Effects of atrazine herbicide on physiological, biochemical and histological biomarkers of developmental stages of larvae and fry in Caspian kutum, Rutilus frisii kutum

To investigation of the toxic effects of atrazine on newly hatched larvae and releasing age fry of the Caspian Kutum, Rutilus frisii kutum, the 96h LC50 was determined as 18.53 ppm and 24.95 ppm, respectively. Newly hatched larvae were exposed to three sublethal concentrations of atrazine (1/2LC50, 1/4LC50 and 1/8LC50) for 7 days. Different histopathological alterations were observed in fins and integument, gills, Kidney, digestive system, liver and the brain of the exposed larvae. Fry’s were exposed to one sublethal concentration of atrazine (1/2LC50) for four days, and like the larvae’s, many histopathological alterations were observed in fins and integument, gills, Kidney, digestive system, liver and the brain of the exposed fry’s, too. Also, measurements of the body ions: Na+, K+, Ca2+, Mg2+ and Cl- in atrazine exposed larvae and fry’s compare to control groups showed that atrazine is changed the body ions composition. No significant differences were found in length growth rate, weight growth rate and the condition factor of the atrazine exposed larvae and fry. Immunohistochemical localization of the Na+, K+-ATPase in integumentary and gill ionocytes, showed no differences in dispersion pattern of the ionocytes in atrazine exposed larvae and fry, compare to control group. Measuring the dimensions of the ionocytes and counting the ionocytes showed that atrazine is affecting on ionocytes by mild increasing in size and mild decreasing in number. Ultrastructural studies, using SEM and TEM, showed that atrazine have significant effects on cellular and subcellular properties. It caused necrosis in surface of the pavement cells in branchial epithelium, necrosis in endoplasmic reticulum of the ionocytes and changed the shape of the mitochondria in these cells. Results showed that sublethal concentrations of atrazine were very toxic to larvae and fry of the Rutilus frisii kutum, and at these levels can made some serious histopathological alterations in their tissues. Related to the severe histopathological alterations in osmoregulatory organs, like gill, kidney and digestive system, and the alterations in the body ion composition, it could be concluded that atrazine could interfere with the osmoregulation process of the Rutilus frisii kutum at the early stages of the life history.

Effect of Aquathol K Treatments on Activity Patterns of Largemouth Bass in Two Coves of Lake Seminole, Georgia

Thirty largemouth bass ( Micropterus salmoide s Lacepde) were implanted with radio tags in late October 2003 in two coves of Lake Seminole, Georgia, and tracked over a 24-hour period about every 10 days to determine their response to herbicide application. After five weeks of tracking, hydrilla ( Hydrilla verticillata Royle) in each cove was treated in early December 2003 with dipotassium salt of endothall (Aquathol K; 7-oxabicyclo [2.2.1] heptane-2,3-dicarboxylic acid) at a rate of 3.5 ppm. Largemouth bass were tracked during application and tracking continued for three months post treatment to assess effects of herbicide treatment on activity patterns. The treatment in Desser Cove successfully reduced hydrilla in approximately half the cove. However, the treatment in Peacock Lake completely eliminated all submersed aquatic vegetation (SAV) by April 2004. Movement and activity centers remained similar between treatment periods in Desser Cove, but increased after treatment in Peacock Lake. Depth occupied by telemetered fish decreased after Aquathol K treatment in both coves. In general, behavior of largemouth bass did not change appreciably during treatment, and only minor changes were observed in the posttreatment period in Peacock Lake, where all SAV was eliminated. Fish showed little attraction to or movement away from treatment areas, and fish migration from either cove was nil after treatment. Application of Aquathol K and subsequent reduction of SAV had little effect on largemouth bass behavior or movement. (PDF has 8 pages.)

Descriptions of Oscillatoria agardhii, O.prolifera and O.rubescens only [Translation from: Translation from: Flora Slodkowodna Polski. Tom 2. Cyanophyta, Glaucophyta (ed. K. Starmach) p350-352. Warsaw, Polska Academia Nauk, 1966]

Short morphological observations are given for the Cyanophyceae Oscillatoria Agardhii, Oscillatoria prolifica and Oscillatoria rubescens.

