scholarly journals Predators indirectly induce stronger prey through a trophic cascade

2017 ◽  
Vol 284 (1866) ◽  
pp. 20171440 ◽  
Author(s):  
Arie J. P. Spyksma ◽  
Nick T. Shears ◽  
Richard B. Taylor
Keyword(s):  
Sea Urchin ◽  
Resource Availability ◽  
Food Supply ◽  
Trophic Cascade ◽  
Prey Species ◽  
Sea Urchins ◽  
Rocky Reefs ◽  
Effect Of Food ◽  
Positive Effect ◽  
Predator Effects

Many prey species induce defences in direct response to predation cues. However, prey defences could also be enhanced by predators indirectly via mechanisms that increase resource availability to prey, e.g. trophic cascades. We evaluated the relative impacts of these direct and indirect effects on the mechanical strength of the New Zealand sea urchin Evechinus chloroticus . We measured crush-resistance of sea urchin tests (skeletons) in (i) two marine reserves, where predators of sea urchins are relatively common and have initiated a trophic cascade resulting in abundant food for surviving urchins in the form of kelp, and (ii) two adjacent fished areas where predators and kelps are rare. Sea urchins inhabiting protected rocky reefs with abundant predators and food had more crush-resistant tests than individuals on nearby fished reefs where predators and food were relatively rare. A six-month long mesocosm experiment showed that while both food supply and predator cues increased crush-resistance, the positive effect of food supply on crush-resistance was greater. Our results demonstrate a novel mechanism whereby a putative morphological defence in a prey species is indirectly strengthened by predators via cascading predator effects on resource availability. This potentially represents an important mechanism that promotes prey persistence in the presence of predators.

Injured conspecifics as an alarm cue for the sea urchin Evechinus chloroticus

2020 ◽  
Vol 641 ◽  
pp. 135-144 ◽  
Author(s):  
AJP Spyksma ◽  
NT Shears ◽  
RB Taylor
Keyword(s):  
New Zealand ◽  
Sea Urchin ◽  
Trophic Cascade ◽  
Sea Urchins ◽  
Grazing Pressure ◽  
Alarm Cues ◽  
Large Fish ◽  
Lethal Effects ◽  
Rocky Reefs ◽  
Urchin Grazing

Predator mediation of sea urchin grazing pressure may occur via lethal removal of individual sea urchins or non-lethal modification of sea urchin behaviour. Several studies have shown that predation-related cues can affect sea urchin movement and grazing rates, but generalisations about the types of cues that prompt responses and the magnitude of those responses will require further research on a wider variety of species. We examined the effects of potential alarm cues on behaviour of the habitat-forming sea urchin Evechinus chloroticus (Echinometridae) on fished rocky reefs in northeastern New Zealand, where predators are uncommon and the sea urchins form barrens. Exposed E. chloroticus (i.e. those not in crevices) rapidly fled from injured conspecifics within a 1 m radius of the cue, but showed no apparent reaction to injured sea urchins belonging to another family (Centrostephanus rodgersii, Diadematidae), diced pilchards or the disturbance caused by fish attracted to the cues. Densities of exposed sea urchins in an area containing injured conspecifics did not return to control values for at least 20 h, while cryptic individuals remained crevice-bound when injured conspecifics were nearby. Injured conspecifics thus provide a strong, albeit localised, cue for E. chloroticus. By restricting sea urchins to crevices where they have a reduced impact on living kelp, this non-consumptive effect may complement the lethal effects of predation in marine reserves where populations of predators such as rock lobsters and large fish are allowed to recover from overharvesting by humans, thereby reinforcing the trophic cascade initiated by those predators.

