ISSN:0175-8659    

DOI:10.1111/j.1439-0426.1994.tb00145.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryThe relationship between fish target strength and the orientation of fish in horizontal (yawing) and vertical (pitching) planes was modelled by the equation TS = m. cos 2 α+ b (also with cos3, cos5and cos7). The cos3model gave the best fit of data for three fish species: brown trout, roach and rudd. The model can be used for 1) estimation of the most probable aspect in the horizontal plane; 2) estimation of the mean all‐aspect target strength of fish and 3) calculation of probability of recording of a fish of given size when a known noise threshold is appli

ISSN:0175-8659    

DOI:10.1111/j.1439-0426.1994.tb00146.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryCatch, fishing effort and yield estimates of the Cape Bolinao reef flat fishery in Lingayen Gulf, Philippines are provided, based on data collected from May 1987 to April 1988. The dynamics of the dominant species, the rabbitfishSiganus fuscescens, suggest that such fisheries are capable of maintaining a high production in site of heavy fish in pressure. However, yield comparisons with those of other reef fisgeries in the Indo‐Pacific region, along with characteristics of the catch and the use of multiple gear types, suggest that current extraction rates should not be increase

ISSN:0175-8659    

DOI:10.1111/j.1439-0426.1994.tb00147.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryExperimental brushparks were constructed in the Negombo Estuary using branches and twigs of six manrove and two non‐mangrove species to investigate whether these materials had any effect on fish yielck. It was observed that amongst the manroves, highest yields were obtained withAvicennia marina;lowest yields were withExcoecaria agallochaandSonneratia caseolaris. The yields from non‐mangroveSyzgium corymbosabrushparks were similar to those of the mangrove speciesA. marina. It is suggestel that utilization of mangrove species such asA. marina, rather thanE. agallocha, and non‐mangrove species such as S. cumini, could not only maximize yields but also prevent the denudation of mangrove fo

ISSN:0175-8659    

DOI:10.1111/j.1439-0426.1994.tb00148.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryThe stomach contents of 246 pipers (Trigla lyra), collected in the Saronikos Gulf (Greece) in 1989 (March to December), were examined to assess the diet, as influenced by season and fish size. Piper is carnivorous from the juvenile stage onward, feeding on a narrow range of epibenthic and benthic prey items. Seasonal variation in feeding activity indicated a higher intensity in summer, which could be related to temerature and/or gonadal maturation. During all seasons mysids constituted the most important foof resource by weight, number and frequency of occurrence and were mainly represented byParamysis helleriandLopogaster typicus. Brachyurans were the second most important food category, while decapods ranied third. Small pipers fed mainly on mysids and shifted to brachyurans and other decapods as their size increased. Dietary overlap was relatively high, indicating that the feeding sectrum of piper chaned little across seasons and size roups. Juvenile piper (<110 mm fork length) isplayed curtailment of feeding between December ancf January.

ISSN:0175-8659    

DOI:10.1111/j.1439-0426.1994.tb00149.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryHistochemical analysis of the cellular components as a supplement to histological studies shows that the epithelia of lips and associated structures inChanna striataare of a mucogenic and unkeratinized nature. Voluminous mucous cells in the lip eithelia secrete profusely at the surface to lubricate and protect the epithelia from abrasion during feeding. Capacity of the folds of skin to distend is an important adaptation enabling the jaws to protrude ant assist the fish to engulf relatively large‐size prey. Profuse mucus secretion at the surface of skin folds may reduce the resistance generated during protrusion of jaws when feeding. The role of sacciform cells located in the rostral cap epithelium is discussed in the production of the fish toxins. Poorly‐developed taste buds in the epithelia of lips and rosual cap sugest that the gustatory function is of less importance in this active predatory fish which feeds mainly by si

