摘要:

Scanning electron microscopy was used to examine the intestinal bulb and the caudal portion of the intestine proper of the goldfish,Carassius auratus. The observations made correlated well with previous light microscope studies by other investigators. The mucosal surface of the entire intestine of the goldfish is thrown up into folds, which are oriented along the long axis of the digestive tract in the intestinal bulb, but run more or less transversely in the caudal intestine. Tops of the folds were observed to be rounded or flattened, and the folds themselves formed wavy or zigzagging patterns in the mucosal surface. Numerous mucus‐secreting goblet cells were seen, which were apparently more numerous or more active in the caudal intestine than in the intestinal bulb. The goblet cells are not uniformly distributed throughout the mucosa: they are more evident on the sides of the folds, although occasionally they appear to be located in clusters on the tips.The goblet cells were observed to contain varying amounts of mucous material, and/or to be of different sizes. Although no histochemical tests were performed, the possibility that digestive enzymes known to be present in the intestine may be elaborated by the goblet cells was considered, based on their variable appearanc

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1984.tb04845.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The dynamics of increase of the predominant white muscle fibres of the myotomal bulk in bluntnose minnow,Pimephales notatus, ranging from 2.0 to 9.1 cmf.l.have been analysed by examination of modal progression of fibre diameter frequency classes in fish fed to satiation and growing at different rates at 15, 25 or 30°C. Recruitment of new fibres appeared to contribute little to increase in muscle bulk above 4 cmf.l., and nothing beyond 6 cm. The dominant means of increase was increase in fibre diameter. The limiting fibre diameter seemed to be 120 μ. These dynamics, which result in an approximately 1: 1 ratio between mean fibre diameter andf.l., are in contrast to those of the myotomal white muscle of rainbow trout,Salmo gairdneri, in which, regardless of differences in somatic growth produced by temperature, ration size or growth hormone administration, mean fibre diameter does not exceed that in bluntnose minnow until trout exceed 30 cmf.l.In trout there is, moreover, input of new fibres up to approximately 50 cmf.l., when subsequent growth, as in the minnow, is by means of fibre diameter increase. The bluntnose minnow is a small, slow growing species; the rainbow trout is a large, fast growing species. The discussion links these facts with the observed differences in fibre growth dynamics in relation to a hypothesis of interspecific differences in fish growth capabilit

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1984.tb04846.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Crappie,Pomoxis annularis, from Lake Decatur, Illinois, were reported to have a high incidence of backbone deformities, an investigation was initiated to determine both the mechanism of vertebral injury and the causative agent. Three groups of fish were collected: normally shaped and abnormally shaped crappies from Lake Decatur and control fish from abnormally shaped crappies from Lake Decatur and control fish from nearby Lake Sangchris. Analysis of organic and inorganic residue levels in fish tissue revealed no significant levels of contaminants in any of the three groups. Evaluation of the mechanical properties, biochemical composition, and density characteristic of vertebral bone showed no significant difference between the three groups. A myxosporidean parasite, found in both normal and abnormally shaped crappies from Lake Decatur, may have been a contributing factor leading to the spinal deformities. We believe that a short‐term exposure to organophosphate insecticides, may have occurred causing muscular contractions and resulting in vertebral damage and abnormally shaped fis

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1984.tb04847.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The uptake of benzocaine hydrochloride and neutralized benzocaine hydrochloride by the skin and the gills ofCyprinus carpio, Oreochromis mossambicusandSalmo gairdneriwere studied. The differences observed can mainly be ascribed to degree of ionization and the lipid solubility of the anaesthetic.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1984.tb04848.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

One hundred zebra fish per tank were maintained for 112 days at 24°C or 28°C in glass aquaria and fed a diet of flaked food made without cellulose (13.45 kJ g−1, metabolizable energy, Type A) or with cellulose (8.71 kJ g−1, metabolizable energy, Type B). Each experimental condition was repeated in triplicate (12 tanks). The weight of food given daily to the fish was based on daily records of survivors (from which mortality rates were calculated) and wet wt of fish (measured every 14 days) in each tank. All fish were fed with the same weight of food per day and the quantity of energy in the food in excess of standard metabolism (as a proportion of SM) was approximately 0–5 for fish maintained at 28°C and fed food B, 1–0 for fish maintained at 24°C and fed food B, 1–5 for fish maintained at 28°C and fed food A, and 2.2 for fish maintained at 24°C and fed food A.Non‐ionized ammonia, nitrite and nitrate nitrogen in the tanks did not reach toxic levels although there was an increase in total ammonium nitrogen in one tank and a subsequent heavy mortality. It was assumed that this was caused by the build up of pathogenic bacteria. Apart from this tank, mortality was highest in tanks at 28°C with fish fed food A and second highest in tanks at 24°C with fish fed on the same diet. Growth was measured in units of length, wet and dry weights, carbon and energy. There was a good correlation (P<0.001) between carbon (mgC mg−1) and calorific (J mg−1) values and a conversion factor of 46.2 J (mgC)−1was derived. Fish maintained at 24°C and fed food A had the highest rates of growth both in weight and in energy value per unit weight. Fish fed the same diet but kept at 28°C had the lowest growth rates. Both these groups of fish had the highest coefficients of variation in wet weights which increased during the experiment, indicating an increase in interaction within the tanks. There was agreement between the energy value of fish sampled for growth and a condition factor based on the length‐weight relationships of fish remaining in the tanks. A correlation (P<0.05) was found between instantaneous mortality and growth rates for fish between tanks when those maintained at 28°C

