Aquaculture Revisited

1976 ◽  
Vol 33 (4) ◽  
pp. 880-887 ◽  
Author(s):  
John E. Bardach
Keyword(s):  
Social Impact ◽  
Information Dissemination ◽  
Raw Materials ◽  
Survival Rates ◽  
Larval Survival ◽  
Larval Rearing ◽  
Tropical Asia ◽  
Economy Of Scale ◽  
The Pacific ◽  
Choice Of Species

Opportunities for and constraints of animal aquaculture are considered with special reference to the Pacific basin. Choice of species for husbandry depends on biological, cultural, and marketability criteria. Seed production (spawning and larval rearing) may be centralized, with certain economy of scale advantages, even in artisanal aquaculture enterprises, provided adequate distribution facilities for postlarvae are made. Larval survival rates for several actual or potential cultivars still need enhancement through applied research. Practices for the growout phase of aquatic stock differ, depending on the intensity of fixed and variable inputs, by analogy with terrestrial systems one may distinguish feedlot, managed pasturage, and ranching modes. For much of tropical Asia best expansion opportunities exist in managed pasturage polyculture possibly combining the grow-out of crustacea for export with local, largely herbivorous and planktivorous semistaple species. Extraneously supplied feeds, when used, will differ with the species and locally available raw materials. Nonbiotechnical constraints to aquaculture expansion are found in the areas of training, credit, extension, social impact of change, and information dissemination. They may be as difficult, if not more difficult, to overcome as purely biological ones.

scholarly journals Does Larval Rearing Diet Lead to Premating Isolation in Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae)?

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 203
Author(s):  
Xue-Yuan Di ◽  
Bin Yan ◽  
Cheng-Xu Wu ◽  
Xiao-Fei Yu ◽  
Jian-Feng Liu ◽  
...  
Keyword(s):  
Mate Choice ◽  
Spodoptera Litura ◽  
Artificial Diet ◽  
Survival Rates ◽  
Intrinsic Rate Of Increase ◽  
Larval Rearing ◽  
Population Parameters ◽  
Premating Isolation ◽  
Behavioral Isolation ◽  
Rate Of Increase

Host plant preference during the larval stage may help shape not only phenotypic plasticity but also behavioral isolation. We assessed the effects of diet on population parameters and mate choice in Spodoptera litura. We raised larvae fed on tobacco, Chinese cabbage, or an artificial diet, and we observed the shortest developmental time and highest fecundity in individuals fed the artificial diet. However, survival rates were higher for larvae on either of the natural diets. Population parameters including intrinsic rate of increase and finite rate of increase were significantly higher with the artificial diet, but this diet led to a lower mean generation time. Copulation duration, copulation time, and number of eggs reared significantly differed between diets. In terms of mate choice, females on the artificial diet rarely mated with males fed on a natural host. Our results support the hypothesis that different diets may promote behavioral isolation, affecting mating outcomes. Thus, findings for populations fed an artificial diet may not reflect findings for populations in the field.

scholarly journals The isotopic differences and implications for Pacific razor clams along the Washington coast

2019 ◽  
Vol 98 ◽  
pp. 12005
Author(s):  
Yongwen Gao ◽  
Joseph Gilbertson ◽  
Hongyan Zhang
Keyword(s):  
Stable Isotope ◽  
Isotope Analysis ◽  
Survival Rates ◽  
Washington State ◽  
Growth And Survival ◽  
Razor Clam ◽  
The Pacific ◽  
Indian Tribes ◽  
Razor Clams ◽  
Biological Differences

The Pacific razor clam fishery in Washington State has been co-managed by the coastal Indian Tribes and the state, but little is known about the growth and population structure of the clams due to difficulties of tagging and monitoring. Here we report the results of a pilot study using stable isotope ratios (δ13C and δ18O) of razor clam shells collected in two groups (juvenile vs. adult) and from two sites (Kalaloch Beach and Roosevelt Beach) where distinct biological differences in clam growth and survival rates were observed. The δ13C values of razor clam shells ranged from -2.9 to -0.3‰, whereas δ18O values of the same samples ranged from -2.2 to +1.4‰. Between the two sites there were significant differences in δ13C values especially for juvenile clams. The δ18O profiles from two representative shells demonstrated similar patterns of rapid growth as juveniles and seasonal patterns throughout the life span. Profiles of δ13C were sinusoidal but did not show seasonality and signatures of ocean acidification. We concluded that stable isotope analysis of razor clam shells is a potential new tool in shellfish research and management.

scholarly journals Lay People Training in CPR and in the Use of an Automated External Defibrillator, and Its Social Impact: A Community Health Study

2019 ◽  
Vol 16 (16) ◽  
pp. 2870 ◽  
Author(s):  
Felipe Villalobos ◽  
Albert Del Pozo ◽  
Cristina Rey-Reñones ◽  
Ester Granado-Font ◽  
David Sabaté-Lissner ◽  
...  
Keyword(s):  
Community Health ◽  
Social Impact ◽  
Survival Rates ◽  
Training Programme ◽  
Health Study ◽  
Lay People ◽  
Resuscitation Guidelines ◽  
Training Courses ◽  
Effectiveness Of Training ◽  
External Defibrillator

Out-of-hospital cardiac arrest (OHCA) mortality remains high. The best survival rates are achieved when trained people provide OHCA victims with cardiopulmonary resuscitation (CPR); however, it is estimated that only 25% of victims receive CPR. This community health study aims to evaluate the effectiveness of a training programme in basic CPR and in the use of an automatic external defibrillator (AED) on knowledge and skills for lay people, and its social impact. The training courses were based on Catalan Council of Resuscitation guidelines. Data were collected on sociodemographic characteristics, evaluation of knowledge and practical skills at baseline and at the end of the training courses, and also on the social impact of the programme. A total of 36 training courses with 482 participants were carried out, and most participants achieved a qualification of suitable. The mean score in knowledge was 3.1 ± 1.1 at baseline and 3.8 ± 1.2 (p = 0.001) at the end of the programme. Participants rated the training courses as very satisfactory, considered the training useful, and felt more qualified to respond to an emergency. This study shows that a high percentage of participants acquired skills in basic CPR and use of an AED, which confirms the usefulness and effectiveness of training courses and its important social impact.

scholarly journals Effects of Temperature on the Survival and Larval Development of Deiratonotus Japonicus (Brachyura, Camptandriidae) as a Biological Indicator

2020 ◽  
Vol 8 (3) ◽  
pp. 213 ◽  
Author(s):  
Il-Kweun Oh ◽  
Seung-Woo Lee
Keyword(s):  
Larval Development ◽  
Brachionus Plicatilis ◽  
Survival Rates ◽  
Biological Indicator ◽  
Larval Survival ◽  
Effect Of Temperature ◽  
Larval Stages ◽  
Kanagawa Prefecture ◽  
Survival And Growth ◽  
Increasing Temperature

Deiratonotus japonicus (D. japonicus) inhabits isolated locations and upstream brackish waters from Kanagawa Prefecture to Okinawa Prefecture in Japan. This species faces the threat of extinction because of changing habitat conditions. Our previous studies have shown that its complete larval development from hatching to metamorphosis consists of five zoeal stages and one megalopal stage. In this study, the effect of temperature on the survival and growth of larval development in D. japonicus under controlled laboratory conditions of 13, 18, 23, 24, 25, and 26 °C was investigated by rearing larvae (30 PSU; 12:12 h light/dark cycle; fed a diet of Brachionus plicatilis rotundiformis and Artemia sp. nauplii). The survival rates and developmental periods were measured for each larval stage. The highest survival rates were obtained at 18–24 °C. Metamorphosis to megalopa occurred at 23–25 °C. There were rapid and synchronous developments at 25–26 °C but delayed and extended developments at 13 °C. The molting period decreased with increasing temperature. With decreasing temperature, the beginning of the development and duration of molting was prolonged. In addition, there were very low survival rates at 13 °C and 26 °C in all zoeal stages. Our results indicate that the early larval stages of D. japonicus are well adapted to 18–24 °C, the range observed in the estuarine marine environment of the Kita River during the breeding season. Optimum larval survival and growth were obtained at 23 °C. Temperature significantly affected the survival rate, developmental period, and molting of the larvae. The relationship between the cumulative periods of development from hatching through individual larval stages (y) and temperatures (T) was described as a power function (y = a × Tb).

