Fish In Question Research Articles

Pengolahan Tulang Ikan Selengek Menjadi Kaldu Bubuk Sebagai Produk Pangan Berdaya Saing Kawasan Kota Tuo Bengkulu

Fish bone is a residual form of fish processing which has not been utilized much and has high potential to be developed as a value-added product. In the Tuo Bengkulu City area, fish are a source of income for the local community, but this potential has not been maximized due to a lack of knowledge and skills in processing fish bones. One of the types of fish in question is the selengek fish or also known as the selengek fish. The meat from the selengek fish can be used as a raw material for making dim sum, dumplings, nuggets and meatballs. Meanwhile, the bones can be processed into powdered broth or food seasoning ingredients. In order for meat and bones to be made into products that have added value, it is necessary to innovate and create products made from selengek fish. In addition, in order for the product to become a new business opportunity, it is necessary to carry out a business feasibility calculation that is used to measure the chances of success for a business in the future. We carried out the activity we meant with the management of the Kelompok Pemanfaatan dan Pemeliharaan (KPP) Kota Tuo.

Actual status of fishing reserves of the Yesil River

In this article, the study and prediction of the state of fish resources in the Yesil River was carried out to determine the boundary reference points of the reserve and management decisions in case they are exceeded, to ensure sustainable fisheries and preserve biological diversity. Ichthyological studies, retrospective analyses and rankings of the effects of the water supply of the Yesil River on fish stocks have been carried out, critical values ​​of the biomass of fishing reserves have been determined, as criteria for biologically safe fishing values and targets for management of fish stocks at reaching the boundary values ​​of 24.03 tonnes have been established. According to the results of studies of basic biological indicators, it was determined that roach, bream, pike and perch populations each had an LC50 above LM50, which indicates their low utilization in the fishery industry. A strategy for management of fish stocks, recommendations for the conservation of fishery resources and their rational use has been developed as a result of these findings. The list and status of the monitored indicators for the careful management of fish stocks, as well as a list and indicators of the boundary indicators for the state of fish stocks, was established. These parameters included the fish size of 50% of the sampled fish and 50% of maturity achieved, where the LC50 was observed in the fish in question from 19 to 45.4 cm and LM50 from 12.3 to 41 cm, respectively. The minimum and maximum river levels that ranged from 111 up to 159 cm, as well as the critical value of the commercial reserve, corresponded to the boundary value of 24.03 tonnes. The results of this work will serve as the basis for making future managerial decisions, necessary for sustainable fisheries and conservation of the biological diversity of the Yesil River.

Trace elements and microbiological parameters in farmed Nile tilapia with emphasis on muscle, water, sediment and feed

Fish may bioaccumulate contaminants from the aquatic environment and extend them to the food chain provoking risks to human health. This study evaluated the microbiological parameters of the pond´s water and trace elements concentrations in samples of water, sediment, feed and muscle of farmed Nile tilapia used for human consumption in southern Brazil. A total of 240 fish were collected from 12 tilapia farms. Sediment, tank water and dry ration used in the animals' diet were collected for analysis. Analysis were performed by Energy Dispersion X-ray Fluorescence (EDXRF), Inductively Coupled Plasma Mass Spectrometer (ICP-MS), Induced Coupled Plasma Optical Emission Spectrometer (ICP-OES), and Atomic Absorption Spectrometer (AAS-VGA). In addition, the microbiological analysis of the water was carried out. The concentrations of Se, I, Fe, Cu and Zn in fish muscle were higher than the recommended by the Brazilian legislation, considering the advised daily intake for adults. The arsenic element had concentrations above the limit stipulated by the present Brazilian legislation, observed in all samples of muscle, sediment and tank water highlighting a possible environmental and fish contamination by the toxic element. Moreover, the arsenic concentration in the water presented a positive correlation (ρ = 0.33) with arsenic in the muscle, suggesting that tilapia is a good environmental bioindicator, once they properly reflect the levels of arsenic in the water. It is suggested to perform an arsenic speciation for quantification of the inorganic form and accurate assessment of the degree of toxicity in the muscle samples and risks it can bring to human health. Regarding the other potentially toxic elements (Hg, Pb and Cd), and microbiological analysis of water it was verified that the consumption of the fish in question does not raise risks, since the values are within a quality benchmark established by law. The concentration of total and fecal coliforms in pond´s water in the facilities was in agreement with the microbiological indexes required by the legislation of CONAMA class II. Western region presented the lowest concentrations of fecal coliforms when compared to the other regions. There was no significant difference in the microbiological counts of total heterotrophic bacteria, Vibrio spp. and Pseudomonas spp. among the regions.

