Examining the link between dietary specialization and foraging modes of stream-dwelling brown troutSalmo trutta

2018 ◽  
Vol 93 (1) ◽  
pp. 143-146 ◽  
Author(s):  
Javier Sánchez-Hernández ◽  
Fernando Cobo
Author(s):  
Jennifer R Hodge ◽  
Yutong Song ◽  
Molly A Wightman ◽  
Analisa Milkey ◽  
Binh Tran ◽  
...  

Abstract Whether distantly related organisms evolve similar strategies to meet the demands of a shared ecological niche depends on their evolutionary history and the nature of form-function relationships. In fishes, the visual identification and consumption of microscopic zooplankters, selective zooplanktivory, is a distinct type of foraging often associated with a suite of morphological specialisations. Previous work has identified inconsistencies in the trajectory and magnitude of morphological change following transitions to selective zooplanktivory, alluding to the diversity and importance of ancestral effects. Here we investigate whether transitions to selective zooplanktivory have influenced the morphological evolution of marine butterflyfishes (family Chaetodontidae), a group of small-prey specialists well known for several types of high-precision benthivory. Using Bayesian ancestral state estimation, we inferred the recent evolution of zooplanktivory among benthivorous ancestors that hunted small invertebrates and browsed by picking or scraping coral polyps. Traits related to the capture of prey appear to be functionally versatile with little morphological distinction between species with benthivorous and planktivorous foraging modes. In contrast, multiple traits related to prey detection or swimming performance are evolving toward novel, zooplanktivore-specific optima. Despite a relatively short evolutionary history, general morphological indistinctiveness, and evidence of constraint on the evolution of body size, convergent evolution has closed a near significant amount of the morphological distance between zooplanktivorous species. Overall, our findings describe the extent to which the functional demands associated with selective zooplanktivory have led to generalisable morphological features among butterflyfishes and highlight the importance of ancestral effects in shaping patterns of morphological convergence.


2021 ◽  
Vol 11 (4) ◽  
pp. 1866-1876
Author(s):  
Laurie A. Hall ◽  
Susan E. W. De La Cruz ◽  
Isa Woo ◽  
Tomohiro Kuwae ◽  
John Y. Takekawa

2007 ◽  
Vol 17 (21) ◽  
pp. R911-R912 ◽  
Author(s):  
Christopher L. Glen ◽  
Michael B. Bennett
Keyword(s):  

2020 ◽  
Author(s):  
C. Sudta ◽  
D.M. Salcido ◽  
M.L. Forister ◽  
T. Walla ◽  
S. Villamarín-Cortez ◽  
...  

AbstractSome of the most common ecological interactions are between plants and herbivorous insects, and these relationships are central to the study of ecological specialization. We address established assumptions about the positive association between local abundance and dietary specialization using a 17-year dataset on the caterpillars of Ecuador. Our long-term data include standardized plot-based samples as well as general, regional collections, allowing for investigations across spatial scales and using different indices of abundance for 1917 morphospecies of Lepidoptera from 33 families. We find that specialists are locally more abundant than generalists, consistent with a key component of the “jack of all trades, master of none” hypothesis, which has otherwise received poor to mixed support from previous studies that have mostly involved fewer species and shorter time series. Generalists achieve greater prevalence across the landscape, and we find some evidence for geographic variation in the abundance-diet breadth relationship, in particular among elevational bands. Interspecific variation in abundance also had a negative relationship with diet breadth, with specialists having more variable abundances across species. The fact that more specialized species can be both rare and common highlights the ecological complexity of specialization.


2021 ◽  
Author(s):  
Kim Vertacnik ◽  
Danielle Herrig ◽  
R Keating Godfrey ◽  
Tom Hill ◽  
Scott Geib ◽  
...  

A central goal in evolutionary biology is to determine the predictability of adaptive genetic changes. Despite many documented cases of convergent evolution at individual loci, little is known about the repeatability of gene family expansions and contractions. To address this void, we examined gene family evolution in the redheaded pine sawfly Neodiprion lecontei, a non-eusocial hymenopteran and exemplar of a pine-specialized lineage evolved from angiosperm-feeding ancestors. After assembling and annotating a draft genome, we manually annotated multiple gene families with chemosensory, detoxification, or immunity functions and characterized their genomic distributions and evolutionary history. Our results suggest that expansions of bitter gustatory receptor (GR), clan 3 cytochrome P450 (CYP3), and antimicrobial peptide (AMP) subfamilies may have contributed to pine adaptation. By contrast, there was no evidence of recent gene family contraction via pseudogenization. Next, we compared the number of genes in these same families across insect taxa that vary in diet, dietary specialization, and social behavior. In Hymenoptera, herbivory was associated with large GR and small olfactory receptor (OR) families, eusociality was associated with large OR and small AMP families, and--unlike investigations among more closely related taxa--ecological specialization was not related to gene family size. Overall, our results suggest that gene families that mediate ecological interactions may expand and contract predictably in response to particular selection pressures, however, the ecological drivers and temporal pace of gene gain and loss likely varies considerably across gene families.


1980 ◽  
Vol 28 (2) ◽  
pp. 223 ◽  
Author(s):  
SD Hopper

The identity, abundance and foraging behaviour of pollinators of the self-compatible, mass-flowering Syzygium tierneyanum were investigated. Forty-five species of nectarivorous animals were recorded. Diurnal visitors included seven bird; nine butterfly. four moth (including two hawkmoth), two bee, two ant, one wasp, three blowfly, one fruit fly, two beetle and one weevil species. while nocturnal visitors included one bat and 12 moth (including three hawkmoth) species. Floral dimensions were such that only the vertebrate and larger insect species regularly contacted anthers and stigmas while foraging. Of these groups the feral honey bee (Apis mellifera) was the most common flowet visitor. Honeyeaters and hawkmoths appeared to be the most important native pollinators; they were abundant in the study area and visited numerous flowers (50-250) in quick succession (1-3 s per flower) on each foraging bout. The only major differences in foraging times observed in the pollinator array were between diurnal, diurnal and crepuscular, and nocturnal floral visitors. Spatial partitioning of the nectar resource was limited to one instance of territoriality involving a Macleay's honeyeater (Meliphaga rnacleayana) on a densely flowering branch prior to peak blooming time, occasional aggressive chases by honeyeaters, and a division of foraging modes into rapid, erratic flights of 0.5– 4 m between flowers (hawkmoths) as against nearest-flower movements (all other groups). This lack of major spatial partitioning may have been due to the mass flowering of S. tierneyanum and the resultant superabundance of nectar. The vast majority (c. 99.95%) of interflower movements observed in foraging bouts of birds (and of hawkmoths) were within the same plant. This suggests that most seeds of S. tierneyanum may be derived from self-pollination.


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