A review of seed production and stock enhancement for commercially important portunid crabs in Japan

2010 ◽  
Vol 19 (2) ◽  
pp. 217-235 ◽  
Author(s):  
Katsuyuki Hamasaki ◽  
Yasuhiro Obata ◽  
Shigeki Dan ◽  
Shuichi Kitada
Keyword(s):  
Seed Production ◽  
Stock Enhancement ◽  
Commercially Important

Pollination services provided by various size classes of flower visitors to Eucalyptus globulus ssp. globulus (Myrtaceae)

2004 ◽  
Vol 52 (3) ◽  
pp. 353 ◽  
Author(s):  
A. B. Hingston ◽  
B. M. Potts ◽  
P. B. McQuillan
Keyword(s):  
Seed Production ◽  
Eucalyptus Globulus ◽  
Seed Set ◽  
Pollen Limitation ◽  
Pollination Services ◽  
Flower Visitors ◽  
Large Numbers ◽  
Introduced Honeybee ◽  
Commercially Important ◽  
Almost All

Flowers of the commercially important tree Eucalyptus globulus Labill. ssp. globulus were visited by a wide variety of insects and birds within its natural distribution. Flowers were visited so frequently that most available nectar was consumed, but seed production within 5 m of the ground was consistently far less than the maximum possible, indicating the presence of large numbers of inefficient pollinators and few efficient pollinators. Pollen limitation was more severe on fully self-incompatible trees than on partially self-compatible trees, demonstrating that pollinator inefficiency resulted from infrequent outcrossing rather than inability to deposit pollen on stigmas. The flower visitors that were responsible for almost all nectar consumption from flowers within 5 m of the ground were insects that were able to permeate cages with 5-mm apertures but not cages with 1-mm apertures, the most abundant of which was the introduced honeybee Apis mellifera L. These insects contributed less than 20% of the maximum possible seed set, indicating that they were inefficient pollinators. Birds and smaller insects made lesser contributions to seed production, but consumed little nectar within 5 m of the ground. However, anthophilous birds appeared to mostly forage higher in the trees and probably consumed more nectar from, and provided more pollination services to, flowers higher in the trees.

Pollinators in seed orchards of Eucalyptus nitens (Myrtaceae)

2004 ◽  
Vol 52 (2) ◽  
pp. 209 ◽  
Author(s):  
A. B. Hingston ◽  
P. B. McQuillan ◽  
B. M. Potts
Keyword(s):  
Seed Production ◽  
Common Species ◽  
Eucalyptus Nitens ◽  
Floral Structure ◽  
Seed Orchards ◽  
The World ◽  
Commercially Important ◽  
Time Of Year ◽  
Insect Activity ◽  
Effective Pollinators

Flowers of the commercially important tree Eucalyptus nitens (Deane & Maiden) Maiden were visited by a diverse array of insects, but not by birds, in Tasmanian seed orchards. Most species of insects that visited the flowers of E. nitens are likely to be effective pollinators because all common species of visitors carried many grains of Eucalyptus pollen, and the open floral structure facilitates frequent insect contact with stigmas. Seed production also suggested that a wide variety of insects were effective pollinators because flowers were consistently well pollinated, despite differences in flower-visitor communities among orchards and particular branches of flowers. The generalised entomophilous pollination system of E. nitens suggests that effective pollinators should occur in seed orchards of this tree throughout the world, provided that flowering occurs at a time of year conducive to insect activity. Although a wide variety of insects appear to be effective pollinators of E. nitens, introduced honeybees, Apis mellifera L., that are often deployed as pollinators in seed orchards were consistently not attracted to the flowers. The reliance on wild insects as pollinators suggests that seed production in E. nitens may benefit from reduced use of broad-spectrum insecticides in, and near, seed orchards.

Predation of hatchery-cultured juvenile red king crabs (Paralithodes camtschaticus) in the wild

2013 ◽  
Vol 70 (3) ◽  
pp. 358-366 ◽  
Author(s):  
Benjamin Daly ◽  
Ginny L. Eckert ◽  
Timothy D. White
Keyword(s):  
Large Scale ◽  
Carapace Width ◽  
Population Level ◽  
Stock Enhancement ◽  
Hermit Crabs ◽  
Paralithodes Camtschaticus ◽  
Video Cameras ◽  
The North ◽  
In The Wild ◽  
Commercially Important

The ecologically and commercially important red king crab (Paralithodes camtschaticus) is depleted throughout much of the North Pacific and thought to be recruitment-limited, making it an appropriate candidate for stock enhancement efforts. Information on predation of newly settled red king crabs in nearshore habitats is needed to assess the feasibility of large-scale releases. We tethered hatchery-cultured red king crabs of two sizes (range: 1.75–4.08 mm carapace width) in the field for 24 h trials in July and September 2011 and used underwater video cameras to identify predators and predation susceptibility. We identified hermit crabs (Pagurus spp.), Alaskan ronquil (Bathymaster caeruleofasciatus), Arctic shanny (Sticheus punctatus), northern rock sole (Lepidopsetta polyxystra), and kelp greenling (Hexagrammos decagrammus) as predators. Survival did not vary by body size or deployment month; however, small crabs were consumed sooner than large crabs. Most predation events occurred in daylight hours, with the exception of Alaskan ronquil. Our results suggest stock enhancement efforts should consider predator assemblages when developing release strategies. Future studies should investigate spatial variation in predation pressure at multiple locations on broad temporal scales to optimize release strategies and understand population-level effects.

Cathodoluminescence of Catalyst Crystallites

1982 ◽  
Vol 40 ◽  
pp. 664-665
Author(s):  
E.D. Boyes ◽  
P.L. Gai ◽  
D.B. Darby ◽  
C. Warwick
Keyword(s):  
Defect Density ◽  
Chemical Properties ◽  
Operating Conditions ◽  
Semiconductor Materials ◽  
Environmental Cell ◽  
High Resolution Structure ◽  
Commercially Important ◽  
Crystallographic Defects ◽  
Resolution Structure

The extended crystallographic defects introduced into some oxide catalysts under operating conditions may be a consequence and accommodation of the changes produced by the catalytic activity, rather than always being the origin of the reactivity. Operation without such defects has been established for the commercially important tellurium molybdate system. in addition it is clear that the point defect density and the electronic structure can both have a significant influence on the chemical properties and hence on the effectiveness (activity and selectivity) of the material as a catalyst. SEM/probe techniques more commonly applied to semiconductor materials, have been investigated to supplement the information obtained from in-situ environmental cell HVEM, ultra-high resolution structure imaging and more conventional AEM and EPMA chemical microanalysis.

Peroxisome proliferation: Organelles or activity as an endpoint?

1993 ◽  
Vol 51 ◽  
pp. 396-397
Author(s):  
Catherine A. Taylor ◽  
Bruce M. Jarnot
Keyword(s):  
Acid Oxidation ◽  
Peroxisome Proliferation ◽  
Post Dose ◽  
Oxidation Activity ◽  
Wasting Syndrome ◽  
Perfluorodecanoic Acid ◽  
Hypolipidemic Agent ◽  
Commercially Important ◽  
Acyl Coa Oxidase ◽  
Mitochondrial Disruption

Peroxisome induction can be expressed as an increase in peroxisome area (proliferation) or as an increase in peroxisomal fatty acid oxidation (activity). This study compares proliferation and activity as endpoints for hepatic peroxisome induction by perfluorodecanoic acid (PFDA). Fluorocarboxylic acids such as PFDA represent a class of compounds possessing commercially important surfactant properties. A single 50 mg/Kg ip. dose of PFDA produces a characteristic “wasting syndrome” in male F-344 rats. Symptoms include hypophagia, weight loss, hepatomegaly, and delayed lethality. Hepatic studies reveal changes similar to those seen with the hypolipidemic agent clofibrate. These include mitochondrial disruption, endoplasmic reticulum and peroxisome proliferation, and increased peroxisomal acyl-CoA oxidase activity.Male Fisher-344 rats received a single ip. dose of 2, 20, or 50mg/Kg PFDA dissolved in 1:1 propylene glycol/water and were sacrificed 8 days post-dose. All control rats received an equal volume of vehicle ip. Animals were provided food and water ad libitum, except pair-fed controls which received the same restrictive food intake consumed by their weight-paired dosed partners (50mg/Kg PFDA group) to simulate the hypophagia associated with PFDA.

Characterizing the impact of recovering sea otters on commercially important crabs in California estuaries

2020 ◽  
Vol 655 ◽  
pp. 123-137
Author(s):  
TM Grimes ◽  
MT Tinker ◽  
BB Hughes ◽  
KE Boyer ◽  
L Needles ◽  
...  
Keyword(s):  
Abiotic Factors ◽  
Sea Otter ◽  
Dungeness Crab ◽  
Sea Otters ◽  
Elkhorn Slough ◽  
Enhydra Lutris Nereis ◽  
Crab Abundance ◽  
Population Sizes ◽  
Commercially Important ◽  
The Impact

Protective legislation and management have led to an increase in California’s sea otter Enhydra lutris nereis population. While sea otter recovery has been linked to ecosystem benefits, sea otter predation may negatively affect commercially valuable species. Understanding the potential influence of sea otters is of particular importance as their range expands into estuaries that function as nurseries for commercially valuable species like Dungeness crab Metacarcinus magister. We consider how sea otter predation has affected the abundance and size of juvenile Dungeness crab in Elkhorn Slough, California, USA, and analyzed cancrid crab abundance and size across 4 California estuaries with and without sea otters to understand how biotic and abiotic factors contribute to observed variation in crab size and abundance. We compared trends in southern sea otters relative to Dungeness crab landings in California to assess whether increasing sea otter abundance have negatively impacted landings. In Elkhorn Slough, juvenile Dungeness crab abundance and size have declined since 2012, coinciding with sea otter population growth. However, the impact of sea otters on juvenile Dungeness crab size was habitat-specific and only significant in unvegetated habitat. Across estuaries, we found that cancrid crab abundance and size were negatively associated with sea otter presence. While abiotic factors varied among estuaries, these factors explained little of the observed variation in crab abundance or size. Although we found evidence that sea otters can have localized effects on cancrid crab populations within estuaries, we found no evidence that southern sea otters, at recent population sizes, have negatively impacted Dungeness crab landings in California from 2000-2014.

Sign in / Sign up

Export Citation Format

Share Document