The development of the Norwegian wrasse fishery and the use of wrasses as cleaner fish in the salmon aquaculture industry     

Enrique Blanco Gonzalez  Femke de Boer 《Fisheries Science》2017,83(5):661-670

Norway leads the world aquaculture production of Atlantic salmon Salmo salar and farmed Norwegian Atlantic salmon is currently consumed around the globe. However, sea lice infestation is a major problem faced by the salmon aquaculture industry in Norway and elsewhere. The use of wild-caught cleaner fish, mainly wrasses, has been recommended over the other available methods as the most economical and environmentally friendly option to control sea lice infestation in salmon farming. Here, we review the development of the Norwegian wrasse fishery and the use of wrasses as cleaner fish. In this document, we address the sea lice problem and introduce the main wrasse species employed as cleaner fish, document the cleaning behaviour of wrasses, present the development of a new wrasse fishery associated with the salmon aquaculture industry, and finally, we identify the main challenges associated with the intensive use of wild-caught cleaner wrasses and provide some insight for future directions of the wrasse fishery and further development of aquaculture techniques to supply salmon facilities with domesticated cleaner fish.  相似文献   

Cannibalism among <Emphasis Type="Italic">Lithodes santolla</Emphasis> (Molina 1782) juveniles: effect of stocking density,stage and molt condition     

M. Paula Sotelano  Gustavo A. Lovrich  Federico Tapella 《Aquaculture International》2016,24(4):1025-1037

Losses of king crabs (deaths) in massive rearing conditions are frequently attributed to cannibalism. As several factors could influence cannibalism intensity during culture, the aim of the present study was to determine the effect of molt condition, stage and density on cannibalism among Lithodes santolla juveniles. Comparisons between intermolt and molt conditions and between C1 and C2 stages during intermolt were performed at three densities (6, 12 and 18 individuals per flask; that is equivalent to 236, 472 and 708 individuals m^?2). After 16 days of juvenile coexistence, cannibalism (injured + dead) was higher during molting (33.9 ± 4.5 %) than intermolt (21.7 ± 3.9 %), even though only 36 % of crabs had molted. Although cannibalism was similar in C1 and C2 stages, the proportion of dead animals was higher by a factor of three in C1 stage, probably due to the fact that animals reach the first juvenile stage with low energetic reserves, after the lecithotrophic larval development. Density was the main factor influencing cannibalism in our experiments. Higher densities promoted higher deaths, while agonistic interactions evidenced by injured crabs remained constant. Walking appendages were lost more often than chelipeds during first agonistic encounters. We recommend the use of intermediate densities (450 crabs m^?2 at most), the early detection of exuviae and the sorting of crabs after molting, for L. santolla rearing.  相似文献   

Effects of light intensity on molting,growth, precocity,digestive enzyme activity,and chemical composition of juvenile Chinese mitten crab <Emphasis Type="Italic">Eriocheir sinensis</Emphasis>   总被引：1，自引：0，他引：1  

Xiaowu LI  Zhongjie LI  Jiashou LIU  Tanglin Zhang  Chaowen Zhang 《Aquaculture International》2011,19(2):301-311

A 74-day growth trial was carried out to investigate the effects of light intensity on the juvenile Chinese mitten crab, Eriocheir sinensis, under semi-natural conditions. The experiment had three light intensity treatment groups, natural light (NL), middle light (ML), and low light (LL), as light intensity became weaker. The results indicated that light intensity had no significant effect on molting interval and molting frequency but did have a significant effect on the molting weight gain of the crab. Molting weight gain in group NL was significantly higher than that in group LL (P < 0.05). Specific growth rate in weight (SGRw) and in carapace width (SGRcw), weight gain, and final body weight were significantly affected by light intensity (P < 0.05). No significant difference was detected in survival between groups (P > 0.05). The precocious rate in groups NL, ML, and LL was 26.14, 15.48, and 17.14%, respectively. The precocious rate in group NL was significantly higher than that in groups ML and LL (P < 0.05). Chemical composition of the crab body was significantly affected by light intensity, but the activity of alkaline phosphatase, trypsin, and pancreatic lipase was not significantly affected by light intensity. The results indicated that the submitted light intensity was useful in reducing the precocious rate without affecting the normal growth of juvenile E. sinensis.  相似文献   

Species identification method for <Emphasis Type="Italic">Scombrops boops</Emphasis> and <Emphasis Type="Italic">Scombrops gilberti</Emphasis> based on polymerase chain reaction-restriction fragment length polymorphism analysis of mitochondrial DNA     