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1984.tb04849.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Two semisynthetic diets differing in the levels of pantothenic acid (PA) supplementation (0 or 40 mg kg−1diet) were fed to rainbow trout,Salmo gairdneriRichardson, initially weighing 0.7 g fish−1. Each diet was fed to two tanks of fish and, at the start of the feeding trial, each tank contained 200 animals. The experiment was conducted for 28 days during which time, every 2 days, gill tissue was sampled and food consumption was determined. Lamellar hyperplasia was first detected in the gills of deficient fish on the 12th day sample, while reduced feed intake was first manifest at 16 days. Hyperplasia first appeared in the distal regions of the gill filaments, but the lesion rapidly progressed in a proximal direction and 35 of 40 fish examined on days 22–28 exhibited hyperplasia on more than 75% of the filament surface. Gill lamellar hyperplasia is a sensitive indicator of PA deficiency in the rainbow trout. Moreover, the lesion is specific to PA deficiency since its developmental pattern differs histologically from the lamellar hyperplasia of the non‐nutritional gill d

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1984.tb04850.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Spotted seatrout,Cynoscion nebulosus(Cuvier), and spot,Leiostomus xanthurusLacèpéde, from two sites along Florida's west coast were collected, weighed, sexed and measured. A systematic search for plerocercoids of the cestodePoecilancistrium caryophyllumyielded infection prevalences of 81.9% forC. nebulosusand 25.0% forL. xanthurus. The maximum infection intensity was 10 (mean = 2.65) plerocercoids per fish inC. nebulosusand six (mean = 1.69) per fish inL. xanthurus. Significant correlations were found between infection prevalence and length inC. nebulosus, and a significant correlation was observed between intensity and length in both species. Condition coefficient (K) and intensity were negatively correlated inC. nebulosusbut not inL. xanthurus. An iterative computer technique based on the truncated negative binomial distribution indicated no parasite‐induced mortality occurred in either species. Sand drum,Umbrina coroidesCuvier, is reported as a new host record forP. caryophyl

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1984.tb04851.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

When plaice were injected intraperitoneally with either oyster glycogen or liveVibrio alginolyticusan acute cellular inflammatory response was observed. The duration of these responses, 7 and 15 days respectively, exceeded the time course of the mammalian cellular inflammatory reaction. Peak leucocyte numbers were found at 2–3 days and neutrophils, which were phagocytic, were more numerous than macrophages. Although the increase in macrophage numbers was less marked, these cells appeared more actively phagocytic than neutrophils. Cortisol injections and environmentally‐induced stress caused a significant reduction in the extent of inflammatory cell infiltrates, while endotoxin significantly enhanced the respo

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1984.tb04852.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Little has been reported on the fine structure of the outer membrane of fish eggs during and after fertilization. When observed in the scanning electron microscope, the unfertilized egg of the winter flounder,Pseudopleuronectes americanus, is characterized by a crisscross pattern of depressions. These depressions radiate in all directions across the membrane surface creating a wrinkled appearance. After fertilization, the surface of the chorion becomes regular with a smoother appearance. The pores of the unfertilized egg are flush with the chorion surface, but become thickened and elevated after fertilization. While the chorion of the unfertilized egg is also smooth and uniformly textured, the chorion of the fertilized egg appears granular by first cleavage of the blastodisc. Although no apparent change occurs in the distance between pores after fertilization, statistically significant decreases in pore diameter occur 5 min after fertilization. These results are compared to those on egg membranes of other species of fish and invertebrates.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1984.tb04853.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The localization of a live, and a formalized vaccine preparation ofAeromonas salmonicidawithin the tissues of rainbow trout,Salmo gairdneri, was followed over a 5 day period. When presented by intraperitoneal injection, both the live bacteria and the vaccine localized in the spleen, liver, kidney and gut. When presented orally, the bacteria and the vaccine were confined almost exclusively to the gut region. Direct immersion resulted in low detectable levels within the tissues, with the spleen and kidney localizing theAeromonasafter its initial attachment to the outer surfaces of the fish.

ISSN:0022-1112    

DOI:10.1111/j.1095-8649.1984.tb04854.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY