The distribution and abundance of electrosensory pores in two benthic sharks: a comparison of the wobbegong shark, Orectolobus maculatus, and the angel shark, Squatina australis

2014 ◽  
Vol 65 (11) ◽  
pp. 1003 ◽  
Author(s):  
Channing A. Egeberg ◽  
Ryan M. Kempster ◽  
Susan M. Theiss ◽  
Nathan S. Hart ◽  
Shaun P. Collin
Keyword(s):  
Similar Pattern ◽  
Feeding Behaviour ◽  
Feeding Strategy ◽  
Gill Slit ◽  
Functional Importance ◽  
Aquatic Animals ◽  
Body Form ◽  
Electrosensory System ◽  
Physiological Adaptations

Electroreception is an ancient sense found in many aquatic animals, including sharks, which may be used in the detection of prey, predators and mates. Wobbegong sharks (Orectolobidae) and angel sharks (Squatinidae) represent two distantly related families that have independently evolved a similar dorso-ventrally compressed body form to complement their benthic ambush feeding strategy. Consequently, these groups represent useful models in which to investigate the specific morphological and physiological adaptations that are driven by the adoption of a benthic lifestyle. In this study, we compared the distribution and abundance of electrosensory pores in the spotted wobbegong shark (Orectolobus maculatus) with the Australian angel shark (Squatina australis) to determine whether both species display a similar pattern of clustering of sub-dermal electroreceptors and to further understand the functional importance of electroreception in the feeding behaviour of these benthic sharks. Orectolobus maculatus has a more complex electrosensory system than S. australis, with a higher abundance of pores and an additional cluster of electroreceptors positioned in the snout (the superficial ophthalmic cluster). Interestingly, both species possess a cluster of pores (the hyoid cluster, positioned slightly posterior to the first gill slit) more commonly found in rays, but which may be present in all benthic elasmobranchs to assist in the detection of approaching predators.

Echolocation and feeding behaviour of Taphozous mauritianus (Chiroptera: Emballonuridae)

1980 ◽  
Vol 58 (10) ◽  
pp. 1774-1777 ◽  
Author(s):  
M. B. Fenton ◽  
G. P. Bell ◽  
D. W. Thomas
Keyword(s):  
Long Range ◽  
Feeding Behaviour ◽  
Second Harmonic ◽  
Feeding Strategy ◽  
Rapid Rise ◽  
Constant Frequency ◽  
Insectivorous Bats ◽  
Sound Energy ◽  
Echolocation Calls ◽  
Human Ear

Observations of free-flying bats in the field in Zimbabwe indicated that Taphozous mauritianus uses multiharmonic constant frequency (CF) search calls followed by multiharmonic approach and terminal calls that combine shallow and steep frequency modulated (FM) sweeps during approaches to targets. The three phases of calls all have rapid rise times to full amplitude, and most of the sound energy is in the second harmonic; the fundamental is usually present (11–13 kHz), making the calls clearly audible to the unaided human ear. This combination of characters, but particularly the CF search calls, serves to distinguish these echolocation calls from those of other insectivorous bats. One light-tagged individual hunting insects reacted to targets at distances of about 3 m, suggesting a long-range feeding strategy.

Size-related shift in feeding strategy and prey-size selection in young grayling (Thymallus thymallus)

1996 ◽  
Vol 74 (9) ◽  
pp. 1597-1603 ◽  
Author(s):  
Philippe Sempeski ◽  
Philippe Gaudin
Keyword(s):  
Body Length ◽  
Feeding Behaviour ◽  
Prey Size ◽  
Feeding Strategy ◽  
River Channel ◽  
Large Prey ◽  
Thymallus Thymallus ◽  
Chironomid Larvae ◽  
Size Selection ◽  
The Mean

Observations of feeding behaviour and analysis of prey-size selection by young grayling revealed a shift in feeding strategy coinciding with a shift in habitat occurring between larval (observed in lateral habitats) and juvenile (observed in the river channel) stages of grayling. The mean number of foraging attempts per minute decreased four times between both stages, while in the same time the mean distance travelled during each foraging attempt decreased from 1.5 body lengths to 1 body length. Gape-limited postemergent larvae fed mainly on small chironomid larvae (<0.5 mm3) but larger larvae and pupae (0.5 – 1 mm3) were consumed with increasing size. The diet spectrum of juveniles >40 mm was characterized by the appearance of very large prey (> 10 mm3), such as simuliid and ephemeropteran larvae, but also by a new increase of the contribution of small chironomid larvae. Changes in the feeding strategy of young grayling are discussed in relation to internal (e.g., morphological limitations) and external (e.g., physical characteristics of habitat) constraints.

scholarly journals Conducta alimentaria de cuatro especies de aves playeras (Charadriiformes: Scolopacidae) en Chametla, B.C.S., México

