Interdemic variation in the African cyprinid Barbus neumayeri: correlations among hypoxia, morphology, and feeding performance

2003 ◽  
Vol 81 (3) ◽  
pp. 430-440 ◽  
Author(s):  
Sarah Schaack ◽  
Lauren J Chapman
Keyword(s):  
Gill Filament ◽  
Prey Type ◽  
Adaptive Change ◽  
Filament Length ◽  
Low Oxygen ◽  
Feeding Performance ◽  
Internal Morphology ◽  
Processing Ability ◽  
Feeding Trials ◽  
Respiratory Apparatus

Adaptive change in one character may affect associated, but functionally unrelated, characters in adaptive or nonadaptive ways. For example, adaptive change in gill size (i.e., larger gills in hypoxic habitats) may alter adjacent feeding structures and therefore have indirect effects on feeding behavior. This study examines whether differences in total gill filament length among populations of the African cyprinid Barbus neumayeri correlate with variation in trophic structures and feeding performance. Morphological measurements revealed larger total gill filament length in populations from low-oxygen habitats. Differences in external and internal morphology of the trophic apparatus correlated with those found in gills and suggest a reduction in food capture and processing ability in fish with larger respiratory apparatus. In paired feeding trials on a novel prey type, large-gilled fish spent more time feeding than small-gilled fish of the same body size without ingesting more food. This suggests less efficient food uptake in large-gilled fish from hypoxic habitats. We suggest that variation in gill size facilitates the broad habitat distribution of B. neumayeri but may limit the success of phenotypes crossing physicochemical gradients.

Hormone action and plant adaptations to poor aeration

1994 ◽  
Vol 102 ◽  
pp. 391-405
Author(s):  
Michael B. Jackson
Keyword(s):  
Morphological Changes ◽  
Stomatal Closure ◽  
Low Oxygen ◽  
Aerenchyma Formation ◽  
Plant Adaptations ◽  
Endogenous Plant Hormones ◽  
Ethylene Precursor ◽  
Internal Morphology ◽  
Morphological Adaptations ◽  
Partial Pressures

SynopsisThe actions of endogenous plant hormones are invoked to explain several morphological adaptations to poor aeration. These include changes to the growth and internal morphology of inundated roots, the promotion of extension growth by stems or leaves of aquatic and semi-aquatic species by submergence, and morphological changes in shoots where only the roots and lower shoot are inundated. This article considers ethylene-promoted aerenchyma formation in maize (Zea mays) and compares the promoting action of ethylene, low oxygen partial pressures and carbon dioxide on shoot extension in rice (Oryza sativa), a rice mimic Echinochloa oryzoides and a submersed aquatic monocot Potamogeton pecrinatus. Different kinds of hormonal messages (positive, negative, accumulative and debit) passing between roots and shoots co-ordinate shoot development with the roots and their environment. Recent progress in quantifying the delivery of abscisic acid (ABA) or the ethylene precursor 1-aminocyclopropane-1-car-boxylic acid (ACC) from roots to shoots in the transpiration stream is summarised in relation to control of stomatal closure and leaf epinastic curvature in flooded plants.

Comparison of Ectoparasite Pathology on Gills of Yellowfin Bream, Acanthopagrus-Australis (Gunther) (Pisces, Sparidae) - a Surface-Area Approach

1987 ◽  
Vol 35 (1) ◽  
pp. 93 ◽  
Author(s):  
FR Roubal
Keyword(s):  
Surface Area ◽  
Size Range ◽  
Unit Length ◽  
Gill Filament ◽  
Host Size ◽  
Filament Length ◽  
Large Size ◽  
Gill Filaments ◽  
Gill Surface Area

The number of gill filaments, length of gill filament and corresponding surface area affected by individual adults of Haliotrerna spariensis (Monogenea) and Ergasilus sp. and individual adults, subadults and larvae of Alella macrotrachelus (Copepoda) are examined in a large size range of the host, Acanthopagrus australis. The effects of these parasites are analysed as proportions of total filament length and total gill surface area. The parasites arranged in order of increasing number of filaments affected are: Ergasilus sp., larval A. macrotrachelus, H. spariensis, subadult A. macrotrachelus and adult A. macrotrachelus. For Ergasilus sp., H. spariensis and larval A. macrotrachelus, the length of filament affected was constant irrespective of host size; adult A. macrotrachelus affect greater lengths of filament in smaller fish, but subadult stages affect greater lengths in larger fish. Possible reasons for this are discussed. The relative pathogenicity is reduced when filament length is converted to surface area. This reduction is greater in smaller fish because they have a smaller surface area per unit length of filament than larger fish.

