48 research outputs found
Infestation of shore crab gills by a free-living mussel species
Parasitic and commensal species can impact the structure and function of ecological communities and are typically highly specialized to overcome host defences. Here, we report multiple instances of a normally free-living species, the blue mussel Mytilus edulis Linnaeus, 1758, inhabiting the branchial chamber of the shore crab Carcinus maenas (Linnaeus, 1758) collected from widely separated geographical locations. A total of 127 C. maenas were examined from four locations in the English Channel, one location in the Irish Sea and two locations at the entrance of the Baltic Sea. The branchial chambers of three crabs (one from the English Channel and two from Gullmar Fjord, Sweden) were infested with mussels resembling the genus Mytilus. Sequencing at the Me15/16 locus on the polyphenolic adhesive protein gene confirmed the identity as M. edulis. Bivalve infestation always occurred in larger red male individuals. Up to 16 mussels, ranging from 2 to 11 mm in shell length, were found in each individual, either wedged between gill lamellae or attached to the branchial chamber inner wall. This is one of the first reports of a bivalve inhabiting crustacean gills and is an intriguing case of a normally free-living prey species infesting its predato
Optimized HPLC -UV method for separation, detection and quantification of endocrine disrupting estrogens in low quality water
International Journal of Chemistry; Vol. 9, No. 3Endocrine disrupting estrogens are emerging contaminants in aquatic ecosystems and environment in general. There are
no guidelines for routine monitoring of these chemicals, despite the existing evidences of their adverse health effect to
living organisms at low concentrations. This study aimed at developing and validating an optimized HPLC-UV method
for detection and quantification of estradiol and ethinylestradiol. Isocratic elution was used for separation and detection
of ethinylestradiol and estradiol. The mobile phase was applied with A; water B; acetonitrile (50:50) at flow rate of
0.7mL/min and injection volume 10mL. The precision and accuracy of the method were within the acceptable range.
Relative standard deviation of peak area for E2 ranged from 1.373 to 3.668%, and for EE2 ranged from 0.829 to
6.495 %. The percentage recovery for E2 ranged from 82.3 to 99.84 %, and for EE2 ranged from 84.6 to 103.52 %.
Linearity of the method was realized at range of 2.5 to 50 ng/mL and 100 to 1000 ng/mL for both E2 and EE2. The
linear regression coefficients were 0.9979 and 0.9973 for E2 whereas for EE2 were 0.9983 and 0.9976. Limit of
detection were found to be 0.05 ng/mL and 0.08 ng/mL for E2 and EE2 respectively. The obtained limits of
quantification were 0.18 and 0.28 ng/mL for E2 and EE2 respectively. In untreated sewage the concentrations of E2 and
EE2 were 0.28 ng/ml and 0.18 ng/ml respectively. But in subsequent wastewater stabilization ponds the concentrations
were below detection limit. Therefore, the optimized HPLC-UV method is suitable for detection and quantification of
endocrine disrupting estrogens when a level of pollution is at least 0.15 ng/ml. At low extent of pollution would require
use of the method in conjunction with ELISA technique
Pollution by endocrine disrupting estrogens in aquatic ecosystems in Morogoro urban and peri-urban areas in Tanzania
Academic Journal Vol. 11(2), pp. 122-131This study aimed to assess the extent of pollution of aquatic ecosystems by endocrine disrupting
estrogens particularly the ethinylestradiol (EE2), estrone (E2) and estradiol (E1). The study was carried
out in Morogoro urban and peri-urban areas. The main sources of fresh water for domestic uses, fishing
and agricultural activities in the study areas including the Mindu dam catchment area, Ngerengere and
Morogoro Rivers were assessed. The endocrine disrupting estrogens in water samples were identified
and quantified using competitive Enzyme Linked Immunosorbent Assay (ELISA) kits. The recovery of
estrogens in this study ranged from 65 to 90.22%, the range which is within the acceptable level. The
levels of estrogens in Ngerengere River ranged from non-detectable levels to 0.68, 0.03 to 8.42 and 0.05
to 16.97 ng/L for EE2, E2 and E1, respectively. At Mindu Dam the levels ranged from 0.07 to 0.3 ng/L,
0.41 to 2.1 ng/L and 2.6 to 6.5 ng/L for EE2, E2 and E1 respectively. Furthermore, for Morogoro River the
levels ranged from undetected to 0.92, 0.34 to 9.53 and 0.17 to 11.49 ng/L for EE2, E2 and E1
respectively. Mean concentrations in control samples and those in upstream and midstream of the
rivers were comparable (p > 0.05). But the mean concentrations in downstream portions were
significantly higher than those in control samples (p < 0.05). These concentrations however, were below
those reported in other studies to cause harmful health effects. Hence, the extent of pollution was not
significant enough to cause adverse health effects to aquatic organisms and human