Ovarian structure and mode of egg production in the seaweed pipefish Syngnathus schlegeli (Syngnathidae)

Sogabe, Atsushi; Takata, Hiromi; Kobayashi, Yasuhisa

doi:10.1007/s10228-012-0313-z

Cited by 3 publications

(3 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Like in all other Syngnathus species, male S. schlegeli provide all postzygotic care of offspring in a brood pouch and brooding takes 14 to 28 days under ambient water temperatures of around 20°C (Watanabe and Watanabe 2001). The mating pattern in this population is most likely characterized by multiple mating by both males and females (i.e., a polygynandrous mating pattern; Sogabe et al 2012Sogabe et al , 2013 and female egg production is asynchronous, thus enabling them to mature eggs continuously and to mate with multiple males in a short time span (Sogabe et al 2013). The reproductive ecology of this species offers interesting contrasts in reproductive states that can be used to test the ETH at the within species level.…”

Section: Introductionmentioning

confidence: 91%

“…Importantly, sexual selection is most likely stronger in females than in males in this species (Watanabe et al 2000). Given that courtship and intrasexual competition are cognitively challenging (Boogert et al 2011), females of S. schlegeli may be under stronger selection to have larger brains than males, on top of the cost associated with rapid and continuous egg production (Sogabe et al 2013 Chong, I. Ahnesjö, and N. Kolm, unpubl. ms.).…”

Section: The Expensive Tissue Hypothesismentioning

confidence: 97%

“…A greater capacity for physiological activities is generally reflected in a greater size of organs responsible for energy turnover (Daan et al 1990;Peterson et al 1990). In S. schlegeli, females have the ability to continuously mature oocytes and egg production is asynchronous (Sogabe et al 2013), like in many other polygamously mating pipefishes (Sogabe and Ahnesjo 2011). This continuous and rapid egg production should increase the synthesis of vitellogenins in the liver (Henderson and Tocher 1987;Tyler and Sumpter 1996;Lubzens et al 2010), and the associated increase in these activities could benefit from an increased capacity of osmoregulation by larger kidneys.…”

Section: Sexual Dimorphism In Organ Sizementioning

confidence: 99%

See 2 more Smart Citations

Within species support for the expensive tissue hypothesis: a negative association between brain size and visceral fat storage in females of the Pacific seaweed pipefish

Tsuboi

Shoji

Sogabe

et al. 2016

Ecology and Evolution

Self Cite

View full text Add to dashboard Cite

The brain is one of the most energetically expensive organs in the vertebrate body. Consequently, the high cost of brain development and maintenance is predicted to constrain adaptive brain size evolution (the expensive tissue hypothesis, ETH). Here, we test the ETH in a teleost fish with predominant female mating competition (reversed sex roles) and male pregnancy, the pacific seaweed pipefish Syngnathus schlegeli. The relative size of the brain and other energetically expensive organs (kidney, liver, heart, gut, visceral fat, and ovary/testis) was compared among three groups: pregnant males, nonpregnant males and egg producing females. Brood size in pregnant males was unrelated to brain size or the size of any other organ, whereas positive relationships were found between ovary size, kidney size, and liver size in females. Moreover, we found that the size of energetically expensive organs (brain, heart, gut, kidney, and liver) as well as the amount of visceral fat did not differ between pregnant and nonpregnant males. However, we found marked differences in relative size of the expensive organs between sexes. Females had larger liver and kidney than males, whereas males stored more visceral fat than females. Furthermore, in females we found a negative correlation between brain size and the amount of visceral fat, whereas in males, a positive trend between brain size and both liver and heart size was found. These results suggest that, while the majority of variation in the size of various expensive organs in this species likely reflects that individuals in good condition can afford to allocate resources to several organs, the cost of the expensive brain was visible in the visceral fat content of females, possibly due to the high costs associated with female egg production.

show abstract