Mangrove Sponges Research Articles

Evaluation of Antibacterial Activity and Characterization of Phytochemical Compounds from Selected Mangrove Plants

The aim of this study was to investigate the antibacterial activity of n-butanol, petroleum ether, ethyl acetate, ethanol, methanol, and chloroform extracts of the sponges and leaves of different mangrove species (Bruguiera cylindrica, Suaeda maritima, Ceriops decandra, Avicennia officinalis, Rhizophora apiculata, Suaeda monoica, Avicennia marina, and Rhizohora mucronata) against Proteus mirabilis ATCC 7002. Methods and Results: Agar well diffusion method was used to evaluate the antimicrobial activity of selected mangrove extracts. The active compounds from mangrove sponges and leaves with various solvents were examined under Fourier transform infrared (FTIR) spectroscopy. The ethyl acetate extracts, methanol extracts, chloroform extracts, n-butanol extracts, and petroleum ether extracts of selected mangrove leaves (B. cylindrical, S. maritime, A. officinalis, S. monoica, A. marina, R. mucronata) showed good antibacterial activity against P. mirabilis ATCC 7002. FTIR analysis of crude methanol extract of S. monoica showed the presence of amide and alkane groups in phytochemicals. For crude methanol extract of R. mucronata, the presence of phenol, nitro, amide, and alkane groups was revealed. Conclusion: the results obtained revealed industrially important mangrove extracts and the functional groups of plant compounds responsible for great antibacterial activity.

Fungal diversity of mangrove-associated sponges from New Washington, Aklan, Philippines

ABSTRACTSponge-associated fungi are the least explored marine fungal groups. It is only in recent years that fungal symbionts of marine sponges have received attention mainly due to the isolation of bioactive metabolites while not much attention was given to their specificity, biogeography and exact roles in marine sponges. The diversity of fungi associated with mangrove sponges (Axinella sp., Halichondria cf. panicea, Haliclona sp., Tedania sp.) collected from New Washington, Aklan, Philippines were investigated using morphological observation. A total of 110 species of sponge-associated fungi belonging to 22 genera of ascomycetes with 18 genera of asexual morphs whose sexual stage is unknown, 2 genera of basidiomycetes, 21 morphospecies of Mycelia sterilia, 1 unidentified yeast species and 11 unidentified hyphomycetes were isolated from four species of mangrove sponges. This is the first study that explored the diversity and ecology of sponge-associated fungi in mangrove habitats from the Philippines. The results of the study suggest host-preference by various fungal taxa and the development of fungi on these hosts appeared to be strongly influenced by the characteristics or nature of the immediate environment.

Bottom-up and top-down controls on coral reef sponges: disentangling within-habitat and between-habitat processes.

Polarized debates about top-down vs. bottom-up control have given way to more nuanced understanding of control by both resources and consumers in many systems, but coral reef sponges have recently been asserted to differ from other groups in being controlled exclusively top-down. This assertion has been countered by reports of exclusively bottom-up control, with both conclusions based on studies of the same species. Accelerating deterioration of coral reefs motivates knowing the contexts in which either consumers or nutrients or both control key ecosystem role players like sponges. Accordingly, genotype- and size-controlled individuals of 12 common Caribbean reef sponge species were transplanted, in the field, into five circumstances differing in predators, competitors, and the picoplankton consumed by sponges. Growth and survival of the experimental transplants for periods of 1-9yr revealed context-dependent control of sponges. Primary control of growth was bottom-up, with more picoplankton resulting in consistent and sustained higher growth rates for all 12 of these ecologically and phylogenetically diverse species. Top-down control was not detected within-habitat, on the coral reef. However, between-habitat control was by predation and competition, with reef sponges excluded from adjacent seagrass meadows by spongivorous starfish, and excluded from mangrove prop roots by faster-growing mangrove sponges. These results highlight the strong importance of experimental design details that consider behavior idiosyncrasies, sufficiently long time scales, and appropriate division of species into categories. Diametrically opposite results from studies of the same species also illustrate the inherently greater difficulty of detecting bottom-up processes and the importance of distinguishing within-habitat vs. between-habitat patterns and processes.