The Relation Between Lobster Abundance, Sea Urchins, and Kelp Beds

1972 ◽  
Vol 29 (5) ◽  
pp. 603-605 ◽  
Author(s):  
K. H. Mann ◽  
P. A. Breen
Keyword(s):  
Sea Urchin ◽  
Food Supply ◽  
Sea Urchins ◽  
Critical Density ◽  
Eastern Canada ◽  
Kelp Beds ◽  
Key Species

When subtidal communities are disturbed and sea urchin populations expand, they frequently overgraze their food supply, eliminating large seaweeds from considerable areas. The hypothesis is advanced that the lobster is a key species, controlling sea urchin populations in eastern Canada, and that reduction of lobster populations below a critical density has led to overgrazing of seaweeds in many places.

scholarly journals The sea urchin – the ultimate herbivore and biogeographic variability in its ability to deforest kelp ecosystems

2013 ◽  
Author(s):  
Jarrett E Byrnes ◽  
Ladd E. Johnson ◽  
Sean D. Connell ◽  
Nick T. Shears ◽  
Selena M McMillan ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Large Scale ◽  
Sea Urchins ◽  
Meta Analysis ◽  
Kelp Forest ◽  
Rocky Reef ◽  
Rocky Reefs ◽  
Iconic Images ◽  
Balance Of Forces ◽  
Almost All

Barren rocky seafloor landscapes, denuded of almost all life by ravenous sea urchins, liberated from their predators, stands as one of the iconic images of trophic cascades in Ecology. While this paradigm has been cited in nearly every temperate rocky reef ecosystem across the globe, there is widespread disagreement as to its generality. Given their biology, sea urchins are clearly one of the ocean’s strongest herbivores in many systems, but where will their impact be strongest? Here we perform a global meta-analysis of sea urchin-kelp relationships in the field. We find that sea urchins appear to be able to control kelp abundances in any system where they can achieve high densities. Furthermore, their ability to create large-scale long-lasting barrens appears to be limited to biogeographic regions where they can achieve high consumptive potential. Based on the literature, we outline a conceptual model that examines when and where sea urchins should be able to have a strong regulating impact on kelp forest ecosystems. We suggest that many elements of global change may shift the balance of forces regulating sea urchin consumptive potential in these ecosystems. Given their ability to have strong impacts on temperate rocky reefs, these drivers need to be considered in concert with their effect on sea urchins when attempting to predict future change to marine ecosystems.

scholarly journals The sea urchin – the ultimate herbivore and biogeographic variability in its ability to deforest kelp ecosystems

2013 ◽  
Author(s):  
Jarrett E Byrnes ◽  
Ladd E. Johnson ◽  
Sean D. Connell ◽  
Nick T. Shears ◽  
Selena M McMillan ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Large Scale ◽  
Sea Urchins ◽  
Meta Analysis ◽  
Kelp Forest ◽  
Rocky Reef ◽  
Rocky Reefs ◽  
Iconic Images ◽  
Balance Of Forces ◽  
Almost All

Barren rocky seafloor landscapes, denuded of almost all life by ravenous sea urchins, liberated from their predators, stands as one of the iconic images of trophic cascades in Ecology. While this paradigm has been cited in nearly every temperate rocky reef ecosystem across the globe, there is widespread disagreement as to its generality. Given their biology, sea urchins are clearly one of the ocean’s strongest herbivores in many systems, but where will their impact be strongest? Here we perform a global meta-analysis of sea urchin-kelp relationships in the field. We find that sea urchins appear to be able to control kelp abundances in any system where they can achieve high densities. Furthermore, their ability to create large-scale long-lasting barrens appears to be limited to biogeographic regions where they can achieve high consumptive potential. Based on the literature, we outline a conceptual model that examines when and where sea urchins should be able to have a strong regulating impact on kelp forest ecosystems. We suggest that many elements of global change may shift the balance of forces regulating sea urchin consumptive potential in these ecosystems. Given their ability to have strong impacts on temperate rocky reefs, these drivers need to be considered in concert with their effect on sea urchins when attempting to predict future change to marine ecosystems.

scholarly journals Use of Echinoderms and Marine and Terrestrial Plant Materials in the Technology of Mayonnaise Sauce

