title: Nervous system disruption and concomitant behavioral abnormality in early hatched pufferfish larvae exposed to heavy oil.
abstract: OBJECTIVE
  Spills of heavy oil (HO) over the oceans have been proven to have an adverse effect on marine life. It has been hypothesized that exposure of early larvae of sinking eggs to HO leads largely to normal morphology, whereas abnormal organization of the developing neural scaffold is likely to be found. HO-induced disruption of the nervous system, which controls animal behavior, may in turn cause abnormalities in the swimming behavior of hatched larvae. To clarify the toxicological effects of HO, we performed exposure experiments and morphological and behavioral analyses in pufferfish (Takifugu rubripes) larvae.
  
  
  METHODS
  Fertilized eggs of pufferfish were exposed to 50 mg/L of HO for 8 days and transferred to fresh seawater before hatching. The hatched larvae were observed for their swimming behavior, morphological appearance, and construction of muscles and nervous system.
  
  
  CONCLUSIONS
  In HO-exposed larvae, we did not detect any anomaly of body morphology. However, they showed an abnormal swimming pattern and disorganized midbrain, a higher center controlling movement. Our results suggest that HO-exposed fishes suffer developmental disorder of the brain that triggers an abnormal swimming behavior and that HO may be selectively toxic to the brain and cause physical disability throughout the life span of these fishes.
authors: Centre for Marine Environmental Studies, Ehime University, 2-5 Bunkyo-cho, Matsuyama, 790-8577, Japan. kawa@sci.ehime-u.ac.jp
authors: Masahumi
authors: M
authors: Kawaguchi
authors: Yuki
authors: Y
authors: Sugahara
authors: Tomoe
authors: T
authors: Watanabe
authors: Kouta
authors: K
authors: Irie
authors: Minoru
authors: M
authors: Ishida
authors: Daisuke
authors: D
authors: Kurokawa
authors: Shin-Ichi
authors: S
authors: Kitamura
authors: Hiromi
authors: H
authors: Takata
authors: Itsuki C
authors: IC
authors: Handoh
authors: Kei
authors: K
authors: Nakayama
authors: Yasunori
authors: Y
authors: Murakami
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D002493:Central Nervous System Diseases / Q000139:chemically induced / Q000473:pathology / Q000662:veterinary*; D005393:Fish Diseases / Q000139:chemically induced* / Q000473:pathology; D010578:Petroleum / Q000633:toxicity*; D013550:Swimming; D023721:Tetraodontiformes; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D010578:Petroleum; D014874:Water Pollutants, Chemical