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Mating behavior of Daphnia: impacts of predation risk, food quantity, and reproductive phase of females.

La GH, Choi JY, Chang KH, Jang MH, Joo GJ, Kim HW - PLoS ONE (2014)

Bottom Line: Mating-related behavior involved male-female contact (mating) as well as male-male contact (fighting).Mating frequency increased while unnecessary fighting decreased in the presence of predation risk.In addition, low food concentration reduced fighting between males.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Education, Sunchon National University, Suncheon, Korea.

ABSTRACT
High predation risk and food depletion lead to sexual reproduction in cyclically parthenogenetic Daphnia. Mating, the core of sexual reproduction, also occurs under these conditions. Assessment of the environmental conditions and alteration of mating efforts may aid in determining the success of sexual reproduction. Here, we evaluated the impacts of predation risk, food quantity, and reproductive phase of females on the mating behavior of Daphnia obtusa males including contact frequency and duration using video analysis. Mating-related behavior involved male-female contact (mating) as well as male-male contact (fighting). Mating frequency increased while unnecessary fighting decreased in the presence of predation risk. In addition, low food concentration reduced fighting between males. Males attempted to attach to sexual females more than asexual females, and fighting occurred more frequently in the presence of sexual females. Duration of mating was relatively long; however, males separated shortly after contact in terms of fighting behavior. Thus, assessment of environmental factors and primary sexing of mates were performed before actual contact, possibly mechanically, and precise sex discrimination was conducted after contact. These results suggest that mating in Daphnia is not a random process but rather a balance between predation risk and energetic cost that results in changes in mating and fighting strategies.

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Related in: MedlinePlus

Contact frequencies and duration times of mating and fighting of Daphnia obtusa according to food quantity.Observation was performed for 10 minutes. Each column represents the mean ± SE of 48 replicates.
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pone-0104545-g004: Contact frequencies and duration times of mating and fighting of Daphnia obtusa according to food quantity.Observation was performed for 10 minutes. Each column represents the mean ± SE of 48 replicates.

Mentions: In terms of mating contacts, D. obtusa exhibited almost identical frequencies regardless of food quantity (14.8 at low food and 14.5 at high food) (Fig. 4A and Table S1). In contrast to the effect of fish kairomones, food quantity had a significant (p = 0.000) impact on the contact frequency of fighting; males tended to attach to other males more frequently when the ambient food concentration was high (9.6 under low food vs. 13.5 under high food conditions) (Fig. 4B and Table S1). Food quantity had no effect on the duration time. The duration of fighting was short, and both males separated quickly regardless of food quantity (Fig. 4C, D and Table S1).


Mating behavior of Daphnia: impacts of predation risk, food quantity, and reproductive phase of females.

La GH, Choi JY, Chang KH, Jang MH, Joo GJ, Kim HW - PLoS ONE (2014)

Contact frequencies and duration times of mating and fighting of Daphnia obtusa according to food quantity.Observation was performed for 10 minutes. Each column represents the mean ± SE of 48 replicates.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4128813&req=5

pone-0104545-g004: Contact frequencies and duration times of mating and fighting of Daphnia obtusa according to food quantity.Observation was performed for 10 minutes. Each column represents the mean ± SE of 48 replicates.
Mentions: In terms of mating contacts, D. obtusa exhibited almost identical frequencies regardless of food quantity (14.8 at low food and 14.5 at high food) (Fig. 4A and Table S1). In contrast to the effect of fish kairomones, food quantity had a significant (p = 0.000) impact on the contact frequency of fighting; males tended to attach to other males more frequently when the ambient food concentration was high (9.6 under low food vs. 13.5 under high food conditions) (Fig. 4B and Table S1). Food quantity had no effect on the duration time. The duration of fighting was short, and both males separated quickly regardless of food quantity (Fig. 4C, D and Table S1).

Bottom Line: Mating-related behavior involved male-female contact (mating) as well as male-male contact (fighting).Mating frequency increased while unnecessary fighting decreased in the presence of predation risk.In addition, low food concentration reduced fighting between males.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Education, Sunchon National University, Suncheon, Korea.

ABSTRACT
High predation risk and food depletion lead to sexual reproduction in cyclically parthenogenetic Daphnia. Mating, the core of sexual reproduction, also occurs under these conditions. Assessment of the environmental conditions and alteration of mating efforts may aid in determining the success of sexual reproduction. Here, we evaluated the impacts of predation risk, food quantity, and reproductive phase of females on the mating behavior of Daphnia obtusa males including contact frequency and duration using video analysis. Mating-related behavior involved male-female contact (mating) as well as male-male contact (fighting). Mating frequency increased while unnecessary fighting decreased in the presence of predation risk. In addition, low food concentration reduced fighting between males. Males attempted to attach to sexual females more than asexual females, and fighting occurred more frequently in the presence of sexual females. Duration of mating was relatively long; however, males separated shortly after contact in terms of fighting behavior. Thus, assessment of environmental factors and primary sexing of mates were performed before actual contact, possibly mechanically, and precise sex discrimination was conducted after contact. These results suggest that mating in Daphnia is not a random process but rather a balance between predation risk and energetic cost that results in changes in mating and fighting strategies.

Show MeSH
Related in: MedlinePlus