Cowries graze verongid sponges on Caribbean reefs

Pawlik, Joseph R.; Deignan, Lindsey K.

doi:10.1007/s00338-015-1279-x

Cited by 7 publications

(9 citation statements)

References 2 publications

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“…Air-breathing hawksbill turtles are mostly restricted to shallow reefs (see above), and the abundance of angelfish species that prey on sponges was reported to be greatly reduced on vertical escarpments below 46 m at sites in the Bahamas and Cayman Islands ( Slattery et al, 2016 ). Invertebrate predators of sponges, such as seastars, nudibranchs, and cowries ( Pawlik & Deignan, 2015 ) may be more important at mesophotic depths where their own predators are less common. Indeed, Caribbean fore-reefs at the depths of the mesophotic zone and into the deep sea are ripe for study: how do changes in the diversity and biomass of demosponges and glass sponges track with sponge predators and sponge food sources as a function of depth?…”

Section: Summary and New Research Directionsmentioning

confidence: 99%

A review of bottom-up vs. top-down control of sponges on Caribbean fore-reefs: what’s old, what’s new, and future directions

Pawlik

Loh

McMurray

2018

PeerJ

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Interest in the ecology of sponges on coral reefs has grown in recent years with mounting evidence that sponges are becoming dominant members of reef communities, particularly in the Caribbean. New estimates of water column processing by sponge pumping activities combined with discoveries related to carbon and nutrient cycling have led to novel hypotheses about the role of sponges in reef ecosystem function. Among these developments, a debate has emerged about the relative effects of bottom-up (food availability) and top-down (predation) control on the community of sponges on Caribbean fore-reefs. In this review, we evaluate the impact of the latest findings on the debate, as well as provide new insights based on older citations. Recent studies that employed different research methods have demonstrated that dissolved organic carbon (DOC) and detritus are the principal sources of food for a growing list of sponge species, challenging the idea that the relative availability of living picoplankton is the sole proxy for sponge growth or abundance. New reports have confirmed earlier findings that reef macroalgae release labile DOC available for sponge nutrition. Evidence for top-down control of sponge community structure by fish predation is further supported by gut content studies and historical population estimates of hawksbill turtles, which likely had a much greater impact on relative sponge abundances on Caribbean reefs of the past. Implicit to investigations designed to address the bottom-up vs. top-down debate are appropriate studies of Caribbean fore-reef environments, where benthic communities are relatively homogeneous and terrestrial influences and abiotic effects are minimized. One recent study designed to test both aspects of the debate did so using experiments conducted entirely in shallow lagoonal habitats dominated by mangroves and seagrass beds. The top-down results from this study are reinterpreted as supporting past research demonstrating predator preferences for sponge species that are abundant in these lagoonal habitats, but grazed away in fore-reef habitats. We conclude that sponge communities on Caribbean fore-reefs of the past and present are largely structured by predation, and offer new directions for research, such as determining the environmental conditions under which sponges may be food-limited (e.g., deep sea, lagoonal habitats) and monitoring changes in sponge community structure as populations of hawksbill turtles rebound.

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Section: Summary and New Research Directionsmentioning

confidence: 99%

A review of bottom-up vs. top-down control of sponges on Caribbean fore-reefs: what’s old, what’s new, and future directions

Pawlik

Loh

McMurray

2018

PeerJ

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“…[ 42 ]). However, cowries in Belize [ 43 ] and limpets in Panama (Vicente, unpublished data ) have recently been observed to feed voraciously on Aplysina spp. despite the substantial chemical defenses.…”

Section: Discussionmentioning

confidence: 99%

“…The chemical extraction procedures for general feeding assays were conducted as described by Marty and Pawlik [ 43 ]. Briefly, the tissue was agitated vigorously in a 1:1 solvent mixture of dichloromethane (DCM) and methanol (MeOH) for a 6 hr extraction period.…”

Section: Methodsmentioning

confidence: 99%

Sponge symbioses between Xestospongia deweerdtae and Plakortis spp. are not motivated by shared chemical defense against predators

