Notes on the Husbandry and Long‐Term Transportation of Bull Ray (Pteromylaeus bovinus) and Dolphinfish (Coryphaena hippurus and Coryphaena equiselis)

Bull rays (Pteromylaeus bovinus) and Dolphinfish (Coryphaena hippurus and Coryphaena equiselis) were collected in Olhão (south of Portugal). These animals hosted multiple parasites, namely Caligus spp., and underwent a variety of treatments to remove them. Of all treatments tested, hydrogen peroxide showed the best results, although only concentrations above 100 ppm were effective in parasite removal. These high concentrations, however, proved to be highly toxic for the fish and led to the loss of some animals, especially those which had been handled before treatment. A total of 14 Bull rays were transported to Bolougne‐Sur‐Mer (France) by road and some animals were lost, which was attributed to excessive time in transit (>45 hr). In another transport, three Bull rays and 10 Dolphinfishes were moved to Stralsund (Germany) by road and air. The mechanical wounds suffered by one of the Bull rays during transport led to its death and, consequently, a deterioration of water quality in the tank containing two other conspecifics. This deterioration of water quality resulted in problems for the other two Bull rays, and one perished approximately 48 hr after arrival. The authors concluded that Dolphinfish can be transported with a low bioload for at least 27 hr, and Bull rays should not undergo transports longer than 35 hr. Special attention must be taken to injured animals, since this can lead to a decrease in water quality and consequently affect other animals in the same transport tank. Zoo Biol. 32:222–229, 2013. © 2012 Wiley Periodicals, Inc.     

Growth and physiological parameters of whiting (Sillaginodes punctata) in relation to salinity

This study assessed the impact of salinity on whiting (Sillaginodes punctata) in an attempt to understand the mechanisms by which salinity could potentially influence habitat selection and growth of King George whiting in southern Australia. The experiment included whiting of two age classes, young of the year (YOY) and 2⁺ year, at three salinities (30, 40, 50 ppt). YOY whiting showed no significant difference in length or weight gain, specific growth rate, feed intake, food conversion ratio or condition factor when exposed to the three salinities for 72 day. Plasma osmolality of YOY whiting was not significantly different at any salinity, although it was significantly lower than that of 2⁺ year whiting. The 2⁺ year whiting showed significantly higher plasma osmolality than the YOY. Blood plasma potassium and chloride levels of 2⁺ year fish at 50 ppt were significantly higher than those at 30 ppt and 40 ppt. Blood sodium levels at 50 ppt were significantly higher than at 30 ppt but the sodium level at 40 ppt was not different from 30 ppt or 50 ppt. Haematocrit of 2⁺ whiting was significantly higher at 30 than at 50 ppt while haematocrit at 40 ppt was not different from 30 or 50 ppt. The 2⁺ year‐old whiting had a more pronounced increase in plasma osmolality and plasma ions at high salinities, indicating poorer osmoregulatory capacity in older fish. This study provides physiological evidence to partially explain habitat occupancy and growth in relation to salinity of different age groups of whiting in southern Australia.     

Long‐term transportation,by road and air,of Devil‐ray (Mobula mobular), Meagre (Argyrosomus regius), and Ocean Sunfish (Mola mola)

Between September 2006 and April 2007 the authors transported one 0.9 m wingspan Mobula mobular from Olhão (South of Portugal) to Valencia (East of Spain), 12 ∼1.0 m long Argyrosomus regius to Tarragona (Northeast of Spain) and four ∼0.4 m long Mola mola to Atlanta (GA, USA). These journeys had a total “water to water” duration of 17, 22 and 33 hr, respectively. The first two transports were conducted by road whereas the third involved a combination of road and air travel. Water quality parameters—specifically dissolved oxygen, temperature, pH and ammonia—were monitored continuously throughout the duration of the trips and were maintained at optimum levels through the use of battery‐powered filtration and chemical supplements. All animals arrived alive and well at their destinations. This paper reports on the specific transport regime adopted in each case and provides some insight for potential improvements in future similar transports. Zoo Biol 27:234–250, 2008. © 2008 Wiley‐Liss, Inc.     

