform glands, on the other hand, were only present in the female spiders. In the twenty-nine dissections performed on the female spiders, eleven were determined to contain orange tubuliform glands. When a chi square analysis was performed, them value was calculated to be .10. Since this p value is still relatively high, the Null hypothesis cannot be disproved, and there is still a chance that the observations occurred due to chance alone. These results lead to the possibility that white tubuliform glands serve a function of producing a type of silk required throughout the lifetime of the spider, most likely scaffolding silk. The orange tubuliform glands, in contrast, are only needed at certain times of the female black widow's life. This observation supports the hypothesis of orange tubuliform glands producing the silk responsible for making the egg cases. In future research, gel work may be performed in order to accurately determine the function of each silk gland. These gels will compare the silk collected from the web to the silo taken directly from the gland.

Location

Pacific Geosciences Center

Start Date

20-4-2002 9:00 AM

End Date

20-4-2002 5:00 PM

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Apr 20th, 9:00 AM Apr 20th, 5:00 PM

The tubuliform glands of the black widow spider (Latrodectus Hesperus)

Pacific Geosciences Center

Two forms of tubuliform glands (white and orange) are present within the abdominal cavity of the black widow spider (Latrodectus Hesperus). It is believed that these glands produce silk used in the production of egg cases. This study was performed to determine if the two different forms produced two different types of silk. The spiders were immobilized using carbon dioxide gas, followed by a microdissection of the abdominal cavity. This procedure was performed repeatedly on both male and female black widow spiders. White tubuliform glands were found in nearly every male and female spider dissected. Orange tubuliform glands, on the other hand, were only present in the female spiders. In the twenty-nine dissections performed on the female spiders, eleven were determined to contain orange tubuliform glands. When a chi square analysis was performed, them value was calculated to be .10. Since this p value is still relatively high, the Null hypothesis cannot be disproved, and there is still a chance that the observations occurred due to chance alone. These results lead to the possibility that white tubuliform glands serve a function of producing a type of silk required throughout the lifetime of the spider, most likely scaffolding silk. The orange tubuliform glands, in contrast, are only needed at certain times of the female black widow's life. This observation supports the hypothesis of orange tubuliform glands producing the silk responsible for making the egg cases. In future research, gel work may be performed in order to accurately determine the function of each silk gland. These gels will compare the silk collected from the web to the silo taken directly from the gland.