This study presents the results of observation on growth and reproduction of
(Linnaeus, 1758) (Gastropoda, Pulmonata) over the course of several years of continuous rearing in the laboratory in order ...to use them as test organisms for toxicity testing of chemicals. Some growth and reproduction features (shell diameter increase, fecundity, hatching time and rate, age at first reproduction, juvenile survival), which could provide more information for culturing
in the laboratory, are presented. The quantitative results of growth and reproduction in laboratory conditions were obtained: heterogenous growth varied between 0.1 mm and 5.3 mm in individual snails, production of 0.6 egg masses per snail/day and 11 eggs per snail/day. A statistically significant negative correlation between initial snail size and growth was noticed. In the second part of the experiment, the reproductive output of 4 isolated snails was compared to that of permanently grouped snails. As a result, 2-fold decreased growth and 4-fold decreased reproductive output in the progeny of isolated animals was noticed.
Background and purpose: Hyperosmotic solutions of calcium chloride and calcium bromide, extensively used in the oil industry, can be a source of aquatic pollution.Materials and methods: In the ...present study, we investigated whether the freshwater snail Planorbarius corneus L., previously chronically exposed to toxic concentrations of these chemicals, can recover fecundity and growth in clean water. We also examined if a higher tolerance could be induced in F1 offspring after parental and developmental chronic exposure to the chemicals.Results: The fitness-recovery study showed a high compensatory potential of the snails to recover fitness through increased reproduction and growth. In the tolerance study, we observed increased tolerance in F1 offspring in hyperosmotic solutions of calcium chloride. However, there was no significant improvement of reproduction performance in bromide-containing solutions.Conclusions: Increased tolerance was associated with a redirection of resources from growth to maintenance and survival.
Concentrated CaCl2 and CaBr2 salt solutions of densities up to 2.3 kg L-1 are regularly used to control hydrostatic pressure in oil wells during special operations in the exploration and production ...of natural gas and crude oil. Various concentrations of high density salts are frequently left in mud pits near the drilling site as waste, polluting fresh and ground waters by spillage and drainage. The toxic effects of these salts have already been observed. This study investigated the effects of CaCl2 and CaBr2 on water flea Daphnia magna Straus in a 21-day reproduction test. The three tested concentrations of CaCl2 (240, 481, and 1925 mg L-1) caused a significant dose-response decrease of reproduction (p<0.001). With CaBr2 (533 and 1066 mg L-1), only aborted eggs were produced, demonstrating the embryotoxicity of the substance. The results suggest that high concentrations of the tested chemicals are harmful to Daphnia's reproduction and could reduce its abundance.
Abstract
Concentrated CaCl
2
and CaBr
2
salt solutions of densities up to 2.3 kg L
-1
are regularly used to control hydrostatic pressure in oil wells during special operations in the exploration and ...production of natural gas and crude oil. Various concentrations of high density salts are frequently left in mud pits near the drilling site as waste, polluting fresh and ground waters by spillage and drainage. The toxic effects of these salts have already been observed. This study investigated the effects of CaCl
2
and CaBr
2
on water flea Daphnia magna Straus in a 21-day reproduction test. The three tested concentrations of CaCl
2
(240, 481, and 1925 mg L
-1
) caused a significant dose-response decrease of reproduction (p<0.001). With CaBr
2
(533 and 1066 mg L
-1
), only aborted eggs were produced, demonstrating the embryotoxicity of the substance. The results suggest that high concentrations of the tested chemicals are harmful to Daphnia’s reproduction and could reduce its abundance.