Photosynthetic and respiratory electron transport in the alkaliphilic cyanobacterium Arthrospira (Spirulina) platensis

Photosynthetic and respiratory electron transport and their interplay with ion transport have been studied in Arthrospira platensis, a filamentous alkaliphilic cyanobacterium living in hypersaline lakes. As typical for alkaliphiles, A. platensis apparently does not maintain an outward positive pH gradient at its plasma membrane. Accordingly, sodium extrusion occurs via an ATP-dependent primary sodium pump, in contrast to the Na⁺/H⁺ antiport in most cyanobacteria. A. platensis is strongly dependent on sodium/bicarbonate symport for the uptake of inorganic carbon. Sodium extrusion in the presence of the Photosystem II inhibitor diuron indicates that a significant amount of ATP is supplied by cyclic electron transport around Photosystem I, the content of which in A. platensis is exceptionally high. Plastoquinol is oxidized by two parallel pathways, via the cytochrome b ₆ f complex and a putative cytochrome bd complex, both of which are active in the light and in the dark. This revised version was published online in August 2006 with corrections to the Cover Date.     

Phenology of Paralemanea mexicana (Batrachospermales,Rhodophyta) in a high‐altitude stream in central Mexico

The morphology and phenology of Paralemanea mexicana (Kützing) Vis et Sheath was evaluated seasonally in a fifth order high‐altitude stream in central Mexico. The gametophytes grew during oligotrophic and eutrophic conditions, and during particular microhabitat conditions: high current velocity (40–240 cm s^?1), low to medium irradiance (5–973 μmol photons m^?2 s^?1), and shallow depth (1–30 cm). The abundance of gametophytes was positively correlated with low temperature, high current velocity and concentrations of soluble reactive phosphorus. Interestingly, monoecious gametophytes formed two types of branches, true branches with sympodial pattern originating from meristematic cells in variable number, and abundant false branches produced during the development of the ‘Chantransia’ stage in the surface of the gametophyte or by uniseriate filaments arising within the thallus lumen. These filaments generally produce gametophytes and suggest that they could support the germination of carpospores. The frequently whorled branches are the result of a false branching pattern and are exclusive to P. mexicana. These morphological and reproductive characteristics appear to be biomechanical adaptations to avoid detachment and increase reproductive success. Efficient reproductive strategies of P. mexicana observed in this study can be interpreted as adaptations to successfully colonize streams; however, these features may not have been common in the study region due to restricted microhabitat conditions and geographic isolation.     

Effects of Tetraethylammoniumchloride (TEA), Vanadate,and Alkali Ions on the Lateral Leaflet Movement Rhythm of Desmodium motorium (Houtt.) Merr

The period (～3-5 min) of the ultradian rhythm of the lateral leaflet movement of Desmodium motorium is strongly lengthened (≤30-40%) by the K⁺ channel blocker tetraethylammoniumchloride (20, 30, and 40 mM) and vanadate (0.5 and 1 mM), which is an effective inhibitor of the plasma membrane-bound H⁺ pump. The alkali ions K⁺, Na⁺, Rb⁺, and Cs⁺ (10-40 mM) shorten the period only slightly (≤ 10–15%). Li⁺ (5-30 mM), however, increases the period of the leaflet rhythm drastically (≤80%). We concluded that the plasmalemma-H⁺-ATP-ase-driven K⁺ transport through K⁺ channels is an essential component of the ultradian oscillator of Desmodium, as has been proposed for the circadian oscillator.     

Influence of sodium selenite on203Hg absorption,distribution, and elimination in male mice exposed to methyl203Hg

To study the effects of long-term selenium supplementation on absorption, distribution, and elimination of methylmercury (MeHg) in mice, three groups of male mice (Balb/c CA) were exposed for 7 wk to 0, 0.6, and 3 ppm sodium selenite in tap water. They were then given a single oral dose of Me²⁰³Hg (2 μmol/kg) by gastric intubation, and elimination of²⁰³Hg was followed by whole-body counting for 49 d at the same Se exposure as previously. Twenty-four hours and 49 d after dosage, 6–7 animals/group were sampled for analysis of²⁰³Hg distribution in the body. Glutathione peroxidase (GSH-PX) activity in blood and selenium levels in the liver were used as measures of selenium status. Gastrointestinal absorption of Me²⁰³Hg was not influenced by the Se status of the animals. Selenium supplementation of MeHg-exposed mice caused an enhanced whole-body elimination of Hg, but selenium-supplemented animals did not have lower Hg levels in the brain and kidney than nonsupplemented animals. The effect of selenium on the accumulation, of Hg in the brain was dose-dependent, a high dose (3 ppm Se) causing a higher initial accumulation of Hg. The intracellular distribution of²⁰³Hg in the liver and kidney was not affected by Se. The results indicate that selenium treatment of MeHg-exposed mice may have a positive effection the health of the animals by decreasing the total body burden of MeHg.     

