PMID- 16171879
OWN - NLM
STAT- MEDLINE
DCOM- 20060605
LR  - 20071114
IS  - 0166-445X (Print)
IS  - 0166-445X (Linking)
VI  - 75
IP  - 3
DP  - 2005 Nov 10
TI  - The effects of acute and chronic ammonia exposure during early life stages of the 
      gulf toadfish, Opsanus beta.
PG  - 225-37
AB  - The gulf toadfish (Opsanus beta) is unusual among teleosts in that it is 
      facultatively ureotelic and adults and juveniles have a particularly high 
      tolerance to environmental ammonia. Male toadfish brood their offspring in 
      confined nests. It has been hypothesized that the potential accumulation of 
      ammonia in nests from the male and the offspring, coupled with suspected low 
      ammonia tolerance in offspring would provide the selective pressure necessary for 
      excretion of the less toxic urea by adult toadfish. This study examines this 
      so-called 'nest-fouling' hypothesis through acute and chronic ammonia toxicity 
      testing on early life stages of O. beta. In addition, nitrogen elimination was 
      examined among embryos, yolk-sac larvae and juveniles where we found an ontogenic 
      shift from ammonotely to ureotely with advancing life history stages. The acute 
      ammonia 96 h LC50 values for embryos and larvae were 63.6 and 5.45 mmol-Nl(-1) 
      total ammonia (TAmm), respectively. Thus, these early life stages are more 
      tolerant to ammonia than either juveniles or adults and LC50 values are at least 
      2 orders of magnitude greater than concentrations naturally occurring at nest 
      sites. Furthermore, 40 days exposures at mean and maximum NH3 concentrations 
      normally found within nests revealed no observable detrimental effects. In fact, 
      growth in terms of wet or dry weight was greatest at the maximum NH3 
      concentration. We therefore conclude that the nest-fouling hypothesis is not a 
      viable explanation for ureotely in the gulf toadfish.
FAU - Barimo, John F
AU  - Barimo JF
AD  - Division of Marine Biology and Fisheries, Rosenstiel School of Marine and 
      Atmospheric Science, University of Miami, Miami, FL 33149-1098, USA. 
      jbarimo@rsmas.miami.edu
FAU - Walsh, Patrick J
AU  - Walsh PJ
LA  - eng
GR  - ES05705/ES/NIEHS NIH HHS/United States
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, U.S. Gov't, Non-P.H.S.
DEP - 20050919
PL  - Netherlands
TA  - Aquat Toxicol
JT  - Aquatic toxicology (Amsterdam, Netherlands)
JID - 8500246
RN  - 0 (Nitrogen Compounds)
RN  - 7664-41-7 (Ammonia)
SB  - IM
MH  - Age Factors
MH  - Ammonia/*toxicity
MH  - Analysis of Variance
MH  - Animals
MH  - Batrachoidiformes/embryology/metabolism/*physiology
MH  - Embryo, Nonmammalian/drug effects/physiology
MH  - Florida
MH  - Growth and Development/*drug effects
MH  - Larva/drug effects/physiology
MH  - Lethal Dose 50
MH  - Nitrogen Compounds/*metabolism
EDAT- 2005/09/21 09:00
MHDA- 2006/06/06 09:00
CRDT- 2005/09/21 09:00
PHST- 2005/06/29 00:00 [received]
PHST- 2005/08/11 00:00 [revised]
PHST- 2005/08/13 00:00 [accepted]
PHST- 2005/09/21 09:00 [pubmed]
PHST- 2006/06/06 09:00 [medline]
PHST- 2005/09/21 09:00 [entrez]
AID - S0166-445X(05)00275-4 [pii]
AID - 10.1016/j.aquatox.2005.08.005 [doi]
PST - ppublish
SO  - Aquat Toxicol. 2005 Nov 10;75(3):225-37. doi: 10.1016/j.aquatox.2005.08.005. Epub 
      2005 Sep 19.