scholarly journals More than Meets the Eye: Functionally Salient Changes in Internal Bone Architecture Accompany Divergence in Cichlid Feeding Mode

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
R. Craig Albertson ◽  
W. James Cooper ◽  
Kenneth A. Mann
Keyword(s):  
Genetic Basis ◽  
Dominant Mode ◽  
Bone Architecture ◽  
Foraging Strategies ◽  
Craniofacial Skeleton ◽  
Suction Feeding ◽  
Foraging Mode ◽  
Feeding Mode ◽  
Adaptive Radiations ◽  
African Cichlids

African cichlids have undergone extensive and repeated adaptive radiations in foraging habitat. While the external morphology of the cichlid craniofacial skeleton has been studied extensively, biomechanically relevant changes to internal bone architecture have been largely overlooked. Here we explore two fundamental questions: (1) Do changes in the internal architecture of bone accompany shifts in foraging mode? (2) What is the genetic basis for this trait? We focus on the maxilla, which is an integral part of the feeding apparatus and an element that should be subjected to significant bending forces during biting. Analyses of μCT scans revealed clear differences between the maxilla of two species that employ alternative foraging strategies (i.e., biting versus suction feeding). Hybrids between the two species exhibit maxillary geometries that closely resemble those of the suction feeding species, consistent with a dominant mode of inheritance. This was supported by the results of a genetic mapping experiment, where suction feeding alleles were dominant to biting alleles at two loci that affect bone architecture. Overall, these data suggest that the internal structure of the cichlid maxilla has a tractable genetic basis and that discrete shifts in this trait have accompanied the evolution of alternate feeding modes.

Prey Selection by Freshwater Predators with Different Foraging Strategies

1985 ◽  
Vol 42 (11) ◽  
pp. 1720-1732 ◽  
Author(s):  
Scott D. Cooper ◽  
Daniel W. Smith ◽  
James R. Bence
Keyword(s):  
Prey Selection ◽  
Foraging Strategies ◽  
Foraging Mode ◽  
Encounter Rates ◽  
Predator Prey ◽  
Anax Junius ◽  
Odonate Larvae ◽  
Selection For ◽  
Predator Foraging ◽  
Pachydiplax Longipennis

We observed several freshwater predators, including the odonate larvae Pachydiplax longipennis and Anax junius, the hemipterans Notonecta unifasciata and Buenoa scimitra, the dytiscid larva Acilius semisulcatus, and juvenile Gambusia affinis, feeding on a variety of microcrustacean prey and determined the frequency of the component parts of predator–prey interactions (encounter, attack, capture, ingestion). Encounter rates were the most important determinant of predator selectivity when predators were presented with a variety of microcrustacean prey. When only copepod species were used as prey, however, both encounter rates and capture success were important in determining predator diets. We used our data to test hypotheses concerning relationships between predator foraging mode and patterns of prey selection: mobile predators exhibited stronger selection for sedentary prey than did sit-and-wait predators; our own and literature data also indicated that macroinvertebrate sit-and-wait predators are better able to capture, and have higher selectivity for evasive prey than do mobile predators. A predator's attack acceleration, however, may be a better predictor of its selectivity for evasive versus nonevasive prey than its mean swimming speed.

scholarly journals Four new species of Cichlidogyrus (Platyhelminthes, Monogenea, Dactylogyridae) from Lake Victoria haplochromine cichlid fishes, with the redescription of C. bifurcatus and C. longipenis

2021 ◽  
Author(s):  
Tiziana P Gobbin ◽  
Maarten PM Vanhove ◽  
Ole Seehausen ◽  
Martine E Maan ◽  
Antoine Pariselle
Keyword(s):  
Nous Avons ◽  
Host Specificity ◽  
Lake Victoria ◽  
Model Systems ◽  
Zoological Nomenclature ◽  
Cichlid Species ◽  
African Great Lakes ◽  
Adaptive Radiations ◽  
African Cichlids ◽  
Host Parasite