Influence of phosphate and zinc on growth,nodulation and mineral composition of chickpea (Cicer arietinum L.) under salt stress

Zn²⁺ at 5 ppm and phosphate at 20 and 40 ppm improved the growth and nodulation of chickpea (Cicer arietinum L.) at two levels of salinity (4.34 and 8.3 dS m^–1). Augmentation with Zn²⁺ at 5 ppm provided protection to the plant under saline conditions by reducing the Na⁺:K⁺ ratio in the shoot. The shoot nitrogen content with 5 ppm Zn²⁺ and 20 ppm phosphate was equal to that of a non-saline control. No significant effect on nitrogenase activity was observed.     

The interrelationships between sodium ion,calcium transport and oxygen utilization in the isolated chick chorioallantoic membrane

Summary The interrelationships between sodium ion, calcium transport and oxygen utilization have been investigated in the chick chorioallantoic membrane. The oxygen uptakes of the two surface layers of the tissue, the ectoderm and the endoderm, were separated into their basal, Na⁺ dependent and Ca⁺⁺ dependent components. The endoderm has a basal rate of respiration of 3.6 liters O₂/cm²/hr and a Na⁺ dependent component of 1.4 liters O₂/cm²/hr. The ectoderm has a basal rate of respiration of about 3.5 liters O₂/cm²/hr, and Na⁺ and Ca⁺⁺ dependent components of 1.1 and 3.6 liters O₂/cm²/hr, respectively. The rate of ectodermal calcium transport and calcium-stimulated oxygen uptake is strictly dependent on the presence of sodium in the bathing medium, and complex kinetics are observed as a function of sodium concentration. On the other hand, in 140mm Na⁺ the rate of calcium transport exhibits simple saturation kinetics as a function of calcium concentration. Ca⁺⁺/O₂ ratios determined for many different rates of transport give a ratio of about 0.5, a value much lower than similar ratios determined for other transport mechanisms. The calcium transport mechanism in the ectoderm responds to changes in transport rate very sluggishly, taking 30 to 50 min to give a maximum response. The differences between the calcium transport mechanism in this membrane and other known transport systems are discussed and it is suggested that these differences may represent the adaptations necessary for transcellular calcium transport.     

Changes from High Potassium (HK) to Low Potassium (LK) in Bovine Red Cells

Red cells of newborn calves contain 105–110 mmole K⁺ and 1–5 mmole Na⁺ per liter of cells. As the animals age the K⁺ content decreases to a value of 25–30 mmole/liter of cells after about 60 days. At approximately the same time, the sodium content reaches a value of 60–70 mmole/liter. The time required for half change (t_½) is 35–37 days for both Na⁺ and K⁺. The activity of (Na + K)-adenosine triphosphatase (ATPase) and the influx of K⁴² and Rb⁸⁶ into the red cells are high at birth and are reduced to 5 and 15% of their original values, respectively, in mature animals. t_½ for both is of the order of 30–35 days. The membrane Mg-ATPase activity is also high at birth and is reduced with a t_½ of 28–32 days to a final value of about 20% of its activity at birth. Separation of red cells according to their age showed that, in animals at the age of transition, newly formed red cells contain a higher K/Na ratio and a higher active transport capacity than older red cells of the same animal. It is suggested that the changes observed are a reflection of the average age of the red cell population as the animal grows.     

Antigen-specific stimulation of amino acid transport in bovine lymphocytes

Treatment of bovine lymphocytes isolated from animals which were either infected with Mycobacterium bovis or sensitized to a purified protein derivative (PPD-B) from this organism induced an increase in the transport of α-aminoisobutyric acid (AIB) and α-methylaminoisobutyric acid (MeAIB). PPD-B did not stimulate these transport activities in lymphocytes from nonsensitized animals. The transport stimulation was first measurable after about 7 hours of treatment, reached about a two-fold enhancement after 20 hours, and continued to increase to 30- to 40-fold after 6 days. The stimulation of AIB transport was inhibited by both ouabain and cycloheximide. Experiments to determine transport system specificities in nonstimulated lymphocytes showed that MeAIB transport was primarily by the Na⁺-dependent, A-system, and leucine transport was mostly by Na⁺-independent system(s). In contrast, AIB transport was about 25% by the A-system, 25% by at least one Na⁺-dependent, non-A-system, and 50% by one or more Na⁺-independent system(s). Analysis of the three components of AIB transport after treatment with PPD-B showed that: (1) transport by both the A-system and the Na⁺-independent system(s) was stimulated; (2) A-system transport was stimulated to a larger extent than Na⁺-independent transport; and (3) Na⁺-dependent, non-A-system transport was not stimulated significantly.     