Mycotoxins and fish farming: A risk left behind?

Mycotoxins produced by various fungi of the genera Aspergillus, Fusarium and Penicillium can easily contaminate cereals, their by-products and many plant and animal products commonly used for manufacturing industrial and homemade fish feed. The most common are: aflatoxins, ochratoxin A, zearalenone and trichothecenes. However, information on the impact of mycotoxins is still scarce, most of it coming from experimental studies. The toxicological effects of mycotoxins on fish depend on the type of mycotoxin and on the relationship between dose and exposure to which the fish are subjected. Subchronic intoxication usually results in decreasing rates of growth, changes in the general condition of the fish, specific lesions in various organs including the liver, immunosuppression and an increased occurrence of opportunistic pathogens. Aflatoxins are often associated with a high incidence of liver tumours. However, significant variations in toxicity are related to various factors, including the species and age of the fish in question. This article provides an overview of the issues related to mycotoxins in fish farming and presents the necessary actions to be undertaken in order to reduce their effects with emphasis on the multifactorial aspects of these contaminants.

Haematology and plasma chemistry of the red top ice blue mbuna cichlid (Metriaclima greshakei)

Clinical haematology and blood plasma chemistry can be used as a valuable tool to provide substantial diagnostic information for fish. A wide range of parameters can be used to assess nutritional status, digestive function, disease identification, routine metabolic levels, general physiological status and even the assessment and management of wild fish populations. However to evaluate such data accurately, baseline reference intervals for each measurable parameter must be established for the species of fish in question. Baseline data for ornamental fish species are limited, as research is more commonly conducted using commercially cultured fish. Blood samples were collected from sixteen red top ice blue cichlids (Metriaclima greshakei), an ornamental freshwater fish, to describe a range of haematology and plasma chemistry parameters. Since this cichlid is fairly large in comparison with most tropical ornamental fish, two independent blood samples were taken to assess a large range of parameters. No significant differences were noted between sample periods for any parameter. Values obtained for a large number of parameters were similar to those established for other closely related fish species such as tilapia (Oreochromis spp.). In addition to reporting the first set of blood values for M. Greshakei, to our knowledge, this study highlights the possibility of using previously established data for cultured cichlid species in studies with ornamental cichlid fish.

First evidence of size-related change of diet (“switching”) in a fossil fish

50 specimens of the Eocene fish species Rhenanoperca minuta from the excavation Site “Turtle Hill” (grid square H/I 7) in Messel were scrutinized for their intestinal food remains. 28 of them (56%) bore traces of undigested food particles in their visceral tracts. Of these, 13 (46%) turned out to have fed exclusively on arthropods (different aquatic larvae of nematocerous Diptera). 15 (54%) other specimens bore no arthropod remains but parts of fish skeletons in certain areas of their intestine. Due to the general difficulty to distinguish the bones of prey from those of the predator, only eight of the latter the results are completely reliable. As expected, there is a clear connection between the body size of the fish in question and their food preference insofar as all but one of the arthropod feeders have total lengths below 30 mm and all fish feeders measure 29 mm or more in total length. These results show that R. minuta changed from opportunistic plankton feeding to fish hunting with total body lengths from 29 mm onwards. Coprolites with bone and insect remains probably were produced by fish in this “switching” period.

Vanadium toxicology--an assessment of general health, haematological aspects and energy response in an Indian catfish Clarias batrachus (Linn).