ISSN:0175-8659    

DOI:10.1111/j.1439-0426.1994.tb00150.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryThe lifecycle of pumpkinseed, (Lepomis gibbosus(L.)), was studied to obtain information on age, growth and reproduction. Using scales, back‐calculation of length indicates a fast growth rate during the first 2 years of life (69.8–83.4 mm, respectively) after which it decreases. The length: weight relationship of a sample of 600 pumpkinseed specimens can be described by the equation W= 12.078 10‐6. FL3.131for both sexes. The average condition factor (K) of all pumpkinseed was 1.40, with a range of 1.39 to 1.41. The studied species were sexuall mature at age 1 + The relationship between fecundity F) and fork length (FL) was F = 0.02438 FL3.08. The mean absolute fecundity was 7169 eggs, ranging from 1122 to 12 293 eggs; mean diameter = 0.8 mm. Spawning occurred from the second half of June until the end of July at water temperature 22

ISSN:0175-8659    

DOI:10.1111/j.1439-0426.1994.tb00151.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryWith the annual floods fish are able to move into the inundated forests and procure fruits and seeds. Feedin trials with youngColossoma macropomum(Characidae) weighing 18 g were carried out to study keir efficiency to metabolize abundant fruits and seeds (Pseudobombax munuba, Oryzasp.,Heveaspp., andCecropia latiloba) from inundated forests. Crude rotein content of the fruits varied between 4.1 and 21.3%. Growth rates of fish were comared wit! those fed a control diet of 35% crude protein. The highest weight increases (2.5% per day) were obtained with the control diet. Within the fruit and seed treatment growth rates were correlated with the protein content of the food source; however, rotein efficiency ratio decreased. Best specific growth rate of 1.3% per day was obtained when feeding,P. mungubaseeds (21.3% crude protein). With the treatments withP. mungubaandOryzasp. crude fat content of the fish body increased while the protein content decreased. As foodplain forests are of importance by nourishing many commercial fish species, negative consequences of floodplain deforestation for lsh communities are discussed.

ISSN:0175-8659    

DOI:10.1111/j.1439-0426.1994.tb00152.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryAs the fact that feedingSpirulinacan improve carcass uality of fish, this study describes the effect on muscle protein in red sea bream,Pagrus major. The fish were fed on a diet supplemented with 2%Spirulinafor 95 days under commercial rearing conditions.Spirulinafeeding elevated protein synthesis, which was estimated by muscle RNA/DNA and RNA/protein ratios. Muscle protein was fractionated into sarcoplasmic, myofibrillar, alkali‐soluble and stromal fractions. The stromal fraction was significantly higher in theSpirulina‐ fed group. The proportion of the fractions approached that of wild fish somewhat bySpirulina‐ feeding. The results possibly indicate thatSpirulinacontributes to elevate protein assimilation and increase stromal fra

ISSN:0175-8659    

DOI:10.1111/j.1439-0426.1994.tb00153.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryZebrafish (Brachydanio rerio) fed diets free of ascorbic acid (vitamin C) or suplemented with 200 mg/kg ascorbic acid for 12 weeks were compared with respect to macroscopically detectable symptoms of pathology and cytoloical alterations of hepatocytes. Fish fed the ascorbic acid‐free diet displayed symptoms of scurvy including hemorrhages, fin erosion, and darker pigmentation. Hepatocytes of male zebrafish developed steatosis, whereas liver cells of female zebrafish were free of microvesicular lipid accumulation within the endoplasmic reticulum cisternae, indicating the presence of sex‐dependent protection mechanisms against ascorbic acid depletion. Female fish showed a reduction of hepatocellular size and a less regular arrangement of the rough endoplasmic reticulum; hepatocellular glycogen depletion as well as induction of smooth endoplasmic reticulum were characterstic of hepatocytes in either sex. Since zebrafish fed the diet supplemented with ascorbic acid were free of pathological alterations in both external appearance and hepatocellular ultrastructure, results indicate that ascorbic acid not only plays a key role in collagen biosynthesis, but also fulfills central functions in the maintenance of a well‐equilibrated lipid metabolism in fish. Accumulation of oxidative reagents represents one possible mechanism leading to hepatocellular steatosis in

ISSN:0175-8659    

DOI:10.1111/j.1439-0426.1994.tb00154.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY