bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acute toxicology to an estuarine teleost of mixtures of cadmium, copper and zinc salts
Authors: Eisler Ronald , Gardner George R. 
Published: January 2006

Effects of mixtures of chloride salts of cadmium, copper and zinc on survival, whole body residues, and histopathology of mummichog, Fundulus heteroclitus (L.), were investigated in synthetic sea water at 20‰ salinity and 20°C. Mixtures of Cu2+ and Zn2+ as indicated by 96 h bioassay studies produced more deaths than expected on the basis of toxicities of individual components. Concentrations of Cd2+ not ordinarily lethal exerted a negative effect on survival of fish intoxicated by salts of copper, zinc, or both.Atomic absorption determinations of Cd, Cu, and Zn residues in mummichog which survived 96 h exposures to each of these toxicants provided useful indices of total body burdens for these metals. Residues from survivors held in mixtures, especially Cd2+ and Zn2+ mixtures, did not conform to patterns observed for single elements. Whole body aggregates of Cd, Cu, and Zn from dead mummichogs were of limited worth owing to possible accumulation of these metals from the medium after death.Renal and lateral line canal lesions were noted in all fish subjected to copper concentrations of 1 mg/1 and higher. Renal lesions observed in fish immersed in mixtures of Cu2+ and Cd2+ assumed a damage pattern characteristic of Cd2+; with mixtures of Cu2+ and Zn2+, lesion were typical of Cu2+‐induced damage. Lesions induced in lateral line epithelium by Cu2+ were not affected by either Cd2+ or Zn2+. Epithelia lining the oral cavity were necrotized by the caustic action of high levels of Zn2+ (60 mg/1) and of Cu2+ (8 mg/1).
Growth increments and some flesh and gonad characteristics of juvenile coho salmon receiving diets supplemented with 17α‐methyltestosterone
Authors: Fagerlund U. H. M. , McBride J. R. 
Published: January 2006

Juvenile coho salmon Oncorhynchus kisutch (Walbaum) received a diet of Oregon Moist Pellets supplemented with either 10, 1, 0.2 or 0 ppm of 17α‐methyltestosterone for 72 weeks. The fish were held in fresh water during the first 57 weeks and in salt water during the remaining time of the study. At the end of the fresh water residency, the fish receiving 10 and 1 ppm of steroid showed a net increase in weight of 125 and 71 % respectively over the controls. Both test groups also gained in length, but the 10 ppm group gained proportionately less, which resulted in a thicker body. After transfer to salt water at the normal time of smolting, there was a decrease in the rate of growth in weight and length of the two groups receiving the high doses of steroid. The decrease was most noticeable in the 10 ppm group and a number of mortalities occurred in this group.Testes of fish receiving 10 ppm of the steroid became hypertrophied and later degenerated with loss of spertnatogonia; the ovaries were not affected. 17α‐methyltestosterone fed at 10 ppm for 49 weeks increased the lipid content of the flesh from 2.4 to 3.5 % and decreased the amount of flesh from 35.0 to 28.5 % of body weight. No change in the moisture content was found. External changes noted in the 10 ppm group included loss of silvering, deepening of the body, particularly in the region of the anal fin, and widening of the lower jaw.
The effects of starvation and force‐feeding on the metabolism of the Northern pike, Esox lucius L.
Authors: Ince Bernard W. , Thorpe Alan 
Published: January 2006

The effects of starvation and force‐feeding on certain tissue and blood constituents were studied in the Northern pike, Esox lucius L. Starvation resulted in a reduction of liver and muscle glycogen and liver lipid. Blood glucose concentration and haematocrit were reduced, total plasma cholesterol levels were increased, while the levels of plasma free fatty acids (FFA), amio acid nitrogen and protein remained unaltered. No significant changes were observed in either muscle protein, muscle water or the response to amino acid loading during the starvation period.The force‐feeding of pike starved for 3 months resulted in liver lipid and muscle glycogen being increased to levels higher than those observed in freshly‐captured fish. Liver glycogen, however, increased to values only slightly higher than those of starved animals. Furthermore, while force‐feeding had little effect on plasma FFA or protein concentrations, blood glucose, plasma cholesterol and haematocrit returned to the levels found in freshlycaptured fish and those of amino acid nitrogen were higher.The results indicate that pike are well adapted for periods of prolonged starvation and that hepatic and extra‐hepatic lipid and glycogen stores serve for metabolic needs during food shortage, while body protein is conserved. The endocrine basis for these changes in the tissue and blood constituents is discussed.
The biology of Lates species (Nile perch) in Lake Tanganyika, and the status of the pelagic fishery for Lates species and Luciolates stappersii (Blgr.)
Authors: Coulter G. W. 
Published: January 2006