AbstractAfrican cichlids are model systems for evolutionary studies and for host-parasite interactions, because of their adaptive radiations and because they harbour many species of monogenean parasites with high host-specificity. Here, we sampled five locations in southern Lake Victoria, the youngest of the African Great Lakes. We surveyed gillinfecting monogeneans from 18 cichlid species belonging to the Lake Victoria radiation superflock and two cichlid species representing two older and distantly related lineages. We found one species of Gyrodactylus (Gyrodactylidae, Monogenea), Gyrodactylus sturmbaueri Vanhove, Snoeks, Volckaert & Huyse, 2011, and seven species of Cichlidogyrus (Dactylogyridae, Monogenea). Four species are herein described: Cichlidogyrus pseudodossoui n. sp., C. nyanza n. sp., C. furu n. sp., C. vetusmolendarius n. sp.. Another species is reported but not formally described (because of few specimens and morphological similarity with C. furu n. sp.). Two other species are redescribed: Cichlidogyrus bifurcatus Paperna, 1960 and C. longipenis Paperna & Thurston, 1969. Our results confirm that the monogenean fauna of Victorian littoral cichlids displays lower species richness and lower host-specificity than that of Lake Tanganyika littoral cichlids. In C. furu n. sp., hooks V are clearly longer than the other hooks, highlighting the need to re-evaluate the current classification system of haptoral configurations that considers hook pairs III-VII as rather uniform. Some morphological features of C. bifurcatus, C. longipenis and C. nyanza n. sp. suggest that these are closely related to other congeners that infect haplochromines. We also found morphological indications that representatives of Cichlidogyrus colonised Lake Victoria haplochromines or their ancestors at least twice, which is in line with the Lake Victoria superflock being colonized by two cichlid tribes (Haplochromini and Oreochromini).DisclaimerThis preprint is disclaimed for purposes of Zoological Nomenclature in accordance with the International Code of Zoological Nomenclature, Fourth Edition Articles 8.2 and 8.3 (ICZN 1999). No new names or nomenclatural changes are available from statements in this preprint.Résumé - Quatre espèces nouvelles de Cichlidogyrus (Platyhelminthes, Monogenea, Dactylogyridae) parasites d’haplochrominé (Cichlidae) du lac Victoria, avec la redescription de C. bifurcatus and C. longipenisA cause des radiations adaptatives qu’ils ont subies, les cichlidés africain sont des systèmes modèles pour étudier l’évolution, mais aussi les relations hôtes/parasites, car ils hébergent de nombreuses espèces de Monogènes parasites qui présentent une spécificité étroite vis-à-vis de leurs hôtes. Dans ce travail, nous avons échantillonné cinq localités dans le Sud du lac Victoria, le plus jeune des grands lacs d’Afrique de l’Est. Nous avons examiné les Monogènes présents sur les branchies de 18 espèces de Cichlidés appartenant à la radiation adaptative « superflock » du lac Victoria et de deux espèces représentant deux lignées anciennes et non étroitement apparentées. Nous avons trouvé une espèce de Gyrodactylus (Gyrodactylidae, Monogenea), Gyrodactylus sturmbaueri Vanhove, Snoeks, Volckaert & Huyse, 2011 et sept espèces de Cichlidogyrus (Dactylogyridae, Monogenea). Quatre espèces nouvelles sont décrites dans le présent travail : Cichlidogyrus pseudodossoui n. sp., C. nyanza n. sp., C. furu n. sp., C. vetusmolendarius n. sp.. Une est signalée mais non décrite formellement (trop peux d’individus recueillis, morphologiquement proche de C. furu n. sp.). Deux autres sont redécrites : Cichlidogyrus bifurcatus Paperna, 1960 and C. longipenis Paperna & Thurston, 1969. Nos résultats confirment que la faune des Monogènes des Cichlidés du lac Victoria fait preuve d’une richesse spécifique et d’une spécificité moins importante que celle du lac Tanganyika. Chez C. furu n. sp. la paire de crochet V étant nettement plus longue que les autres, il faudra reconsidérer le système de classification actuel des types de hapteurs chez les Cichlidogyrus, qui considère que tous les crochets (III à VII) ont la même taille. Quelques caractéristiques morphologiques de C. bifurcatus, C. longipenis et C. nyanza n. sp. pourraient être la preuve d’une ascendance commune avec des congénères présents chez d’autres Haplochrominés. De même, certains caractères indiqueraient que des représentants des Cichlidogyrus ont colonisé les Haplochrominés du lac Victoria, ou leurs ancêtres, au moins à deux reprises, ce qui est cohérent avec une colonisation du lac par deux lignées de cichlidés distinctes (Haplochromini and Oreochromini).

