Ascorbate concentration in fish ontogeny

Abstract

The ontogenetic trend of ascorbate has been quantified in three freshwater fishes: roach (Rurilus rufilus), whitefish (Coregonus lavarefus) and Arctic charr (Salvelinus ulpinus). Total ascorbate (reduced and oxidized) declined from 150 to 5 pg g-' as newly hatched larvae grew to become several-months-old juveniles. Declining total ascorbate with increasing size of metamorphosing fish could not be reversed by feeding on brine shrimp, Arfemiu salina nauplii, zooplanktonic food containing > 74 pg g I total ascorbate. The proportion of reduced ascorbate in total ascorbate increases with fish size/age. The physiological mechanism of the changes in transferable ascorbate forms remains unknown, but high dehydroascorbate concentrations suggest high vulnerability of larval fish to oxidation stress. This is the first report on quantity ofvitamin C retained inactivelyfeeding larval and juvenile fish. The efficiency of ascorbate transfer from zooplankters to larval fish amounted to 5-20%. The ecological significance of larval fish feeding on various zooplankters and/or phytoplankton may reflect a trend toward maximum transfer of this vitamin in freshwater food webs.

Evaluation of vitamin C-enriched Artemia nauplii for larvae of the giant freshwater prawn

“…Since the extra dietary vitamin C also resulted in increased AA levels in the predator larvae (>500 I~g AA g-1 DW for the 20%-AP diet), and the only biological response measured was an increased stress resistance, it may be assumed that the latter positive effect was caused by feeding vitamin C-enriched live food (Table 2). These results support the hypothesis that stress creates increased ascorbate requirements for larval fish and crustaceans, and that in this respect body vitamin C concentration may reflect the survival potential more acurately than variation in growth rate (Dabrowski, 1992). Moreover, at day 28 a significant drop in AA concentration was detected in the postlarvae as compared with the levels found in the larvae.…”

“…skeletal development, growth, survival) as well as physiological functions (e.g. resistance to toxicants and stress, immunoactivity) might be enhanced by supplemental dietary ascorbate (Dabrowski, 1992). Recently we were able to demonstrate that for larvae of the African catfish (Clarias gariepinus) high dietary levels of AA (up to 2500 ~g AA g-1 DW) significantly increased the growth rate and stress resistance (Merchie et al, 1995c), whereas for European sea bass (Dicentrarchus labrax) larvae only stress resistance was affected (Merchie et al, 1995b).…”

Biochemical composition during growth and starvation of early larval stages of cultured spiny lobster (Jasus edwardsii) phyllosoma

“…However, concentrations decreased considerably from just before moult at day 8 (333 μg g -1 ; late stage I) to just after moult at day 12 (156 μg g -1 ; early stage II), which supports the suggestion by Dabrowski (1992) that ascorbic acid is metabolised for stressful events, such as ecdysis, creating a high demand on reserves. From day 12 up to day 18, feeding reestablished tissue concentrations of ascorbic acid to above pre-moult levels, whereas starved phyllosoma showed strong retention with no significant change in the concentration of the vitamin.…”

Relationship between biochemical constituents of fish semen and fertility: the effect of short-term storage

“…Seminal plasma level of ascorbic acid in fish, reported here for the first time, exceeds many times those found in rainbow trout blood plasma (Dabrowski 1992). The vitamin C apparently is derived from blood, since teleost fish have no ascorbate synthesizing ability (Dabrowski 1990a).…”