OCCURRENCE OF LINDANE AND ITS EFFECTS ON SOME HEMATOLOGICAL AND HISTOLOGICAL ASPEcrS OF TILAPIA ZILLII (GERV.)

OCCURRENCE OF LINDANE AND ITS EFFECTS ON SOME

HEMATOLOGICAL AND HISTOLOGICAL ASPEcrS

OF TILAPIA ZILLII (GERV.)

BY
MOURAD, M.*; ABDALLAH, M. AND ABD-ALLAH, A.
*National Institute ofOceanography and Fisheries, Alexandria, Egypt.
Key words: Lindane; insecticide; Bioaccumulation; Physiological response;
Histological changes; Tilapia zillU.
ABSTRACT
Residues, lethal and sublethal toxicity of organochlorine
insecticide lindane to Tilapia zillli (Gerv.) were investigated Lindane.
was positively detected in all samples collectedfrom Nile River. Its
level increased upward from south to north along the River showing
its highest mean concentration (10. 7nglg) in fish from Rosetta while
the lowest level (2. 7 nglg) was found in fish from Aswan. Median
lethal concentrations of lindane were experimentally estimated at 24
and 96 hr. The LC50 values were 32.0 and 21.7 pg!J, respectively.
Subjecting fish to sublethal concentrations (10 & 20 pg/l) a/lindane
induced
treated fish,
both
blood
hemato(ogicaland
glucose level
histological
decreased after
changes.
3, 6
In
and
lindane24 hr.
whereas hyperglycemia was noticedfollowing 48, 96, and J68 hr. of
exposure. Mean cell hemoglobin concentration (MCHC) decreased at
all detected time periodsfollOWingfish exposure to 10 pg/l oflindane.
On the other hand, when fish were exposed to 20 p.g/l (jlindane,
MCHC decreased after 3 and 6 hr. then increased by increasing the
time of exposure to 24, 48, 96 and 168 hr. Transaminase enzyme
(PGOT), plasma protein, sodium andpotassium ions increased at all
the detected time periods of exposure. Microscopic exantination of
gills showed hyperplasia in the primary gill lamellae, hypertrophy
and
lamellar
shortening
spaces.
in
Livers
the secondary
of lindane-treated
lamellae with
fish
blocking
showed
of
severe
the interfatty
. ·depositionwith destruction in both hepatOCytesand bile~ducls.