The pervasive occurrence of vanadium in nature and its use in various industrial processes has increased its inputs in the environment. This has prompted us to elucidate the impact of vanadium on aquatic environment, the primary body for industrial effluent discharge. The energy response of the fish, Clarias batrachus, its haematological status including haemoglobin (Hb), haematocrit (Ht), leutocrit (Lt), mean corpuscular haemoglobin (MCH), mean corpuscular volume (MCV), mean corpuscular haemoglobin concentration (MCHC) etc. And overall general health conditions have been observed to be significantly hampered leading to deleterious alterations in the general metabolism of the fish following long term exposure to vanadate. The increase in muscle and tissue lactic acid (2-12 fold) in association with decrease in pyruvic acid (72% in muscle; 26% in liver) reflect a shift towards an anaerobic metabolism of the fish. We conclude that vanadium could be toxic for the fish in question under long term exposure at the doses under observation (2-10 mg L-1).

Why Don’t Great Lakes Fish Reflect Environmental Concentrations of Organic Contaminants? – An Analysis of Between-Lake Variability in the Ecological Partitioning of PCBS and DDT

We have reviewed the literature on PCBs and DDT in the Great Lakes ecosystem, in an attempt to explain between-basin and between-species variation in fish contamination. Empirical models were developed, using log-linear multiple regressions, to link tissue contaminant concentrations to environmental levels (water and sediments) as well as basin-specific ecological attributes. Concentrations of PCBs and DDT in sediment and water can explain between-basin variability in fish contaminant levels only when basin-specific ecological attributes are taken into account. The important factors that appear to determine the ecological partitioning of persistent organic contaminants are fish lipid content, trophic level of the fish in question, and the trophic structure of the food chain. Multiple regressions of these variables explain 59% (DDT) to 72% (PCBs) of the variation in contaminant concentrations of 25 species of Great Lakes fish.

Predation by the three-spined stickleback (Gasterosteus aculeatus L.): the influence of hunger and experience.

Predation by the three-spined stickleback (Gasterosteus aculeatus L.): the influence of hunger and experience.

サケ・マス流網の投揚網時刻と魚群の羅網との関係

For enlightening the efficiency of drift net operation in salmon fishery, some available data of catches of red salmon, chum salmon and pink salmon were schematized as stated below and looked at from new angles independent of the extreme divergency of their actual catches: 1. According to the number of fish individuals actually caught in every one of 12 sections constituting a stretch of drift net and differing inevitably from section to section as regards the times of laying out and hauling up, daily ranks of catches were decided for each one of these sections of net as well as for each one of said kinds of salmons. From the daily ranks the corresponding averages of daily ranks, the average daily ranks so to speak, were further calculated in proportion to the days on which the drift net was actually operated and divided into 2 groups, one higher and the other lower than the mean of ranks 12-1, viz., 6.5. These groups were marked with ?? and ??, respectively, and entered in panes of a rectangular chart on the co-ordinates of which the times of day of laying out and hauling up of net-sections were graduated. Similar types of charts were prepared for the avearge daily ranks for (i) the whole interval of fishing season from June to August, (ii) the catches in June and July, respectively, (iii) the cases in which the sum of caught individuals of red salmon and chum salmon was greater and smaller, respectively, as compared with those of pink salmon and (iv) the cases in which big catches and small catches of said three kinds of salmon were respectively experienced (Figs. 1, 2 and 3). 2. Comparing between the charts the kind of marks of said two groups, or in other words, examining whether the marks in corresponding panes are concordant or discordant with each other, efficiency of catching chum salmon may be said to be likely bound up with the times of day at which a drift net is laid out and hauled up (Figs. 2, b)-g) and Table 1), while any positive rule can hardly be found as for efficient catches of red salmon and pink salmon (Figs. 1, b)-g), 3, b)-g) and Table 1). 3. According as the average daily ranks above and below 6.5 assigned to the panes in Figs. 1-3, b)-g) were predominant at least 3 times over each other, three charts carrying the panes marked with ?? and ?? were prepared for visualizing the times of day of effective catches of chum salmon (Fig. 4, a)), red salmon (Fig. 4, b)) and pink salmon (Fig. 4. c)). On the basis of Figs. 4, a)-c), it may be said that chum salmon and pink salmon are caught most effectively by keeping the net laid out rather for a long and a short time, respectively, while any positive comment is difficult to be made upon the time of effective catch of red salmon. The fact that effective duration of drift net operation varies according to the species of salmon to be caught seems to be explained to some degree from the ecology of the fish in question, Thus pink salmon, being small in size, may perhaps be liable to get out of the net in which it became once entangled so that the apparently strange situation is met with that an effective catch of this fish is realized with a net kept laid out rather for a short time. Actually observed body portion by which the different kinds of salmons are held entrapped (Table 2) suggests that these fishes differ likely from one another also in regard to the tendency of getting out of the net. 4. From many assumed types of catch in which a fish may visit a drift net and fall entangled therein, the types indicated in Figs. 5, a) and b) were picked up as bearing closest resemblances to those in Fig. 2, a) and Fig. 1, a) respectively.

