Condition factor and hepatosomatic index as estimates of energy status in male three‐spined stickleback

Abstract

Seasonal variation in direct and indirect measures of energy status was examined using estimates of glycogen, lipid and protein levels in a single cohort of male three-spined sticklebacks from an annual population collected each month over one complete year. Condition factor, somatic condition factor and hepatosomatic index (HSI) were calculated as indirect indices of energy status and the accuracy of these indirect measures as predictors of energy status was investigated. Results indicate that both condition factors were significant predictors of energy reserves (lipid, protein, glycogen and total energy), but that the proportion of variance accounted for was small. Both condition factors perform better as predictors of energy content per unit body weight. The HSI was a significant, but a weak predictor of total glycogen levels over the whole year. On a seasonal basis the relationship between HSI and energy reserves was highly variable. These indices are therefore poor predictors of energy reserves in male three-spined sticklebacks. '(', 1995 The Fisheries Sociely of the British Isles

Ovarian development and spawning of Serra Spanish mackerel in coastal waters of Northeastern Brazil

“…The onset of sexual maturity represents a critical transition in the life history, since resource allocation is related mainly to growth before and to reproduction after sexual maturity (Potts and Wootton, 1984;Chellappa et al, 1995). The present study establishes four macroscopic stages and five stages of ovarian oocyte development for females of Serra Spanish mackerel.…”

Who is in control of the stickleback immune system: interactions between Schistocephalus solidus and its specific vertebrate host

“…For the host, mounting such a strong immune response that late during infection, with no chance of eliminating the parasite, only causes costs, namely for mounting the immune response, but probably more importantly immunopathological costs (Lochmiller & Deerenberg 2000). This is reflected in the hepatosomatic index, a measure of the short-term energy reserves (Chellappa et al 1995), which was significantly reduced in infected compared with control sticklebacks at 57 and 67 dpe. Such energetic costs of the elevated respiratory burst activity were also shown in a previous study on the same system (Hammerschmidt & Kurtz 2005a).…”

Variability in the sonic muscles of the Lusitanian toadfish (Halobatrachus didactylus): acoustic signals may reflect individual quality

“…Both condition and hepatosomatic indices (analogous to the residuals of eviscerated body mass and liver mass used in the present study) are thought to represent good measures of condition in fish (Chellappa et al 1995) and show minimal values at the end of the breeding season in the Lusitanian toadfish, probably associated to gamete production in females and to the increased metabolic needs of territorial defence and vocal activity in males (Modesto and Canário 2003b). Likewise the residuals of accessory gland mass contributed to sonic muscle mass in males.…”