Effects of heavy oil in the developing spotted halibut, Verasper variegatus.
It is well known that heavy oil (HO) on the sea surface causes serious problems in the aquatic environment. In particular, some species of teleosts which develop on the sea surface are thought to be affected by the HO which flows out from tankers or coastal industry. However, the toxicological effects of HO are not fully understood. We performed exposure experiments using the Pleuronectiformean fish, spotted halibut (Verasper variegatus), which is an important fishery resource in Japan. In course of the development, HO-exposed embryos showed remarkable delay in developmental processes including somite formation. We further observed abnormal development of the head morphology. Notably, treated embryos had relatively small eyes and craniofacial structures. These findings strongly suggest that HO seriously affects the cell proliferation and differentiation of the embryo. In addition, HO-exposed embryos showed abnormal neuronal development. We also performed the exposure in the larval stage. Treatment of post-hatching larvae with HO resulted in significantly greater mortality compared with controls. Through these observations, we finally conclude that HO is strongly toxic to halibut in their early life stages.
Murakami
Yasunori
Y
Department of Biology, Faculty of Science, Ehime-University, Bunkyo-cho 2-5, Matsuyama 790-8577, Japan. bothrops@sci.ehime-u.ac.jp
Kitamura
Shin-Ichi
S
Nakayama
Kei
K
Matsuoka
Satoru
S
Sakaguchi
Hideo
H
D000818:Animals; D019465:Craniofacial Abnormalities / Q000139:chemically induced / Q000662:veterinary; D004625:Embryo, Nonmammalian / Q000187:drug effects; D005393:Fish Diseases / Q000139:chemically induced; D005432:Flounder / Q000254:growth & development*; D048788:Growth and Development / Q000187:drug effects*; D007814:Larva / Q000187:drug effects; D009420:Nervous System / Q000187:drug effects; D009421:Nervous System Malformations / Q000139:chemically induced / Q000662:veterinary; D010578:Petroleum / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D010578:Petroleum; D014874:Water Pollutants, Chemical