Variation in stable-isotope ratios between fin and muscle tissues can alter assessment of resource use in tropical river fishes.

Carbon and nitrogen stable-isotope ratios were compared of fin and muscle tissue from 15 fish species collected from seven headwater rivers in eastern and western Thailand. In addition, two-source stable-isotope mixing models were used to derive estimates of each fish's reliance on allochthonous and autochthonous energy based on fin and muscle tissues. Across the dataset, fish fin was enriched in C relative to muscle by c.

Garra fluviatilis, a new hillstream fish species (Cypriniformes: Cyprinidae) from the Kwai Noi River system, Mae Khlong basin, Thailand.

Garra fluviatilis is a new species described herein from the Kwai Noi, Mae Khlong basin, in the Thong Pha Phum District of Kanchanaburi Province in western Thailand. It is diagnosed by the following combination of morphological characters: well developed upper lip with unculiferous papillae, mottled pigmentation pattern, a pleated papilliferous fold at the junction of the anterolateral lobe and anteromedial fold on the lower lip, 4-5 anal scales, relatively deep body, keeled nape, and a laterally straight anterior margin of the anteromedial fold. Based on shared apomorphic morphological characters, we hypothesize that the new species is most closely related to G.

Acute and subchronic toxicity of metal complex azo acid dye and anionic surfactant oil on fish Oreochromis niloticus.

The acute toxicity study of metal complex dark green azo acid dye, anionic surfactant oil and their mixture determined the 96 hr LC50, and fish behaviours. Subchronic toxicity determined haematology parameters and concentrations of copper and chromium in blood. The 96 hr LC50 was determined by probit analysis and subchronic toxicity was conducted in 90 days.

Effects of Wheat Naturally Contaminated with Fusarium Mycotoxins on Growth Performance and Selected Health Indices of Red Tilapia (Oreochromis niloticus × O. mossambicus).

An 8-week feeding trial was conducted to examine effects of wheat naturally contaminated with Fusarium mycotoxins (deoxynivalenol, DON 41 mg·kg(-1)) on growth performance and selected health indices of red tilapia (Oreochromis niloticus × O. mossambicus; initial weight = 4.3 g/fish).

Cytochrome P450 1A activity in liver and fixed wavelength fluorescence detection of polycyclic aromatic hydrocarbons in the bile of tongue-fish (Cynoglossus acrolepidotus, Bleeker) in relation to petroleum hydrocarbons in the eastern Gulf of Thailand.

This investigation was conducted in an area of oil spill along the east coast of Thailand to examine the relations among cytochrome P450 1A activity in liver and PAHs in the bile of the tonguefish and petroleum hydrocarbons in the sediments. PAH sediment concentrations in the reference and oil spill areas were 5.03 +/- 0.

Evidence for 15alpha- and 7alpha-hydroxylase activity in gonadal tissue of the early-life stages of sea lampreys, Petromyzon marinus.

Gonads of premetamorphosing larval (PML), transforming (TL) and newly metamorphosed (juvenile) sea lampreys (JL) (Petromyzon marinus) were incubated in vitro with tritiated pregnenolone ([(3)H]P(5)), progesterone ([(3)H]P(4)), and androstenedione ([(3)H]A(4)) to identify the major products of steroidogenesis in early developmental stages. Reverse-phase high-performance liquid chromatography, using two mobile phase gradients, was used to separate the radioactive steroid metabolites. 7alpha-Hydroxylase activity was evident, based on the loss of radioactivity from [(3)H]P(5) labelled at position 7, appearing as tritiated water, and on the appearance of radiolabelled 7alpha-hydroxypregnenolone in the incubation medium.

Blood steroid profile and in vitro steroidogenesis by ovarian follicles and testis fragments of adult sea lamprey, Petromyzon marinus.

The main purpose of the study was to identify the principal gonadal steroids synthesized by male and female sea lampreys, Petromyzon marinus. To achieve this, we used high performance liquid chromatography to separate the steroids in the serum of sexually mature animals, and to separate the steroids produced by gonadal tissue incubated in the presence of radiolabelled precursor steroids, as a means of identifying the major steroidogenic pathways. We were unable to detect evidence of the 'classical' steroids, such as 17beta-estradiol (E(2)) or testosterone (T) in the serum of either male or female lampreys.

Dietary essential amino acids and heat increment in rainbow trout (Oncorhynchus mykiss).

