Oxygen consumption of gestating female Sebastes schlegeli: estimating the reproductive costs of livebearing

Abstract

SynopsisDuring gestation, live-bearing fishes incur physiological energy costs, including provision of energy and respiratory gases to the developing embryos and removal of waste products. Fecundity in the genus Sebastes is high, and the ovaries represent a significant portion of the weight of gestating females. In this study, we compare oxygen consumption of gestating females with non-gestating females and males of kurosoi, Sebastes schlegeli, to estimate these costs. Oxygen consumption by pregnant females is significantly higher than that of males and immature females at similar sizes and weights. We estimate that a 1.5 kg gestating female consumes 68% more oxygen than a non-gestating fish during the 51.5-day period of gestation. Such an increase in oxygen consumption rates may have important implications to the metabolic scope of gestating females. The additional oxygen consumed by gestating females is greater than that predicted for the embryos alone, suggesting that costs of increased gill ventilation, ionic and osmotic regulation and cardiac output are relatively high. Such energetic costs represent a quantifiable expense of the viviparous mode of reproduction in Sebastes as compared with oviparous species.

Metabolic costs of viviparity in yellowtail rockfish,Sebastes flavidus

“…3). However, these differences are possibly due to differences in methodology (Boehlert et al 1991) and the less frequent developmental intervals tested (Dygert & Gunderson 1991).…”

“…It also showed that subtle environmental changes such as changes in light conditions can affect metabolism measurements. The methods used by Boehlert et al (1991) on S. schlegeli differed considerably with acclimations of 3-5 minutes and average measurement periods of 43 minutes. While this may have been appropriate for the cultured and domesticated S. schlegeli it would have been unsuitable for the wild S. flavidus used in this study.…”

Effects of intraspecific variation in reproductive traits, pectoral fin use and burst swimming on metabolic rates and swimming performance: a study on the Trinidadian guppy (Poecilia reticulataPeters)

“…A number of studies have reported elevated metabolic rate (Webb and Brett, 1972;Boehlert et al, 1991;Hopkins et al, 1995;Timmerman and Chapman, 2003;Skov et al, 2010) and diminished swimming performance (Plaut, 2002;Ghalambor et al, 2004;Belk and Tuckfield, 2010) in pregnant live-bearing fish. The studies differ from the present study in a number of ways.…”

“…Elevated metabolic rate in relation to gravidity or pregnancy has been reported in many animals, including the eastern garter snake (Thamnophis sirtalis) (Birchard et al, 1984), mountain spiny lizard (Sceloporus jarrovi) (DeMarco, 1993), yellowtail rockfish (Sebastes flavidus) (Hopkins et al, 1995), Korean rockfish (Sebastes schlegeli) (Boehlert et al, 1991), sailfin molly (Poecilia latipinna) (Timmerman and Chapman, 2003), striped surfperch (Embiotoca lateralis) (Webb and Brett, 1972) and European eelpout (Zoarces viviparus) (Skov et al, 2010). Several studies have demonstrated diminished locomotor performance caused by gravidity or pregnancy.…”

Microsatellite variation in the Mexican rockfish <i>Sebastes macdonaldi</i>

“…Rockfishes all have internal fertilisation, an unusual feature among marine teleosts, and matrotrophic viviparity has been shown in some species (e.g. Boehlert et al, 1991). The very large number of species is undoubtedly their best known attribute, as Sebastes represents the most numerous genus in the family Scorpaenidae, with more than 110 species worldwide (Eitner et al, 1999;Nelson, 1994).…”