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Male coercive mating in externally fertilizing species: male coercion, female reluctance and explanation for female acceptance.

Matsumoto Y, Takegaki T - Sci Rep (2016)

Bottom Line: Most males that used small, tight nests acquired new eggs but with experimentally enlarged nests, 90% of the males without eggs failed to confine the females.In the nests where the first eggs were deposited in the early period, subsequent matings with other females were more likely to occur, whereas in the late period, most parental care of the eggs failed without additional matings.The females that spawned in the late period may have been compelled to accept male coercive mating due to time constraints.

View Article: PubMed Central - PubMed

Affiliation: Center for Coastal Fisheries and Aquaculture, Tohoku National Fisheries Research Institute, Fisheries Research Agency, Iwate, Japan.

ABSTRACT
Male coercive mating exerts a strong evolutionary pressure on mating-related traits of both sexes. However, it is extremely rare in externally fertilizing species probably because the male mating behaviour is incomplete until females release their eggs. Here we showed that males of the externally fertilizing fish Rhabdoblennius nitidus coercively confine females to the nests until spawning, and investigated why females accept male coercive mating. The females entered the males' nests following male courtship displays, but they usually tried to escape when there were no eggs because males tended to cannibalize all the eggs when there were few. Most males that used small, tight nests acquired new eggs but with experimentally enlarged nests, 90% of the males without eggs failed to confine the females. Spawning tended to occur during the early/late spawning period in nests with no eggs (i.e. male coercive mating). In the nests where the first eggs were deposited in the early period, subsequent matings with other females were more likely to occur, whereas in the late period, most parental care of the eggs failed without additional matings. The females that spawned in the late period may have been compelled to accept male coercive mating due to time constraints.

No MeSH data available.


Related in: MedlinePlus

Flowchart illustrating the mate-sampling behaviour of the focal females and the fates of their eggs.For female mate-choice copying, the mate-sampling behaviour was initially divided into two types based on the presence of other females in the nests that the focal females visited (a,b). The encircled numbers indicate the number of visits to the eggless nests without spawning. The following chart shows the presence or absence of eggs in the nests where females spawned (c–g), the presence or absence of additional mating (eggs) by other females in the nests, and the failure rate of parental care for their eggs.
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f2: Flowchart illustrating the mate-sampling behaviour of the focal females and the fates of their eggs.For female mate-choice copying, the mate-sampling behaviour was initially divided into two types based on the presence of other females in the nests that the focal females visited (a,b). The encircled numbers indicate the number of visits to the eggless nests without spawning. The following chart shows the presence or absence of eggs in the nests where females spawned (c–g), the presence or absence of additional mating (eggs) by other females in the nests, and the failure rate of parental care for their eggs.

Mentions: In this study, we observed 45 female mate-samplings that ended with spawning (Fig. 2). Twenty-five of these females visited nests where other females were already present (i.e. attempts at mate-choice copying; Fig. 2a), among which 12 spawned in these nests (Fig. 2c). However, the remaining 13 females left without spawning and resumed mate-sampling, where only 2 spawned in the nests with eggs (Fig. 2d), but 11 spawned in the nests with no eggs (Fig. 2e). Among the other 20 females that did not visit the nests with other females (Fig. 2b), 9 females spawned in the nests with eggs (Fig. 2f) and 11 in the nests with no eggs (Fig. 2g).


Male coercive mating in externally fertilizing species: male coercion, female reluctance and explanation for female acceptance.

Matsumoto Y, Takegaki T - Sci Rep (2016)

Flowchart illustrating the mate-sampling behaviour of the focal females and the fates of their eggs.For female mate-choice copying, the mate-sampling behaviour was initially divided into two types based on the presence of other females in the nests that the focal females visited (a,b). The encircled numbers indicate the number of visits to the eggless nests without spawning. The following chart shows the presence or absence of eggs in the nests where females spawned (c–g), the presence or absence of additional mating (eggs) by other females in the nests, and the failure rate of parental care for their eggs.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4834473&req=5

f2: Flowchart illustrating the mate-sampling behaviour of the focal females and the fates of their eggs.For female mate-choice copying, the mate-sampling behaviour was initially divided into two types based on the presence of other females in the nests that the focal females visited (a,b). The encircled numbers indicate the number of visits to the eggless nests without spawning. The following chart shows the presence or absence of eggs in the nests where females spawned (c–g), the presence or absence of additional mating (eggs) by other females in the nests, and the failure rate of parental care for their eggs.
Mentions: In this study, we observed 45 female mate-samplings that ended with spawning (Fig. 2). Twenty-five of these females visited nests where other females were already present (i.e. attempts at mate-choice copying; Fig. 2a), among which 12 spawned in these nests (Fig. 2c). However, the remaining 13 females left without spawning and resumed mate-sampling, where only 2 spawned in the nests with eggs (Fig. 2d), but 11 spawned in the nests with no eggs (Fig. 2e). Among the other 20 females that did not visit the nests with other females (Fig. 2b), 9 females spawned in the nests with eggs (Fig. 2f) and 11 in the nests with no eggs (Fig. 2g).

Bottom Line: Most males that used small, tight nests acquired new eggs but with experimentally enlarged nests, 90% of the males without eggs failed to confine the females.In the nests where the first eggs were deposited in the early period, subsequent matings with other females were more likely to occur, whereas in the late period, most parental care of the eggs failed without additional matings.The females that spawned in the late period may have been compelled to accept male coercive mating due to time constraints.

View Article: PubMed Central - PubMed

Affiliation: Center for Coastal Fisheries and Aquaculture, Tohoku National Fisheries Research Institute, Fisheries Research Agency, Iwate, Japan.

ABSTRACT
Male coercive mating exerts a strong evolutionary pressure on mating-related traits of both sexes. However, it is extremely rare in externally fertilizing species probably because the male mating behaviour is incomplete until females release their eggs. Here we showed that males of the externally fertilizing fish Rhabdoblennius nitidus coercively confine females to the nests until spawning, and investigated why females accept male coercive mating. The females entered the males' nests following male courtship displays, but they usually tried to escape when there were no eggs because males tended to cannibalize all the eggs when there were few. Most males that used small, tight nests acquired new eggs but with experimentally enlarged nests, 90% of the males without eggs failed to confine the females. Spawning tended to occur during the early/late spawning period in nests with no eggs (i.e. male coercive mating). In the nests where the first eggs were deposited in the early period, subsequent matings with other females were more likely to occur, whereas in the late period, most parental care of the eggs failed without additional matings. The females that spawned in the late period may have been compelled to accept male coercive mating due to time constraints.

No MeSH data available.


Related in: MedlinePlus