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The effects of a chronic mercury exposure on survival, reproduction and population dynamics of Mysidopsis Bahia
Author(s) -
Gentile J. H.,
Gentile S. M.,
Hoffman G.,
Heltshe J. F.,
Hairston N.
Publication year - 1983
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620020107
Subject(s) - toxicant , brood , mercury (programming language) , biology , population , reproduction , toxicology , toxicity , zoology , sexual maturity , reproductive toxicity , ecology , medicine , demography , sociology , computer science , programming language
The epibenthic mysid Mysidopsis bahia was chronically exposed throughout its entire life cycle to inorganic mercury. The experimental design permitted the precise measurements of survival rates; individual and population growth rates; and sublethal reproductive responses, including time to sexual maturation and first brood release, egg development time, brood size and frequency of reproduction. Mercury was acutely toxic (96‐h LC 50 ) to juveniles at 3.5 μg L −1 , chronically toxic (35‐d LC 50 ) at 1.8 μg L −1 and differentially toxic to males and females (α = 0.05). Male and female mortality rates were 35 and 18%, respectively, from sexual maturation (day 14) through termination of the assay (day 35). Reproductive effects included delays in sexual maturation and brood release at 1.6 μg L −1 , a doubling of brood development time at 2.5 μg L −1 and subsequent abortion and significant decreases in the total broods released (and therefore juveniles produced) at 1.6 μg L −1 . Intrinsic rates of population increase ( r ), calculated from life‐tables, decreased with increasing mercury concentration. The critical value (r = 0) for mercury occurs at 1.6 μg L −1 , which corresponds well with the upper limit of the maximum acceptable toxicant concentration, the usual endpoint of life‐cycle toxicity tests. The toxicity test system is a sensitive, precise model for studying lethal, sublethal and potential population consequences of pollution.