Variation in abundances of herbivorous invertebrates in temperate subtidal rocky reef habitats

The present study assessed variation in the abundances of large herbivorous invertebrates in south-western Australia. There was some habitat partitioning between different parts of the reef: of the most frequently recorded species, the sea urchins Phyllacanthus irregularis and Centrostephanus tenuispinus were found primarily at the base of steep rock faces, whereas the gastropods Turbo torquatus and Australium squamifera were found primarily on open sections of reef. The sea urchin Heliocidaris erythrogramma was evenly distributed between these two habitats. For C. tenuispinus and H. erythrogramma, differences among locations (separated by tens to hundreds of kilometers) were the main source of variation in abundances. Phyllacanthus irregularis was more evenly distributed among locations. Abundances of sea urchins at each reef varied little over 26 months, suggesting low mortality and low recruitment. Turbo torquatus and A. squamifera varied significantly in abundance among reefs separated by < 10 km, although these differences were influenced by fluctuations over time. Broad patterns in abundances were evident: overall, abundances of herbivorous invertebrates were low, but certain areas supported high abundances. This suggests that herbivory may be a minor process in this region; however, the importance of herbivory at reefs with and without high abundances of herbivores deserves further attention.

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DENSIDAD POBLACIONAL DE CUATRO ESPECIES DE ERIZO (ECHINODERMATA: ECHINOIDEA) EN EL ARRECIFE DE LA ENTREGA, OAXACA

CICIMAR Oceánides ◽

10.37543/oceanides.v20i1-2.22 ◽

2005 ◽

Vol 20 (1-2) ◽

pp. 65

Author(s):

P. Zamorano ◽

G. E. Leyte-Morales

Keyword(s):

Population Density ◽

Sea Urchin ◽

Sea Urchins ◽

Depth Range ◽

Deep Zone ◽

Total Abundance ◽

Subsequent Increase ◽

Shallow Zone ◽

Over Time ◽

Shallow Part

De octubre de 2002 a agosto de 2003 se realizaron muestreos bimestrales de la abundancia de erizos en el arrecife de La Entrega. El arrecife fue dividido en dos profundidades (somero 0-6 m y profundo 6-12 m). En cada profundidad se realizaron seis transectos de 50 m de largo por 1 m de ancho. La mayor densidad anual correspondió a Diadema mexicanum (5.96±0.85 ind/m2), seguido de Eucidaris thouarsii (0.46±0.14 ind/m2); Echinometra vanbrunti y Toxopneustes roseus presentaron densidades bajas (0.03±0.01 ind/m2 y 0.02±0.01 ind/m2, respectivamente). Las cuatro poblaciones de erizos presentaron diferencias entre profundidades observándose mayor densidad en lo profundo; si consideramos la abundancia total de erizos en el arrecife, no se registraron diferencias temporales. Empero, al analizar por separado las profundidades, sólo E. thouarsii no presentó diferencias temporales en ambas profundidades. En diciembre, las densidades de D. mexicanum y E. thouarsii disminuyeron en lo profundo y aumentaron en lo somero, posiblemente porque sucedió una mortalidad coralina en lo somero del arrecife y el incremento de las algas motivó a estas especies a desplazarse a la parte dañada. Actualmente el arrecife de La Entrega se encuentra en avanzado estado de erosión lo que puede favorecer que la abundancia de erizos se incremente al igual que su actividad bioerosionadora. Population density of four species of sea urchin (Echinodermata: Echinoidea) at La Entrega Reef, Oaxaca Bimonthly samples of sea urchins fauna inhabiting the La Entrega Reef, Oaxaca, Mexico, were obtained from October 2002 to August 2003. The reef area was divided in two sampling zones, corresponding to shallow (0-6 m) and deep (6-12 m) water. Six transects of 50 m length by 1 m wide were sampled in each zone. Greatest annual density corresponded to Diadema mexicanum (5.96 ± 0.85 ind/m2),followed by Eucidaris thouarsii (0.46 ± 0.14 ind/m2); Echinometra vanbrunti and Toxopneustes roseus presented low densities (0.03 ± 0.01 indv/m2 and 0.02 ± 0.01 ind/m2, respectively). Density of the four populations varied considerably and higher densities were observed in the deep zone. Total abundance of sea urchins (shallow and deep samples) did not vary significantly over time. Abundance per depth range, however, was different over time for all species except for E. thouarsii. In December densities of D. mexicanum and E. thouarsii decreased in the deep zone and increased in the shallow zone, due to massive mortality of coral in the shallow part of the reef and to subsequent increase of algal coverage attracting these species to the shallowest part of the reef. The La Entrega reef is presently in an advanced state of erosion that could favor an increase of sea urchins abundance and of their bioerosion activity.