2020 ◽  
Author(s):  
Vladimir Grokhovsky ◽  
Lyudmila Kuranova ◽  
Alexandra Bondarenko ◽  
Ivan Molchanovsky
Keyword(s):  
Sea Urchin ◽  
Sea Urchins ◽  
Raw Materials ◽  
New Product ◽  
The Body ◽  
Plant Materials ◽  
Ideal Protein ◽  
Valuable Product ◽  
Positive Effect ◽  
The Ideal

Sea urchin caviar is a valuable product, as well as a therapeutic and prophylactic agent for cancer, it removes radionuclides from the body, increases the body’s resistance to various types of infections, with physical and mental fatigue, under stress. In addition to the above mentioned aspects, the ingestion of sea urchin caviar helps to increase the human body’s resistance to adverse and harmful environmental factors, and has a positive effect on the cardiovascular system and thyroid function. The gonads of sea urchins contain a set of all amino acids not synthesized by the human body, moreover, in a ratio close to the composition of the “ideal protein”. The technology for manufacturing a new mayonnaise sauce using such valuable ingredients as sea urchin caviar, kelp, and nettle has been scientifically substantiated and created. A prescription composition of a new product has been developed; samples of mayonnaise sauce were made and their study during storage was carried out. The implementation of such a technology will allow not only rational use of stocks of marine non-fish raw materials and plants, but also expand the range and properties of functional products.

Evidence for Association of Vibrio Echinoideorum with Tissue Necrosis on Body Shell of the Green Sea Urchin Strongylocentrotus Droebachiensis

2021 ◽  
Author(s):  
Jonathan Hira ◽  
Klara Stensvåg
Keyword(s):  
Sea Urchin ◽  
Virulence Genes ◽  
Vibrio Vulnificus ◽  
Sea Urchins ◽  
Opportunistic Pathogen ◽  
Significant Degree ◽  
Strongylocentrotus Droebachiensis ◽  
Host Immune System ◽  
Progressive Development ◽  
Green Sea Urchin

Abstract “Sea urchin lesion syndrome” is known as sea urchins disease with the progressive development of necrotic epidermal tissue and loss of external organs, including appendages on the outer body surface. Recently, a novel strain, Vibrio echinoideorum has been isolated from the lesions of green sea urchin (Strongylocentrotus droebachiensis), an economically important mariculture species in Norway. V. echinoideorum has not been reported elsewhere in association of with green sea urchin lesion syndrome. Therefore, in this study, an immersion based bacterial challenge experiment was performed to expose sea urchins (wounded and non-wounded) to V. echinoideorum, thereby mimicking a nearly natural host-pathogen interaction under controlled conditions. This infection experiment demonstrated that only the injured sea urchins developed the lesion to a significant degree when exposed to V. echinoideorum. Pure cultures of the employed bacterial strain was recovered from the infected animals and its identity was confirmed by the MALDI-TOF MS spectra profiling. Additionally, the hemolytic phenotype of V. echinoideorum substantiated its virulence potential towards the host, and this was also supported by the cytolytic effect on red spherule cells of sea urchins. Furthermore, the genome sequence of V. echinoideorum was assumed to encode potential virulence genes and were subjected for in silico comparison with the established virulence factors of Vibrio vulnificus and Vibrio tasmaniensis. This comparative virulence profile provided novel insights about virulence genes and their putative functions related to chemotaxis, adherence, invasion, evasion of the host immune system, and damage of host tissue and cells. Thus, it supports the pathogenicity of V. echinoideorum. In conclusion, the interaction of V. echinoideorum with injured sea urchins appears to be essential for the development of lesion syndrome and therefore, revealing its potentiality as an opportunistic pathogen.