scholarly journals WOOD ANATOMY OF THE VANGUERIEAE (IXOROIDEAERUBIACEAE), WITH SPECIAL EMPHASIS ON SOME GEOFRUTICES

IAWA Journal ◽  
2000 ◽  
Vol 21 (4) ◽  
pp. 443-455 ◽  
Author(s):  
Frederic Lens ◽  
Steven Jansen ◽  
Elmar Robbrecht ◽  
Erik Smets
Keyword(s):  
Pacific Ocean ◽  
Wood Anatomy ◽  
Secondary Xylem ◽  
Vessel Diameter ◽  
Underground Structures ◽  
Axial Parenchyma ◽  
Tropical Asia ◽  
Primary Xylem ◽  
The Pacific ◽  
The Pacific Ocean

The Vanguerieae is a tribe consisting of about 500 species ordered in 27 genera. Although this tribe is mainly represented in Africa and Madagascar, Vanguerieae also occur in tropical Asia, Australia, and the isles of the Pacific Ocean. This study gives a detailed wood anatomical description of 34 species of 15 genera based on LM and SEM observations. The secondary xylem is homogeneous throughout the tribe and fits well into the Ixoroideae s.l. on the basis of fibre-tracheids and diffuse to diffuse-in-aggregates axial parenchyma. The Vanguerieae include numerous geofrutices that are characterised by massive woody branched or unbranched underground parts and slightly ramified unbranched aboveground twigs. The underground structures of geofrutices are not homologous; a central pith is found in three species (Fadogia schmitzii, Pygmaeothamnus zeyheri and Tapiphyllum cinerascens var. laetum), while Fadogiella stigmatoloba shows central primary xylem which is characteristic of roots. Comparison of underground versus aboveground wood shows anatomical differences in vessel diameter and in the quantity of parenchyma and fibres.

The Impact of Tributyl Tin (TBT) Antifouling Paints on Molluscan Fisheries

1986 ◽  
Vol 18 (4-5) ◽  
pp. 193-202 ◽  
Author(s):  
J. E. Thain ◽  
M. J. Waldock
Keyword(s):  
Field Experiments ◽  
Reproductive Behaviour ◽  
Larval Survival ◽  
Organotin Compounds ◽  
Contributory Factor ◽  
Ostrea Edulis ◽  
Antifouling Paints ◽  
The Pacific ◽  
The Uk ◽  
The Impact

Laboratory and field experiments carried out during 1982–84 confirmed that some UK estuaries contained sufficient organotin compounds to cause reduced meat yields and shell thickening in the Pacific oyster, Crassostrea gigas. Historically the European flat oyster, Ostrea edulis, has been the basis of an important fishery on the east coast of England but the population has recently declined to an all-time low. Laboratory experiments have been carried out to compare larval survival, growth of spat and the development of gametes in adult O. edulis, and the growth of spat of four other bivalve species in the presence and absence of organotin toxins. The results from these experiments are discussed in relation to the concentrations of organotin compounds in samples of water and oyster tissues, from several sites in the UK, and the reproductive behaviour of adult oysters from natural stocks in the Crouch/Roach estuary system. The data strongly suggest that TBT is at least a contributory factor and probably a major cause of the failure in recent years of O. edulis to reproduce naturally in the Crouch Estuary. The UK Government has proposed legislation to control and reduce organotin emissions into the marine environment and this is briefly outlined.

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