Three Lates species, L. mariae (Stdr.), L. microlepis (Blgr.), L. angustifrons (Blgr.) and Luciolates stappersii (Blgr.) which belongs to a monotypic genus occur only in Lake Tanganyika. They are the principal predators in the pelagic and benthic fish communities. Data are presented on distribution, growth, length‐weight relationships, condition, reproduction and food in the Lates spp. After a post‐larval pelagic phase, each Lates sp, spends 1 year in littoral weed. Thereafter, L. mariae adopts a benthic habitat moving into deep water, L. microlepis becomes exclusively pelagic and L. angustifrons occurs from the littoral to near the limit of the oxygenated zone. Cycles in breeding correspond with seasonal maxima in clupeid prey, and changes in growth rate within a year are probably related to physiological cycles rather than to variations in the physical environment. Salient morphological and ecological adaptations are discussed.Local abundance and vagility of Lates stocks seem related to basin morphometry and depth of the oxygenated layer. L. microlepis has most vagility. The Lates appear highly susceptible to intensive fishing by purse‐seines, and have been fished‐up in the southeast arm in Zambia and in the Burundi sector, where only small populations remain. With reduced predation, the clupeid biomass has increased. The change to dominance of small species may be accomplished rapidly in L. Tanganyika under such conditions of exploitation. However, the type of species successions well‐known in large temperate lakes are unlikely to occur because of the high degree of specialization in these fishes. A simplified pelagic community is foreseen, consisting almost entirely of clupeids and Luciolates, in which the total fish biomass will be determined above some intensive level of fishing and from year to year by the environmental factors controlling survival of young and plank‐tonic food supply. Quantitative equilibrium between the few species will be determined mainly by gear selectivity and total fishing stress, and the community may be sufficiently robust by reason of its rapid turn‐over rates to permit a largely empirical approach to management.
Occult haemoglobin in fish skin mucus as an indicator of early stress
Authors: Smith Albert C. , Ramos Franklin 
Published: January 2006

Early induced stress may result in the release of free haemoglobin into the skin mucus of teleostean fishes. If this were the case, it could be indicated quickly and simply by the colour change of a commercially available haemoglobin test strip. Preliminary tests on Mugil cephalus (grey mullet) encouraged more extensive investigations with Chanos chanos (milkfish), Caranx ignobilis (papio), Albula vulpes (bonefish), and Chaetodon miliaris (butterfly fish). The results indicated that unstressed individuals of these species have no detectable haemoglobin in their skin mucus but, within 2–4 min, the pigment will appear in occult amounts if stress is applied. Additional studies confirmed that it was haemoglobin and no other possible contaminants in the mucus which caused the colour change of the test strip.The technique is simple and quick, and is itself harmless to the fish. It is of immediate potential value to fish culturists for the detection of early stress conditions. Efforts can then be made to lessen or remove the stress conditions before debility and possibly overt disease take over. A further application of the technique may be the identification of individuals genetically better able to resist disease.
Growth and diet dependant structural adaptations of the digestive tract in juvenile grass carp (Ctenopharyngodon idella, Val.)
Authors: Stroband H. W. J. 
Published: January 2006