Mangrove sponges from Bangka Island (North Sulawesi, Indonesia) with the description of a new species

Mangroves create unique ecological environments, furnishing a habitat opportunity for many species. The majority of published information on mangrove sponges comes from the Caribbean while few data are available from Indo-Pacific mangrove sponges. In general, species diversity of sponges in mangroves is lower than adjacent subtidal habitats in both the Caribbean and Indo-Pacific. The aim of this study is to report the first data about sponge species diversity of two mangrove forests from Bangka Island (North Sulawesi, Indonesia) and to describe a new sponge species associated with the mangroves. The survey found 19 species, belonging to 11 families and 15 genera; the samples were collected on mangrove trunks, on the roots or on the surrounding bottom. The majority of the species are typical of coral reef but two of them have been previously found only in lagoons or in mangrove habitats. These new data enlarge our knowledge about Indonesian sponges diversity and suggest the urgency to consider Indonesian mangroves as an important but underestimated element in coral reef ecological dynamics.

Ecology of fouling assemblages associated with mangrove's roots: An artificial substrate for manipulative experiments

Several of the most influential studies in marine ecology are based on results obtained from experiments using units of artificial habitats. However, there are few studies that have measured the effectiveness of those experimental substrates as surrogates of natural ones, in terms of reflecting natural patterns of colonization and development of the natural assemblages. Such considerations are necessary to extrapolate the described patterns and processes in artificial habitats to natural communities. This situation is particularly noticeable in ecological studies dealing with the identification of process that sustain the high levels of species diversity reported for epibiont communities that grow on the roots of Rizophora mangle in the Caribbean Sea. That is, no study has demonstrated the validity of artificial substrate as surrogate of mangrove roots. Consequently, in this study we tested whether wooden sticks can be used as surrogates for natural prop roots. Furthermore, and in order to propose possible mechanisms explaining the observed patterns, we also tested whether differences in epibiotic assemblages on natural mangrove prop roots were due primarily to intrinsic (biological) differences among roots. The experiment was conducted in four randomly chosen localities of La Restinga National Park, Venezuela, to test for the generality of the observed outcomes. We used two types of substrates: broomsticks as artificial mangrove roots (AMR) and natural mangrove roots (NMR) denuded from epibionts. We recorded the presence and estimated the abundance of sessile species growing on the experimental treatments after 30, 130 and 200days. No significant differences in species richness between the two substrates at any locality and at any time were detected. However, the effect of the substrate on the composition and abundance of species varied among localities and increased over time. Multivariate dispersion was not different between substrates, indicating that intrinsic biological characteristics of prop roots are not responsible for the observed differences among neighboring roots. Despite spatial differences at the scale of localities, most of the species recorded in this study colonized both types of substrates, although some species were more abundant over AMR (e.g. cirripeds, bryozoans), while others were more abundant on NMR (e.g. oyster, algae). Typical mangrove sponges and tunicates colonized similarly both types of substrates. Results obtained in this work suggest that broomsticks are appropriate surrogates of mangrove roots to experimentally evaluate processes associated with species diversity, but should not be used to evaluate processes that affect the abundance and structure of epibiont assemblages.

Root-derived organic matter confines sponge community composition in mangrove ecosystems

IntroductionCaribbean mangrove-associated sponge communities are very distinct from sponge communities living on nearby reefs, but the mechanisms that underlie this distinction remain uncertain. It has been hypothesized that dissolved organic matter (DOM) leaching from mangrove roots and the ability of mangrove-associated sponge-bacterial consortia to degrade mangrove DOM may cause this distinction.MethodsThis study tested whether mangrove DOM, leaching from mimicry substrates or directly injected in sponge tissue, affected the performance of a reef and a mangrove sponge species.ResultsControls and the mangrove sponge remained unaffected by mangrove DOM leaching from mimicry substrates or directly injected in sponge tissue, but the reef species showed substantial necrosis when exposed to mangrove DOM.ConclusionsResults presented in this study suggest that mangrove DOM confines the composition of sponge communities in mangrove ecosystems, explaining the exclusion of typical reef species and the adjacent occurrence of distinct sponge communities.

A skeleton‐less sponge ofCaribbean mangroves: invasive or undescribed?

