week 2 - Mating plugs in polyandrous giants: which sex produces them, when, how, and why? KUNTNER ET AL 2012

Question 1

authors

Answer 1

kuntner et al 2012

Question 2

why do males usually produce mating plugs?

Answer 2

to reduce sperm competition

Question 3

why would females produce mating plugs?

Answer 3

to prevent unwanted, superfluous and energetically costly matings

Question 4

in spiders mating plugs may consist of what? (2)

Answer 4

male genital parts

amorphous covers consisting of glandular or sperm secretions

Question 5

study species

Answer 5

Giant wood spider

Nephila pilipes

Question 6

information about the study species

Answer 6

highly sexually dimorphic

polygamous species

Question 7

males are known to produce what in the giant wood spider?

Answer 7

ineffective embolic plugs through genital damage

Question 8

what is known about additional amorphous AP plugs?

Answer 8

they cover female genitals but nothing is known about the origin and function of these AP plugs

Question 9

what did Kuntner et al 2012 test?

Answer 9

alternative hypotheses of the nature and function of APs in N.pilipes

Question 10

how did Kuntner et al 2012 test these hypotheses?

Answer 10

by staging mating trials with varying degrees of polyandry

Question 11

what rules out the possibility of male AP formation in Kuntner et al 2012 results?

Answer 11

that no APs were ever formed during mating trials

Question 12

what confirmed that females produced APs in Kuntner et al 2012 resulst?

Answer 12

females that oviposited produced the AP from a liquid secreted during egg sac formation

Question 13

the results from Kuntner et al 2012 found which females were more likely to produce an AP? (3)

Answer 13

those that were polyandrous were more likely to lay eggs and produce AP
mated longer
more total insertions

Question 14

WHat did further tests in Kuntner et al 2012 reveal about the AP?

Answer 14

that in spite of being a side product of egg sac production, AP when hardened prevented any subsequent copulation

Question 15

what were the 4 main conclusions Kuntner et al 2012 came to?

Answer 15

in the giant wood spider:

1. APs are produced by the female
2. repeated copulations are necessary for egg fertilisation and AP formation
3. AP represents a female adaptation to sexual conflict through the prevention of unwanted excessive copulations
4. considering the largely unknown origin of AP plugs in other spiders they predict a similar origin

Question 16

Among vertebrates copulatory plugs are known in a diverse taxa of ___ and ____, but there is more variety in the ____,_____,and _____ of mating plugs in ____

Answer 16

mammals 
reptiles
form
function
origin
invertebrates

Question 17

mating plugs are relatively widespread across animal taxa and their function is well studied, but little is known about their ____ _____.

Answer 17

proximate mechanisms

Question 18

the vast majority of documented invertebrate mating plugs are produced by males either through (4)

Answer 18

glandular secretions or ejaculates

utilising severed male somatic or genital parts as copulatory barriers

Question 19

what is emasculation?

Answer 19

mate plugging through genital mutilation

using genital parts as copulatory plugs

Question 20

emascualtion has been shown to do what by Fromhage and Schneider 2006)?

Answer 20

to serve males paternity protection

Question 21

why is male initiated plugging an adaptation to sperm competition? (Fromhage and Schneider 2006)

Answer 21

because plugged females are monopolised and thus are unavailable to subsequent males as long as plugs remain effective

Question 22

what is monopolised?

Answer 22

taken over, control of, possession

Question 23

what can additional plug substances do to females? (3)

Answer 23

lower female receptivity
female attraction
sperm dumping

Question 24

how did Kuntner et al 2012 answer their 3 questions?

Answer 24

staging mating trials with varying degrees of polyandry

Question 25

what were the 3 questions Kuntner et al 2012 addressed?

Answer 25

which sex produces the AP and how is it formed? when in relation to mating occurrence is the AP produced? does the AP prevent copulation?

Question 26

How could solely female produced AP plugs be determined?

Answer 26

if their observed production was subsequent to mating in the absence of any male

Question 27

what should female produced plugs function as?

Answer 27

protection against unwanted male harrasment.

Question 28

based on the logic of what female produced plugs should function as what did Kuntner et al 2012 predict?

Answer 28

that multiply mated females and older females would be more likely to produce the plugs and egg sacs

Question 29

how did Kuntner et al 2012 test the function of the APs?

Answer 29

by staging additional mating trials of intact males with plugged females

Question 30

what are the 5 results of Kuntner et al 2012?

Answer 30

No APs were ever formed during mating which rules out the possibility of male plug formation 9/29 females produced eggs females that produced an egg sac also produced AP Logisitc regression showed that egg sac laying strongly co occurred with AP formation and both depended on copulation effort No intact males successfully mated with plugged females