Feeding ecology and behavior of postbreeding male Blue-winged Teal and Northern Shovelers

1985 ◽  
Vol 63 (6) ◽  
pp. 1292-1297 ◽  
Author(s):  
Paul J. DuBowy
Keyword(s):  
Foraging Strategies ◽  
Feeding Behaviors ◽  
Foraging Mode ◽  
Time Activity ◽  
Anas Discors ◽  
Food Items ◽  
Anas Clypeata ◽  
Foraging Method ◽  
And Behavior ◽  
Foraging Specialization

This study examined foraging strategies in male Northern Shovelers (Anas clypeata) and Blue-winged Teal (Anas discors). Differences in time–activity budgets and esophageal contents between the two species indicated major differences in the degree of foraging specialization. Preflightless male Northern Shovelers spent 84.2% of time foraging, with dabbling in the water column as the principal foraging mode (83.4%), while postflightless male shovelers spent 81.6% of time foraging (78.7% dabbling). Preflightless male Blue-winged Teal spent 68.6% of time foraging, with dabbling in mud (32.5%) and picking in vegetation (29.4%) as the two principal modes, whereas postflightless male bluewings spent 85.9% of time foraging (dabbling in mud 40.6%, and picking 34.2%). Most male Northern Shoveler food items were cladocerans (85.5%) or chironomid pupae (12.9%); this was related to the specialized foraging method employed by shovelers. Male Blue-winged Teal food items were principally gastropods (44.3%), culicids (29.2%), seeds and vegetation (15.5%), and chironomids (5.6%), which corresponded to the plastic feeding behaviors of bluewings. Examination of esophageal items revealed that male Northern Shovelers did little feeding during the summer flightless period, while male Blue-winged Teal fed throughout the period.

scholarly journals A toothless dwarf dolphin (Odontoceti: Xenorophidae) points to explosive feeding diversification of modern whales (Neoceti)

2017 ◽  
Author(s):  
Robert Boessenecker ◽  
Danielle Fraser ◽  
Morgan Churchill ◽  
Jonathan Geisler
Keyword(s):  
Phylogenetic Analysis ◽  
South Carolina ◽  
Feeding Behaviour ◽  
Stabilizing Selection ◽  
Suction Feeding ◽  
Feeding Mode ◽  
Milk Teeth ◽  
Feeding Morphology ◽  
Tooth Count

Toothed whales (Odontoceti) are adapted for catching prey underwater and possess some of the most derived feeding specializations of all mammals, including the loss of milk teeth (monophyodonty), high tooth count (polydonty), and the loss of discrete tooth classes (homodonty). Many extant odontocetes possess some combination of short, broad rostra, reduced tooth counts, fleshy lips, and enlarged hyoid bones - all adaptations for suction feeding upon fish and squid. We report a new fossil odontocete from the Oligocene (~30 Ma) of South Carolina (Inermorostrum xenops, gen. et sp. nov.) that possesses adaptations for suction feeding: toothlessness and a shortened rostrum (brevirostry). Enlarged foramina on the rostrum suggest the presence of enlarged lips or perhaps vibrissae. Phylogenetic analysis firmly places Inermorostrum within the Xenorophidae, an early diverging odontocete clade typified by long-snouted, heterodont dolphins. Inermorostrum is the earliest obligate suction feeder within the Odontoceti, a feeding mode that independently evolved several times within the clade. Analysis of macroevolutionary trends in rostral shape indicate stabilizing selection around an optimum rostral shape over the course of odontocete evolution, and a post-Eocene explosion in feeding morphology, heralding the diversity of feeding behaviour amongst modern Odontoceti.

scholarly journals A toothless dwarf dolphin (Odontoceti: Xenorophidae) points to explosive feeding diversification of modern whales (Neoceti)

2017 ◽  
Vol 284 (1861) ◽  
pp. 20170531 ◽  
Author(s):  
Robert W. Boessenecker ◽  
Danielle Fraser ◽  
Morgan Churchill ◽  
Jonathan H. Geisler
Keyword(s):  
Phylogenetic Analysis ◽  
South Carolina ◽  
Feeding Behaviour ◽  
Stabilizing Selection ◽  
Suction Feeding ◽  
Feeding Mode ◽  
Milk Teeth ◽  
Feeding Morphology ◽  
Tooth Count

