Effect of habitable space on substrate selection by Paragnetina media (Walker) (Plecoptera: Perlidae)

Hydrobiologia ◽  
1986 ◽  
Vol 131 (3) ◽  
pp. 277-279 ◽  
Author(s):  
Blair W. Feltmate ◽  
Philip J. Pointing
1989 ◽  
Vol 46 (9) ◽  
pp. 1575-1580 ◽  
Author(s):  
Blair W. Feltmate ◽  
D. Dudley Williams

Stonefly (Paragnetina media) density was reduced in a rainbow trout (Oncorhynchus mykiss) enclosure by approximately 35%, whereas in a trout exclosure no significant changes in density occurred. Of the 35% reduction, approximately two-fifths and three-fifths were attributable, respectively to direct consumption of stoneflies by trout, and emigration by stoneflies from the predator-stressed section of stream. With trout present in laboratory aquaria, predator avoidance behaviour resulted in stoneflies remaining significantly more on dark substrate on which they were less vulnerable to trout predators. Stoneflies consumed significantly fewer prey (enchytraeid whiteworms) over 24 h, in the presence of both small (2.0–4.0 cm) and large (10.0–12.0 cm) rainbow trout in aquaria, compared with stoneflies feeding in trout-free aquaria. Feeding rate and substrate selection did not differ between well-fed and starved (5 d) nymphs.


1986 ◽  
Vol 43 (8) ◽  
pp. 1582-1587 ◽  
Author(s):  
Blair W. Feltmate ◽  
Robert L. Baker ◽  
Philip J. Pointing

Effects of prey distribution, presence of a predator, current speed, and substrate composition on distribution of the predaceous stonefly nymph Paragnetina media (Walker) were examined in a large laboratory stream. Distribution of prey (Hydropsyche sparna, H. bronta) did not affect distribution of well-fed or non-fed (48 h) nymphs. However, P. media distribution was significantly influenced by independent and interactive effects of current speed (0.33–0.41 m∙s−1) and substrate composition (53.0–110.0 mm in diameter). In the presence of rainbow trout (Salmo gairdneri), P. media selected more specifically for larger substrate on which risk of predation was less than on smaller size classes. Lighting condition had no effect on substrate selection. Laboratory findings were consistent with distribution of P. media observed in the Credit River, Ontario, during midsummer, late fall, and early spring.


Glycobiology ◽  
2021 ◽  
Author(s):  
Hannah M Stephen ◽  
Trevor M Adams ◽  
Lance Wells

Abstract Thousands of nuclear and cytosolic proteins are modified with a single β-N-acetylglucosamine on serine and threonine residues in mammals, a modification termed O-GlcNAc. This modification is essential for normal development and plays important roles in virtually all intracellular processes. Additionally, O-GlcNAc is involved in many disease states, including cancer, diabetes, and X-linked intellectual disability. Given the myriad of functions of the O-GlcNAc modification, it is therefore somewhat surprising that O-GlcNAc cycling is mediated by only two enzymes: the O-GlcNAc transferase (OGT), which adds O-GlcNAc, and the O-GlcNAcase (OGA), which removes it. A significant outstanding question in the O-GlcNAc field is how do only two enzymes mediate such an abundant and dynamic modification. In this review, we explore the current understanding of mechanisms for substrate selection for the O-GlcNAc cycling enzymes. These mechanisms include direct substrate interaction with specific domains of OGT or OGA, selection of interactors via partner proteins, posttranslational modification of OGT or OGA, nutrient sensing, and localization alteration. Altogether, current research paints a picture of an exquisitely regulated and complex system by which OGT and OGA select substrates. We also make recommendations for future work, toward the goal of identifying interaction mechanisms for specific substrates that may be able to be exploited for various research and medical treatment goals.


2021 ◽  
Vol 9 (6) ◽  
pp. 634
Author(s):  
Euichi Hirose ◽  
Noburu Sensui

Ascidians are marine sessile chordates that comprise one of the major benthic animal groups in marine ecosystems. They sometimes cause biofouling problems on artificial structures underwater, and non-indigenous, invasive ascidian species can potentially and seriously alter native faunal communities. Ascidian larvae are usually tadpole-shaped, negatively phototactic, and adhere on substrates by secreting a glue from their adhesive organs. Although larvae often prefer hydrophobic surfaces, such as a silicone rubber, for settlement, hydrophobic materials are often used to reduce occurrence of fouling organisms on artificial structures. This inconsistency may indicate that an attractive surface for larvae is not always suitable for settlement. Micro-scale structures or roughness may enhance the settlement of ascidian larvae, but settlement is significantly reduced by a nano-scale nipple array (or moth-eye structure), suggesting functional properties of similar structures found on the body surfaces of various invertebrates. The substrate preferences of larvae should be one of the important bases in considering measures against biofouling, and this review also discusses the potential uses of materials to safely reduce the impacts of invasive species.


2015 ◽  
Vol 2 (18) ◽  
pp. 1500423 ◽  
Author(s):  
Silvia Trabattoni ◽  
Luisa Raimondo ◽  
Marcello Campione ◽  
Daniele Braga ◽  
Vincent C. Holmberg ◽  
...  

2013 ◽  
Vol 38 (1) ◽  
pp. 182-187 ◽  
Author(s):  
Catherine M. Zettel Nalen ◽  
Sandra A. Allan ◽  
James J. Becnel ◽  
Phillip E. Kaufman

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