Fish Species Of Commercial Value Research Articles

Morphological Characteristics of Digestive Tract and Clark Index of Ellochelon vaigiensis (Quoy & Gaimard, 1825) in some Coastal Estuarine Areas in the Mekong Delta

Ellochelon vaigiensis (Quoy & Gaimard, 1825) distributes widely from marine to brackish and freshwater in the Indo-Pacific region, including Vietnam. In the Mekong Delta, this fish distributes mainly in the estuaries and is a commercial value fish species. However, information about this fish digestive tract morphology and energy storage capacity had been still unknown. These characteristics, after being elucidated, wil be the basis for further research on artificially rearing them, contributing to the diversity of cultured subjects. This study was carried out in several coastal areas of provinces in the Mekong Delta from Ben Tre to Tra Vinh, Soc Trang and Bac Lieu. The analysis results of a total of 656 samples (289 females and 367 males) collected monthly, from March to October 2021, showed that E. vaigiensis had a small mouth, thick gill comb, short stomach and long intestines. This showed that they belong to the group of herbivorous fish. Ellochelon vaigiensis displayed a high energy storage capacity due to its relatively large Clark coefficient (0.73±0.03 SE). This value in the wet season (0.66±0.01 SE) is lower than in the dry season (0.85±0.01 SE, t=16.98, p<0.01). This value changed significantly according to the study sites (1-way ANOVA, F=4.50, p<0.01), with the highest value in Thanh Phu, Ben Tre (0.77±0.02 SE) and the lowest in Duyen Hai, Tra Vinh (0.70±0.02 SE), but this coefficient was not statistically significant between males (0.73±0.01 SE) and female (0.73±0.01 SE, t=0.64 p=0.52).

Potential Analysis of Low Economic Value Fish in Lamongan Regency, East Java, Indonesia

The purpose of this study was to determine the potential of low commercial value fish species in Lamongan Regency, East Java, Indonesia. The processed data included primary and secondary data. Data were processed using the LQ method and analyzed descriptively by way of compiling data into tables. The survey results showed that there are ten types of low commercial value fish in Lamongan Regency, East Java, Indonesia, namely Sardinella fimbriata (Tembang fish), Leiognathus bindus (Peperek fish), Harpadon nehereus (Puso fish), Sardinella lemuru, (Lemuru fish), Saurida tumbil (Beloso fish), Gerres abbreviatus (Kapasan fish), Anodontostoma chacunda (Juwi fish), and Cynoglossus lingua (Lidah fish). The results of the LQ method showe that there are three types of fish that have the potential to be made of high economic value products, namely L. bindus (11.36), A. chacunda (2.35), and S. fimbriata (2.32). Fish Auction (TPI) that has the potential in terms of fish productivity to be developed is TPI Weru, Lamongan, East Java, Indonesia. The typology of fishermen in TPI Weru has less experience working as a fisherman than other TPI but the level of education is higher and the age of fishermen is younger so that it affects the productivity of fish catches.

MALDI-TOF mass spectrometry for rapid differentiation of Tenacibaculum species pathogenic for fish.

Tenacibaculosis is a fish disease that limits the culture of a variety of marine fish species of commercial value in the world. The genus Tenacibaculum includes several species, and their discrimination is of clinical interest in order to improve the management of an outbreak of the disease. In this study, a novel proteomic approach based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis was evaluated for the identification and differentiation of Tenacibaculum species. The peak mass lists derived from MALDI-TOF-MS analysis were examined for the detection of potential biomarkers, similarity and cluster analysis and principal component analysis (PCA). Culture media used for bacterial growth did not affect the mass fingerprints. Eight genus-specific peaks were found in all the Tenacibaculum species analysed. Moreover, at least one species-specific peak was found in the species Tenacibaculum maritimum, Tenacibaculum soleae, Tenacibaculum dicentrarchi, Tenacibaculum litoreum and Tenacibaculum ovolyticum. These peaks could serve as biomarkers for the rapid identification of these bacterial fish pathogens. The cluster and PCA clearly separated the species T. maritimum, T. soleae, T. dicentrarchi and T. ovolyticum in different clusters. However, species of Tenacibaculum discolor and Tenacibaculum gallaicum were difficult to distinguish based on their protein fingerprints. To our knowledge, this is the first study that deals with the characterization and determination of biomarkers of Tenacibaculum species by MALDI-TOF mass spectrometry. This approach proved to be an effective and reliable technique for the discrimination of the Tenacibaculum species; therefore, it could be integrated as a routine diagnostic tool in microbiological laboratories.