The morphology of the intestinal epithelium is described and compared with published data. In the gut of this stomachless fish, three zones can be distinguished based on light and electron microscopic observations of absorptive cells: a rostral zone with numerous fat droplets, a second zone with large P.A.S.‐positive supranuclear vacuoles and pinocytotic vesicles, and a third zone without these characteristics. In these zones deep invaginations of the cell membrane is a feature of the basal part of the cells. The presence of pinocytotic vesicles in the second zone is considered evidence of the uptake of undigested protein‐like substances.Juvenile grass carp from 15 to 335 days, fed on either animal or vegetable food, were measured. The growth rates indicate that animal food stimulates rapid growth. The data also show a vegetable diet causes a slight increase in relative gut length, mainly in the length of the first zone.
Annual cycle in female Three‐spined sticklebacks (Gasterosteus aculeatus L.) from an upland and lowland population
Authors: Wootton R. J. , Evans G. W. , Mills L. 
Published: January 2006

The annual cycles in female Three‐spined sticklebacks from an upland (275 m) and a lowland (25 m) population were compared. The average length and weight of the lowland females were greater, but in both populations growth was checked in winter and again in the breeding season. Both populations also showed a winter decline in condition followed by a sharp increase in spring associated with the maturation of the ovaries. The hepato‐somatic index of the females also increased during the spring, but the dry matter content of the liver declined during the spring and early summer. Lowland females had larger livers than the upland fish. In both populations average gonadosomatic index increased steadily throughout the winter, then abruptly in spring. The lowland population bred from May to early August, but the upland population bred only in May.The energy content of the carcases of females was lowest in winter and again during the breeding season whereas the ash content showed maxima at these two periods. Lipid and glycogen analyses of the carcase, liver and ovaries also suggested that winter and the breeding season were periods of depletion from the carcase and liver, but not from the ovaries.The observations indicate that the ovaries are to some extent insulated from fluctuations in resource availability. This supports experimental studies which indicate that egg production in the female stickleback can be subsidised by depletion from the carcase and liver when necessary.
Some physiological consequences of angling stress in muskellunge, Esox masquinongy Mitchill
Authors: Beggs G. L. , Holeton G. F. , Grossman E. J. 
Published: January 2006

Capture of muskellunge by angling resulted in a reduction of blood pH, elevated lactic acid concentrations, and a drop in total carbon dioxide and bicarbonate concentrations. The acidaemia was most severe immediately after capture and began to decline well before the blood lactate levels rose. Blood lactate levels were not as high as those characterizing fatigue in most other species. Recovery from the acidosis required 12 to 18 h and was accompanied by declines of 22% and 40% in haemoglobin and haematocrit levels respectively. With the exception of dying fish, there were only slight fluctuations in plasma sodium and potassium levels during recovery, indicating that there was no severe ionoregulatory dysfunction.Thirty per cent of all angled muskellunge died. The last stages immediately preceding death were characterized by declining blood pH and elevated potassium levels.
Substances involved in the natural resistance of fish to infection–A review
Authors: Ingram G. A. 
Published: January 2006

Natural‘antibodies’are substances found in the blood of animals that have not been immunised against infective agents. However, exposure to these agents or to cross‐reacting antigens may well have taken place. Fish contain naturally‐occurring, relatively nonspecific, lectin‐like proteins or glycoproteins, which are distinct from immunoglobulins, and which react with a wide variety of antigens and may confer some degree of immunity against natural infection. In most cases the cause of the antigenic stimulus is not obvious although the formation of these‘antibodies’may have been brought about by exposure to various micro‐organisms. Many of these antibody‐like molecules behave in a similar manner to immune antibodies or immunoglobulins and cross‐react with specific carbohydrate moieties on the cell walls of bacteria, erythrocytes and certain other cellular antigens, due to the presence of similar antigenic determinants.It is difficult to ascribe an appropriate definition to the term‘natural antibody’. In fish, these‘antibodies’have been so designated on the basis of functional rather than structural criteria. Such naturally‐occurring, low grade, antibody‐like‘immune’substances include‘acute phase’proteins, lysozyme and chitinase, interferon, agglutinins, lysins, complement and properdin, precipitins, and non‐immunoglobulin, lectin‐like molecules. In addition to the above non‐immunoglobulin materials, natural immunoglobulins identifiable as IgM have also been reported in fish. Furthermore, mucus contains many biochemical agents capable of reaction against infective organisms and thus providing the host with an immediate or a first line of defence mechanism.This review compiles some of the relevant information in the literature concerned with natural‘immune’substances, present in the serum and mucus of fish, involved in protection against pathogens. Wherever possible the basic physicochemical properties of these substances are indicated and their potential immunobiological functions discussed.
Quantitative seasonal changes in the protein, lipid and energy content of the carcass, ovaries and liver of adult female plaice, Pleuronectes platessa L.
Authors: Dawson A. S. , Grimm A. S. 
Published: January 2006

