Limits...
Protogyny in a tropical damselfish: females queue for future benefit.

McCormick MI - PeerJ (2016)

Bottom Line: In situ behavioural observations found that alpha-females have priority of access to the nest site that the male guarded, and access to higher quality foraging areas.Examination of otolith microstructure showed that those individuals which change sex to males have different embryonic characteristics at hatching, suggesting that success may involve a component that is parentally endowed.The relative importance of parental effects and social organisation in affecting the importance of female queuing is yet to be studied, but will likely depend on the strength of social control by the dominant members of the group.

View Article: PubMed Central - HTML - PubMed

Affiliation: ARC Centre of Excellence for Coral Reef Studies, and Department of Marine Biology and Aquaculture, James Cook University , Townsville , Queensland , Australia.

ABSTRACT
Membership of the group is a balance between the benefits associated with group living and the cost of socially constrained growth and breeding opportunities, but the costs and benefits are seldom examined. The goal of the present study was to explore the trade-offs associated with group living for a sex-changing, potentially protogynous coral reef fish, the Ambon damselfish, Pomacentrus amboinensis. Extensive sampling showed that the species exhibits resource defence polygyny, where dominant males guard a nest site that is visited by females. P. amboinensis have a longevity of about 6.5 years on the northern Great Barrier Reef. While the species can change sex consistent with being a protogynous hermaphrodite, it is unclear the extent to which the species uses this capability. Social groups are comprised of one reproductive male, 1-7 females and a number of juveniles. Females live in a linear dominance hierarchy, with the male being more aggressive to the beta-female than the alpha-female, who exhibits lower levels of ovarian cortisol. Surveys and a tagging study indicated that groups were stable for at least three months. A passive integrated transponder tag study showed that males spawn with females from their own group, but also females from neighbouring groups. In situ behavioural observations found that alpha-females have priority of access to the nest site that the male guarded, and access to higher quality foraging areas. Male removal studies suggest that the alpha-females can change sex to take over from the male when the position becomes available. Examination of otolith microstructure showed that those individuals which change sex to males have different embryonic characteristics at hatching, suggesting that success may involve a component that is parentally endowed. The relative importance of parental effects and social organisation in affecting the importance of female queuing is yet to be studied, but will likely depend on the strength of social control by the dominant members of the group.

No MeSH data available.


Related in: MedlinePlus

Rank affects access to resources for females.Proximity of female Pomacentrus amboinensis to the male (A) or nest site (B). Errors are standard errors. Letters represent Tukey’s HSD groupings of means. N = 8 social groups.
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fig-7: Rank affects access to resources for females.Proximity of female Pomacentrus amboinensis to the male (A) or nest site (B). Errors are standard errors. Letters represent Tukey’s HSD groupings of means. N = 8 social groups.

Mentions: Alpha females had half the cortisol concentrations within their ovarian tissue than β-females (13.45 versus 28.2 ng/g; Paired t14,0.05 = − 3.497, p = 0.004), suggesting the dominant females were less stressed. Alpha females were found closer to the male than either β-females or juveniles (F2,472 = 91.054, p < 0.0001; Fig. 7A). However, β-females were further away from the nest site than either α-females or juveniles (F2,472 = 168.326, p < 0.0001; Fig. 7B).


Protogyny in a tropical damselfish: females queue for future benefit.

McCormick MI - PeerJ (2016)

Rank affects access to resources for females.Proximity of female Pomacentrus amboinensis to the male (A) or nest site (B). Errors are standard errors. Letters represent Tukey’s HSD groupings of means. N = 8 social groups.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4933090&req=5

fig-7: Rank affects access to resources for females.Proximity of female Pomacentrus amboinensis to the male (A) or nest site (B). Errors are standard errors. Letters represent Tukey’s HSD groupings of means. N = 8 social groups.
Mentions: Alpha females had half the cortisol concentrations within their ovarian tissue than β-females (13.45 versus 28.2 ng/g; Paired t14,0.05 = − 3.497, p = 0.004), suggesting the dominant females were less stressed. Alpha females were found closer to the male than either β-females or juveniles (F2,472 = 91.054, p < 0.0001; Fig. 7A). However, β-females were further away from the nest site than either α-females or juveniles (F2,472 = 168.326, p < 0.0001; Fig. 7B).

Bottom Line: In situ behavioural observations found that alpha-females have priority of access to the nest site that the male guarded, and access to higher quality foraging areas.Examination of otolith microstructure showed that those individuals which change sex to males have different embryonic characteristics at hatching, suggesting that success may involve a component that is parentally endowed.The relative importance of parental effects and social organisation in affecting the importance of female queuing is yet to be studied, but will likely depend on the strength of social control by the dominant members of the group.

View Article: PubMed Central - HTML - PubMed

Affiliation: ARC Centre of Excellence for Coral Reef Studies, and Department of Marine Biology and Aquaculture, James Cook University , Townsville , Queensland , Australia.

ABSTRACT
Membership of the group is a balance between the benefits associated with group living and the cost of socially constrained growth and breeding opportunities, but the costs and benefits are seldom examined. The goal of the present study was to explore the trade-offs associated with group living for a sex-changing, potentially protogynous coral reef fish, the Ambon damselfish, Pomacentrus amboinensis. Extensive sampling showed that the species exhibits resource defence polygyny, where dominant males guard a nest site that is visited by females. P. amboinensis have a longevity of about 6.5 years on the northern Great Barrier Reef. While the species can change sex consistent with being a protogynous hermaphrodite, it is unclear the extent to which the species uses this capability. Social groups are comprised of one reproductive male, 1-7 females and a number of juveniles. Females live in a linear dominance hierarchy, with the male being more aggressive to the beta-female than the alpha-female, who exhibits lower levels of ovarian cortisol. Surveys and a tagging study indicated that groups were stable for at least three months. A passive integrated transponder tag study showed that males spawn with females from their own group, but also females from neighbouring groups. In situ behavioural observations found that alpha-females have priority of access to the nest site that the male guarded, and access to higher quality foraging areas. Male removal studies suggest that the alpha-females can change sex to take over from the male when the position becomes available. Examination of otolith microstructure showed that those individuals which change sex to males have different embryonic characteristics at hatching, suggesting that success may involve a component that is parentally endowed. The relative importance of parental effects and social organisation in affecting the importance of female queuing is yet to be studied, but will likely depend on the strength of social control by the dominant members of the group.

No MeSH data available.


Related in: MedlinePlus