Limits...
The effects of food limitation on life history tradeoffs in pregnant male gulf pipefish.

Paczolt KA, Jones AG - PLoS ONE (2015)

Bottom Line: Syngnathid fishes (pipefishes, seahorses and seadragons) are characterized by a unique mode of paternal care in which embryos develop on or in the male's body, often within a structure known as a brood pouch.Offspring survivorship, on the other hand, does not differ between food treatments, suggesting that male Gulf pipefish sacrifice investment in somatic growth, and thus indirectly sacrifice future reproduction, in favor of current reproduction.However, a positive relationship between number of failed eggs and male growth rate in our low-food treatments suggests that undeveloped eggs reduce the pregnancy's overall cost to the male compared to broods containing only viable offspring.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, 3258 TAMU, Texas A&M University, College Station, Texas, 77843, United States of America.

ABSTRACT
Syngnathid fishes (pipefishes, seahorses and seadragons) are characterized by a unique mode of paternal care in which embryos develop on or in the male's body, often within a structure known as a brood pouch. Evidence suggests that this pouch plays a role in mediating postcopulatory sexual selection and that males have some control over the events occurring within the pouch during the pregnancy. These observations lead to the prediction that males should invest differently in broods depending on the availability of food. Here, we use the Gulf pipefish to test this prediction by monitoring growth rate and offspring survivorship during the pregnancies of males under low- or high-food conditions. Our results show that pregnant males grow less rapidly on average than non-pregnant males, and pregnant males under low-food conditions grow less than pregnant males under high-food conditions. Offspring survivorship, on the other hand, does not differ between food treatments, suggesting that male Gulf pipefish sacrifice investment in somatic growth, and thus indirectly sacrifice future reproduction, in favor of current reproduction. However, a positive relationship between number of failed eggs and male growth rate in our low-food treatments suggests that undeveloped eggs reduce the pregnancy's overall cost to the male compared to broods containing only viable offspring.

No MeSH data available.


Related in: MedlinePlus

The effects on growth of pregnancy and food availability.Growth was measured before and during pregnancy and standardized to correct for the effect of male body length. Positive values indicate pregnant males grew more than non-pregnant males of the same size; negative values indicate pregnant males grew less than non-pregnant males of the same size. (a) Males grow less during pregnancy than in the time period before pregnancy (repeated measures ANOVA, within subjects, time: F1,30 = 5.4317, P = 0.0167). (b) Pregnant males on high food grow more than males on low food, regardless of mate size (two-way ANOVA, mate: F1,32 = 0.31, P = 0.58; food: F1,32 = 5.06, P = 0.03; mate*food: F1,32 = 0.008, P = 0.93).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4430282&req=5

pone.0124147.g001: The effects on growth of pregnancy and food availability.Growth was measured before and during pregnancy and standardized to correct for the effect of male body length. Positive values indicate pregnant males grew more than non-pregnant males of the same size; negative values indicate pregnant males grew less than non-pregnant males of the same size. (a) Males grow less during pregnancy than in the time period before pregnancy (repeated measures ANOVA, within subjects, time: F1,30 = 5.4317, P = 0.0167). (b) Pregnant males on high food grow more than males on low food, regardless of mate size (two-way ANOVA, mate: F1,32 = 0.31, P = 0.58; food: F1,32 = 5.06, P = 0.03; mate*food: F1,32 = 0.008, P = 0.93).

Mentions: We first investigated the effects of resource availability on growth rate. Males grew less while pregnant than in the period before pregnancy (Fig 1A, repeated measures ANOVA, within subjects, time: F1,30 = 5.43, P = 0.017). Pregnant males in high food also grew more than pregnant males in low food (Table 1, two-way ANOVA, mate: F1,32 = 0.31, P = 0.58; food: F1,32 = 5.06, P = 0.03; mate*food: F1,32 = 0.008, P = 0.93, Fig 1B, mean all high food = 0.21 mm/day, mean all low food = 0.16 mm/day). This result shows that our low food treatment was sufficient to cause a measurable effect.


