Albo et al., 2013 (spider nuptial gifts)

Question 1

Which spider?

Answer 1

Pisaura mirabilis (nursery web spider)

• a polyandrous species

Question 2

Measured the number of sperm stored by female spiders in response to copulation with males with or without a … ….

This was to test the hypothesis that females may gain indirect benefits through … sperm storage from gift-giving males if the gift signals male ….

… … was controlled

Answer 2

nuptial gift

preferential, quality

copulation duration

Question 3

Then assessed whether gift presence and copulation duration had an effect on …-… success

Answer 3

egg-hatching

Question 4

Females mated to gift-giving males stored … sperm and experienced … higher egg-hatching success, compared to those mated to no-gift males, despite matched copulation durations.

Answer 4

more, 17%

Question 5

The study confirms the prediction that the … … as an indicator of male quality is under … … selection by females through … … storage.

Answer 5

nuptial gift, positive sexual, cryptic sperm

Question 6

The gift also facilitates … … and increased … …, providing two types of advantage to gift-giving males.

Answer 6

longer copulations, sperm transfer

Question 7

Cryptic male choice = … … during mating (syncopulatory) or afterwards (…) that leads to differences in sperm use among competing males.

Answer 7

sexual selection, postcopulatory

Question 8

Nuptial gifts may be an … signal of male quality (e.g. good hunting ability - gathering resources + heritable trait = beneficial to female to mate and have offspring that shares his genes)

Answer 8

honest

Question 9

in this species nuptial gifts come in the form of…

Answer 9

insect prey wrapped in silk (which the female feeds on during copulation)

• in the experiment, gift-giving males were given a housefly to construct this with

Question 10

Females appear to have full control over the … and duration of copulations

Answer 10

initiation, duration

Question 11

Males use … sperm transfer, using their …, and females can store sperm from multiple males in sperm storage organs called …, for later fertilisation.

Answer 11

external, pedipalps (intromittent organ), spermatheca

Question 12

Males with no gift face a much lower…

Answer 12

acceptance rate from the female

Question 13

Copulation duration was the sum of…

Answer 13

the duration of all insertions of the male pedipalps into the female genital tract during the trial
(= total potential time of sperm transfer)

Question 14

… group = males had no nuptial gift
… group = males had nuptial gift but were limited to 10 mins of copulation (average length for those with no nuptial gift)
… group = males with nuptial gift and uninterrupted copulation

Answer 14

NG
GT
G

Question 15

Number of sperm in the female spermatheca differed significantly among the three groups.

• significantly lower in the … group compared with the … group

… … also differed significantly among the three groups.and was significantly lower in the … group compared with the … group

Answer 15

NG, GT

hatching success, NG, GT

Question 16

A positive relationship was found between … … and hatching success

Answer 16

copulation duration

Question 17

By allowing gift donors to store more sperm, females can gain indirect benefits, either through … processes (if females produce “sexy sons” who are more likely to provide nuptial gifts) or by elevated offspring … if gift-giving males pass on genes that are superior for … traits.

Answer 17

Fisherian, fitness, survivorship (e.g. good hunting abilities - better ability to capture prey for nuptial gifts, and can afford to expend this energy without eating themselves)

Question 18

In conclusion, what are the two different types of advantage to gift-giving males?

Answer 18

• Favoured by cryptic female choice as females store more sperm from gift-giving males
• Gift-giving increases the number of sperm transferred by prolonging copulation duration (which females are in control of)

(so higher paternity success for gift-giving males
+ potential indirect benefits for female)