AbstractRecent surveys of sponges occurring on Caribbean mangrove roots demonstrated the presence of a skeleton‐less sponge of the genusHalisarca,very similar in its morphology to the temperateH. dujardinii. This study evaluated the possibility that the mangrove sponge was actuallyH. dujardiniithat had been introduced into the Caribbean mangroves. Detailed histology revealed differences between the mangrove sponge andH. dujardiniiin cuticle thickness, and in characteristics of the choanocytes, spherulous, and granular cells. Also, phylogenetic reconstruction and genetic distance estimates based on cytochrome oxidase I gene sequences clearly differentiated the mangroveHalisarcasp. fromH. dujardinii. Therefore, we rejected the hypothesis of the invasion ofH. dujardinii, recognizing instead the mangroveHalisarcasp. as a new species and naming itH. restingaensissp. nov. Estimated levels of genetic variation in the ribosomal internal transcribed spacers indicated that populations ofH. restingaensissp. nov. are highly differentiated between Venezuela and Panama (Fst=0.71). This level of population differentiation is consistent with the short larval competence period that is common in members of the genusHalisarca.

Mangrove-sponge associations: a possible role for tannins

A positive correlation between sponge coverage and tannin concentrations in prop roots of Rhizophora mangle L. has previously been reported. However, the ecological role of tannins within the mangrove sponge association remains speculative. This study investigated whether tannins play a role in sponge recruitment and assessed tannin and polyphenol production in R. mangle roots in response to sponge colonization. We demonstrated in a field experiment using artificial substrates with different tannin concentrations that tannins are positively involved in larval recruitment of the sponge Tedania ignis and that roots significantly enhanced tannin and polyphenolic content in response to natural and experimental sponge fouling. Differential recruitment in response to tannins may have been the result of a behavioral response in sponge larvae. It is also possible that tannins affected the structure of the fouling microbial biofilm on the artificial substrate, or tannins affected the post-settlement dynamics of sponge recruits. Elevations in concentrations of tannins and polyphenolic compounds upon coverage with sponges, combined with differential recruitment of T. ignis in response to differences in tannin concentrations, may indicate a positive feedback in recruitment. This may in part explain the typical heterogeneity in sponge coverage and community composition among roots.

Diversity and spatial heterogeneity of mangrove associated sponges of Curaçao and Aruba

Sponges are major epibionts of mangrove roots in the Caribbean. Mangrove sponge communities in the Caribbean mainly consist of species that are typical to this habitat and community compositions often differ from those found on coral reefs nearby. Heterogeneity in species distributions between locations and within locations between roots is often reported. This study quantifies the diversity and abundance of mangrove associated sponges in the inner bays of Curaçao and Aruba and correlates variability of regional sponge diversity with environmental variables measured along the surveyed sites. Tannin concentrations vary between mangrove roots, and were correlated to sponge cover as a possible cause for habitat heterogeneity on a smaller scale. A total of 22 species was observed. Heterogeneity in species richness and abundance was apparent, and several sponge species were restricted in their depth of occurrence. Statistical data reduction suggests that sponge diversity may be partly explained by the distance towards adjacent reefs and to the degree of eutrophication, in which the latter is comprised of rate of planktonic respiration, total carbon and turbidity. Tannin concentrations did not determine within locality species heterogeneity as a priori postulated, but were positively related to sponge cover for reasons not yet elucidated.

Adaptation of reef and mangrove sponges to stress: evidence for ecological speciation exemplified by Chondrilla caribensis new species (Demospongiae, Chondrosida)

Sponges (Porifera) in mangroves have adapted to a wide range of environmental parameters except for extended periods of exposure to freshwater or air. Many marine mangrove islands are located in the shallow backwaters of coral reefs in Belize and elsewhere in the Caribbean and have a mean tidal range of only 15 cm. They are densely populated by sponges, mostly attached to subtidal red-mangrove stilt roots and peat banks lining tidal channels. Some species are endemic to mangroves, others are immigrants from nearby reefs. Mangrove endemics endure environmental hardships, such as occasional exposure to air during spring tides, temperature and salinity extremes, fine sediments, even burial in detritus. Reef immigrants into mangroves enjoy protection from spongivores that do not stray into the swamp but they eventually succumb to environmental stress. There is evidence exemplified by the common demosponge Chondrilla aff. nucula, that sponges flourishing in both mangrove and reef habitats may develop separate ecologically specialized and reproductively isolated populations. Such processes can lead to genetic modifications and thus serve as mechanisms for ecological speciation. Because Chondrilla nucula Schmidt was first described from the Mediterranean Sea, it was long suspected that the western Atlantic population may be a separate species. New morphological and molecular evidence prompt us to describe it under a new name, Chondrilla caribensis, with two ecological forms, forma caribensis from mangroves and lagoons, and forma hermatypica from open reefs.

