Diseased Sponges Research Articles

Brown Rot Syndrome and Changes in the Bacterial Сommunity of the Baikal Sponge Lubomirskia baicalensis.

Mass mortality events have led to a collapse of the sponge fauna of Lake Baikal. We describe a new Brown Rot Syndrome affecting the endemic species Lubomirskia baicalensis. The main symptoms are the appearance of brown patches at the sponge surface, necrosis, and cyanobacterial fouling. 16S rRNA gene sequencing was used to characterize the bacterial community of healthy versus diseased sponges, in order to identify putative pathogens. The relative abundance of 89 eubacterial OTUs out of 340 detected has significantly changed between healthy and diseased groups. This can be explained by the depletion of host-specific prokaryotes and by the appearance and proliferation of disease-specific OTUs. In diseased sponges, the most represented OTUs belong to the families Oscillatoriaceae, Cytophagaceae, Flavobacteriaceae, Chitinophagaceae, Sphingobacteriaceae, Burkholderiaceae, Rhodobacteraceae, Comamonadaceae, Oxalobacteraceae, and Xanthomonadaceae. Although these families may contain pathogenic agents, the primary causes of changes in the sponge bacterial community and their relationship with Brown Rot Syndrome remain unclear. A better understanding of this ecological crisis will thus require a more integrative approach.

Microbiome analysis of a disease affecting the deep-sea sponge Geodia barretti

Reports of sponge disease are becoming increasingly frequent, although almost all instances involve shallow-water, tropical species. Here, we describe the first disease affecting the deep-water sponge, Geodia barretti. The disease is characterised by brown/black discolouration of the sponge tissue, extensive levels of tissue disintegration and increased levels of fouling. Disease prevalence was quantified using video survey transects conducted between 100 and 220 m in Korsfjorden, Norway, and the microbial communities of healthy and diseased sponges were compared using 16S rRNA gene sequencing. Highly divergent community profiles were evident between the different health states, with distinct community shifts involving higher relative abundances of Bacteroidetes, Firmicutes and Deltaproteobacteria in diseased individuals. In addition, three operational taxonomic units were exclusively present in diseased individuals and were shared between the disease lesions and the apparently healthy tissue of diseased individuals, suggesting a non-localised infection or dysbiosis. Genomic analysis of the G. barretti microbiome combined with experimental work to assess the mechanisms of infection will further elucidate the role of microorganisms in the disease.

First detection of benthic cyanobacteria in Lake Baikal producing paralytic shellfish toxins

Cyanobacteria were screened from the surface of diseased sponges, stone and bedrock in Lake Baikal for the presence of saxitoxin using enzyme-linked immunosorbent assay. In sequel, eight paralytic shellfish toxin (PST) variants were identified using a MALDI mass spectrometry. Microscopic examination found that Tolypothrix distorta dominated in the biofouling samples. PCR and sequencing detected sxtA gene involved in saxitoxin biosynthesis, thereby providing evidence of the PST producing potential of Baikal cyanobacterial communities inhabiting different substrates.

Exploring Individual- to Population-Level Impacts of Disease on Coral Reef Sponges: Using Spatial Analysis to Assess the Fate, Dynamics, and Transmission of Aplysina Red Band Syndrome (ARBS)

BackgroundMarine diseases are of increasing concern for coral reef ecosystems, but often their causes, dynamics and impacts are unknown. The current study investigated the epidemiology of Aplysina Red Band Syndrome (ARBS), a disease affecting the Caribbean sponge Aplysina cauliformis, at both the individual and population levels. The fates of marked healthy and ARBS-infected sponges were examined over the course of a year. Population-level impacts and transmission mechanisms of ARBS were investigated by monitoring two populations of A. cauliformis over a three year period using digital photography and diver-collected data, and analyzing these data with GIS techniques of spatial analysis. In this study, three commonly used spatial statistics (Ripley’s K, Getis-Ord General G, and Moran’s Index) were compared to each other and with direct measurements of individual interactions using join-counts, to determine the ideal method for investigating disease dynamics and transmission mechanisms in this system. During the study period, Hurricane Irene directly impacted these populations, providing an opportunity to assess potential storm effects on A. cauliformis and ARBS.ResultsInfection with ARBS caused increased loss of healthy sponge tissue over time and a higher likelihood of individual mortality. Hurricane Irene had a dramatic effect on A. cauliformis populations by greatly reducing sponge biomass on the reef, especially among diseased individuals. Spatial analysis showed that direct contact between A. cauliformis individuals was the likely transmission mechanism for ARBS within a population, evidenced by a significantly higher number of contact-joins between diseased sponges compared to random. Of the spatial statistics compared, the Moran’s Index best represented true connections between diseased sponges in the survey area. This study showed that spatial analysis can be a powerful tool for investigating disease dynamics and transmission in a coral reef ecosystem.