Koncentrirane otopine soli CaCl
2
i CaBr
2
gustoće do 2,3 kg L
-1
redovito se koriste za kontrolu hidrostatskoga tlaka u bušotinama tijekom posebnih operacija u istraživanju i proizvodnji prirodnoga plina i sirove nafte. Različite koncentracije soli visoke gustoće često su bile ostavljene u isplačnim jamama u blizini područja bušenja te su prelijevajući se ili ocjeđujući u podzemlje zagađivale slatke i podzemne vode. Iako je dosad već provedeno nekoliko istraživanja toksičnoga učinka koncentriranih otopina soli CaCl
2
i CaBr
2
, u ovom radu istraživan je učinak CaCl
2
i CaBr
2
na vodenbuhu Daphnia magna u dvadesetjednodnevnom testu reprodukcije. Tri ispitane koncentracije CaCl
2
(1925, 481 i 240 mg L
-1
) prouzročile su značajan, o dozi ovisan pad reprodukcije (p<0,001). U otopinama CaBr
2
(533 i 1066 mg L
-1
) proizvedena su samo abortirana jaja, što pokazuje embriotoksičnost te tvari. Rezultati upućuju na to da su visoke koncentracije ispitivanih tvari štetne za razmnožavanje vodenbuhe te mogu smanjiti brojnost tih organizama.
Concentrated CaCl
and CaBr
salt solutions of densities up to 2.3 kg L
are regularly used to control hydrostatic pressure in oil wells during special operations in the exploration and production of ...natural gas and crude oil. Various concentrations of high density salts are frequently left in mud pits near the drilling site as waste, polluting fresh and ground waters by spillage and drainage. The toxic effects of these salts have already been observed. This study investigated the effects of CaCl
and CaBr
on water flea Daphnia magna Straus in a 21-day reproduction test. The three tested concentrations of CaCl
(240, 481, and 1925 mg L
) caused a significant dose-response decrease of reproduction (p<0.001). With CaBr
(533 and 1066 mg L
), only aborted eggs were produced, demonstrating the embryotoxicity of the substance. The results suggest that high concentrations of the tested chemicals are harmful to Daphnia’s reproduction and could reduce its abundance.
Koncentrirane otopine soli CaCl
i CaBr
gustoće do 2,3 kg L
redovito se koriste za kontrolu hidrostatskoga tlaka u bušotinama tijekom posebnih operacija u istraživanju i proizvodnji prirodnoga plina i sirove nafte. Različite koncentracije soli visoke gustoće često su bile ostavljene u isplačnim jamama u blizini područja bušenja te su prelijevajući se ili ocjeđujući u podzemlje zagađivale slatke i podzemne vode. Iako je dosad već provedeno nekoliko istraživanja toksičnoga učinka koncentriranih otopina soli CaCl
i CaBr
, u ovom radu istraživan je učinak CaCl
i CaBr
na vodenbuhu Daphnia magna u dvadesetjednodnevnom testu reprodukcije. Tri ispitane koncentracije CaCl
(1925, 481 i 240 mg L
) prouzročile su značajan, o dozi ovisan pad reprodukcije (p<0,001). U otopinama CaBr
(533 i 1066 mg L
) proizvedena su samo abortirana jaja, što pokazuje embriotoksičnost te tvari. Rezultati upućuju na to da su visoke koncentracije ispitivanih tvari štetne za razmnožavanje vodenbuhe te mogu smanjiti brojnost tih organizama.
Ovo istraživanje obuhvaća rezultate istraživanja rasta i razmnožavanja vrste Planorbarius corneus (Linnaeus, 1758) (Gastropoda, Pulmonata) tijekom višegodišnjeg kontinuiranog uzgoja u laboratoriju u ...svrhu njihovog korištenja kao test organizama za testiranje toksičnosti kemikalija. Prikazane su neke značajke rasta i razmnožavanja (rast kućice, plodnost, vrijeme izlijeganja i brojnost izleženih puževa, vrijeme početka razmnožavanja, preživljavanje mladih) koje bi mogle pružiti više informacija za laboratorijski uzgoj vrste P. corneus. U laboratorijskim uvjetima dobiveni su kvantitativni rezultati rasta i razmnožavanja: heterogeni rast varirao je između 0,1 mm i 5,3 mm kod pojedinih puževa; proizvodnja od 0.6 mrijestova po pužu dnevno i 11 jaja po pužu dnevno. Uočena je statistički značajna negativna korelacija između početne veličine puževa i rasta. U drugom dijelu pokusa četiri puža su izolirana iz laboratorijske kulture kako bi se usporedila njihova reprodukcija s puževima u skupinama. Uočeno je dvostruko smanjenje rasta i četverostruko smanjenje reproduktivnog učinka u potomstvu izoliranih životinja.