Abiotic factors control sponge ecology in Florida mangroves

It is well documented that biotic effects play an important role in determining the distri- bution and abundance of sponges on Caribbean coral reefs: predation by fishes restricts some species to refugia, and allelopathic interactions result in a competitive hierarchy for space. Recently, it has been proposed that biotic effects are similarly important in mangrove habitats; specifically, that sponges common to mangrove habitats grow fast and rapidly out-compete species otherwise found in reef habitats for prop-root space. To begin to test this hypothesis, 9 species of common reef sponges were transplanted to prop roots at 3 mangrove sponge sites with different flow regimes (as measured with plaster clods) near Key Largo, Florida. Reef sponges transplanted to all 3 mangrove sites declined in health and died, most within 60 d, while those back-transplanted to a reef site survived and grew. Reef sponge decline was most rapid at sites with the lowest flow during periods of the month with the least tidal flux, when a combination of freshwater input, high temperature and turbid- ity were likely responsible for their demise. We conclude that some mangrove sites that support sponge growth do so because the species found there can endure the abiotic conditions of mangrove habitats, and not because of competitive dominance over species otherwise found on the reef.

Interactions among Florida sponges. II. Mangrove habitats

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 303:145-152 (2005) - doi:10.3354/meps303145 Interactions among Florida sponges. II. Mangrove habitats Sebastian Engel1, 2, Joseph R. Pawlik1, * 1University of North Carolina at Wilmington, Center for Marine Science, 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409, USA2Present address: Scripps Institution of Oceanography, La Jolla, California 92093, USA *Corresponding author. Email: pawlikj@uncw.edu ABSTRACT: This study documents interference interactions between Florida sponge species. In a companion study, we conducted transect surveys to examine interspecific interactions between reef sponges in Key Largo, Florida, USA. Herein, we conducted similar transect surveys to assess interspecific interactions between mangrove sponges growing on the prop roots of the red mangrove Rhizophora mangle in Florida Bay. We surveyed 10 transect sites at 2 locations with mean densities of 2.6 ± 0.8 and 3.4 ± 1.2 sponges on each meter of prop root. Overall, 73.5% of all available root space was overgrown by a total of 1195 sponges comprising 10 species. Chondrilla nucula, Lissodendoryx isodictyalis, and Tedania ignis were the most abundant sponges and overgrew more available root space than any other species. We used a nearest-neighbor technique to determine the degree and frequency of interactions between all sponges. Overall, 31.1% of sponges occurred alone, 3.3% in proximity to, and 65.6% in contact with other sponge species. Among all sponges in contact interactions, 39.0% were epibionts, 24.3% were basibionts, and 36.7% occurred in ‘equal’ interactions in which it was not possible to determine the epi- from the basibiotic species. Differences in the frequencies of each interaction category were statistically tested for all species to determine the ability of 1 sponge to overgrow or resist overgrowth by other species. Among all sponges surveyed in this study, Dysidea etheria and Clathrina canariensis were never overgrown, while Geodia gibberosa and Halichondria sp. were frequently overgrown by other species. The overgrowth ability of a sponge species appeared to be dependent on growth rate or the production of allelochemicals. KEY WORDS: Allelopathy · Interference interactions · Mangroves · Nearest-neighbor · Overgrowth · Sponges Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 303. Online publication date: November 21, 2005 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2005 Inter-Research.