Toothed whales (Odontoceti) are adapted for catching prey underwater and possess some of the most derived feeding specializations of all mammals, including the loss of milk teeth (monophyodonty), high tooth count (polydonty), and the loss of discrete tooth classes (homodonty). Many extant odontocetes possess some combination of short, broad rostra, reduced tooth counts, fleshy lips, and enlarged hyoid bones—all adaptations for suction feeding upon fishes and squid. We report a new fossil odontocete from the Oligocene (approx. 30 Ma) of South Carolina ( Inermorostrum xenops , gen. et sp. nov.) that possesses adaptations for suction feeding: toothlessness and a shortened rostrum (brevirostry). Enlarged foramina on the rostrum suggest the presence of enlarged lips or perhaps vibrissae. Phylogenetic analysis firmly places Inermorostrum within the Xenorophidae, an early diverging odontocete clade typified by long-snouted, heterodont dolphins. Inermorostrum is the earliest obligate suction feeder within the Odontoceti, a feeding mode that independently evolved several times within the clade. Analysis of macroevolutionary trends in rostral shape indicate stabilizing selection around an optimum rostral shape over the course of odontocete evolution, and a post-Eocene explosion in feeding morphology, heralding the diversity of feeding behaviour among modern Odontoceti.

scholarly journals Suction Flows Generated by the Carnivorous Bladderwort Utricularia—Comparing Experiments with Mechanical and Mathematical Models

Fluids ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 33 ◽  
Author(s):  
Krizma Singh ◽  
Roberto C. Reyes ◽  
Gabriel Campa ◽  
Matthew D. Brown ◽  
Fatima Hidalgo ◽  
...  
Keyword(s):  
Solid Mechanics ◽  
Larval Fish ◽  
Fish Larvae ◽  
Experimental Studies ◽  
Axial Flow ◽  
Aquatic Organisms ◽  
Suction Feeding ◽  
Scaled Model ◽  
Feeding Mode ◽  
Biological Studies

Suction feeding is a well-understood feeding mode among macroscopic aquatic organisms. The little we know about small suction feeders from larval fish suggests that small suction feeders are not effective. Yet bladderworts, an aquatic carnivorous plant with microscopic underwater traps, have strong suction performances despite having the same mouth size as that of fish larvae. Previous experimental studies of bladderwort suction feeding have focused on the solid mechanics of the trap door’s opening mechanism rather than the mechanics of fluid flow. As flows are difficult to study in small suction feeders due to their small size and brief event durations, we combine flow visualization on bladderwort traps with measurements on a mechanical, dynamically scaled model of a suction feeder. We find that bladderwort traps generate flows that are more similar to the inertia-dominated flows of adult fish than the viscosity-dominated flows of larval fish. Our data further suggest that axial flow transects through suction flow fields, often used in biological studies to characterize suction flows, are less diagnostic of the relative contribution of inertia versus viscosity than transverse transects.

scholarly journals Ontogeny of feeding morphology and kinematics in juvenile fishes: a case study of the cottid fish Clinocottus analis

1996 ◽  
Vol 199 (9) ◽  
pp. 1961-1971
Author(s):  
A Cook
Keyword(s):  
High Speed ◽  
Prey Capture ◽  
Least Squares Regression ◽  
Suction Feeding ◽  
Juvenile Period ◽  
Feeding Mode ◽  
Feeding Morphology ◽  
Suction Index ◽  
And Behavior

The development of feeding morphology, kinematics and behavior was examined in the juveniles of the cottid fish Clinocottus analis. The attacks of 18 juvenile C. analis, between 17.59 mm and 42.15 mm in standard length (SL), feeding on brown worms were filmed using high-speed video. Feeding mode, ram- or suction-dominated, kinematic variables and morphology were quantified and compared over the juvenile period. The analysis of these three factors was based on the following questions: (1) do they change over ontogeny; (2) how do their values compare with those of larvae, juveniles and adults of other species; and (3) what is the level of stereotypy, as measured by the variance in these factors, at this stage in ontogeny and does it change? Small C. analis juveniles have the small gape and large buccal cavity of a suction feeder, and this morphology becomes more pronounced as they become larger. The kinematic variables of C. analis juveniles are similar to those of adult suction-feeding cottids and least-squares regression analysis showed significant changes in only two variables (time to prey capture and absolute attack predator­prey distance) over the juvenile period. Feeding mode, as measured by the ram-suction index, shows an increase in the suction component of the strike with increasing size. This study demonstrates that, in C. analis, suction feeding behavior develops during the juvenile period. Within the juvenile stage, morphology, prey-capture kinematics and feeding mode are not tightly linked ontogenetically such that suction-feeder kinematics (short predator­prey distance and low attack velocity) and basic morphology (small gape, large buccal volume) develop much earlier than the employment of a large suction component during the strike.

scholarly journals Fishing behaviour by Black Caracaras (Daptrius ater) in the Amazon