The effects of food limitation on life history tradeoffs in pregnant male gulf pipefish.

Paczolt KA, Jones AG - PLoS ONE (2015)

The effects on growth of pregnancy and food availability.Growth was measured before and during pregnancy and standardized to correct for the effect of male body length. Positive values indicate pregnant males grew more than non-pregnant males of the same size; negative values indicate pregnant males grew less than non-pregnant males of the same size. (a) Males grow less during pregnancy than in the time period before pregnancy (repeated measures ANOVA, within subjects, time: F1,30 = 5.4317, P = 0.0167). (b) Pregnant males on high food grow more than males on low food, regardless of mate size (two-way ANOVA, mate: F1,32 = 0.31, P = 0.58; food: F1,32 = 5.06, P = 0.03; mate*food: F1,32 = 0.008, P = 0.93).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4430282&req=5

pone.0124147.g001: The effects on growth of pregnancy and food availability.Growth was measured before and during pregnancy and standardized to correct for the effect of male body length. Positive values indicate pregnant males grew more than non-pregnant males of the same size; negative values indicate pregnant males grew less than non-pregnant males of the same size. (a) Males grow less during pregnancy than in the time period before pregnancy (repeated measures ANOVA, within subjects, time: F1,30 = 5.4317, P = 0.0167). (b) Pregnant males on high food grow more than males on low food, regardless of mate size (two-way ANOVA, mate: F1,32 = 0.31, P = 0.58; food: F1,32 = 5.06, P = 0.03; mate*food: F1,32 = 0.008, P = 0.93).
Mentions: We first investigated the effects of resource availability on growth rate. Males grew less while pregnant than in the period before pregnancy (Fig 1A, repeated measures ANOVA, within subjects, time: F1,30 = 5.43, P = 0.017). Pregnant males in high food also grew more than pregnant males in low food (Table 1, two-way ANOVA, mate: F1,32 = 0.31, P = 0.58; food: F1,32 = 5.06, P = 0.03; mate*food: F1,32 = 0.008, P = 0.93, Fig 1B, mean all high food = 0.21 mm/day, mean all low food = 0.16 mm/day). This result shows that our low food treatment was sufficient to cause a measurable effect.

Bottom Line: Syngnathid fishes (pipefishes, seahorses and seadragons) are characterized by a unique mode of paternal care in which embryos develop on or in the male's body, often within a structure known as a brood pouch.Offspring survivorship, on the other hand, does not differ between food treatments, suggesting that male Gulf pipefish sacrifice investment in somatic growth, and thus indirectly sacrifice future reproduction, in favor of current reproduction.However, a positive relationship between number of failed eggs and male growth rate in our low-food treatments suggests that undeveloped eggs reduce the pregnancy's overall cost to the male compared to broods containing only viable offspring.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, 3258 TAMU, Texas A&M University, College Station, Texas, 77843, United States of America.

ABSTRACT
Syngnathid fishes (pipefishes, seahorses and seadragons) are characterized by a unique mode of paternal care in which embryos develop on or in the male's body, often within a structure known as a brood pouch. Evidence suggests that this pouch plays a role in mediating postcopulatory sexual selection and that males have some control over the events occurring within the pouch during the pregnancy. These observations lead to the prediction that males should invest differently in broods depending on the availability of food. Here, we use the Gulf pipefish to test this prediction by monitoring growth rate and offspring survivorship during the pregnancies of males under low- or high-food conditions. Our results show that pregnant males grow less rapidly on average than non-pregnant males, and pregnant males under low-food conditions grow less than pregnant males under high-food conditions. Offspring survivorship, on the other hand, does not differ between food treatments, suggesting that male Gulf pipefish sacrifice investment in somatic growth, and thus indirectly sacrifice future reproduction, in favor of current reproduction. However, a positive relationship between number of failed eggs and male growth rate in our low-food treatments suggests that undeveloped eggs reduce the pregnancy's overall cost to the male compared to broods containing only viable offspring.

No MeSH data available.


Related in: MedlinePlus