Length-Weight and Length-Length Relationships of Heterotis niloticus (Cuvier, 1829) and Raiamas senegalensis (Steindachner, 1870)

The sustainable exploitation of freshwater fish species of commercial value is inevitable for fishery to continuously play its role in the social and economic growth of Nigeria. Heterotis niloticus and Raiamas senegalensis are two commercially available species in Lake Alau. The length-weight relationship (LWR) and length-length relationship (LLR) of these species were investigated to determine their growth patterns and state of wellbeing. Fish samples were collected from fishermen landings weekly for four months. The morphometric indices such as Total Length (TL), Standard Length (SL) and Body Weight (BW) were assessed using standard methods. A total of 1583 specimens comprising 602 H. niloticus (51.61% males and 48.39% females) and 981 R. Senegalensis (56.57% males and 43.43% females) were collected. TL ranged from 10.2 to 42.8 cm; 15.5 to 41.6 cm, SL 9.5 to 39.9 cm; 14.0 to 39.9 cm and weighed between 128.50 and 420.14 g; 123.05 and 401.8 cm for H. niloticus and R. Senegalensis, respectively. The growth coefficient (b) ranged between 3.127 and 3.340 for H. niloticus and 2.592 and 3.193 for R. Senegalensis. This indicates positive allometric growth pattern for the two-species investigated. The LLR varied from 1.511 to 2.148 and 1.506 to 1.820 for H. niloticus and R. Senegalensis, with mean condition factor of 2.04 ± 1.76 (H. niloticus) and 1.97 ± 1.98 (R. Senegalensis). This study therefore concludes that Lake Alau is favourable to good growth, reproduction, and survival of these species.

TRACE ELEMENTS IN FISH TISSUE WITH COMMERCIAL VALUE OF THE DANUBE DELTA BIOSPHERE RESERVE

Researches and analysis of heavy metals concentrations in the fish species exploited as a food source are of great interest due to long term toxic effects on human health even at very low concentrations. Therefore, we have conducted this study in an area of great interest in terms of aquatic biodiversity, but also of tourism and trade. Depending on the degree of toxicity in delta aquatic ichtyofauna, five heavy metals (Cr, Cu, Hg, Ni, Pb) and a metalloid (As) concentrations were measured in the muscle tissue of fifteen commercial value fish species in order to assess their impact on human health. Samples were collected seasonally (twice a year) between 2013-2014 from Somova-Parches aquatic complex (situated near Tulcea - Romania industrial area in predeltaic area) and four representative aquatic complexes for Danube Delta, respectively Sontea-Fortuna, Matita-Merhei, Gorgova-Uzlina and Rosu-Puiu. The determination of elements from collected samples was done differently, mercury was analysed by cold vapor atomic absorption, while the other five elements (arsenic, chromium, copper, nickel and lead) were determined using mass spectrometry with inductively coupled plasma. The investigations of heavy metals revealed interspecific differences, important not only because of each specie particularities and food chain, but also for intraspecific variation caused by geographical location. The statistical analysis of the 4800 measurements in correlation with the analysis of the bioaccumulation factor (BCF) reflected the degree of contamination on the exploited Danube Delta Biosphere Reserve fish resources and also showed an irregular distribution of heavy metals and metalloids depending on anthropogenic pollutants.

The importance of deep-sea vulnerable marine ecosystems for demersal fish in the Azores

Cold-water corals and sponges aggregations are important features of the deep sea, recently classified as vulnerable marine ecosystems (VMEs). VMEs increase habitat complexity, believed to act as feeding, reproductive, nursery and refuge areas for a high number of invertebrates and fish species. In the Azores archipelago (NE Atlantic), VMEs are prevalent but their ecological role has not received much attention. The objective of this study was to investigate the importance of VMEs in influencing the distribution of demersal fish in the Azores. With data collected during experimental longline surveys , we modeled the catch of six demersal fish species of commercial value (Helicolenus dactylopterus, Pagellus bogaraveo, Mora moro, Conger conger, Phycis phycis, Pontinus kuhlii) in relation to the presence of VMEs and other environmental factors using General Additive Models (GAMs). Our study demonstrated that total fish catch was higher inside VMEs but the relationship between fish and VMEs varied among fish species. Species specific models showed that catch was strongly influenced by environmental factors, mainly depth, whilst the presence of VMEs was only important for two rockfish species; juvenile and adult P. kuhlii and juvenile H. dactylopterus. Although the association between deep-sea demersal fish and VMEs may be an exception to the rule, we suggest that VMEs act as an important habitat for two commercially important species in the Azores.

Jellyfish as prey: frequency of predation and selective foraging of Boops boops (Vertebrata, Actinopterygii) on the mauve stinger Pelagia noctiluca (Cnidaria, Scyphozoa).

In recent years, jellyfish blooms have attracted considerable scientific interest for their potential impacts on human activities and ecosystem functioning, with much attention paid to jellyfish as predators and to gelatinous biomass as a carbon sink. Other than qualitative data and observations, few studies have quantified direct predation of fish on jellyfish to clarify whether they may represent a seasonally abundant food source. Here we estimate predation frequency by the commercially valuable Mediterranean bogue, Boops boops on the mauve stinger jellyfish, Pelagia noctiluca, in the Strait of Messina (NE Sicily). A total of 1054 jellyfish were sampled throughout one year to quantify predation by B. boops from bite marks on partially eaten jellyfish and energy density of the jellyfish. Predation by B. boops in summer was almost twice that in winter, and they selectively fed according to medusa gender and body part. Calorimetric analysis and biochemical composition showed that female jellyfish gonads had significantly higher energy content than male gonads due to more lipids and that gonads had six-fold higher energy content than the somatic tissues due to higher lipid and protein concentrations. Energetically, jellyfish gonads represent a highly rewarding food source, largely available to B. boops throughout spring and summer. During the remainder of the year, when gonads were not very evident, fish predation switched towards less-selective foraging on the somatic gelatinous biomass. P. noctiluca, the most abundant jellyfish species in the Mediterranean Sea and a key planktonic predator, may represent not only a nuisance for human leisure activities and a source of mortality for fish eggs and larvae, but also an important resource for fish species of commercial value, such as B. boops.

Cormorant Catch Concerns for Fishers: Estimating the Size-Selectivity of a Piscivorous Bird

Conflict arises in fisheries worldwide when piscivorous birds target fish species of commercial value. This paper presents a method for estimating size selectivity functions for piscivores and uses it to compare predation selectivities of Great Cormorants (Phalacrocorax carbo sinensis L. 1758) with that of gill-net fishing on a European perch (Perca fluviatilis L. 1758) population in the Curonian Lagoon, Lithuania. Fishers often regard cormorants as an unwanted “satellite species”, but the degree of direct competition and overlap in size-specific selectivity between fishers and cormorants is unknown. This study showed negligible overlap in selectivity between Great Cormorants and legal-sized commercial nets. The selectivity estimation method has general application potential for use in conjunction with population dynamics models to assess fish population responses to size-selective fishing from a wide range of piscivorous predators.

Age and growth of bassan barbel, <I>Barbus pectoralis</I> (Actinopterygii: Cypriniformes: Cyprinidae), under conditions of a dam reservoir

Background. Bassan barbel, Barbus pectoralis Heckel, 1843, is widely distributed in the lakes and river systems of Turkey and its neighbouring countries. Bassan barbel is a fish species of commercial value. The aim of this study was to provide necessary biological features of bassan population from Kemer Reservoir. Materials and methods. Biological aspects of Bassan barbel were studied based on a total of 206 specimens collected from Kemer Reservoir, during the period December 2004–November 2005. The fish age was determined from scales. Length–weight relation and Fulton’s condition factor were used to evaluate fish condition. Results. The fish were from 1 to 6 year-old. Fork length (FL)–weight (W) relations were estimated as W = 0.011 · FL2.980 for all specimens studied. The estimated growth parameters of the von Bertalanffy equation were: L∞ = 34.8 cm, W∞ = 549.58 g, K = 0.168 · year-1 and t0 = -1.590 year for all specimens examined. Conclusion. The fish from Kemer Reservoir were characterized by an average growth rate and it was observed that the specimen grew fast during the first two years of life. The reason why bassan barbel had low condition values is probably because the environmental conditions in the reservoir were poor.

Fate of oil hydrocarbons in fish and shrimp after major oil spills in the Arabian Gulf.

Pollution of the marine environment with crude oil represents one of the most serious environmental problems that confront Saudi Arabia and other Gulf states. Oil pollution in the Arabian Gulf environment may affect the inhabitants through (1) human health hazard resulting from the consumption of contaminated sea food, (2) loss of food due to alteration of species productivity or elimination of some species, and (3) deterioration of recreation areas. Moreover, the problem of oil spill may be more severe in this part of the world. This is mainly because the source of drinking water in various Gulf states depends largely on sea water from which desalinated water is produced. Contamination of sea water with crude oil may adversely affect the quality of desalinated water and may badly damage desalination plants. During the last twelve years, the Arabian Gulf has been affected by two major oil spills. The first spill occurred on February 4, 1983 during the Iraq-Iran War, and the second major oil spill occured during the 1991 Gulf War. There is limited information about the level of oil hydrocarbons in edible fish, but two studies were carried out after both spills. This paper summarized the results of both studiesmore » carried out to assess the extent of contamination of various fish species of commercial value from the Arabian Gulf with oil hydrocarbons.« less