Gill Surface-Area and Its Components in the Yellowfin Bream, Acanthopagrus-Australis (Gunther) (Pisces, Sparidae)

1987 ◽  
Vol 35 (1) ◽  
pp. 25 ◽  
Author(s):  
FR Roubal
Keyword(s):  
Surface Area ◽  
Gill Filament ◽  
Weighting Factor ◽  
Head Length ◽  
Regression Equations ◽  
Middle Zone ◽  
Filament Length ◽  
Basal Zone ◽  
Gill Filaments ◽  
Gill Surface Area

As head length (HL) of Acanthopagrus australis increases, fewer gill filaments are added, total gill filament length (TFL) increases linearly, and total gill surface area (TSA) increases exponentially. Changes in surface area components [surface area per lamella (SA), distance between adjacent lamellae (DBT) and number of lamellae per zone on one side of the filament (NPZ)] with increasing HL were examined in the distal, middle and basal zones (relative lengths 3:10:1) of a corresponding filament on the external hemibranch of the four gill arches. SA was the smallest in the basal zone and largest in the middle zone; DBT was greatest in the distal zone and smallest in the basal zone; SA and DBT increased at similar rates in different gill arches within the distal and middle zones but at different rates in each zone within an arch; growth of NPZ in the middle zone differed among gill arches but did not in the distal zone. Surface area of lamellae in the middle zone contributed most to increasing TSA. Compared with other fish of intermediate activity, the estimate of TSA for A. australis was smaller than expected; although DBT and TFL were as expected, SA was smaller than expected; possible reasons include method of measurement in situ, shrinkage caused by fixation, and absence of a weighting factor. The method employed enables large numbers of lamellae and filaments in a large number of fish to be measured, and enables regression equations to be derived that relate surface area per filament zone to head length and filament length in order to estimate the loss of surface area caused by ectoparasites.

scholarly journals Hydrodynamic Simulations of the Performance Landscape for Suction-Feeding Fishes Reveal Multiple Peaks for Different Prey Types

2020 ◽  
Vol 60 (5) ◽  
pp. 1251-1267 ◽  
Author(s):  
Karin H Olsson ◽  
Christopher H Martin ◽  
Roi Holzman
Keyword(s):  
Prey Capture ◽  
Mechanistic Model ◽  
Prey Type ◽  
Kinematic Parameter ◽  
Phenotypic Trait ◽  
Phenotypic Traits ◽  
Suction Feeding ◽  
Multiple Peaks ◽  
Feeding Performance ◽  
Extant Species

Abstract The complex interplay between form and function forms the basis for generating and maintaining organismal diversity. Fishes that rely on suction-feeding for prey capture exhibit remarkable phenotypic and trophic diversity. Yet the relationships between fish phenotypes and feeding performance on different prey types are unclear, partly because the morphological, biomechanical, and hydrodynamic mechanisms that underlie suction-feeding are complex. Here we demonstrate a general framework to investigate the mapping of multiple phenotypic traits to performance by mapping kinematic variables to suction-feeding capacity. Using a mechanistic model of suction-feeding that is based on core physical principles, we predict prey capture performance across a broad range of phenotypic trait values, for three general prey types: mollusk-like prey, copepod-like prey, and fish-like prey. Mollusk-like prey attach to surfaces, copepod-like prey attempt to escape upon detecting the hydrodynamic disturbance produced by the predator, and fish-like prey attempt to escape when the predator comes within a threshold distance. This approach allowed us to evaluate suction-feeding performance for any combination of six key kinematic traits, irrespective of whether these trait combinations were observed in an extant species, and to generate a multivariate mapping of phenotype to performance. We used gradient ascent methods to explore the complex topography of the performance landscape for each prey type, and found evidence for multiple peaks. Characterization of phenotypes associated with performance peaks indicates that the optimal kinematic parameter range for suction-feeding on different prey types are narrow and distinct from each other, suggesting different functional constraints for the three prey types. These performance landscapes can be used to generate hypotheses regarding the distribution of extant species in trait space and their evolutionary trajectories toward adaptive peaks on macroevolutionary fitness landscapes.

