Early–life‐stage toxicity in offspring from exposed parent medaka, Oryzias latipes, to mixtures of tributyltin and polychlorinated biphenyls

Abstract

The present study examined the effects of tributyltin (TBT), polychlorinated biphenyls (PCBs), and mixtures of both chemicals on reproduction in Japanese medaka, Oryzias latipes. For 21 d we gave groups of medaka freeze-dried brine shrimp flakes contaminated with a mixture of either 0, 1, 5, or 25 microg TBT g(-1) plus 0 or 25 .micro PCBs g(-1). We measured the fecundity and fertility of the parent fish and assessed the deformity, hatchability, time-to-hatching, and swim-up failure rate of the next generation. Fertilization success in the third week of the administration period was significantly decreased by administration of 25 microg TBT g(-1) (77%) compared with the control group (87%). Both TBT and PCBs were transferred maternally into the eggs of the next generation, causing early life-stage toxicity. Administration of 1 microg TBT g (-1) was not toxic to embryological development, but abnormal eye development (i.e., small eyes or no eyes) occurred when TBT at the same concentration was mixed with PCBs (6.4%). Administration of TBT alone significantly decreased hatchability and increased swim-up failure, and administration of PCBs alone significantly increased time-to-hatching. Statistical analysis by two-way analysis of variance detected an interaction between TBT and PCBs in these three parameters. TBT induces abnormal development of the eyes, reduced hatchability, and increased swim-up failure, whereas PCBs delay time-to-hatching. Administration of mixtures of TBT and PCBs has more adverse effects on the developmental stage of medaka than does that of each chemical alone.

Prolonged ELS test with the marine flatfish sole (Solea solea) shows delayed toxic effects of previous exposure to PCB 126

“…Moreover, environmentally contaminated parent fish and consequently the eggs are exposed to complex mixtures of toxicants. Recent research with the Japanese medaka (Oryzias laptipes) showed for instance that parental exposure to a combination of PCB and TBT has a more adverse effect on the embryonic development than the added effect of the individual substances (Nakayama et al, 2005).…”

Malformations of the endangered Chinese sturgeon, Acipenser sinensis , and its causal agent

“…Also, TBT and TPT can inhibit reproduction (14,15). Therefore, in the present study, the following questions were addressed.…”

“…Ocular and morphological malformations have been observed in embryos and larvae of European minnows (Phoxinus phoxinus) and zebrafish (Danio rerio) after in ovo exposure of TPT (12,13) and in the offspring of medaka (Oryzias latipes) maternally exposed to TBT and TPT (14,15). Also, TBT and TPT can inhibit reproduction (14,15).…”

Alteration of monoamine concentrations in the brain of medaka, Oryzias latipes, exposed to tributyltin

“…Thus, there is evidence that TBT may affect the neuroendocrine system of fish. We previously reported that TBT impaired reproduction of medaka and suppressed sexual behavior of males (Nakayama et al, 2004a(Nakayama et al, , 2005. These results suggest that reduced 5-HT and DA in TBT-exposed medaka could disrupt secretion of GnRH or GTH and consequently induce reproductive impairment and suppression of sexual behavior.…”