Concentrated CaCl^sub 2^ and CaBr^sub 2^ salt solutions of densities up to 2.3 kg L^sup -1^ are regularly used to control hydrostatic pressure in oil wells during special operations in the ...exploration and production of natural gas and crude oil. Various concentrations of high density salts are frequently left in mud pits near the drilling site as waste, polluting fresh and ground waters by spillage and drainage. The toxic effects of these salts have already been observed. This study investigated the effects of CaCl^sub 2^ and CaBr^sub 2^ on water flea Daphnia magna Straus in a 21-day reproduction test. The three tested concentrations of CaCl^sub 2^ (240, 481, and 1925 mg L^sub -1^) caused a significant dose-response decrease of reproduction (p<0.001). With CaBr^sub 2^ (533 and 1066 mg L^sup -1^), only aborted eggs were produced, demonstrating the embryotoxicity of the substance. The results suggest that high concentrations of the tested chemicals are harmful to Daphnia's reproduction and could reduce its abundance.
Concentrated CaCl sub( 2) and CaBr sub( 2) salt solutions of densities up to 2.3 kg L super( -1) are regularly used to control hydrostatic pressure in oil wells during special operations in the ...exploration and production of natural gas and crude oil. Various concentrations of high density salts are frequently left in mud pits near the drilling site as waste, polluting fresh and ground waters by spillage and drainage. The toxic effects of these salts have already been observed. This study investigated the effects of CaCl sub( 2) and CaBr sub( 2) on water flea Daphnia magna Straus in a 21-day reproduction test. The three tested concentrations of CaCl sub( 2) (240, 481, and 1925 mg L sub( -1)) caused a significant dose-response decrease of reproduction (p<0.001). With CaBr sub( 2) (533 and 1066 mg L super( -1)), only aborted eggs were produced, demonstrating the embryotoxicity of the substance. The results suggest that high concentrations of the tested chemicals are harmful to Daphnia's reproduction and could reduce its abundance.
Saturated water solutions of calcium chloride (481.3 g CaCl
2/L) and calcium bromide (1065.9 g CaBr
2/L) and their mixtures, commercially prepared as “high density brines”, are regularly used during ...special operations in exploration and production of natural gas and crude oil. After operations, all workover fluids are left in the environment as waste. In the present study, the effects of several sublethal concentrations of these solutions (CaCl
2 1202 ppm, 2403 ppm and 4796 ppm, CaBr
2 1065 ppm, 2663 ppm and 5325 ppm, 1:1 volume mixture 773.9 ppm, 1931 ppm, 3855 ppm and 5779 ppm) on the fecundity of the freshwater snail
Planorbarius corneus L. were laboratory tested. During the six week exposure a considerably reduced fecundity was found. The tested CaCl
2· solution concentrations reduced fecundity by 53.9–84.4 %, CaBr
2 by 72.3–90.8 % and the mixture by 72.5–94.0 % compared with the control groups.
The possible toxicity of waste materials used in the oil industry to Planorbarius corneus L., an indigenous species of freshwater snail in north-western Croatia was investigated. Freshwater snails ...had an important role in the trophic chain as grazers. Waste materials used in the experiment were sublethal concentrations (1202 ppm, 2403 ppm and 4796 ppm) of calcium chloride and sublethal concentrations (1065 ppm, 2663 ppm and 5325 ppm) of calcium bromide. These 'high density' brines were regularly utilized in the exploration and production of natural gas and crude oil and remained in the environment as waste. The effects of the above concentrations on the fecundity of P. Corneus was measured over a 6 week 'invitro' experimental period, during which time the egg-masses were removed and counted at weekly intervals. Data were analysed using a nonparametric Friedman ANOVA and a Wilcoxon-Wilcoxon test. A decrease in egg-mass production was observed with increases in concentration of chemicals. Bromide had a stronger effect on fecundity than did chloride. The highest egg-masses number was obtained with a 0.75 per cent mixture (5779 ppm salt).
PDF
