Kualitas Kolagen Gelembung Renang Ikan Gulamah (Johnius trachycephalus) Dari Perairan Pesisir Kota Tarakan

Gulamah fish is a bycatch that is commonly found in the waters of the City of Tarakan. Gulamah fish in Tarakan City is processed into salted fish which produces offal waste and swimming bubbles. Swimming bubbles are known to have high collagen content. The purpose of this study was to obtain information about the length relationship between fish weight and swim bladder as well as the collagen characteristics of the gulamah swim bladder. The research was conducted in 2 stages, namely the length-weight analysis stage with swimming bubbles, and the second stage, namely the extraction and characterization of collagen from the swimming bladder of gulamah fish. The relationship between fish length and weight is a positive allometric, while the relationship between fish length and fish weight and swimming bladder of fish is a negative allometry. The physical chemical parameters of collagen obtained water content values of 29.28% - 29.30%, protein 2.86% - 2.88%, fat 9.53% - 9.55% and viscosity 11.5 ?sp.Gulamah fish is a bycatch that is commonly found in the waters of the City of Tarakan. Gulamah fish in Tarakan City is processed into salted fish which produces offal waste and swimming bubbles. Swimming bubbles are known to have high collagen content. The purpose of this study was to obtain information about the length relationship between fish weight and swim bladder as well as the collagen characteristics of the gulamah swim bladder. The research was conducted in 2 stages, namely the length-weight analysis stage with swimming bubbles, and the second stage, namely the extraction and characterization of collagen from the swimming bladder of gulamah fish. The relationship between fish length and weight is a positive allometric, while the relationship between fish length and fish weight and swimming bladder of fish is a negative allometry. The physical chemical parameters of collagen obtained water content values of 29.28% - 29.30%, protein 2.86% - 2.88%, fat 9.53% - 9.55% and viscosity 11.5 ?sp.

Evaluation of Genomic Selection for Seven Economic Traits in Yellow Drum (Nibea albiflora)

Yellow drum (Nibea albiflora) is an important maricultural fish in China, and genetic improvement is necessary for this species. This research evaluated the application of genomic selection methods to predict the genetic values of seven economic traits for yellow drum. Using genome-wide single-nucleotide polymorphisms (SNPs), we estimated the genetic parameters for seven traits, including body length (BL), swimming bladder index (SBI), swimming bladder weight (SBW), body thickness (BT), body height (BH), body length/body height ratio (LHR), and gonad weight index (GWI). The heritability estimates ranged from 0.309 to 0.843. We evaluated the prediction performance of various statistical methods, and no one method provided the highest predictive ability for all traits. We then evaluated and compared the use of genome-wide association study (GWAS)–informative SNPs and random SNPs for prediction and found that GWAS-informative SNPs obviously increased. It only needed 5 and 100 informative SNPs for LHR and BT to achieve almost the same predictive abilities as using genome-wide SNPs, and for BL, SBI, SBW, BH, and GWI, about 1000 to 3000 informative SNPs were needed to achieve whole-genome level predictive abilities. It can be concluded from the test results that breeders can use fewer SNPs to save the breeding costs of genomic selection for some traits.

Ontogenetic development of tetra Astyanax lacustris (Characiformes: Characidae)

ABSTRACT Ontogenetic development of the tetra Astyanax lacustris was studied under laboratory conditions. Larvae obtained by induced reproduction were maintained individually in tissue-culture plates, at 25°C. Daily observations and morphometric measurements were performed. Larvae hatched with a total length (TL) of 3.02 ± 0.34 mm (average ± standard deviation) without pigmentation and 0.06 ± 0.02 mm³ of yolk reserves. The yolk-sac larval period lasted 26 h post-hatching (hph). During this period, eye pigmentation started, the digestive tract emerged, the anus opened, and the animals began to show steady movements. Inflation of the swimming bladder initiates the preflexion stage, which extended until 230 hph. During this stage, the transition from endogenous to exogenous feeding was observed, with the yolk reserve being completely absorbed after 74 hph (TL: 4.17 ± 0.36 mm). Up to 86 hph it was possible to observe the first food ingested within the digestive tract. This period was followed by the flexion stage, with the folding of the notochord tip and development of the caudal fin (11-13 days post-hatching). Finally, during the last larval developmental stage (postflexion), the segmentation of the fin rays was completed, and the emergence of scales was observed (TL: 5.97 ± 0.65 mm). The larval ontogenetic development of A. lacustris was completed after 22 post-hatching days (dph).

