Preliminary assessment of large‐scale co‐culture of sandfish (Holothuria scabra) with the Babylon snail (Babylonia areolata) in earthen ponds and in raceways

Holothuria scabra (sandfish) and Babylonia areolata were trialed in two large‐scale co‐culture experiments. Experiment 1 assessed co‐culture in 4 × 400 m² earthen ponds where Babylonia were cultured in a central pen at a density of 400 individuals/m² with sandfish occupying the remaining pond space at 1.1 individuals/m². Sandfish grew from 18.20 ± 6.67 g to 119.03 ± 17.74 g in 92 days and Babylonia (fed trash fish in both experiments) grew from 0.90 ± 0.38 g to 4.93 ± 1.44 g, but Babylonia growth was not increased in co‐culture compared to monoculture. Water and sediment quality varied between co‐culture and monoculture ponds. Neither showed clear improvement due to sandfish culture. Experiment 2 compared non‐segregated sandfish‐Babylonia co‐culture with Babylonia monoculture in 20 m² concrete raceways. Sandfish were cultured at 2 individuals/m² and Babylonia at 300 individuals/m². Sandfish grew up to 1.91 g.day^?1 with 100% survival. Babylonia weight gain was significantly greater in co‐culture raceways (3.35 ± 0.64 g over 61 days), which was double that of Babylonia in monoculture. Substrate total N was reduced by 20% in co‐culture compared with monoculture (p = .032). This provisional study of commercial scale sandfish‐Babylonia co‐culture demonstrates culture compatibility, providing a basis for further system development.     

Growth performance,carcass quality characteristics and colonic microbiota profiles in finishing pigs fed diets with different inclusion levels of rice distillers’ by‐product

The aim of this study was to evaluate the effects of diets containing rice distillers’ by‐product (RDP) on growth performance, carcass characteristics, meat quality, and gut microbiota of fattening pigs. Twenty‐four crossbred finishing pigs (Duroc × Landrace × Yorkshire), 56.9 ± 3.1 kg initial body weight, were randomly allocated to three groups. For 56 days, pigs were fed one of three diets including RDP0 (control), RDP15 (15% RDP in DM), and RDP30 (30% RDP in DM). With RDP level in diet, average daily gain and backfat thickness linearly increased (p < 0.05), and drip loss tended to increase (p ≤ 0.08). In addition, 16S ribosomal RNA gene amplicon profiling showed that RDP was associated with modulation of colonic microbiota composition, especially at family and genus levels. Relative abundance of Porphyromonadaceae and Erysipelotrichaceae families in colonic digesta increased with inclusion of RDP, while that of Enterobacteriaceae decreased. The proportion of genera unclassified Erysipelotrichaceae, and Butyrivibrio increased as inclusion of RDP. These results indicate that up to 30% inclusion in diet of finishing pigs, RDP can modulate colonic microbiota composition, and induces an improvement of animal growth and fat deposition.     

Developing socioeconomic indicators for an ecosystem-based fisheries management approach: An application to the Korean large purse seine fishery

Developing socioeconomic indicators for ecosystem-based fisheries management is particularly important. This is because socioeconomic factors have direct effects on ecosystems, and ecosystems have direct effects on socioeconomic factors. Therefore, it is imperative that socioeconomic indicators are developed and evaluated in order to predict changes in ecosystems and to provide advice for effective fisheries management. In this study, socioeconomic indicators have been developed to be combined with biological and ecological indicators, in order to conduct the ecosystem-based fisheries assessment. In terms of socioeconomic indicators, five socioeconomic criteria were considered as important attributes of socioeconomic changes. These were economic production, business conditions, levels of income, the state of the market, and levels of employment. In order to establish reference points for the evaluation of indicators, target reference points and limit reference points were set through a comparison with other industries or other fisheries rather than by using the Traffic Light System (TLS) method, which has been used in many previous studies. In addition, on the basis of the application of developed indicators and reference points to the Korean large purse seine fishery, the socioeconomic conditions of the fishery and the usefulness of the indicators were evaluated and management implications were discussed.     

