The non-linear relationship between body size and function in parrotfishes

  title={The non-linear relationship between body size and function in parrotfishes},
  author={Jerker Lokrantz and Magnus Nystr{\"o}m and Matilda Thyresson and Catarina Johansson},
  journal={Coral Reefs},
Parrotfishes are a group of herbivores that play an important functional role in structuring benthic communities on coral reefs. Increasingly, these fish are being targeted by fishermen, and resultant declines in biomass and abundance may have severe consequences for the dynamics and regeneration of coral reefs. However, the impact of overfishing extends beyond declining fish stocks. It can also lead to demographic changes within species populations where mean body size is reduced. The effect… 

The non-linear relationship between grazing function and size of two parrotfish species in the Red Sea for coral reef resilience

. Parrotfish, a herbivorous reef fish, is considered to play an important role within coral reef ecosystems, enhancing coral reef resilience by keeping algal growth in check, allowing slower-growing

The ecosystem role of parrotfishes on coral reefs

The results provide new information on the differences between scraping and excavating parrotfishes and emphasize the importance of different functional groups in the structuring of benthic communities on coral reefs.

Parrotfish Body Size As An Indicator of Diurnal Fish Species Richness On Fringing Coral Reefs in Barbados

The purpose of this study is to assess whether or not family Scaridae (common name: parrotfish) body size can be used as an index to evaluate the diurnal fish diversity on coral reefs.

Site-Level Variation in Parrotfish Grazing and Bioerosion as a Function of Species-Specific Feeding Metrics

Small-bodied fish assemblages can maintain ecosystem functions, but only if key species are present in sufficiently high numbers, as well as for a given level of parrotfish biomass, grazing and bioerosion levels were higher on Maldivian reefs than in the Chagos Archipelago.

Dynamics of parrotfish grazing scars

New information is provided on the differences between scraping and excavating parrotfishes and, in a system with just one abundant large excavating species, the potential for low functional redundancy in high diversity coral reef systems is emphasized.

Comparative analysis of foraging behavior and bite mechanics reveals complex functional diversity among Caribbean parrotfishes

Recognizing that different species of parrotfishes interact with the benthos in fundamentally different ways will enable scientists and managers to better predict how changes in the structure ofParrotfish assemblages may affect benthic communities and ecosystem processes.

Influence of habitat condition and competition on foraging behaviour of parrotfishes

The study suggests that predicted changes in coral cover are likely to alter the way reef herbivores forage, and will shape the extent to which they can compensate for declining habitat condition through changes in their feeding behaviour.

Positive and Negative Effects of a Threatened Parrotfish on Reef Ecosystems

The results suggest that the world's largest parrotfish, a globally imperiled species, may not have universally positive impacts on ecosystems and that it may be necessary for environmental managers to consider the diverse effects of such species and the forces that mediate the strength of their influence.

Inter-Habitat Variability in Parrotfish Bioerosion Rates and Grazing Pressure on an Indian Ocean Reef Platform

New insights into within-reef variability in parrotfish ecological functions are provided and the importance of considering how these interact to influence reef geo-ecology is demonstrated.

Parrotfish movement patterns vary with spatiotemporal scale

A comprehensive evaluation of the movement patterns of the parrotfish Chlorurus microrhinos at multiple spatial and temporal scales at Palmyra Atoll in 2013−2015 found that these fish have large home ranges when accounting for migrations to spawning and night refuge sites, but that within feeding territories, their activity is highly non-random and is quite spatially constrained and temporally episodic.



A functional analysis of grazing in parrotfishes (family Scaridae): the ecological implications

SynopsisThe assumption that parrotfishes represent a single group of grazing herbivores is addressed by morphological, functional and ecological analyses. This assumption is rejected. The 24 scarine

Quantifying herbivory across a coral reef depth gradient

The results of the current study provide support for the hypothesis that algal community structure is shaped by levels of herbivory, as shown in the example of the Great Barrier Reef, Australia.


Coral reef herbivores were classified into three functional groups according to criteria describing the frequency and intensity of disturbance to the algal community created by their herbivory, resulting in higher overall ecosystem primary productivity and apparently facilitate the flow of energy and materials from the highly productive algal turf component to higher levels in the reef trophic web.

The impact of exploiting grazers (Scaridae) on the dynamics of Caribbean coral reefs.

  • P. Mumby
  • Environmental Science
    Ecological applications : a publication of the Ecological Society of America
  • 2006
A spatially explicit simulation model of a Caribbean coral reef is used to examine the ecosystem requirements for grazing which is primarily conducted by parrotfishes (Scaridae) and suggests that failure to manage scarid populations outside reserves will have a profoundly negative impact on the functioning of the reserve system and status of non-reserve reefs.

Batch fecundity of Lutjanus carponotatus (Lutjanidae) and implications of no-take marine reserves on the Great Barrier Reef, Australia

Greater batch fecundity, longer spawning seasons and potentially greater larval survival due to larger egg size from bigger individuals might significantly enhance the potential benefits of no-take marine reserves on the Great Barrier Reef.

Fishing, Trophic Cascades, and the Process of Grazing on Coral Reefs

Increase in density of large parrotfishes caused a fourfold reduction in the cover of macroalgae, which highlights the potential importance of reserves for coral reef resilience.

Sleeping Functional Group Drives Coral-Reef Recovery

Bioerosion and sediment ingestion by the Caribbean parrotfish Scarus vetula and Sparisoma viride: Implications of fish size, feeding mode and habitat use

Parrotfish foraging preferences, and the effects of food type and skeletal density of substrates on the size of the grazing scars, cause large differences in bioerosional rates on a small spatial scale, and they decrease with depth.

Limits to grazing by herbivorous fishes and the impact of low coral cover on macroalgal abundance on a coral reef in Belize

It is suggested that grazing by herbivorous fishes can exclude macroalgae from mid-depth reefs with high cover of hard corals, but that on low- cover reefs, the amount of space occupied by algae overwhelms the ability of grazing fishes to crop it down.