et al. 2017

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The recently described epizoic sponge-sponge symbioses between Xestospongia deweerdtae and two species of Plakortis present an unusual series of sponge interactions. Sponges from the genus Plakortis are fierce allelopathic competitors, rich in cytotoxic secondary metabolites, and yet X. deweerdtae flourishes as an epizoic encrustation on Plakortis deweerdtaephila and Plakortis symbiotica. Our objective in this study was to evaluate the hypothesis that X. deweerdtae grows epizoic to these two species of Plakortis due to a shared chemical defense against predators. We collected free-living individuals of X. deweerdtae and symbiotic pairs from a wide geographical range to generate crude organic extracts and a series of polarity fractions from sponge extract. We tested the deterrency of these extracts against three common coral reef predators: the bluehead wrasse, Thalassoma bifasciatum, the Caribbean sharpnose puffer, Canthigaster rostrata, and the white spotwrist hermit crab, Pagurus criniticornis. While the chemical defenses of P. deweerdtaephila and P. symbiotica are more potent than those of X. deweerdtae, all of the sponge species we tested significantly deterred feeding in all three generalist predators. The free-living form of X. deweerdtae is mostly defended across the region, with a few exceptions. The associated form of X. deweerdtae is always defended, and both species of Plakortis are very strongly defended, with puffers refusing to consume extract-treated pellets until the extract was diluted to 1/256× concentration. Using diode-array high performance liquid chromatography (HPLC) coupled with high-resolution mass spectrometry (LC-MS/IT-TOF), we found two secondary metabolites from P. deweerdtaephila, probably the cyclic endoperoxides plakinic acid I and plakinic acid K, in low concentrations in the associated—but not the free-living—form of X. deweerdtae, suggesting a possible translocation of defensive chemicals from the basibiont to the epibiont. Comparing the immense deterrency of Plakortis spp. extracts to the extracts of X. deweerdtae gives the impression that there may be some sharing of chemical defenses: one partner in the symbiosis is clearly more defended than the other and a small amount of its defensive chemistry may translocate to the partner. However, X. deweerdtae effectively deters predators with its own defensive chemistry. Multiple lines of evidence provide no support for the shared chemical defense hypothesis. Given the diversity of other potential food resources available to predators on coral reefs, it is improbable that the evolution of these specialized sponge-sponge symbioses has been driven by predation pressure.

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“…Interestingly, these defenses do not extend to certain nocturnal and cryptic molluscan predators, such as cowries, which leave behind grazing trails and pits on the surfaces of several species, including Aplysina fistularis (Pawlik and Deignan, 2015). Ecologically relevant bioassays have also been used to demonstrate that the secondary metabolites of sponges of this genus have potent antimicrobial (Kelly et al, 2005) and allelopathic effects (Pawlik et al, 2007).…”

Section: Introductionmentioning

confidence: 98%

Metabolite variability in Caribbean sponges of the genus Aplysina

Puyana

Pawlik

Blum

et al. 2015

Revista Brasileira de Farmacognosia

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BJP 168 1-8 Revista Brasileira de Farmacognosia xxx (2015) xxx-xxx w w w . s b f g n o s i a . o r g . b r / r e v i s t a Original Article a b s t r a c tSponges of the genus Aplysina are among the most common benthic animals on reefs of the Caribbean, and display a wide diversity of morphologies and colors. Tissues of these sponges lack mineralized skeletal elements, but contain a dense spongin skeleton and an elaborate series of tyrosine-derived brominated alkaloid metabolites that function as chemical defenses against predatory fishes, but do not deter some molluscs. Among the earliest marine natural products to be isolated and identified, these metabolites remain the subject of intense interest for commercial applications because of their activities in various bioassays. In this study, crude organic extracts from 253 sponges from ten morphotypes among the species Aplysina archeri, Aplysina bathyphila, Aplysina cauliformis, Aplysina fistularis, Aplysina fulva, A. insularis, and Aplysina lacunosa were analyzed by liquid chromatography-mass spectrometry (LC-MS) to characterize the pattern of intra-and interspecific variabilities of the twelve major secondary metabolites present therein. Patterns across Aplysina species ranged from the presence of mostly a single compound, fistularin-3, in A. cauliformis, to a mixture of metabolites present in the other species. These patterns did not support the biotransformation hypothesis for conversion of large molecular weight molecules to smaller ones for the purpose of enhanced defense. Discriminant analyses of the metabolite data revealed strong taxonomic patterns that support a close relationship between A. fistularis, A. fulva and A. insularis, while two morphotypes of A. cauliformis (lilac creeping vs. brown erect) were very distinct. Two morphotypes of A. lacunosa, one with hard tissue consistency, the other soft and thought to belong to a separate genus (Suberea), had very similar chemical profiles. Of the 12 metabolites found among samples, variation in fistularin-3, dideoxyfistularin-3 and hydroxyaerothionin provided the most predictive influence in decreasing order. Except for one morphotype, weak relationships were found from within-morphotype analyses of metabolite concentrations as a function of geographic location (Florida, N Bahamas, S Bahamas) and depth (<10 m, 10-20 m, >20 m). Our data suggest that metabolite profiles are strongly influenced by sponge phenotype rather than by the diverse microbiome which many Aplysina species share.

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Cowries graze verongid sponges on Caribbean reefs

Cited by 7 publications

References 2 publications

A review of bottom-up vs. top-down control of sponges on Caribbean fore-reefs: what’s old, what’s new, and future directions

A review of bottom-up vs. top-down control of sponges on Caribbean fore-reefs: what’s old, what’s new, and future directions

Sponge symbioses between Xestospongia deweerdtae and Plakortis spp. are not motivated by shared chemical defense against predators

Metabolite variability in Caribbean sponges of the genus Aplysina

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