1969 ◽  
pp. 239-243
Author(s):  
Georgina Brabata ◽  
Roberto Carmona
Keyword(s):  
Feeding Behaviour ◽  
Feeding Strategy ◽  
Foraging Strategies ◽  
Foraging Efficiency ◽  
Wintering Area ◽  
Numenius Americanus

Feeding behaviour of four species for large shorebirds (Scolopacidae) was studied in a tidal mudflat, Chametla, Mexico, to determine the foraging efficiency of Limosa fedoa, Numenius phaeopus, Numenius americanus and Catoptrophorus semipalmatus in a stopover/wintering area; and their activity with the tide cicle. The study area was visited in the winter of 1993 during the daylight hours. Each species was observed for 15 min during each tide type. The tide type does not affect the frequency with which the species use the different foraging strategies. In general, probing was more efficient than pecking. Considering distribution and prey, L. fedoa had the highest efficiency with this feeding strategy. Both species of Numenius were more efficient with pecking than other species. C. semipalmatus has the highest efficiency because it is an oportunistic species, L. fedoa is generalistic, both Numenius are especialists and C. semipalmatus is oportunistic.

Diet and feeding strategy of the forkbeard Phycis phycis (Pisces: Phycidae) from the Portuguese continental coast

2017 ◽  
Vol 98 (7) ◽  
pp. 1757-1765
Author(s):  
Ana Rita Silva ◽  
Ana Rita Vieira ◽  
Vera Sequeira ◽  
Rafaela Barros Paiva ◽  
Leonel Serrano Gordo ◽  
...  
Keyword(s):  
Feeding Behaviour ◽  
Feeding Strategy ◽  
Prey Group ◽  
Important Prey ◽  
Decapod Crustacea ◽  
Shift Pattern ◽  
The Mean ◽  
Generalist Diet ◽  
Taxonomic Categories ◽  
Phycis Phycis

The diet and feeding behaviour of the forkbeard Phycis phycis was studied based on 246 stomachs collected between May 2011 and April 2012 from a commercial fleet operating off the central west coast of Portugal. A total of 44 prey items were identified in the stomachs which were merged into major groups to avoid problems with low expected frequencies. The following taxonomic categories were considered: non-decapod Crustacea, Caridea, Anomura, Munida spp., Processa spp., Brachyura, Pisces, Trisopterus luscus. In order to investigate possible diet differences between fish size classes, a cluster analysis was performed using the mean abundance of each prey group by forkbeard 5 cm length class, and three length groups (LG) were obtained: <22.5, 27.5–37.5 and >42.5 cm. Seasonally, Caridea was the main prey group during winter and autumn while Pisces was predominant during the rest of the year. Caridea was the most important prey group for LG1 and LG2 while in LG3 Pisces was the principal one. The forkbeard feeding behaviour may be characterized as presenting a shift pattern from a more generalist diet (small Crustacea, mainly Caridea) in the young adults to a more specialist strategy (teleosts) in the adults.

scholarly journals Morphological and physiological adaptations of wood-boring beetle larvae in timber

2011 ◽  
Vol 43 (2) ◽  
pp. 47 ◽  
Author(s):  
Elisabetta Chiappini ◽  
Rinaldo Nicoli Aldini
Keyword(s):  
Convergent Evolution ◽  
Feeding Behaviour ◽  
Wood Powder ◽  
Wood Substrate ◽  
Functional Characteristics ◽  
Essential Nutrients ◽  
Physiological Adaptations ◽  
Feeding Activities ◽  
Specific Activities ◽  
Wood Boring

Beetles which develop boring tunnels inside and feed on seasoned wood present morphological and physiological adaptations related to the specific activities of their larvae in such a peculiar substrate. As far as protection of antiquarian goods made of wood is concerned, we are dealing mainly with three Coleoptera families, namely Lyctidae, Anobiidae, and Cerambycidae, which include species with wood-boring larvae. The adaptation to wood-boring and wood-feeding activities in beetle larvae was reached independently by phyletic lines not closely related, as a convergent evolution due to feeding behaviour. Among these adaptations, the following are examined with reference to the three families mentioned above. The conformation and activity of the larval mandibles and their possible correlations with the characteristics of the wood attacked are considered together with the presence of body structures for anchoring the larvae to the wood substrate inside the tunnel during the gnawing action. Intracellular endosymbiosis (endocytobiosis) with yeasts or bacteria, capable of supplementing larval diets lacking in some essential nutrients, and its main features are summarized. Last, structural and functional characteristics are discussed as regards tracheal spiracles, provided with filter devices important for preventing intrusion of wood powder into tracheae from larval tunnels as well as useful for avoiding dehydration.