Amphimedon species (Porifera: Niphatidae) from the Gulf of Aqaba, Northern Red Sea: Filling the gaps in the distribution of a common pantropical genus

Amphimedon (Porifera, Demospongiae, Haplosclerida, Niphatidae), a pantropical genus of reef and mangrove sponges, was recently recorded for the first time from the Red Sea suggesting a rarity which is not sustained by new reef surveys in the Gulf of Aqaba. Here we describe four species of Amphimedon occurring commonly in the Gulf of Aqaba. Among these, three are new to science, A. dinae sp.nov., A. jalae sp.nov. and A. hamadai sp.nov., the fourth one has been recently described as A. chloros Ilan et al., 2004. Although the latter species and our three new species are the first definite Ampimedon species recorded from the Red Sea, at least one previously described sponge from the region, Ceraochalina ochracea Keller, 1889 is suspected to belong to this genus as well. The status of the described and suspected Red Sea Amphimedon is discussed and compared to species recorded from neighbouring Indian Ocean waters.

Trade‐offs in resistance to competitors and predators, and their effects on the diversity of tropical marine sponges

Summary Consistently very high regional diversity of tropical marine sponges reflects a combination of high within‐habitat diversity and distinctness of species composition among habitats. Distinctive sponge faunas of Caribbean coral reefs and mangroves seem to support the assumption that abiotic factors determine sponge diversity within habitats and faunal differences between habitats because these habitats differ greatly in abiotic characteristics and because lower species diversity on mangroves appears to reflect their inferiority as sponge habitat. A way to test this assumption is provided by unusual mangrove cays in Belize that are inhabited by the typical Caribbean reef sponge fauna. Reciprocal transplant experiments, combined with caging (predator‐free space) and artificial substrata (competitor‐free space), demonstrated control of community membership by biological interactions for 12 common species: spongivorous predators excluded typical mangrove sponges from reef sponge assemblages, and reef sponges were excluded from mangrove sponge assemblages by competition. Variation in growth rate was related inversely to variation in defences against predators in the species studied, suggesting a trade‐off between resistance to competitors and to predators. This trade‐off influences community structure, as the key importance of competition for space among mangrove species results in lower within‐habitat diversity, while multiple challenges, including predation, may maintain high diversity of reef sponges. Differences in species composition between habitats are maintained, as this trade‐off precludes success of individual species as members of both faunas. Most surprising is that typical faunas of mangroves and reefs are not tied to these habitats by abiotic factors. Greater sponge species diversity on the reef does not necessarily indicate superior conditions for sponges. Instead reefs may be a refuge for species that grow too slowly to coexist with typical mangrove species.

Sponge species richness and abundance as indicators of mangrove epibenthic community health

In the Caribbean Sea, sponges are diverse and common colonizers of subtidal mangrove substrates such as aerial roots and peat banks. On the other hand, few species are widely distributed, whereas the majority is rare. Biodiversity studies should therefore cover appropriately sized survey areas to allow the encounter with species that have low population densities. h the characterization of sponge population structure at specific sites, it is preferable to use a large number of short transects rather than a few long ones. Trials conducted at mangrove islands on the southern Belize barrier reef platform show that surveying multiple transects of 15-20 m length along the fkinge of tidal channels (covering 50-70 stilt roots) reveal more than 90% of the epibiont species present at each site. We found that the majority of the widely distributed species are among the most frequent colonizers and their abundance, with the exception of a few, is maintained over at least a six-year period. Sponge species richness can serve as a bioindicator of subtidal community health as long as there are baseline data to determine its variation over time. However, this method is not suitable for comparing geographically distant mangrove systems. Common and widely distributed mangrove species, such as Haliclona manglaris, H. curacaoensis, H. implexiformis, Mycale magniraphidiphera, Clathria venosa, and Geodiapapyracea, and other generalist species, notably Tedania ignis, Hyrtios proteus, Spongia tubulifera, Chondrilla nucula, Mycale microsigmatosa, and Scopalina ruetzleri, may best reflect changes in the environmental conditions at particular sites. The families Chalinidae, order Haplosclerida (six Haliclona spp. and two Chalinula spp.), and Mycalidae, order Poecilosclerida (four Mycale spp.), include the most diversified taxa among mangrove sponge populations. Up to 20 percent of mangrove roots at Twin Cays harbored two or three Haliclona species each, whereas Mycale species were common but rarely two co-occurred on the same root. These families, in particular, are being investigated for their suitability as bio-indicators of mangrove health by evaluating changes in their population dynamics and responses to natural and anthropogenic ecological stress conditions.