Shiro Itoi  Noriyuki Takai  Satomi Naya  Keitaro Dairiki  Akira Yamada  Seiji Akimoto  Kiyoshi Yoshihara  Haruo Sugita 《Fisheries Science》2008,74(3):503-510

ABSTRACT:   Gnomefish Scombrops boops and Scombrops gilberti are commercially important fishes in Japan, but these species are often confused in the markets because of their morphological similarity. To identify these two species, we performed nucleotide sequencing and restriction fragment length polymorphism (RFLP) analysis on 16S ribosomal RNA (rRNA) gene and the control region in mitochondrial DNA. Five and 12 nucleotide substitutions were observed between species in the 777-bp 16S rRNA gene and 471-bp control region, respectively. Diagnostic restriction sites for discriminating between S. boops and S. gilberti were found in the 16S rRNA gene, but not in the control region. Polymerase chain reaction (PCR)–RFLP analysis using two enzymes, Eco NI and Mva I, clearly discriminated between S. boops and S. gilberti identified by meristic characters. The PCR–RFLP analysis identified most of the 168 Scombrops young caught in the coastal waters of the Izu and Miura peninsulas as S. boops , suggesting that S. gilberti juveniles are rare in this area.  相似文献   

Migration history of Sakhalin taimen <Emphasis Type="Italic">Hucho perryi</Emphasis> captured in the Sea of Okhotsk,northern Japan,using otolith Sr:Ca ratios     

Kyoko Suzuki  Tomoyasu Yoshitomi  Yoichi Kawaguchi  Masaki Ichimura  Kaneaki Edo  Tsuguo Otake 《Fisheries Science》2011,77(3):313-320

Sakhalin taimen Hucho perryi populations have decreased drastically to near extinction. It is urgent to establish an effective conservation strategy based on an understanding of the characteristics of migration and habitat use of this species. We examined the migration history of anadromous Sakhalin taimen captured off the Sarufutsu coast, northern Hokkaido, Japan, using otolith Sr:Ca ratios and also examined the relationship between their otolith Sr:Ca ratios during freshwater and seawater residence in a rearing experiment. Otolith Sr:Ca ratios of some fish from the Sarufutsu coast showed freshwater levels (0.5–4.0 × 10⁻³) near the core, which thereafter increased to brackish water levels (4.0–6.0 × 10⁻³), and then to seawater levels (6.0–10.0 × 10⁻³) in the outermost regions. Those findings indicate that specimens from the Sarufutsu coast migrated to the brackish water region or the sea and spent most of their lives there. The anadromous migration pattern including the timing of downstream migration seems to be flexible among individuals in the species. They migrate between freshwater and seawater or brackish water several times during their lives, showing extensive habitat use. It is essential to secure the continuity among the freshwater, brackish water, and seawater areas for their effective conservation.  相似文献   

Binding profiles and cytokine-inducing effects of fish rhamnose-binding lectins on Burkitt’s lymphoma Raji cells     

Masahiro Hosono  Shigeki Sugawara  Atsushi Matsuda  Takeo Tatsuta  Yasuhiro Koide  Imtiaji Hasan  Yasuhiro Ozeki  Kazuo Nitta 《Fish physiology and biochemistry》2014,40(5):1559-1572

Rhamnose-binding lectin (RBL) is one of the animal lectin categories which take part in the innate immune responses of fish. Osmerus lanceolatus lectin (OLL) from shishamo smelt eggs is an RBL composed of two tandem-repeated domains, both of which are considered to be a carbohydrate-recognition domain. SAL, catfish (Silurus asotus) egg RBL composed of three domains, binds to Burkitt’s lymphoma Raji cells through globotriaosylceramide (Gb3) carbohydrate chain and to reduce cell size and growth by altering membrane composition without causing cell death. In this experiment, we tried to compare the binding effects of these two RBLs on Raji cells. Flow cytometric and fluorescence microscopic analyses revealed that OLL also directly bound to and shrunk Raji cells with ten times less reactivity than SAL but reduced cell growth with decreasing cell viability. Anti-Gb3 antibody completely blocked the binding of SAL to Raji cells but not that of OLL. In addition, the direct bindings of OLL and SAL to Raji cells were comparably inhibited by melibiose, but lactose was more effective inhibitor for the binding of OLL than that of SAL. These results suggest that OLL has slightly different cell-binding property compared with SAL and binds not only to Gb3 but also to the other carbohydrate receptor-bearing β-galactoside chains. The quantitative RT-PCR analysis revealed that SAL induced the expression of TNF-α but not of IFN-γ, IL-1β, and IL-10. Thus, SAL-induced cytostatic effect on Raji cells might be partially caused by TNF-α-mediated signaling pathway.  相似文献   