A detailed study was made of the seasonal changes in energy reserves in adult female plaice, Pleuronectes platessa L. The weights of lipid, protein, glycogen and ash in the carcass, liver and ovaries were measured in females approximately 35 cm long on ten occasions during one year. These data were converted to data for a‘real’growing female by using a growth curve to take account of increasing length during the year. Growth of the whole body and of the body components was assumed to be isometric.Plaice show a marked seasonal cycle of body weight and energy content. A six year old female plaice of 330 g, 32.6 cm long and with an energy content of 406 kcal in May, assimilates 560 kcal before December when it ceases to feed. Of this, 234 kcal is used to produce eggs, 159 kcal is used for metabolism during starvation, and the remainder 167 kcal, is used in growth. There is an increase in length to 35.9 cm and in weight to 462 g over the year. From December until March, when plaice do not feed but grow large ovaries, 40% of the protein in the body is utilised, 33% is devoted to egg production and 7% is metabolised to provide energy; 64% of the lipid is used, only 14% being used for egg production but 50% is metabolised for energy. Lipid supplies 75% of the energy for metabolism and so forms the major reserve; 42% of the energy assimilated during the year is devoted to reproduction. The main source of lipid and protein reserves is the carcass.
Morphometric examination of the gills of walleye, Stizostedion vitreum vitreum (Mitchill) and rainbow trout, Salmo gairdneri Richardson
Authors: Niimi A. J. , Morgan S. L. 
Published: January 2006

Observations on the gill morphology of individual gill arches of walleye, Stizostedion vitreum vitreum and rainbow trout, Salmo gairdneri suggest that the first two arches account for the highest proportion of gill filament number, secondary lamellae number, lamellae area, and gill surface area. Interspecific comparisons suggest walleye contain a larger number of gill filaments, with a lower secondary lamellae count, but a larger gill surface area than a trout of the same weight. This is partially attributed to the larger surface area of each lamella in a walleye than in a trout.A detailed examination suggests the surface area of a lamella is dependent on its position on the gill filament, and the position of the gill filament on the gill arch.
Recovery growth following periods of restricted rations and starvation in rainbow trout Salmo gairdneri Richardson
Authors: Weatherley A. H. , Gill H. S. 
Published: January 2006

Fingerling rainbow trout (6.9 to 11.6 cm fork length) maintained at 12° C were either: fed restricted rations (3% of dry body weight/day) for 16 weeks, or starved for 3 weeks (14.5% weight loss), or for 13 weeks (32.5% weight loss). Whole body wet weights and dry weights (as % of wet weight), and wet and dry weights of tissues (heart, spleen, liver, skin, gonad, gut, visceral fat, and ‘carcase’) resulting from these treatments were compared to corresponding weights of an ‘initial sample’. Visceral fat was completely utilized during both short and long‐term starvation and gut was significantly reduced in the extended starvation group.During subsequent recovery growth on full rations, following food deprivation, fish grew at approximately the same rate as fully‐fed controls, which had not suffered food deprivation, as regards body wet weight and condition (K), but tended to surpass controls in % dry weight.Heart, liver, gonad, gut and visceral fat also increased during recovery growth in a manner suggestive of overcompensation in response to former food deprivation. Gut, skin and carcase dry weights were less in the control, and in the 14.5% weight loss groups following recovery growth than in those in 3% rations and in the severely starved group, indicating that the effects of slow growth resulting from limited rations resemble those of severe starvation more than those of limited starvation.
Sexual maturation in triploid male plaice (Pleuronectes platessa) and plaice x flounder (Platichthys flesus) hybrids
Authors: Lincoln R. F. 
Published: January 2006