An ecosystem-based assessment of the Korean blue crab trammel net fishery in the Yellow Sea and management implications

Landings in the blue crab, Portunus trituberculatus, fishery in Korean waters of the Yellow Sea have declined substantially from 11,000 t in the 1980s to 2,300 t in 2004. Blue crab habitat quality in the Yellow Sea has been degraded by anthropogenic activities including sand mining, land reclamation, and coastal pollution. Various traditional management measures have been implemented, including closed seasons during spawning and size limits, but these measures alone have been unsuccessful to conserve blue crab stocks. Consequently, a total allowable catch and a stock-rebuilding program using an ecosystem-based management approach were implemented in 2003 and 2006, respectively to rebuild blue crab stocks and restore habitats. This program involved assessment of both blue crab stock status and trammel-net fishery impacts at an ecosystem-level using an ecosystem-based fisheries assessment method ( [Zhang et al., 2009] and [Zhang et al., 2010]), which considered fishery data from catch and effort time-series, crab population biology, and ecosystem characteristics, including habitats and environmental conditions. Recent (2008) management status indices have shown significant positive change compared to conditions in 2000 with respect to sustainability of the stock and fishery and with regards to biodiversity and ecosystem habitat quality.     

Osmoregulatory and immunological status of the pond-raised striped catfish (<Emphasis Type="Italic">Pangasianodon hypophthalmus</Emphasis> S.) as affected by seasonal runoff and salinity changes in the Mekong Delta,Vietnam

In Vietnam, the production of striped catfish Pangasianodon hypophthalmus S. reached more than 1.2 millions of tons in 2014 and is mainly gathered in the Mekong Delta (South Vietnam). A survey was carried out during the dry season 2013 (March–April) and rainy season 2014 (July–August) in 12 fish farms of the lower (Tra Vinh Province) and higher (Can Tho Province) Mekong River Delta. This study allowed drawing up current key osmoregulatory and innate immune parameters of striped catfish in aquaculture depending on the geographical location, particularly the proximity to the River Mekong Estuary and the seasonal surface runoff. In the dry season, plasma osmolality was positively correlated with salinity. Gill Na⁺K⁺ ATPase dropped in the rainy season, while kidney Na⁺K⁺ ATPase remained stable. Abundance of immune blood cells, especially thrombocytes and monocytes, tended to increase in farms located in tidal area. Production of reactive oxygen species in the spleen, kidney lysozyme activity and plasma complement activity did not vary whatever the season or the proximity to the estuary. Plasma lysozyme activity was 50-fold higher than in kidney and increased in the rainy season as well as in tidal sites. Kidney complement activity decreased in the dry season, especially in tidal sites. In conclusion, regarding key osmoregulatory and immune factors, striped catfish farms located in the Mekong Delta may be affected by seasonal and regional salinity and runoff fluctuations.     

Determination of amino acid and fatty acid composition of goldband goatfish [Upeneus moluccensis (Bleeker, 1855)] fishing from the Gulf of Antalya (Turkey)

In this study, we aimed to determine the basic food components, fatty acids and amino acids, and variations in these components with months in goldband goatfish (Upeneus moluccensis) that fishing from Gulf of Antalya. As a result of the analyzes, the crude fat values were determined between 1.43 and 3.78%, and the crude protein values were determined between 20.79 and 22.16%. The most abundant fatty acids were determined: palmitic acid (C16:0), stearic acid (C18:0), palmitoleic acid (C16:1c9), oleic acid (C18:1c9), linoleic acid (C18:2n-6), eicosatrienoic acid (C20:3n-3), arachidonic acid (C20:4n-6), eicosapentaenoic acid (C20:5n-3), docosapentaenoic acid (C22:5n-6), and docosahexaenoic acid (C22:6n-3). The most abundant amino acids were determined lysine and leucine, aspartic acid, glutamic acid, alanine, and glycine. The differentiations of essential nutrient components, fatty acids, and amino acids were found generally significant (P < 0.05).