Fluoride in tissues of Krill Euphausia superba Dana and Meganyctiphanes norvegica M. Sars in relation to the moult cycle

Summary The fluoride content of whole animals and different tissues of the euphausiid species Euphausia superba and Meganyctiphanes norvegica was analyzed by two different and improved methods of isolation and determination. In contrast to other authors our findings show that the internal organs (muscle, hepatopancreas and hemolymph) contain less than 6 ppm d.w. fluoride this being the same order of magnitude as for vertebrates. The high concentrations reported by other authors must be mainly due to contamination of the soft tissue during storage (post-mortem migration of fluoride from shell) and/or contamination caused by minute fractions of cuticle during dissection. Over 99% of the total fluoride content is located in the cuticle (i.e. integument) of the euphausiids (2600 ppm/d.w. in E. superba and 3300 ppm/d.w. in M. norvegica in pleon cuticle). Analysis of F^- levels in relation to the moulting cycle showed that the uptake in both euphausiids occurs at a comparable and fast rate during the same physiological phase shortly after moult, parallel to the general construction of the cuticle. The internal organs show homeostasis in respect to fluoride. Accordingly, no internal deposition takes place, and F^- is reaccumulated from the external medium at each moult.This work was supported by grants from the DFG No. Ad 24/9 and Bu 548/1     

Transport Speed of the Mucous Feeding Filter in Clavelina lepadiformis (Aplousobranchiata,Tunicata)

The transport speed of latex spheres trapped in the mucous feeding filter of 30 specimens of Calvelina lepadiformis (Müller 1776) was measured by microscopical examination and a stop watch. The speed across the gill screen increased from 24 μm s^?1 in small animals to 220 μm s^?1 in large ones. The net translocation speed of the food roll behind the dorsal Lamina was generally much slower but revealed a similar trend (7–78 μm s^?1). The increased feeding filter speed in larger animals was parallelled by an increased branchial circumference in such a way that the duration of water filtration through each part of the filter remained almost constant (between 38 and 56 s as means for all groups of animals). The amount of filter secreted by large animals approached 150 cm² h^?1 or 2.5 m² week^?1. Based on available data on water filtration rates it could be calculated that the speed of water through the filter was of the same order of magnitude as the observed translocation speed of the filter.     

The antimutagenic effect of selenium on 7,12-dimethylbenz(a)anthracene and metabolites in the amesSalmonella/microsome system

The antimutagenic effect of selenium as sodium selenite, sodium selenate, selenium dioxide, and seleno-methionine was studied in the AmesSalmonella/microsome mutagenicity test using 7,12-dimethylbenz(a)anthracene (DMBA) and some of its metabolites. Selenium (20 ppm) as sodium selenite reduced the number of histidine revertants on plates containing up to 100 μg DMBA/plate. Increasing concentrations of selenium as sodium selenite, sodium selenate, and selenium dioxide up to 40 ppm Se progressively decreased the number of revertants caused by 50 μg DMBA. DMBA and its metabolites 7-hydroxymethyl-12-methylbenz(a)anthracene, 12-hydroxymethyl-7-methylbenz(a)anthracene, and 3-hydroxy-7,12-dimethylbenz(a)anthracene were mutagenic forSalmonella typhimurium TA100 in the presence of an S-9 mixture. Selenium supplementation as Na₂SeO₃ reduced the number of revertants induced by these metabolites to background levels. The antimutagenic effect of inorganic selenium compounds cannot be explained by toxicity of selenium as determined by viability tests withSalmonella typhimurium TA100. Selenium supplementation in all forms examined, except sodium selenate, decreased the rate of spontaneous reversion. Selenium as sodium selenate was slightly mutagenic at concentrations of 4 ppm or less. Higher concentration of Na₂SeO₄ inhibited the mutagenicity of DMBA. The present studies support the anticarcinogenic potential of selenium and indicate that form and concentration are important factors in this trace element's efficacy.     