マグロ青肉に関する研究-I

“Greening” is a term referred to a phenomenon which makes tuna meat discolor into a disagreeable greenish brown as is often met with the meat precooked for canning. A few investigators, reporting the independency of this phenomenon on either of the method of catch and the degree of freshness, have assigned its origin before to some individual abnormality inherent to the fish in question. Any further information, however, has not been presented thereafter about the nature of the origin of “greening”. The authors, now, considering some anomaly in vitamin B group and minerals in muscular system for the cause of the greening, measured their quantities in both greened and normal samples of yellowfin tuna. From the results may be formed the following summary: In comparison with normal meat, green meat is rich not only in moisture but in B12 and poor in B6. As for the contents of riboflavin, folic acid and pantotheic acid no striking contrast prevails between the two types of meat (Tables 1 ?? 2, Figs. 1 ?? 3). Nevertheless, it may be worthy of note that, while for normal meat little positive relation can be found between the contents of riboflavin and folic acid, these two vitamins vary in amount in a distinct correlation with each other in greened meat (Table 3). The amount of mineral constituents seems to be independent of the degree of greening, but it should be remarked that two samples of green meat showed an extraordinary low level of phosphorus content. These findings will provide a clue to the resolution of biochemical causes of the greening.

The Measurement of Spoilage in Fish

The increase in volatile nitrogenous bases in codfish muscle between the pre-rigor period and the first appearance of odour is approximately 6 mg. per 100 grams of tissue, and is due almost entirely to the action of bacteria. It can be used to follow the course of spoilage only if the original value of the fish in question is known, as the range in variation of the original values is as great as the increase to the appearance of odour. A method for the rapid determination of "trimethylamine" in cod muscle has been devised. Its increase parallels the increase in bacterial population. Odours always appear at approximately the same level of "trimethylamine". The increase resulting from autolysis is negligible. The increase during the development of spoilage is fifteen to twenty times the original value. Spoilage can be followed in fish preserved with borates as well as in untreated fish.

On Some Karroo Fishes from East Africa

From Mr. G. M. Stockley I have received a small collection of fish remains. Most of the specimens are incomplete, but the following notes will indicate the nature of the fauna, of which further collections will undoubtedly increase our knowledge. The genus Australosomus was founded by Piveteau ( C.R. Acad. Sci., Paris, cxci , pp. 456–8) on specimens from Madagascar which had been identified by Priem as Pristisomus merlei . Piveteau pointed out that the characters of the fish in question must cause it to be removed from Pristisomus, and he made the new genus the type of a new family which, in his opinion, possessed features of both the Palæoniscidæ and Saurichthyidae. In view of the fact that the genus is being further investigated by Dr. E. I. White, it is proposed here merely to draw attention to the occurrence of members of the same genus in the Karroo of Tanganyika. The specimens under consideration were collected by Mr. Stockley at Vikindu, about 15 miles west of Pangani Rapids, near the Rufiji-Ruaha confluence. They are preserved in a calcareous shale, and most are weathered and fragmentary. Two of them, however, are nearly complete, and the chief features can be ascertained from these and from some of the fragments. The complete fish was from about 100 to 105 mm. long, the head and shoulder-girdle together occupying about one-sixth of the total length. The maximum depth of the body is about 17·5 mm., so that the fish is more slender in build than A. merlei .