Triploid male plaice, Pleuronectes platessa, and plaice x flounder, Platichthys flesus, hybrids produced from cold‐shocked eggs were reared to maturity at three years of age. The testes of triploid hybrids were similar in macroscopic appearance and size to those from control fish but in histological section spermatocyte and spermatid cell formation was grossly abnormal. In two fish the majority of cells appeared to be aborted spermatids and spermatocytes although there were some spermatozoa with enlarged heads and thick bent flagellae.The testes of mature triploid plaice were similar to controls both in shape and size and in histological section. Spermatocyte and spermatid cell formation was normal, apart from an increase in cell and nuclear size, and fully motile spermatozoa were produced from several fish. Plaice eggs fertilized with semen from triploids showed a slight reduction in fertility compared with controls but developed normally to gastrulation with little mortality. Beyond gastrulation there was increasing mortality associated with abnormalities in the appearance of embryos. Few hatched and none of these survived longer than 48 h. The value of triploidy in fish farming is briefly discussed.
Comparison of early developmental stages and adults of grass carp, Ctenopharyngodon idella, and hybrid carp (female grass carp × male bighead Aristichthys nobilis)
Authors: Kilambi R. V. , Zdinak A. 
Published: January 2006

Hybrid carp and grass carp from the zygote to the prolarval stage and adults were compared to establish distinguishing characteristics. Zygote diameter, yolk sac and embryo length were not different between the fishes. Body pigmentation patterns showed distinct separation among the prolarvae of the hybrids and grass carp. Total and preanal myomeres were higher in grass carp larvae than in the hybrids. The grass carp and hybrid larvae also differed in 38% of the proportional morphometric characters.Average meristic counts of adults were significantly higher in hybrids compared with grass carp. Adults of the two fishes showed significant differences in 63% of the proportional morphometric measurements. Gill raker counts showed no overlap and lateral line scales were smaller and more numerous in the hybrid adults.
Age, growth and rate of food consumption in an upland population of the three‐spined stickleback, Gasterosteus aculeatus L.
Authors: Allen J. R. M. , Wootton R. J. 
Published: January 2006

In a population of Gasterosteus aculeatus living in an infertile, upland lake, the fish bred at the age of one year and few survived to breed again. The highest growth rates were achieved in the first month of life, but in comparison with other populations of G. aculeatus growth was slow during the autumn and ceased during the winter. But in spring and early summer, there was a spurt in the growth rate.Laboratory studies provided regression models for the prediction of the rate of food consumption from measurements of growth. The estimates of the consumption rate indicated the effect of the growth in body size and seasonal variations during the first year of life. It was estimated that a fish of mean length in the population consumed 3150 mg of food in a year in which it grew from 65.8 to 552.0 mg, with an overall gross growth efficiency of 15.4%.The study illustrated the integration of laboratory and field studies to obtain reasonable estimates of the rate of food consumption by fish throughout their first year of life.
The Oriental Goby, Acanthogobius flavimanus (Temminck and Schlegel), an introduced fish in the coastal waters of New South Wales, Australia
Authors: Middleton M. J. 
Published: January 2006

Since 1971 over 100 specimens of the oriental goby, Acanthogobius flavimanus, have been collected from New South Wales’ waters. When this species, a native of Japan, was introduced to San Francisco Bay (U.S.A.) it underwent a population explosion, becoming a common member of estuarine fish communities in that area.The occurrence of both reproductively maturing females and juveniles in the harbours of the Sydney region (central New South Wales coast) suggests that the species may have bred successfully here. However, the relatively low numbers of A. flavimanus collected during the study indicate that as yet there has been no population explosion in New South Wales waters. A number of aspects of the biology and ecology of the species was examined in an attempt to identify features which may limit its distribution and abundance in the Sydney region.The inhibition of successful reproduction by the relatively warm‐water temperatures in this area and the potential for competition with native fishes are proposed as possible explanations.