Variability in the chemical defense of the sponge Chondrilla nucula against predatory reef fishes

Chondrilla nucula is a common Caribbean demosponge that grows in a range of habitats, from coral reefs to mangrove swamps. On reefs, C. nucula grows as a thinly encrusting sheet, while in mangrove habitats it surrounds submerged mangrove roots as fleshy, lobate clumps. Previous feeding experiments using predatory reef fish revealed a high degree of variability in the chemical defenses of C. nucula. The present study was undertaken to determine whether a relationship exists between habitat, growth form, and chemical defense of C. nucula. Both laboratory and field feeding-assays of crude extracts confirmed that C. nucula possesses a chemical defense with high intercolony variability, but there was no significant variation in feeding deterrency between reef and mangrove habitats at either geographic location (Bahamas and Florida). Extracts of C. nucula collected during September and October 1994 from the Bahamas were significantly more deterrent than those collected during August 1993, May 1994, and May 1995 from Florida, and extracts of these spring and summer Florida collections were more deterrent than extracts of C. nucula collected in December 1994 and February 1995 in the same locations. There was no evidence that deterrent compounds were concentrated in the surface tissues of the sponge, or that chemical defense could be induced by simulated predation. Laboratory and field assays of the fractionated crude extract revealed that feeding deterrency was confined to the most polar metabolites in the extract. Field transplants were used to determine whether predation influenced the growth form of C. nucula. Uncaged sponges transplanted from the mangrove to the reef were readily consumed by spongivorous reef fishes. Lobate mangrove sponges became thinner after being caged on the reef for 3 mo, but encrusting reef sponges did not become thicker after being caged in the mangroves for the same period of time. Reef sponges that were caged for 3 to 15 mo thickened by only a small amount (<1 mm) compared to uncaged and open-caged (i.e. in cages lacking tops) sponges. Simulated bite marks on both reef and mangrove sponges were repaired at a rapid rate (0.8 to 1.6 mm d−1). Fish predation has an important impact on the distribution and abundance of C. nucula, but the thin growth form common to reef environments may be more the result of hydrodynamics than of grazing by spongivorous fishes.

Video-monitored predation by Caribbean reef fishes on an array of mangrove and reef sponges

Although predation by fishes is thought to structure benthic invertebrate communities on coral reefs, evidence to support this claim has been difficult to obtain. We deployed an array of eight sponge species on Conch Reef (16 m depth) off Key Largo, Florida, USA, and used a remote video-camera to record fish activity near the array continuously during five daylight periods (6 h for 1 d, at least 11.5 h for 4 d) and one night period (11 h). Of the eight sponge species, four were from adjacent reefs (Agelas wiedenmayeri, Geodia neptuni, Aplysina fistularis, and Pseudaxinella lunaecharta), and four were from a nearby mangrove habitat (Chondrosia collectrix, Geodia gibberosa, Halichondria sp., andTedania ignis). Each species of reef sponge was chosen to match the corresponding mangrove species in form and color (black, brown, yellow, and red, respectively). Predation events only occurred during daylight hours. Tallies of the number of times fishes bit sponges revealed intense feeding by the expected species of sponge-eating fishes, such as the angelfishHolacanthus bermudensis, H. tricolor, andPomacanthus arcuatus, the cowfishLactophrys quadricornis, and the filefishCantherhines pullus, but surprisingly also by the parrotfishSparisoma aurofrenatum andS. chrysopterum. Of 35 301 bites recorded, 50.8% were taken by angelfish, 34.8% by parrotfish, and 13.7% by trunkfish and filefish. Mangrove sponges were preferred by all reef fishes; 96% of bites were taken from mangrove species, with angelfish preferringChondrosia collectrix and parrotfish preferringGeodia gibberosa. Fishes often bit the same sponge repetitively, and frequently consumed entire samples within 30 min of their deployment. Sponge color did not influence fish feeding. Two of the four mangrove sponge-species deployed on the array were also found living in cryptic habitats on adjacent reefs and were rapidly consumed by fishes when exposed. Our results demonstrate the importance of fish predation in controlling the distribution of sponges on Caribbean reefs.

Mangrove sponge disease induced by cyanobacterial symbionts: failure of a primitive immune system?

Mangrove sponge disease induced by cyanobacterial symbionts: failure of a primitive immune system?