The effect of 2-chloro, 6-(trichloromethyl) pyridine on the chemoautotrophic metabolism of nitrifying bacteria

Studies were conducted to elucidate the mechanism of action of 2-chloro-6-(trichloromethyl)pyridine or Technical N-SERVE on the nitrification process brought about byNitrosomonas europaea. The growth ofNitrosomonas was completely inhibited in the presence of 0.2 ppm N-SERVE while 1.0 ppm of the chemical was effective in the complete inhibition of ammonia oxidation by fresh cell suspensions. Cells stored at 4 C for a period of three days required somewhat higher concentrations (1.5 ppm) of N-SERVE for the complete inhibition of their ammonia oxidizing ability while the cytochrome oxidase of these cells was inhibited to the extent of 65 to 70 percent in the presence of a corresponding amount of N-SERVE. A 45 – 70 percent reversal of the inhibition of ammonia oxidation caused by N-SERVE was obtained by the addition of 6×10^–4 M Cu⁺⁺. An equivalent concentration of Cu⁺⁺ was also effective for the complete reversal of the inhibition of cytochrome oxidase present in whole cells.Hydroxylamine oxidation by intactNitrosomonas cells was not affected by levels of N-SERVE ranging from 1 – 3 ppm. The cytochrome oxidase effective in hydroxylamine oxidation and present in cell-free extracts was not inhibited by even 100 ppm N-SERVE. Likewise, the hydroxylamine activating enzyme hydroxylamine cytochromec reductase was also not inhibited by such levels of the chemical. Raising the concentration to 170 ppm N-SERVE, however, caused a 90 percent inhibition of the enzyme.Although a 5×10^–6 M concentration of allylthiourea completely inhibited ammonia oxidation byNitrosomonas cells, concentrations up to 10^–3 M of this compound did not affect the cytochrome oxidase activity of whole cells or cell-free extracts. The inhibition of ammonia oxidation caused by 5×10^–6 M allythiourea, unlike the inhibition by N-SERVE, could not be reversed by the addition of 6×10^–4 M Cu⁺⁺.Evidence is presented that the action of N-SERVE is on that component of cytochrome oxidase which is involved in ammonia oxidation.     

Characterization of equilibrative and concentrative Na+-dependent (cif) nucleoside transport in acute promyelocytic leukemia NB4 cells

Nucleoside transport processes can be classified by the transport mechanism, e = equilibrative and c = concentrative, by the sensitivity to inhibition by nitrobenzylthioinosine (NBMPR), s = sensitive and i = insensitive, and also by permeant selectivity. To characterize nucleoside transport in acute promyelocytic NB4 cells, nucleoside transport was resolved into different components by selective elimination of transport processes with NBMPR and with Na⁺-deficient media. Initial transport rates were estimated from time course experiments. For adenosine, uridine, and formycin B, equilibrative transport accounted for approximately 60% of their uptake, with ei and es transport contributing almost equally, and Na⁺-dependent transport accounting for the remaining 40% of the total uptake. Thymidine uptake was mediated exclusively by equilibrative systems with ei and es systems each contributing 50% to total uptake. Adenosine accumulated above equilibrative concentrations, suggesting that a concentrative transport process was active and/or that metabolism led to adenosine's accumulation. Formycin B, a nonmetabolizable analog, also accumulated in the cells, supporting the concentrative potential of the Na⁺-dependent transporter. Kinetic analyses also provided evidence for three distinct high affinity transport mechanisms. NBMPR binding assays indicated the presence of two high affinity (K_m 0.10 and 0.35 nM) binding sites. In conclusion, NB4 cells express ei and es transport, as well as a large ci transport component, which appears to correspond to cif (f = formycin B or purine selective) nucleoside transport, not previously described in human cells. © 1996 Wiley-Liss, Inc.     