長崎縣五島西村及び伊豆網代赤石崎に於けるブリ網の漁況に就いて

The present paper is based on the daily records of the catch of the keddle nets (1) in the Nisimura fishing ground of Goto in Nagasaki Prefecture and (2) in the Akaisizaki fishing ground on the east coast of Idu Peninsula. The former covers nine fishing seasons of “Buri” (Seriola quinqueradiata T. & S.) 1918 to 1926 inclusive, and the latter six seasons of the same, 1927 to 1932 inclusive. The catches from the above mentioned two fishing areas consist of “Buri, ” “Iwasi” (Amblygaster melanosticta T. & S.), “Saba” (Scomber japonicus Houttuyn), “Maguro” (Thynnus thynnus (L.)), “Tobiuwo” (Cypsilurus agoo T. & S.) and “Sawara” (Scomberomus niphonius Cuvier and Valenciennes). In the present study, especial reference has been given to the analysis of fluctuation in the catch of “Buri, ” with the following results: - (1) The size of the yearly catch of “Buri” in the Nisimura fishing ground is significantly correlated with the number of the catches of 1, 000 individuals and over a day (r=+0.82). (2) The size of the yearly catch is mostly determined by the size of stock of the predominant year class which again depends on the conditions of life during the period of hatching which took place 4-6 years before the fishing. As to “Buri” fished on the Nisimura ground, a very large stock of it is obtained when the meteorological and hydrographical conditions are moderate (Fig. 3). (3) The correlation between the time of first catch and the average water temperature in January is negligibly low (r=-0.16), and that between the time of the last catch and the average water temperature in March and April is not so high (r=+0.13 and r=+0.45). But the duration of the fishing period between the first and the last catches is longer than usual when the average water temperature in March is lower than that in January (r=+0.65), and when the rising of water temperature is slower than that in average year (Fig. 4). (4) If the duration of the fishing season of “Buri” is represented by T days, the number of daily catches of “Buri” in T days by n', that of any other fishes by n and the number of coincidences of both daily catches by p, then the probability of existence of any cause from which the catch of “Buri” is resulted to occur in coin cidence with (or against to) the catch of the other fish in question is numerically represented by the magnitude of the difference of P/T/(n'/T×n/T) from 1. The data from the Akaisizaki fishing ground give that P/T/(n'/T×n/T) is 1.0-1.3 for “Iwasi, ” 0.6-1.3 for “Maguro” and 0.5-1.0 for “Saba.”

Garfish—Wild Fowl

WITH reference to Mr. Archer's note in NATURE last week (p. 226), may I remark that the beak of the garfish of southern waters (Hemiramphus, A.) is of rather too fragile a nature to be capable of making a slit of four inches in length in a hard felt hat? May not the fish in question have been more likely a young and small Xiphias—or, as is equally probable, a juvenile Pristis or sawfish—emulating with the thoughtless exuberance of youth the habits of Exocetus?