Mucus production and its role in the feeding behaviour of Diarthrodes nobilis (Copepoda: Harpacticoida)

1979 ◽  
Vol 59 (2) ◽  
pp. 321-330 ◽  
Author(s):  
Geoffrey R. F. Hicks ◽  
John Grahame
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Feeding Behaviour ◽  
Feeding Strategy ◽  
Harpacticoid Copepod ◽  
Inorganic Materials ◽  
Gut Contents ◽  
Mucus Production ◽  
Behavioural Sequence ◽  
Scanning Electron

Using light microscope histology and scanning electron microscopy, the secretion, storage and discharge of copious quantities of mucus has been demonstrated in the algadwelling harpacticoid copepod Diarthrodes nobilis (Baird). The mucus is secreted by cells closely associated with large haemocoelomic reservoirs, located in the cephalothorax and urosome, which store the mucus prior to its discharge through large integumental vents (up to 38 μm in greatest dimension). A denned behavioural sequence is recognized whereby the animal utilizes discharged mucus to construct an enmeshing capsule. Late stage nauplii are also capable of capsule fabrication.The mucus bag presumably, acts as a rich and rapidly degradable substrate to marine prokaryotes and is therefore rapidly colonized; suspended organic and inorganic materials are also trapped by the mucus. Observations on gut contents and browsing activity of capsule inhabitants indicate a direct trophic dependence of D. nobilis on the bacteria and organic agglutinations that adhere to the mucus. Utilization of such nutritive materials supports a ‘mucus-trap’ hypothesis recently proposed as a feeding strategy in meiobenthic nematodes.

Tidal shifts in microhabitat use by Gobius cobitis: an adaptation to its feeding strategy?

2008 ◽  
Vol 89 (3) ◽  
pp. 641-643 ◽  
Author(s):  
C. Faria ◽  
V.C. Almada
Keyword(s):  
Feeding Behaviour ◽  
Feeding Strategy ◽  
High Tide ◽  
Microhabitat Use ◽  
Fish Predator ◽  
Ambush Predator ◽  
Considerable Size

During high-tide, the majority of Gobius cobitis exhibit a microhabitat shift, moving up to the mid-intertidal walls and cliffs, a typical blenniid habitat that is not used by this species during low-tide. Observations on feeding behaviour that showed that fish behave as an ambush predator, being capable of hunting fish of considerable size, combined with its movements to typical blenniid habitats, suggest that this species may have a predatory role as a fish predator on the rock intertidal.

Localization of Sodium in Normal and Inhibited Transporting Epithelia

1971 ◽  
Vol 29 ◽  
pp. 392-393
Author(s):  
G. I. Kaye ◽  
J. D. Cole
Keyword(s):  
Plasma Membrane ◽  
Similar Pattern ◽  
Fixation Method ◽  
Colonic Epithelium ◽  
Gallbladder Epithelium ◽  
Rabbit Colon ◽  
Rabbit Gallbladder

For a number of years we have used an adaptation of Komnick's KSb(OH)6-OsO4 fixation method for the localization of sodium in tissues in order to study transporting epithelia under a number of different conditions. We have shown that in actively transporting rabbit gallbladder epithelium, large quantities of NaSb(OH)6 precipitate are found in the distended intercellular compartment, while localization of precipitate is confined to the inner side of the lateral plasma membrane in inactive gallbladder epithelium. A similar pattern of distribution of precipitate has been demonstrated in human and rabbit colon in active and inactive states and in the inactive colonic epithelium of hibernating frogs.

Membrane microdomains: lessons from microscopy

1995 ◽  
Vol 53 ◽  
pp. 776-777
Author(s):  
J.M. Robinson ◽  
J.M Oliver
Keyword(s):  
Spatial Distribution ◽  
Plasma Membrane ◽  
Epithelial Cells ◽  
Plasma Membranes ◽  
Cell Types ◽  
Imaging Modalities ◽  
Membrane Microdomains ◽  
Membrane Domains ◽  
Lateral Heterogeneity ◽  
Functional Importance

Specialized regions of plasma membranes displaying lateral heterogeneity are the focus of this Symposium. Specialized membrane domains are known for certain cell types such as differentiated epithelial cells where lateral heterogeneity in lipids and proteins exists between the apical and basolateral portions of the plasma membrane. Lateral heterogeneity and the presence of microdomains in membranes that are uniform in appearance have been more difficult to establish. Nonetheless a number of studies have provided evidence for membrane microdomains and indicated a functional importance for these structures.This symposium will focus on the use of various imaging modalities and related approaches to define membrane microdomains in a number of cell types. The importance of existing as well as emerging imaging technologies for use in the elucidation of membrane microdomains will be highlighted. The organization of membrane microdomains in terms of dimensions and spatial distribution is of considerable interest and will be addressed in this Symposium.

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