Oxygen consumption attributable to apparent heat increment (AHI) was measured in relation to varying essential amino acid proportions (EAA) infused into rainbow trout,Oncorhynchus mykiss (250-450 g), induced to swim at ≈1 BL s(-1). Five diets, mimicking EAA concentrations in trout whole body protein, deficient in the branched chain amino acids (isoleucine, leucine and valine), containing unbalanced proportions of EAAs and supplying lysine in excessive and limiting proportions, were tested. Following infusion of the experimental diets, a significant increase in oxygen consumption was observed.

Dietary carbohydrate and growth, body composition and heat increment in rainbow trout (Salmo gairdneri).

A study was conducted to determine growth, body composition and heat increment (HI) of rainbow trout reared on isonitrogenous high digestible carbohydrate (HC) and high fat (HL) diets at 15°C. Trout reared on the HC diet had a significantly lower final body weight and carcass lipid content and a significantly higher feed:gain ratio and carcass protein content than trout reared on the HL diet after 12 weeks on the test diets. The lower carcass lipid composition indicates that trout do not readily convert dietary carbohydrates into fat.

Diurnal impact of locomotory activity and melatonin and N-acetylserotonin treatment on blood metabolite levels in the rainbow trout.

In rainbow trout forced to swim continuously at sustained speeds for six weeks, selected doses of melatonin or N-acetylserotonin (1.25 and 5.0 mg/kg body weight) injections caused no change in haematocrit.

Bioenergetics of acclimation to permethrin (NRDC-143) by rainbow trout.

Metabolic rates associated with sustained, prolonged and critical swimming speeds were examined in 10 g trout exposed to 5% 96 hr LC50 (0.75 microgram X l-1) and 10% 96 hr LC50 (1.50 micrograms X l-1) at 12 degrees C.

Specific dynamic action and diet in largemouth bass, Micropterus salmoides (Lacépède).

Apparent specific dynamic action (SDA) in largemouth bass (5-28 g) was equated to oxygen uptake subsequent to the ingestion of a meal. The effects of six diets on apparent SDA were investigated, one balanced or standard diet and five consisting of different proportions of protein and carbohydrate. Apparent SDA was positively related to gross energy ingested and to the level of dietary protein.

Effect of vasotocin on plasma free fatty acid level in the migrating anadromous sea lamprey.

The effect of injections of arginine vasotocin (AVT) on plasma free fatty acid (FFA) levels was studied in anadromous sea lampreys collected in the St. John River, New Brunswick, during their upstream spawning migration. Plasma FFA was significantly higher in lampreys injected with a single dose of 1 000 mU vasotocin/kg body weight than in those receiving only the vehicle solution, the difference being the greater at 90 than at 30 min post-injection.

Structure and ultrastructure of the pituitary gland in the sea lamprey, Petromyzon marinus at different stages in its life cycle.

The structure and fine structure of the pituitary gland in the sea lamprey, Petromyzon marinus L., are described at all major stages in the life cycle. Synthetically active adenohypophysial cells are evident in even the smallest ammocoetes examined (body length 2.

A critical review of atomic absorption, spectrochemical, and x-ray fluorescence methods for the determination of the noble metals--II.

The review is a continuation of the initial reviews and covers the period of abstracting up to and including April, 1967. Work on the atomic-absorption determination of noble metals is also included.

Study of osmium and ruthenium distillation with radioactive tracers.

The distillation characteristics of osmium and ruthenium, which have been studied by using both radioactive tracers and inactive compounds, are reported. The tracer solutions were prepared from hexachloro and hexabromo compounds and from the purified sponges of both metals. A quantitative separation of osmium from ruthenium can be made by distillation from peroxide-sulphuric acid solution at 110 degrees for about 40 min.

Isolation of osmium and ruthenium by ionexchange paper and subsequent determination by X-ray fluorescence.

Quantitative separations of microgram quantities of osmium and ruthenium from large proportions of copper, iron and nickel were accomplished by the use of anion-exchange paper. Accurate determinations of osmium and ruthenium were made by adaptation of X-ray fluorescence. Wet methods for the dissolution of the paper and exchanger and subsequent wet determinations of osmium and ruthenium are discussed.

A critical review of methods of isolating and separating the noble metals-III Chromatography, precipitation and fire assay.

This review deals with the chromatographic, precipitation and fire-assay methods of separating the seven noble metals, published subsequent to the previous reviews and prior to January 1966. The noble metal species present in solution are discussed in so far as they relate to separation and determination.

A critical review of methods of isolating and separating the noble metals--II. Ion-exchange and solvent extraction.

This review deals with ion-exchange and solvent extraction methods of separating the seven noble metals, published subsequent to the previous reviews and prior to January 1966. The noble metal species present in solution are discussed in so far as they relate to separation and determination.