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

10.7287/peerj.preprints.174v1 ◽

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.

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

10.7287/peerj.preprints.174 ◽

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

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Characterization of the Teeth Skeletal Matrix from Arbacia lixula

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.672.168 ◽

2016 ◽

Vol 672 ◽

pp. 168-182

Author(s):

Julia Maxi Kanold ◽

Françoise Immel ◽

Arul Marie ◽

Laurent Plasseraud ◽

Gérard Alcaraz ◽

...

Keyword(s):

Acetic Acid ◽

Sea Urchin ◽

Composite Structures ◽

Matrix Protein ◽

Sea Urchins ◽

Organic Matrix ◽

Matrix Proteins ◽

The Matrix ◽

A Minor ◽

Arbacia Lixula

The teeth of sea urchins are highly complex composite structures, composed predominantly of high magnesium calcite, and of a minor heterogeneous assemblage of organic macromolecules that are occluded within the mineral. The organic matrix fulfils important functions in mineralization, in addition to giving the mineral phase peculiar mechanical properties, different from that of purely inorganic calcite. Nevertheless, the composition and function of individual components of the organic matrix still remains largely unknown. Up to now, the detailed protein repertoire of teeth from a single sea urchin species (Strongylocentrotus purpuratus, order Camarodonta) was investigated. In this study, we characterized for the first time the teeth skeletal matrix of another sea urchin, Arbacia lixula (order Arbacioida). The acetic acid soluble and acetic acid insoluble matrices, namely ASM and AIM respectively, were extracted and characterized with different biochemical methods including mono-dimensional SDS-PAGE, FT-IR spectroscopy, HPAE-PAD for monosaccharide analysis, and finally, proteomics. In spite of the paucity of peptide data, several of them displayed a high abundance of hydrophobic residues, i.e., alanine, glycine and valine, and of the apolar proline. We assert that the alanine- and proline-rich domains are important features of some of the matrix proteins associated to the teeth of sea urchins. None of the known skeletal matrix proteins from S. purpuratus teeth were identified in the organic matrix of A. lixula teeth. This might suggest major differences in teeth matrix protein repertoires of these two species belonging to orders that diverged in the Mesozoic times.

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Growth and age structure of sea urchins (Heliocidaris erythrogramma) in complex barrens and native macroalgal beds in eastern Tasmania

ICES Journal of Marine Science ◽

10.1093/icesjms/fsm168 ◽

2007 ◽

Vol 65 (1) ◽

pp. 1-11 ◽

Cited By ~ 20

Author(s):

Hugh G. Pederson ◽

Craig R. Johnson

Keyword(s):

Sea Urchin ◽

Age Structure ◽

Sea Urchins ◽

Growth Models ◽

Resource Limitation ◽

Small Scale ◽

Frequency Distributions ◽

Heliocidaris Erythrogramma ◽

Community Types ◽

Size At Age

Abstract Pederson, H. G., and Johnson, C. R. 2008. Growth and age structure of sea urchins (Heliocidaris erythrogramma) in complex barrens and native macroalgal beds in eastern Tasmania. – ICES Journal of Marine Science, 65: 1–11. The formation of small-scale barrens of sea urchins on the east coast of Tasmania allows for direct comparison of the growth rates and age structures of sea urchin populations in barrens and habitats dominated by native macroalgae. However, such barrens are atypical of any previously described in temperate regions worldwide mainly because of the establishment and seasonal colonization by the introduced macroalga Undaria pinnatifida. Growth models were fitted to sea urchin (Heliocidaris erythrogramma) data, based on tag-recapture information from two distinct community types, a native macroalgal bed and a sea urchin barren colonized by U. pinnatifida. Despite the distinct contrast in habitats, size-at-age relationships and age frequency distributions were not significantly different between the two populations. However, the relationship between jaw length and test diameters was significantly different between populations, sea urchins in barrens possessing larger jaws relative to conspecifics of similar test diameter in native macroalgal habitats. It is proposed that the growth of sea urchins on barrens is not adversely affected by the loss of native macroalgae in the presence of U. pinnatifida. However, sea urchins display a level of resource limitation in barrens because of differences in the relationships of sea urchin morphometrics.