Effect of Selenium,Zinc, and Copper Supplementation on Blood Metabolic Profile in Male Buffalo (<Emphasis Type="Italic">Bubalus bubalis</Emphasis>) Calves

Twenty male buffalo calves (15 months, 200.2 ± 9.75) were divided into four groups of five animals in each and fed diets without (T1) or supplemented with 0.3 ppm selenium (Se) + 40 ppm zinc (Zn) (T2), 0.3 ppm Se + 40 ppm Zn + 10 ppm copper (Cu) (T3), and 40 ppm Zn + 10 ppm Cu (T4) for 120 days, during which blood samples were collected on days 0, 40, 80, and 120. Concentrations of glucose, total protein, albumin, globulin, urea, uric acid, and creatinine were similar in all the four groups. The level of different serum enzymes viz. lactate dehydrogenase, alkaline phosphatase, glutamate pyruvate transaminase, and glutamate oxaloacetate transaminase, and hormones viz. T₃, T₄, testosterone and insulin were similar (P > 0.05) among the four groups but the ratio of T₄/T₃ was reduced (P < 0.05) in the groups (T2 and T3) where selenium was supplemented at 120th day of supplementation. It was deduced that supplementation of 0.3 ppm Se and/or 10.0 ppm of Cu with 40 ppm Zn had no effect on blood metabolic profile in buffalo calves, except the ratio of T₄ and T₃ hormone which indicates that selenium plays an important role in converting T₄ hormone to T₃ which is more active form of thyroid hormone.     

Reduction of Cr(VI) by Desulfovibrio vulgaris and Microbacterium sp.

Many industrial wastes contain Cr(VI), a carcinogen and mutagen, the toxicity of which can be ameliorated by reduction to Cr(III). Microbacterium sp. NCIMB 13776 andDesulfovibrio vulgaris NCIMB 8303 reduced Cr(VI) to Cr(III) anoxically using 25 mM sodium citrate buffer (pH 7), with 25 mM sodium acetate and 25 mM sodium formate as electron donors at 30 °C, under which conditions the rates of reduction of 500 M sodium chromate were 77 and 6 nmol h^–1 mg dry cell wt for D. vulgaris and Microbacterium sp., respectively, these being increased to 127 and 17 nmol h^–1 mg dry cell wt in the presence of 20 mM MOPS/NaOH buffer.     

SHORT-TERM IMPACTS OF FORMULATIONS OF BACILLUS THURINGIENSIS VAR. ISRAELENSIS DE BARJAC AND THE ORGANOPHOSPHATE TEMEPHOS,USED IN BLACKFLY (DIPTERA: SIMULIIDAE) CONTROL,ON RHEOPHILIC BENTHIC MACROINVERTEBRATES IN THE MIDDLE ORANGE RIVER,SOUTH AFRICA

Summary

The impacts of larvicides used in the control of blackflies (Diptera: Simuliidae) on macroinvertebrates in the stones-in-current biotope were assessed during 8 field trials in the middle Orange River, South Africa. Two Bacillus thuringiensis var. israelensis (B.t.i.) products (Vectobac^R 12AS and Teknar^R HP-D) and the organophosphate temephos (Abate^R 200EC) were applied at recommended and high dosages to simulate “operational” and “worst-possible” scenario's respectively. Mortality was evaluated either by direct counting of invertebrates on stones before and after application, or by ranking invertebrates on a 4-point relative abundance scale before and after application. In addition, the re-appearance of benthic invertebrate population densities after temephos application was examined.

At the recommended dosage (1.2 ppm/10 min), B.t.i. significantly reduced blackfly larval numbers (P<0.001) and those of the chironomid Rheotanytarsus fuscus Freeman (P<0.05). At high dosage (20 ppm/10 min), numbers of the filter-feeding mayfly Tricorythus discolor (Burmeister) (P<0.01) and the chironomid Cardiocladius sp. (P<0.05) were also significantly reduced. No Simulium predators were directly affected by B.t.i., but there were indications of food shortage amongst Hydropsychidae and Hirudinea.

Temephos caused significant reductions in the relative abundance of 5 taxa at 0.05 ppm, 3 to 6 taxa at 0.1 ppm, and 9 taxa at 1.0 ppm (P<0.05). “Non-target” organisms which were most affected included the chironomid R. fuscus, the mayflies Baetis glaucus Agnew and Choroterpes elegans Barnard, and the caddisflies Cheumatopsyche thomasseti Ulmer and Amphipsyche scottae Kimmins. The mayfly T. discolor was tolerant of temephos, even at high dosage (1.0 ppm/10 min). In winter, most taxa re-appeared within 19 days, and population densities were back to pre-treatment levels within 35 days.

It is concluded that good reduction of blackfly populations may be obtained with minimal direct impact on the “non-target” fauna, provided recommended dosages of temephos are not exceeded. Overdosing with temephos may result in high mortality of “non-target” organisms, including blackfly predators, and should be avoided.