Assessing the use of hard parts in faeces to identify harbour seal prey: results of captive-feeding trials

1996 ◽  
Vol 74 (5) ◽  
pp. 875-880 ◽  
Author(s):  
Paul E. Cottrell ◽  
Edward H. Miller ◽  
Andrew W. Trites
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Prey Type ◽  
Phoca Vitulina ◽  
Clupea Harengus ◽  
Merluccius Productus ◽  
Juvenile Chinook Salmon ◽  
Walleye Pollock Theragra Chalcogramma ◽  
Harbour Seals ◽  
Feeding Trials

Faeces were collected from four captive harbour seals (Phoca vitulina) that consumed known amounts of herring (Clupea harengus), walleye pollock (Theragra chalcogramma), Pacific hake (Merluccius productus), surf smelt (Hypomesus pretiosus), and juvenile chinook salmon (Oncorhynchus tshawytscha). The goal was to determine which structures (hard parts) passed through the digestive tract (e.g., eye lenses, scales, vertebrae, otoliths), and which of these could be used to determine the type and number of fish consumed. Nearly 5000 fish were consumed, from which over 50 000 hard parts were recovered from seal faeces. Scales were the most numerous of the 23 structures recovered (>20 000), followed by vertebrae, eye lenses, and otoliths. Morphological distinctiveness and digestive erosion of the structures varied among fish taxa. Two to five structures accounted for over 90% of the taxon-specific elements recovered, depending upon the species of fish consumed. Otoliths, which are used routinely to characterize pinniped diets, accounted for only 17% of the identified taxon-specific hard parts. The variation in types of structures and rates of recovery across taxa underscores the importance of using several types of hard parts to identify prey. Identifying several different prey structures increases the likelihood of identifying a prey type.

Assessing the potential impact of invasive cane toads on a commercial freshwater fishery in tropical Australia

2011 ◽  
Vol 38 (5) ◽  
pp. 380 ◽  
Author(s):  
Ruchira Somaweera ◽  
Michael R. Crossland ◽  
Richard Shine
Keyword(s):  
Developmental Stages ◽  
Prey Type ◽  
Economic Damage ◽  
Wet Season ◽  
Cane Toad ◽  
North Eastern ◽  
Feeding Trials ◽  
Tropical Australia ◽  
Potential Impact ◽  
Eggs And Larvae

Context The toxins produced by cane toads (Rhinella marina) are fatal to many Australian predators that ingest these invasive anurans. To date, the potential economic impact of the cane toad invasion has attracted little attention. Toads have recently arrived at a large impoundment (Lake Argyle) in north-eastern Western Australia, that supports a commercial fishery for silver cobbler (shovel-nosed catfish, Arius midgleyi), raising concern that the toads may inflict significant economic damage by killing fish. Aims Our research aimed to clarify the vulnerability of silver cobblers to the eggs and larvae of cane toads by determining (a) whether catfish are adversely affected if they prey on toad eggs or tadpoles, and (b) whether surviving catfish learn to avoid cane toad eggs and tadpoles in subsequent encounters. Methods We conducted laboratory feeding trials to examine feeding responses of catfish to cane toad eggs and tadpoles in early and late developmental stages. Fish that survived exposure to toad eggs and/or tadpoles were re-tested with potential prey of the same sizes and developmental stages four days later. Key results Our laboratory trials confirmed that some catfish eat toad eggs and die; but most catfish avoided the eggs. Catfish readily consumed toad tadpoles at both early and late developmental stages, but without experiencing mortality; and soon learned not to consume this toxic new prey type. Conclusions and implications Despite potential frequent episodes of mortality of small numbers of catfish during the wet season, the overall impacts of cane toads on the Lake Argyle fishery likely will be minimal.

Feeding performance in the Western Ribbon Snake (Thamnophis proximus): ontogeny and the effects of prey type and size

2011 ◽  
Vol 89 (10) ◽  
pp. 945-950 ◽  
Author(s):  
Paul M. Hampton
Keyword(s):  
Prey Size ◽  
Prey Availability ◽  
Prey Type ◽  
Prey Preference ◽  
Head Length ◽  
Age Classes ◽  
Feeding Performance ◽  
Trophic Morphology ◽  
Improved Performance

It has been suggested that juveniles have exaggerated morphologies or improved performance to compensate for the disadvantages of being small. As gape-limited predators, juvenile snakes are at a particular disadvantage in terms of prey availability, capture, and ingestion. Prey preference often changes with snake size yet previous studies generally compare only one prey type or relative prey size among age classes. Using Western Ribbon Snakes ( Thamnophis proximus (Say in James, 1823)), I investigated the ontogeny of head dimensions and feeding performance on frogs and fish using a range of relative prey sizes. Comparison among snake sizes indicated that smaller individuals had larger relative head sizes than larger conspecifics; however, larger individuals had larger heads. Initial bite position differed between juveniles and adults fed fish but not frogs. Both frogs and fish were generally consumed headfirst by adults and juveniles. Head length did not influence feeding performance in terms of time or pterygoid protractions for snakes fed either fish or frogs. In general, this study suggests that allometry of trophic morphology does not improve feeding performance.