2009 ◽  
Vol 9 (3) ◽  
pp. 399-401 ◽  
Author(s):  
Fabio Olmos ◽  
Ivan Sazima
Keyword(s):  
Shallow Water ◽  
Aquatic Plants ◽  
Foraging Strategies ◽  
Small Fish ◽  
Feeding Mode ◽  
Small Prey ◽  
Riverine Habitats ◽  
Amazonas State ◽  
Amazonian Lowlands ◽  
Diversified Portfolio

The Black Caracara is a widespread raptor in the Amazonian lowlands, mostly associated to riverine habitats. This bird is considered as a generalist scavenger that occasionally takes small prey and feeds on fruit. Here we report on Black Caracaras foraging on live small fish caught while moving upriver in the Rio Roosevelt rapids in the Amazonas state, northwestern Brazil. Fish were picked individually either with the bill or talons in a stretch of shallow water plenty of aquatic plants. This fishing behaviour seems unreported and adds another feeding mode to the already diversified portfolio of foraging strategies for the Caracarini.

scholarly journals Energy expenses on prey processing are comparable, but paid at a higher metabolic scope and for a longer time in ambush vs active predators: a multispecies study on snakes

Oecologia ◽  
2021 ◽  
Author(s):  
Stanisław Bury
Keyword(s):  
Energy Expenditure ◽  
Functional Performance ◽  
Standard Metabolic Rate ◽  
Specific Dynamic Action ◽  
Foraging Strategies ◽  
Foraging Mode ◽  
Fasting Period ◽  
Metabolic Scope ◽  
A Minor ◽  
Ambush Predators

AbstractSnakes are characterized by distinct foraging strategies, from ambush to active hunting, which can be predicted to substantially affect the energy budget as a result of differential activity rates and feeding frequencies. Intense foraging activity and continuously upregulated viscera as a result of frequent feeding leads to a higher standard metabolic rate (SMR) in active than in ambush predators. Conversely, the costs of digestion (Specific Dynamic Action—SDA) are expected to be higher in ambush predators following the substantial remodelling of the gut upon ingestion of a meal after a long fasting period. This prediction was tested on an interspecific scale using a large multispecies dataset (> 40 species) obtained from published sources. I found that the metabolic scope and duration of SDA tended to reach higher values in ambush than in active predators, which probably reflects the greater magnitude of postprandial physiological upregulation in the former. In contrast, the SDA energy expenditure appeared to be unrelated to the foraging mode. The costs of visceral activation conceivably are not negligible, but represent a minor part of the total costs of digestion, possibly not large enough to elicit a foraging-mode driven variation in SDA energy expenditure. Non-mutually exclusive is that the higher costs of structural upregulation in ambush predators are balanced by the improved, thus potentially less expensive, functional performance of the more efficient intestines. I finally suggest that ambush predators may be less susceptible than active predators to the metabolic ‘meltdown effect’ driven by climate change.

scholarly journals Parasite escape through trophic specialization in a species flock

2017 ◽  
Author(s):  
Pascal I. Hablützel ◽  
Maarten P.M. Vanhove ◽  
Pablo Deschepper ◽  
Arnout F. Grégoir ◽  
Anna K. Roose ◽  
...  
Keyword(s):  
Foraging Strategy ◽  
Foraging Strategies ◽  
Ecological Niches ◽  
Species Flock ◽  
Trophic Specialization ◽  
Parasite Communities ◽  
Selective Foraging ◽  
Adaptive Radiations ◽  
Host Evolution ◽  
Different Levels

AbstractIn adaptive radiations species diversify rapidly to occupy an array of ecological niches. In these different niches, species might be exposed to parasites through different routes and at different levels. If this is the case, adaptive radiations should be accompanied by a turnover in parasite communities. How the adaptive radiation of host species might be entangled with such a turnover of parasite communities is poorly documented in nature. In the present study, we examined the intestinal parasite faunas of eleven species belonging to the tribe Tropheini, one of several adaptive radiations of cichlid fishes in Lake Tanganyika. The most parsimonious ancestral foraging strategy among Tropheini is relatively unselective substrate ingestion by browsing of aufwuchs. Certain lineages however evolved more specialized foraging strategies, such as selective combing of microscopic diatoms or picking of macro-invertebrates. We found that representatives of such specialized lineages bear reduced infection with intestinal acanthocephalan helminths. Possibly, the evolution of selective foraging strategies entailed reduced ingestion of intermediate invertebrate hosts of these food-web transmitted parasites. In Tropheini, trophic specialization is therefore intertwined with divergence in parasite infection. We conclude that the study of parasite communities could improve our understanding of host evolution, ecological speciation and the origin of adaptive radiations.

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