Review of investigation on the feeding of the European grayling [Translation from: Flora Slodkowodna Polski. Tom 2. Cyanophyta, Glaucophyta (ed. K. Starmach) p350-352. Warsaw, Polska Academia Nauk, 1966]

The composition of the food of the European grayling and the character of its feeding has been studied fully enough, but this knowledge is scattered in the literature and often contradictory. rare exceptions, analysis of the results of different investigations. Therefore the proposed short outline of the history of the study of the problem with a description of the basic data on the feeding of the grayling in different geographical areas is presented as expedient and opportune, primarily in relation to the determination of immediate problems and the trend of research.

The 66 k-Da protein identified as a light meromyosin is involved in the setting of surimi

The 66 kilo-Dalton (k-Da) protein split off from the cross linked myosin heavy chain (CMHC) formed due to the setting of Alaska pollack surimi, frozen-storage of Pacific cod flesh, and vinegar-curing of Pacific mackerel mince was identified as a light meromyosin (LMM). Puncture and stress-relaxation tests showed that the actomyosin subunits (AMS) of Alaska pollack surimi, upon setting at 30°C, transformed into gel, although the elasticity of this gel was very low when compared to the gels from surimi or actomyosin (AM). Electrophoretic studies showed that the band due to LMM in the gel from AMS gradually disappeared with the progress of setting but higher molecular weight polymer did not form. The intensity of the bands due to other myosin sub-fragments decreased a little. The findings suggest that at setting temperature, LMM of MHC molecule leads to an unfolding resulting in an intramolecular aggregation through non-covalent interactions, and thus plays a significant role in the crosslinking of MHC.

Skipjack tuna (K. pelamis, L.) resources in the seas around Ceylon

Details are given of the source and processing of data, size composition, seasonal variation in occurrence, abundance and oceanic potential of Katsuwonus pelamis resources in the seas around Sri Lanka. The indirect evidences are indicative of the presence of skipjack resource in the oceanic range around the island, particularly the south and west of Sri Lanka.

Suitability of sodium lactate as cryoprotectant and its effect on gel forming ability and protein denaturation of croaker fish surimi during frozen storage

The effect of sodium lactate is compared with sucrose + sorbitol + sodium tri-poly phosphate as cryoprotectant on gel forming ability & protein denaturation of croaker surimi during frozen storage at -20±2°C for 90 days was evaluated. The quality of Croaker surimi with 6% (w/v) sodium lactate was examined in terms of biochemical parameters of muscle protein, thaw drip, gel strength and calcium ATPase activity :.omparing with those of surimi added with sucrose/sorbitol & without additive as control. Both the cryoprotectants minimized the negative effects of frozen storage on physico-chemical traits of myofibrillar proteins which was evident from the biochemical and sensory parameters. The residual Ca2+ ATPase activity and gel strength of surimi with sodium lactate were higher than those of control throughout 90 days of storage. Ca2+ A TPase activity and gel strength found a high positive correlation. From the results, it was found that sodium lactate was equally effective in preservation of croaker muscle protein native structure during frozen storage as the sucrose/ sorbitol and also less sweet without any risk of maillard browning.

Effect of thermal pollution on the hydrological parameters of River Jhelum (J & K)

The Buniyar hydroelectric project and the lower Jhelum Barrier at Gantamulla constructed across river Jhelum are in operation from several years. The two power stations have changed the hydrological features of the area where dam is situated. Therefore, the impact of hydroelectric projects on fishery resources of river Jhelum is a matter of great concern. The treated water from the power house is released through turbines, having cooling effect on them. The change in the hydrological parameters such as increase in temperature, depletion of oxygen etc. might have brought fishes under stress which is the main cause in decreased population of finfishes from site to site. The golden mahseer, Tor putitora which was once an abundant species in river Jhelum has disappeared due to human intervention. The prevailing water quality around hydroelectric projects is unsuitable for finfishes of river Jhelum.