[en] The study focussed on the effects of triclosan (TCS) exposure on mobility and hearing capacities of Cyprinodon variegatus larvae. TCS is an omnipresent antimicrobial and contaminant of aquatic ecosystems, which can act as endocrine disruptor, mainly by modifying thyroid functioning. Larval stages are particularly vulnerable to deleterious effects of endocrine disrupters because of potential impairment of fish development and behaviour. Exposure to TCS was conducted at fertilization of eggs at concentrations likely to be found in the environment: 20, 50 and 100 μg.l-1. The analysis of growth parameters of C. variegatus showed no effect of TCS on the fertility of eggs, survival and larval weight. Subsequently, THs concentrations were measured on 15 days post hatching larvae. THs are initially produced as T4 (thyroxine) cells and then converted in the bioactive form of T3 (triiodothyronine) cells. The observed increase of T4 and T3 cells in larvae exposed to 50 and 100 μg.l-1 suggests an increase in THs synthesis as a consequence of TCS exposure. Auditory thresholds of larvae were determined using ABR (Auditory Brainstem Response) technique, and finally larval mobility was measured. For both parameters no significant differences were observed among the three different treatments. Audiograms showed that the auditory system is not yet completely established at 30 days post hatching. However, these results allowed us to consider C. variegatus as an “hearing generalist” because this species have a hearing sensitivity lower than 2000 Hz. Regarding locomotion, our result summarized short time experiences targeting only swimming speed, distance and degree of mobility. It would be interesting to expand the behavioural aspects on other parameters of locomotion and integrate Cyprinodon reaction to different stress (light or touch). In conclusion, our results require an extensive long-term study on the full life cycle of C. variegatus, in order to evaluate the impact of triclosan on neural function and behaviour through several generations.
Research Center/Unit :
MARE - Centre Interfacultaire de Recherches en Océanologie - ULiège AFFISH-RC - Applied and Fundamental FISH Research Center - ULiège
Disciplines :
Zoology
Author, co-author :
Benichou, Farida; ULiège - University of Liège [BE]
Rahmouni, Chahrazed
Denoël, Mathieu ; Université de Liège > Département de Biologie, Ecologie et Evolution > Biologie du comportement - Ethologie et psychologie animale
Colleye, Orphal ; Université de Liège > Département de Biologie, Ecologie et Evolution > Morphologie fonctionnelle et évolutive
Das, Krishna ; Université de Liège > Département de Biologie, Ecologie et Evolution > Océanologie
Schnitzler, Joseph ; Université de Liège > Département de Biologie, Ecologie et Evolution > Océanologie
Language :
English
Title :
Impact of triclosan on behaviour and neural development of Cyprinodon variegatus
Publication date :
12 December 2014
Event name :
ZOOLOGY 2014 - 21st Benelux Congress of Zoology
Event place :
Liège, Belgium
Event date :
12-13 December 2014
Audience :
International
Peer reviewed :
Peer reviewed
Funders :
F.R.S.-FNRS - Fonds de la Recherche Scientifique [BE]