Sex reversal and growth performance in juvenile females of the freshwater crayfish <Emphasis Type="Italic">Cherax quadricarinatus</Emphasis> (Parastacidae): effect of increasing temperature and androgenic gland extract in the diet     

Mariana Sánchez De Bock  Laura Susana López Greco 《Aquaculture International》2010,18(2):231-243

Monosex male culture of C. quadricarinatus is proposed for increasing yields because males reach a larger size at harvest than females. An experiment was done to evaluate the effects of androgenic gland extract and temperature on sex reversal and somatic growth in early juvenile females. Females were exposed to the following experimental conditions: C: control food and temperature maintained at 26 ± 1°C; HT (high temperature): control food and temperature maintained at 28.5 ± 1°C; VHT (very high temperature): control food and temperature maintained at 31 ± 1°C; AG: food with enriched with androgenic gland (1/10 dose for each juvenile per day) and temperature maintained at (26 ± 1)°C. The juveniles were weighed, sexed, and growth increment (GI) and growth rate (GR) were calculated twice a month. The HT and AG groups differed from the C group in GI and GR indicating a greater somatic growth. At the end of the experiment, the HT and AG groups had similar weight but only the HT group had enhanced oocyte diameter, with some vitellogenic oocytes compared to the C group. In the HT group, there was significant sex reversal, as indicated by development of male and intersex male characteristics in different individuals. Both temperature and AG diet have a high potential for culture of this species because of their enhancement of somatic growth; higher temperature increases the proportion of males, a desirable characteristic of cultured populations.  相似文献   

Ontogenetic development of digestive enzymes and effect of starvation in miiuy croaker <Emphasis Type="Italic">Miichthys miiuy</Emphasis>  larvae     

Shan XJ  Huang W  Cao L  Xiao ZZ  Dou SZ 《Fish physiology and biochemistry》2009,35(3):385-398

The ontogenetic development of the digestive enzymes amylase, lipase, trypsin, and alkaline phosphatase and the effect of starvation in miiuy croaker Miichthys miiuy larvae were studied. The activities of these enzymes were detected prior to exogenous feeding, but their developmental patterns differed remarkably. Trypsin activity continuously increased from 2 days after hatching (dah), peaked on 20 dah, and decreased to 25 dah at weaning. Alkaline phosphatase activity oscillated at low levels within a small range after the first feeding on 3 dah. In contrast, amylase and lipase activities followed the general developmental pattern that has been characterized in fish larvae, with a succession of increases or decreases. Amylase, lipase, and trypsin activities generally started to increase or decrease at transitions from endogenous to exogenous feeding or diet changes, suggesting that these enzymatic activities can be modulated by feeding modes. The activities of all the enzymes remained stable from 25 dah onwards, coinciding with the formation of gastric glands and pyloric caecum. These results imply that specific activities of these enzymes underwent changes due to morphological and physiological modifications or diet shift during larval development but that they became stable after the development of the digestive organs and associated glands was fully completed and the organs/glands functioned. Trypsin and alkaline phosphatase were more sensitive to starvation than amylase and lipase because delayed feeding up to 2 days after mouth opening was able to adversely affect their activities. Enzyme activities did not significantly differ among feeding groups during endogenous feeding; however, all activities were remarkably reduced when delayed feeding was within 3 days after mouth opening. Initiation of larvae feeding should occur within 2 days after mouth opening so that good growth and survival can be obtained in the culture.  相似文献   

Sperm proteins in teleostean and chondrostean (sturgeon) fishes     

Li P  Hulak M  Linhart O 《Fish physiology and biochemistry》2009,35(4):567-581

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Seasonal Changes in Rigor Development and Flesh Texture of Wild Japanese Sea Bass (Lateolabrax japonicus)     

Teruo Nakayama  Keiko Hatae  Midori Kasai  Atsushi Ooi 《Journal Of Aquatic Food Product Technology》2017,26(5):578-592

The season for finding the firmest sashimi made from wild Japanese sea bass was investigated. Flesh rigor tension and contraction were measured by a “new” device with isometric (muscle length kept constant) and isotonic (balance beam moves freely) transducers. Both flesh rigor tension and contraction peaks appeared at the same postmortem times, with attainment of ultimate pH and adenosine triphosphate/inosine monophosphate ratio in four seasons. Seasonal seawater temperature correlated negatively to seasonal maximum rigor contraction and positively to seasonal flesh breaking strength at 72 h postmortem. After rigor peak tension attainment, the tension relaxation was much lower than that of other wild fish species, especially in summer. The sea bass muscle resisted structure disruption in rigor isometric tension generation. Wild sea bass sashimi was firmest in breaking strength in summer.  相似文献