Fróðskaparrit - 01.01.1998, Qupperneq 66

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ORGANOTIN ANDIMPOSEXIN THE LITTORAL ZONE ON FAROEISLANDS
Fig. 2. Stages 1 to 6 in the development ofimposex in
Nucella lapillus based on vas deferens sequence (VDS)
(Gibbs et al., 1987). Abbreviations: a, anus; b,
‘blister’; cg, capsule gland; gp, genital papilla; n,
‘nodule ’; p, penis; v, vulva; vd, vas deferens. In stage
6, drawn as an insert to stage 5, aborted egg capsules
may be seen around the genital papilla.
Mynd 2. Myndin vísir tey ymisku stigini, frá 1 til 6, í
framvøkstrinum av sáðleiðarum, vas deferens hjá
kvenndýrum av purpurkúvingum Nucella lapillus.
Styttingar: a, anus; b, ’bløðra1; cg. egghylkiskertil; gp,
genital papilla; n, ’knubbi’; p, penis; v, vulva; vd, vas
deferens. Vas deferens sequence, VDS, (Gibbs et al.,
1987) lýsir fyribrigđið imposex kvantitativt. Hjá
kúvingum, ið hava VDS í stigi 6, víst í myndini sum
eitt innskot til stig 5 lýsingina, kunnu aborterað egg
síggjast við kynsvørtuna (genital papilla).
overgrown, aborted egg capsules can be
seen, fíg. 2 (insert b). Snails in a VDS stage
of 5 or 6 are sterile as they are unable to re-
lease egg capsules from the genital papilla.
The VDSI of a population is the mean VDS
stages determined for the individual fe-
males. No less than 20 individuals of each
sex was used for imposex determination.
The same animals were used for chemical
analysis.
Organotin determination
Reagents
Organotin standards were obtained from
Alfa-Johnson Matthey GmBH, Aldrich- I
Chemie, Strem Chemicals (Germany) and j
Fluka Chemica-Biochemica (Switzerland).
Stock solutions of each organotin com-
pound (10 mg Sn mL"1) were prepared by
dissolving the standards in n-hexane or
methanol. The n-hexane and methanol used
throughout the method were HPLC- and
p.a. grade obtained from Rathbum Chemi-
cals Ltd. (Scotland) and Merck KGaA
(Germany) respectively. The tissue-solu-
biliser, 25% tetraethylammonium hydrox-
ide (TEAH) in methanol (purum grade).
was obtained from Fluka Chemica-Bio-
Chemica (Switzerland) and diluted to 10 %
in methanol. Sodium tetraethylborate (Na-
BEt4, min. 98 %) was obtained from Strem
Chemicals Inc. (Germany). Batches of 5 g
were diluted in methanol to a concentration
of 10 % and stored under argon (99.999%,
AGA) at +4 °C. Hydrochloric acid, acetic
acid, and sodium acetate trihydrate, all of
p.a. quality, were obtained from Merck
(Germany). Ultra pure water from an Op-
tion 3 Water Purifier, ELGA, was used di-