Host use pattern and life history of Liopetrolisthes mitra, a crab associate of the black sea urchin Tetrapygus niger

2000 ◽  
Vol 80 (4) ◽  
pp. 639-645 ◽  
Author(s):  
J.A. Baeza ◽  
M. Thiel
Keyword(s):  
Sea Urchin ◽  
Black Sea ◽  
Sea Urchins ◽  
Austral Summer ◽  
Average Density ◽  
The Black Sea ◽  
Reproductive Pattern ◽  
Host Use ◽  
Austral Spring ◽  
Use Pattern

The porcellanid crab Liopetrolisthes mitra is a common associate of the black sea urchin, Tetrapygus niger in north central Chile. The host-use pattern, population dynamics and reproductive pattern of L. mitra on sea urchins were examined between January 1996 and February 1997. Each month, between 60 and 95 per cent of all collected urchins hosted crabs, with the highest frequency of cohabitation occurring during the austral summer (January to March). Group sizes of crabs on individual urchins ranged from 1 to 25 crabs per host. The average density of crabs on the urchins ranged from 2 to 5.5 crabs per host. Large urchins were inhabited by crabs more frequently than small urchins but urchin size had no effect on the number or size of crabs. The sex ratio of adult crabs was ˜1:1 during most months. Reproduction occurred throughout the year but was most intense during the austral spring and summer (October to March), when the highest percentage of ovigerous females were found. Similarly, recruitment of L. mitra occurred throughout the year but reached a peak during austral summer and early autumn (January to May). All life stages of L. mitra including recently settled megalopae and reproductive adults were found on urchins. Size–frequency analysis indicated that many crabs live >1.5 years. The results of this study confirm that the association between L. mitra and T. niger is strong and persists throughout the benthic life of the commensal crab.

scholarly journals Effects of five southern California macroalgal diets on consumption, growth, and gonad weight, in the purple sea urchin Strongylocentrotus purpuratus

2014 ◽  
Author(s):  
Matthew C Foster ◽  
Jarrett E Byrnes ◽  
Daniel C Reed
Keyword(s):  
Sea Urchin ◽  
Sea Urchins ◽  
Strongylocentrotus Purpuratus ◽  
Macrocystis Pyrifera ◽  
Reproductive Capacity ◽  
Giant Kelp ◽  
Mixed Diet ◽  
Gonad Weight ◽  
Consumption Growth ◽  
Purple Sea Urchin

Consumer growth and reproductive capacity are direct functions of diet. Strongylocentrotid sea urchins, the dominant herbivores in California kelp forests, strongly prefer giant kelp (Macrocystis pyrifera), but are highly catholic in their ability to consume other species. The biomass of Macrocystis fluctuates greatly in space and time and the extent to which urchins can use alternate species of algae or a mixed diet of multiple algal species to maintain fitness when giant kelp is unavailable is unknown. We experimentally examined the effects of single and mixed species diets on consumption, growth and gonad weight in the purple sea urchin Strongylocentrotus purpuratus. Urchins were fed single species diets consisting of one of four common species of macroalgae (the kelps Macrocystis pyrifera and Pterygophora californica, and the red algae Chondracanthus corymbiferus and Rhodymenia californica (hereafter referred to by genus) or a mixed diet containing all four species ad libitum over a 13-week period in a controlled laboratory setting. Urchins fed Chondracanthus, Macrocystis and a mixed diet showed the highest growth (in terms of test diameter, wet weight and jaw length) and gonad weight while urchins fed Pterygophora and Rhodymenia showed the lowest. Urchins consumed their preferred food, Macrocystis at the highest rate when offered a mixture, but consumed Chondracanthus or Macrocystis at similar rates when the two algae were offered alone. The differences in urchin feeding behavior and growth observed between these diet types suggest the relative availability of the algae tested here could affect urchin populations and their interactions with the algal assemblage. The fact that the performance of urchins fed Chondracanthus was similar or higher than those fed the preferred Macrocystis suggests purple sea urchins could sustain growth and reproduction during times of low Macrocystis abundance as is common following large wave events.

Sign in / Sign up

Export Citation Format

Share Document