Respiratory gill surface area of a facultative air-breathing loricariid fish, Rhinelepis strigosa

1994 ◽  
Vol 72 (11) ◽  
pp. 2009-2015 ◽  
Author(s):  
C. T. C. Santos ◽  
M. N. Fernandes ◽  
W. Severi
Keyword(s):  
Surface Area ◽  
Body Mass ◽  
Gill Filament ◽  
B Value ◽  
Filament Length ◽  
Air Breathing ◽  
Rate Of Development ◽  
Secondary Lamellae ◽  
Gill Filaments ◽  
Gill Surface Area

The respiratory surface area of the gill in relation to body mass of the facultative air-breathing loricariid fish Rhinelepis strigosa was analyzed using logarithmic transformation (log Y = log a + b log W) of the equation Y = aWb. The data revealed differences in growth pattern for each gill element. The increase in gill surface area was not isometric with body mass (b = 0.76). The total number of secondary lamellae (b = 0.38) and the average bilateral surface area of the secondary lamellae (b = 0.46) contributed most to the rate of development of the gill surface area (total area of the secondary lamellae) with increase in body mass. Gill filament length (b = 0.339) was more important than the frequency (number/mm) of secondary lamellae in determining the increase in the total number of secondary lamellae. The number of gill filaments showed the lowest b value, 0.072. Rhinelepis strigosa has a larger gill surface area than most other air-breathing fish, indicating that it is better adapted for breathing in water than in air.

Some Geometrical Characteristics of the Long-Lived Solar Filaments

1994 ◽  
Vol 144 ◽  
pp. 387-389
Author(s):  
P. Duchlev ◽  
Z. Mouradian ◽  
V. N. Dermendjiev
Keyword(s):  
Filament Length ◽  
Geometrical Characteristics ◽  
Solar Filaments

AbstractTwo basic geometric quantities - the filament length and the height above the limb of the long-lived filaments are studied. Some statistical relations are obtained.

HIF1-α-Mediated Gene Expression Induced by Vitamin B1 Deficiency

2013 ◽  
Vol 83 (3) ◽  
pp. 188-197 ◽  
Author(s):  
Rebecca L. Sweet ◽  
Jason A. Zastre
Keyword(s):  
Gene Expression ◽  
Thiamine Deficiency ◽  
Glucose Transporter ◽  
Neuroblastoma Cell ◽  
Hypoxia Inducible Factor ◽  
Clinical Manifestations ◽  
Vitamin B1 ◽  
Low Oxygen ◽  
Glucose Transporter 1 ◽  
Metabolic Intermediates

It is well established that thiamine deficiency results in an excess of metabolic intermediates such as lactate and pyruvate, which is likely due to insufficient levels of cofactor for the function of thiamine-dependent enzymes. When in excess, both pyruvate and lactate can increase the stabilization of the hypoxia-inducible factor 1-alpha (HIF-1α) transcription factor, resulting in the trans-activation of HIF-1α regulated genes independent of low oxygen, termed pseudo-hypoxia. Therefore, the resulting dysfunction in cellular metabolism and accumulation of pyruvate and lactate during thiamine deficiency may facilitate a pseudo-hypoxic state. In order to investigate the possibility of a transcriptional relationship between hypoxia and thiamine deficiency, we measured alterations in metabolic intermediates, HIF-1α stabilization, and gene expression. We found an increase in intracellular pyruvate and extracellular lactate levels after thiamine deficiency exposure to the neuroblastoma cell line SK-N-BE. Similar to cells exposed to hypoxia, there was a corresponding increase in HIF-1α stabilization and activation of target gene expression during thiamine deficiency, including glucose transporter-1 (GLUT1), vascular endothelial growth factor (VEGF), and aldolase A. Both hypoxia and thiamine deficiency exposure resulted in an increase in the expression of the thiamine transporter SLC19A3. These results indicate thiamine deficiency induces HIF-1α-mediated gene expression similar to that observed in hypoxic stress, and may provide evidence for a central transcriptional response associated with the clinical manifestations of thiamine deficiency.

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