Effect of Concentration and Temperature on the Rheological Behavior of Collagen from Swimming Bladder of Grass Carp

Type I collagen was obtained from grass carp swimming bladder. Dynamic viscoelastic properties of the collagen solutions with concentrations of 0.1–1.0% (w/w) were characterized by means of oscillatory rheometry at temperatures ranging from 20 to 50°C. All collagen solutions showed a shear-thinning flow behavior. Both storage modulus (G’) and loss modulus (G’’) increased with the increase of frequency and concentration. The experiment results also showed the viscoelastic of collagen was similar to viscous behavior of liquid (G’>G’’) in low frequency and elasticity of solid (G’<G”) in high frequency. Changes in the temperature range (20-50°C) slightly affected the rheological properties extensively including the sudden decrease of the crossover frequencies at the temperature of 30°C.

The swelling of fish skins in solutions of inorganic and organic acids

In experiments carried out partly in the laboratory and partly in breweries, it was noticed that when the method commonly used for the preparation of clarifying medium from isinglass was applied to fish skins, the latter were found to contain a high percentage of collagen, but they showed only slight swelling and very little gelatin diffused from them. When the organic acid used was varied, it was noticed that the behaviour of the skins changed considerably. In extreme cases shrinkage replaced swelling. The constitution of gelatin obtained from fish skins is different from that obtained from mammalian skins, and the great difference in the behaviour of gelatin according to whether it is obtained from fish skins or from mammalian skins may, with certainty, be attributed to this difference in chemical composition. No attempt is made in this paper to describe at length the chemical constitution of fish gelatin. We limit ourselves merely to a suggestion as to how its chemical constitution may influence the action of the reagents used to bring about swelling. Gelatin from fish skins is also likely to differ chemically from that extracted from the swim bladder. Though there is no exact knowledge of the chemistry of the two gelatins, the fact that the swimming bladder develops from the meso-blast, whilst the skin develops from the epi-blast, justifies one in looking for profound chemical differences. In this case also, the difference in chemical constitution is probably the cause of the difference in the behaviour of the respective materials to swelling agents. One specific difference between material of mammalian and material of fish origin may be noted here. Gelatin from calf skin, and the skin itself will absorb considerable quantities of water and yet retain the original structure. Fish skins, however, and the gelatin extracted from them, and isinglass absorb only a little water, up to a certain definite point. When this point is passed, there is disruption accompanied by considerable diffusion of nitrogenous products into the aqueous phase.

On the Swimming Bladder and Flying Powers of Dactylopterus volitans

Dactylopterus volitans, the so-called “flying gurnard,” is not included by Günther in the genus Triglidæ, as its name might imply, but is assigned to the small allied family of Cataphracti.Günther diagnoses it as follows :—“Dactylopterus, no lateral line, pectoral fins very large, an organ of flight, with the upper portion detached and shorter, granular teeth in the jaws, none on the palate, air bladder divided into two lateral halves, each with a large muscle.”Before proceeding to describe in detail the swimming bladder and other anatomical peculiarities, it may be well to state, that the skull is provided with a superficial bony covering which projects backwards over the region of the “shoulder” in two flattened plates, each terminating in a spine (seen in fig. 2). Also that the first four vertebræ of the column have coalesced so as to form a rigid tube, the neural spines being united as a vertical plate, which for convenience I have termed the neural plate.