     

Putting the pieces together: Recent growth,nutritional condition,and mortality of Engraulis anchoita larvae in the Southwest Atlantic

Dynamics of clupeiform fish populations such as anchovy are frequently impacted by environmental variations which can affect the success of the species recruitment. Herein, we have analyzed recent otolith growth rate, RNA/DNA nutritional condition index (sRD), and mortality rate of argentine anchovy larvae Engraulis anchoita from three different nursery areas in the Southwest Atlantic. We have evaluated the relationship between the environmental variables (abundance of copepod nauplii, temperature, chlorophyll‐a concentration, and abundance of E. anchoita larvae) and larval endogenous variables (size, weight, age, and otolith radius) to sRD and recent growth rate. Fast larval growth rates were observed toward the northern sector of the studied area, characterized by higher temperature. High values of sRD were associated with higher nauplii abundance in the proximity of coastal fronts. The larvae with the lowest growths and lowest minimum values of nutritional condition coincided with the area where there was less abundance of nauplii and higher larval mortality. Larval size and nauplii abundance were positive explanatory factors for both recent growth rate and sRD index. Temperature had a positive effect on recent growth rate and a negative effect on sRD index. This condition index was poorly explained in terms of model fit in comparison with the growth model. The results herein provided could be significant to better understand the recruitment of the species, as to determining favorable areas for the growth and survival of anchovy larvae.     

Biochemical comparison of lectins among three different color strains of the red alga Kappaphycus?alvarezii

The red alga Kappaphycus alvarezii is economically important as an edible species and as a source of carrageenan, and has been extensively cultivated in many tropical countries. For this species, different color strains, which differ from each another in growth rate and carrageenan content, have been reported for decades. In this study, lectins from brown, red, and green strains of K. alvarezii cultivated in Vietnam were isolated and characterized for evaluation of their biochemical properties and contents. The results showed that each color strain contained in common the three lectins, named KAA-1, KAA-2, and KAA-3, which shared the hapten-inhibition profile of hemagglutination, 20 N-terminal amino acid sequence, and equivalent molecular mass within a range of 28,016 ± 1.2 to 28,021 ± 1.8 Da, but differed in their yields, with the highest yield of KAA-2. These properties of the three isolectins were also comparable among the three different color strains. However, the sum of the yields of the three isolectins decreased in the order: red (21.4 mg) to green (15.9 mg) to brown strains (15.1 mg), from 500 g fresh alga. Thus, this algal species can be a good source of useful lectins, irrespective of color strain.     

Geographical comparison of genetic diversity in Asian landrace wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.) germplasm based on high-molecular-weight glutenin subunits

Glutenin largely determines wheat bread baking quality. As high-molecular-weight glutenin subunit (HMW-GS), related to Glu-1 loci, determines wheat flour elasticity, it correlates strongly with bread-making quality. This study was aimed at clarifying genetic variations in bread-making characteristics between East and West Asian wheat landrace germplasms, by investigating HMW-GS allelic composition of 1068 wheat accessions. Herein, the accession number having reported HMW-GS pattern in previous studies was 855. However, the accession number with newly detected HMW-GS patterns was 114. These new HMW-GS patterns were classified into 4 types based on similarity. Eight Korean accessions with these four types were identified. Concerning landrace germplasm nature, 99 accessions showed heterogeneous patterns caused by seed mixture. The Glu-1 loci allelic variation analysis, revealed that the percentages of Glu-A1c (73.6%), Glu-B1b (60.2%), and Glu-D1a (68.5%) were highest at Glu-A1, Glu-B1, and Glu-D1 loci, respectively. The incidence of preferable alleles for bread baking was high in Chinese accessions. In bread-making quality evaluation using Glu-1 score, 24 among 35 accessions with full score were from China. The polymorphic information content index of each origin based on HMW glutenin subunit combination showed that West Asian and neighboring-regional landraces, excluding Afghanistan ones, were more diverse than East Asian landraces excluding Chinese ones. Cluster analysis based on Glu-1 allelic combination showed that many Korean, Japanese, and Afghan accessions were in the same group. However, many Chinese and other West Asian accessions were in the other group despite geographical distance.