scholarly journals Nutrient balancing in grasshoppers: behavioural and physiological correlates of dietary breadth

2003 ◽  
Vol 206 (10) ◽  
pp. 1669-1681 ◽  
Author(s):  
D. Raubenheimer
Keyword(s):  
Dietary Breadth ◽  
Nutrient Balancing

scholarly journals Diet Diversity in Carnivorous Terebrid Snails Is Tied to the Presence and Absence of a Venom Gland

Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 108
Author(s):  
Juliette Gorson ◽  
Giulia Fassio ◽  
Emily S. Lau ◽  
Mandë Holford
Keyword(s):  
Venom Gland ◽  
Molecular Study ◽  
Strongly Correlated ◽  
Animal Evolution ◽  
Diet Diversity ◽  
Dietary Breadth ◽  
Venom Composition ◽  
Marine Snails ◽  
Predatory Strategy ◽  
Definition Of

Predator-prey interactions are thought to play a driving role in animal evolution, especially for groups that have developed venom as their predatory strategy. However, how the diet of venomous animals influences the composition of venom arsenals remains uncertain. Two prevailing hypotheses to explain the relationship between diet and venom composition focus on prey preference and the types of compounds in venom, and a positive correlation between dietary breadth and the number of compounds in venom. Here, we examined venom complexity, phylogenetic relationship, collection depth, and biogeography of the Terebridae (auger snails) to determine if repeated innovations in terebrid foregut anatomy and venom composition correspond to diet variation. We performed the first molecular study of the diet of terebrid marine snails by metabarcoding the gut content of 71 terebrid specimens from 17 species. Our results suggest that the presence or absence of a venom gland is strongly correlated with dietary breadth. Specifically, terebrid species without a venom gland displayed greater diversity in their diet. Additionally, we propose a revision of the definition of venom complexity in conoidean snails to more accurately capture the breadth of ecological influences. These findings suggest that prey diet is an important factor in terebrid venom evolution and diversification and further investigations of other understudied organisms, like terebrids, are needed to develop robust hypotheses in this area.

The Comparative Feeding Ecology of Six Species of Shark and Four Species of Ray (Elasmobranchii) In The North-East Atlantic

1996 ◽  
Vol 76 (1) ◽  
pp. 89-106 ◽  
Author(s):  
J.R. Ellis ◽  
M.G. Pawson ◽  
S.E. Shackley
Keyword(s):  
Feeding Ecology ◽  
Stomach Contents ◽  
Generalist Predators ◽  
Dietary Overlap ◽  
East Atlantic ◽  
Dietary Breadth ◽  
North East ◽  
The North ◽  
North Eastern ◽  
Commercial Species

The stomach contents of ten species of elasmobranch from the north-eastern Atlantic indicate that most are generalist predators, eating a variety of polychaetes, molluscs, crustaceans and teleosts. Two species, Mustelus asterias and Squatina scjuatina were found to be specialist feeders, consuming portunid crabs and pleuronectids, respectively. Measures for both dietary breadth and dietary overlap are given and the implications of elasmobranch predation on the prey communities and on commercial species are discussed.

scholarly journals Generalism in Nature…The Great Misnomer: Aphids and Wasp Parasitoids as Examples

Insects ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 314 ◽  
Author(s):  
Hugh D. Loxdale ◽  
Adalbert Balog ◽  
Jeffrey A. Harvey
Keyword(s):  
Ecological Niche ◽  
Large Degree ◽  
Parasitoid Wasps ◽  
Pest Species ◽  
Entry And Exit ◽  
Relaxed Selection ◽  
Dietary Breadth ◽  
Trade Offs ◽  
Enemy Free Space ◽  
Living Organisms

In the present article we discuss why, in our view, the term ‘generalism’ to define the dietary breadth of a species is a misnomer and should be revised by entomologists/ecologists with the more exact title relating to the animal in question’s level of phagy—mono-, oligo, or polyphagy. We discard generalism as a concept because of the indisputable fact that all living organisms fill a unique ecological niche, and that entry and exit from such niches are the acknowledged routes and mechanisms driving ecological divergence and ultimately speciation. The term specialist is probably still useful and we support its continuing usage simply because all species and lower levels of evolutionary diverge are indeed specialists to a large degree. Using aphids and parasitoid wasps as examples, we provide evidence from the literature that even some apparently highly polyphagous agricultural aphid pest species and their wasp parasitoids are probably not as polyphagous as formerly assumed. We suggest that the shifting of plant hosts by herbivorous insects like aphids, whilst having positive benefits in reducing competition, and reducing antagonists by moving the target organism into ‘enemy free space’, produces trade-offs in survival, involving relaxed selection in the case of the manicured agro-ecosystem.

scholarly journals Dietary change among hominins and cercopithecids in Ethiopia during the early Pliocene

2015 ◽  
Vol 112 (40) ◽  
pp. 12304-12309 ◽  
Author(s):  
Naomi E. Levin ◽  
Yohannes Haile-Selassie ◽  
Stephen R. Frost ◽  
Beverly Z. Saylor
Keyword(s):  
Carbon Isotope ◽  
Morphological Changes ◽  
Great Apes ◽  
Dietary Change ◽  
Morphological Evidence ◽  
Ecological Context ◽  
Isotope Data ◽  
Dietary Breadth ◽  
Ecological Changes ◽  
Combined Data

The incorporation of C4resources into hominin diet signifies increased dietary breadth within hominins and divergence from the dietary patterns of other great apes. Morphological evidence indicates that hominin diet became increasingly diverse by 4.2 million years ago but may not have included large proportions of C4foods until 800 thousand years later, given the available isotopic evidence. Here we use carbon isotope data from early to mid Pliocene hominin and cercopithecid fossils from Woranso-Mille (central Afar, Ethiopia) to constrain the timing of this dietary change and its ecological context. We show that both hominins and some papionins expanded their diets to include C4resources as early as 3.76 Ma. Among hominins, this dietary expansion postdates the major dentognathic morphological changes that distinguishAustralopithecusfromArdipithecus, but it occurs amid a continuum of adaptations to diets of tougher, harder foods and to committed terrestrial bipedality. In contrast, carbon isotope data from cercopithecids indicate that C4-dominated diets of the earliest members of theTheropithecus oswaldilineage preceded the dental specialization for grazing but occurred after they were fully terrestrial. The combined data indicate that the inclusion of C4foods in hominin diet occurred as part of broader ecological changes in African primate communities.

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