Societies and Academies

LONDON Linnean Society, March 16.—Sir John Lubbock, Bart., M.P., F.R.S., president, in the chair.—Messrs. H. M. Brewer, V. I. Chamberlain, and A. P. Withiel Thomas were elected Fellows of the Society.—Mr. J. Worthington Smith called attention to certain very destructive Australian fungi new to England, viz. Capnodmm australe, fatal to conifers, especially Thuyas and Isaria fuciformis, a great pest to grass in Kent and Sussex. The latter plant is popularly supposed to induce a disease similar to diphtheria, and said to be fatal to cattle. Isaria frequently grows on animal substances, dead and living, as on larvæ and pupæ of ichneumons, spiders, moths, wasps, &c.—Mr. Smith showed a bee caught alive in this country, and having a profuse growth of the Isaria-condition ef the Cordiceps sphecocephala, a West Indian form, the latter genus being closely allied to Claviceps, or Ergot.—Dr. Francis Day read a paper upon the Salmones found in the British Isles, remarking how great changes are occasioned by retaining any of them in unsuitable localities. He objected to the augmentation in number of the British forms of migratory trout, from three to seven, as made by Dr. Günther, holding that we merely possess two, The Lochleven trour, which is in reality a marine form, acclimatized to fresh water, whereas the remainder are solely trout races of the common brook trout.—A most interesting fact was brought forward, viz. that Mr. Arthur, in New Zealand, having lately examined the trout which were introduced there in 1869 from ova originally obtained from the Thames and the west of England, found great structural changes had taken place. The fish in question, moreover, living in different streams in New Zealand had also assumed local peculiarities of size and change of form; and, doubtless due to increased food, the annual increment of weight had risen from 11/2 to 21/2 pounds, and an example had been seen weighing 20 pounds. The cœcal appendages hitherto held as significant of species were found augmented from 33 to 50, as exemplified in British fish, to from 43 to 54 in the New Zealand examples, therefore showing that these organs are inconstant as to number. Having alluded to the different species, Dr. Day concluded that, as the various species of non-migratory trout, accepted by Dr. Günther, interbreed, and the results classed hybrids are not sterile, such gives increased reason for supposing these various forms are local races, and not different species; that if they are really distinct species division has not proceeded sufficiently far, because tha Gillaroo, or form of trout with a thickened middle coat of the stomach, has been termed Salmo stomachicus, Günther, whereas the great lake trout with a ihickened stomach, and the Charr having a similarly transformed organ, have not yet been differentiated into species. Dr. Day considers that all our non-migratory freshwater trout (including the Loch Leven) are merely local races; that interbreeding will produce mongrels, in which sterility need not be anticipated, while introducing new races (unless in the principle of preventing breeding in and in) will not be of much benefit to fisheries, unless the food is in excess of local requirements, for if not the new-comers will revert to the colour, form, and size of the original tenants of the water.—Two papers by Mr. Charles Darwin—(1) on the action of carbonate of ammonia on the roots of certain plants; and (2) the influence of carbonate of ammonia on chlorophyll bodies were read, abstracts of which appeared in last weeks NATURE.—The twelfth part of the Rev. A. Boog Watson's contributions to the mollusca of the Challenger Expedition was also read.

VII.—On the Cranial Osteology of Rhizodopsis

In a paper by Mr E. W. Binney on the Fossil Fishes of the Pendleton Coal Field, published in 1841, the dentary bone of Rhizodopsis is figured as the “upper jaw of a new species of Holoptychius,” to which, however, he did not attach any specific name. In the same paper its scales are also figured and referred to the same genus. Scales belonging to the same fish were afterwards figured by Professor Williamson under the name of Holoptychius sauroides, and again by Mr Salter, as those of Rhizodus granulatus. Both of these specific names occur under Holoptychius in Agassiz's general list of Ganoids published in 1843, but as they were unaccompanied either by figures or descriptions, it is really immaterial which of them, if indeed either, was applied by him to the fish in question. The authority for the term “sauroides” as applied to the common species of Rhizodopsis, the only species of the genus which is as yet known with certainty, must therefore remain with Professor Williamson. Holoptychius sauroides of Binney and of Messrs Kirkby and Atthey is quite another fish, now also distinguished generically as Strepsodus, and for it the specific name “sauroides” is therefore equally valid.

Observations on Fish

IN May last the writer dug a tank within the premises at Garden Reach. About the end of July it was stocked with young fish of several kinds, among others a species of carp, called by the natives “Katlah,” which abounds in the turbid waters of the Hooghly, within the range of the tides. The fry varied from half an inch to an inch in length, some even smaller. The “Kutlah” does not breed in fresh water, but attains an extraordinary size in a wonderfully short time in ponds. So very rapid has been the increase of the fish in question, that the fact seems worthy of chronicle in the pages of NATURE. On Sept. 22, the tank was swept with nets to catch one or two fish of the pike species that had been introduced accidentally with the others, and attained a size that rendered them dangerous to the fry of other kinds. In the net several dozens of the “carp “referred to were taken ; one of the largest weighed 14 oz , and measured 11 inches from the end of the upper lip to the tip of the tail, 1 3/4 inches thick behind the shoulder, and 3 1/2 inches in breadth ; the others were only one or two ounces lighter.