Metabolic costs of viviparity in yellowtail rockfish,Sebastes flavidus

Abstract

We estimated the energy utilized by developing embryos and larvae of yellowtail rockfish, Sebastesflavidus, by determining the routine metabolic rate of adult females throughout gestation and subtracting the mean metabolic rate of non-gestating fish. The pattern of maternal oxygen consumption during gestation was such that metabolic demands did not become significantly elevated until intra-ovarian embryos had hatched and larvae were being incubated (i.e. 24-28 d post-fertilization).Metabolic rates of females in this latter stage of gestation were 82% higher than spent females and 101% higher than those of non-reproductive males. We determined that 0.08996 cal embryo-' was consumed during gestation as compared to the change in energy content of embryos from fertilization to birth which was 0.08690 cal embryo-'. The difference between the energy consumed and the energy lost during the 29 d gestation period indicated that extra embryonic sources contributed only 3.4% or 0.00306 cal embryo-' of the energy utilized after fertilization. Our observations agree with previous work which determined that embryos and larvae of S. flavidus are primarily lecithotrophic and that the relatively high fecundity of S. $?avidus coupled with a small egg size, rapid embryogenesis and brief gestation period characterize this species as a relative r-strategist within a genus whose species range broadly over the 'K end' of the r-K continuum.

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.…”

“…Pre-exercise M O 2 at 2BLs −1 is indicated using a solid line (dashed lines are 95% CL). Locomotor cost and maximal performance Hopkins et al, 1995;Skov et al, 2010). We were unable to make repeated measurements on individual fish because of the destructive nature of measuring RA, and our samples included no reproductively inactive fish (all wet RA ≥4.93%).…”

“…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.…”

Melanin pattern morphs do not differ in metabolic rate: implications for the evolutionary maintenance of a melanophore polymorphism in the green swordtail, Xiphophorus helleri

“…In this study, we investigated whether this hypothesis can contribute to explaining the maintenance of a melanophore pattern polymorphism in X. helleri by examining whether spotted and nonspotted morphs of X. helleri differ in routine metabolic rate. We tested both adult males and juveniles (we did not measure the metabolic rate of females because it may vary with reproductive state and this could be a confounding factor; Hopkins et al 1995). We chose the green swordtail X. helleri as our study system because it belongs to a different clade of Xiphophorus and its pattern polymorphism is phenotypically but not necessarily genetically different (Kallman and Atz 1966).…”

Effect of hypoxia on rockfish movements: implications for understanding the roles of temperature, toxins and site fidelity

“…Hopkins et al (1995) used oxygen consumption rates to determine metabolic rates of yellowtail rockfish Sebastes flavidus. They found that females incubating larvae had an 82 to 101% higher metabolic rate than spent females and males (Hopkins et al 1995). This study also calculated the maternal nutrient contribution to the embryo.…”