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Persistence of sea urchin (Heliocidaris erythrogramma) barrens on the east coast of Tasmania: inhibition of macroalgal recovery in the absence of high densities of sea urchins

Botanica Marina ◽

10.1515/bot.2005.025 ◽

2005 ◽

Vol 48 (2) ◽

Cited By ~ 45

Author(s):

Joseph P. Valentine ◽

Craig R. Johnson

Keyword(s):

Sea Urchin ◽

East Coast ◽

Sea Urchins ◽

Heliocidaris Erythrogramma

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Population structure of the purple sea urchin Heliocidaris erythrogramma along a latitudinal gradient in south-west Australia

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315413001604 ◽

2013 ◽

Vol 94 (5) ◽

pp. 1033-1040 ◽

Cited By ~ 4

Author(s):

Dan A. Smale ◽

Thomas Wernberg

Keyword(s):

Sea Urchin ◽

Survey Design ◽

Sea Urchins ◽

Gonad Index ◽

Population Level ◽

Habitat Types ◽

Heliocidaris Erythrogramma ◽

Purple Sea Urchin ◽

South West ◽

Size Condition

Sea urchins are key herbivores in many coastal ecosystems. The purple sea urchin, Heliocidaris erythrogramma, is widely distributed across temperate Australia where it exhibits considerable plasticity in feeding behaviour and ecophysiology. In this study we examined H. erythrogramma populations on subtidal reefs along ~4° of latitude in south-west Australia. We used a multi-factorial survey design to assess variability in H. erythrogramma abundances between locations (>200 km part), sites (≥1 km apart) and habitat types (reef flats and slopes). We also examined spatial variability in urchin size, condition (measured by gonad index), and the relative abundances of two co-occurring subspecies. Urchin densities were generally low and did not vary between locations, but did vary between habitat types and amongst sites. Site-level variability in urchin size and condition was also pronounced. The southernmost population comprised smaller individuals and greater relative abundance of the H. e. erythrogramma subspecies, which is abundant on the east coast of Australia. We observed no indication of population-level responses to a recent extreme warming event that impacted the wider ecology of the region, but further investigation into the effects of both gradual warming and short-term climatic events on the ecology of H. erythrogramma and other key herbivores is required.

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Recreational Harvest of Sharks and Rays in Western Australia Is Only a Minor Component of the Total Harvest

Sustainability ◽

10.3390/su13116215 ◽

2021 ◽

Vol 13 (11) ◽

pp. 6215

Author(s):

Matias Braccini ◽

Eva Lai ◽

Karina Ryan ◽

Stephen Taylor

Keyword(s):

Western Australia ◽

Minor Component ◽

The North ◽

Commercial Harvest ◽

Unknown Status ◽

Reef Sharks ◽

Conservation Concern ◽

Taxonomic Groups ◽

A Minor ◽

Port Jackson

Sharks and rays are a global conservation concern with an increasing number of species considered at risk of extinction, mostly due to overfishing. Although the recreational harvest of sharks and rays is poorly documented and generally minimal, it can be comparable to the commercial harvest. In this study, we quantified the recreational harvest of sharks and rays in Western Australia, a region with a marine coastline greater than 20,000 km. A total of 33 species/taxonomic groups were identified, with the harvest dominated by dusky and bronze whalers, blacktip reef sharks, gummy sharks, Port Jackson sharks, wobbegongs, and rays and skates. Eighty-five percent of individuals were released with an unknown status (alive or dead). We found a latitudinal gradient of species composition, with tropical and subtropical species of the genus Carcharhinus dominating in the north and temperate species from a range of families dominating in the south. Overall, our findings showed that the recreational harvest was negligible when compared with commercial landings.

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

10.21203/rs.3.rs-1085079/v1 ◽

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.

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

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400002460 ◽

2000 ◽

Vol 80 (4) ◽

pp. 639-645 ◽

Cited By ~ 36

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.

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