Molecular community profiling reveals impacts of time, space, and disease status on the bacterial community associated with the Caribbean spongeAplysina cauliformis

Reports of marine sponge diseases have increased in recent years, but few etiologic agents have been identified. Aplysina red band syndrome (ARBS), a condition observed in the Caribbean sponge Aplysina cauliformis, is characterized by a rust-colored leading margin. Culture-independent methods (terminal restriction fragment length polymorphism and clone library analyses) were used to assess bacterial communities associated with healthy and ARBS-affected sponges from two locations over 2 years. Although the bacterial communities associated with healthy and ARBS-affected sponges were significantly different, the sponges maintained a core bacterial community across space, time, and health status. Ten terminal restriction fragments were shown to change significantly between sponge health conditions, with six increasing in abundance with disease and four decreasing. The prevalence of the photosymbiont Synechococcus spongiarum decreased with ARBS infection, suggesting a functional consequence of disease. After cultivating a red-pigmented Leptolyngbya strain from ARBS lesions, transmission studies were conducted to determine whether this organism was the ARBS pathogen. Despite significantly increased abundance of Leptolyngbya spp. in diseased sponges, signs of ARBS were not observed in healthy sponges following 24 days of contact with the cultured strain. Additional work with this model system is needed to increase our understanding of the dynamics of marine diseases.

Sponge white patch disease affecting the Caribbean sponge Amphimedon compressa

We report on a novel sponge disease, hereafter termed 'sponge white patch' (SWP), affecting the Caribbean sponge species Amphimedon compressa. SWP is characterized by distinctive white patches of variable size that are found irregularly on the branches of diseased sponges. Nearly 20% of the population of A. compressa at Dry Rocks Reef, Florida, USA, showed symptoms of SWP at the time of investigation (November 2007-July 2010). Approximately 21% of the biomass of SWP individuals was bleached, as determined by volume displacement. Scanning electron microscopy analysis showed severe degradation of bleached tissues. Transmission electron microscopy of the same tissues revealed the presence of a spongin-boring bacterial morphotype that had previously been implicated in sponge disease (Webster et al. 2002; Mar Ecol Prog Ser 232:305-309). This particular morphotype was identified in 8 of 9 diseased A. compressa individuals investigated in this study. A close relative of the aforementioned disease-causing alphaproteobacterium was also isolated from bleached tissues of A. compressa. However, whether the spongin-boring bacteria are true pathogens or merely opportunistic colonizers remains to be investigated. Molecular fingerprinting by denaturing gradient gel electrophoresis (DGGE) demonstrated a distinct shift from the microbiota of healthy A. compressa to a heterogeneous mixture of environmental bacteria, including several phylotypes previously implicated in sponge stress or coral disease. Nevertheless, tissue transplantation experiments conducted in the field failed to demonstrate infectivity from diseased to healthy sponges, leaving the cause of SWP in A. compressa to be identified.

Disease and nutrient enrichment as potential stressors on the Caribbean sponge Aplysina cauliformis and its bacterial symbionts

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 456:101-111 (2012) - DOI: https://doi.org/10.3354/meps09716 Disease and nutrient enrichment as potential stressors on the Caribbean sponge Aplysina cauliformis and its bacterial symbionts D. J. Gochfeld1,2,*, C. G. Easson2, C. J. Freeman3, R. W. Thacker3, J. B. Olson4 1National Center for Natural Products Research and 2Environmental Toxicology Research Program, University of Mississippi, University, Mississippi 38677-1848, USA 3Department of Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA 4Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama 35487, USA *Email: gochfeld@olemiss.edu ABSTRACT: Sponge diseases have recently emerged as potential forces structuring coral reefs. The increasing prevalence of disease on reefs may be due to changes in the virulence of pathogens and/or to decreases in host resistance as a result of changing environmental conditions. Coral reef ecosystems typically thrive in oligotrophic waters; however, runoff of fertilizers or sewage that contains elevated concentrations of nutrients can lead to eutrophic conditions. Aplysina cauliformis is a dominant member of the Caribbean sponge community, and is susceptible to Aplysina Red Band Syndrome (ARBS), a disease that causes reduced sponge growth and survival. We assessed the independent and interacting effects of nutrient enrichment and disease on A. cauliformis, using a factorial field experiment in which healthy and diseased sponges were exposed to nutrient-enriched or non-enriched treatments. Impacts on ARBS virulence (rate of lesion growth) and host response (both sponge and cyanobacterial symbiont growth and physiology) were assessed. ARBS lesions increased rapidly regardless of nutrient treatment, and disease had a significantly greater detrimental impact on sponges than did nutrient enrichment, as evidenced by a decline in sponge mass and reduced total protein content. The sponge−cyanobacterial symbiont relationship was less impacted by disease, although the sponge-associated bacterial community was significantly affected by sponge condition, with healthy sponges and diseased tissue hosting significantly different bacterial assemblages. In contrast, nutrient enrichment had no effects on sponge or symbiont physiology. Disease is a much greater stressor than eutrophication on the growth and physiology of A. cauliformis and its cyanobacterial symbionts. KEY WORDS: Sponge disease · Nutrient enrichment · Symbiosis · Stressors Full text in pdf format PreviousNextCite this article as: Gochfeld DJ, Easson CG, Freeman CJ, Thacker RW, Olson JB (2012) Disease and nutrient enrichment as potential stressors on the Caribbean sponge Aplysina cauliformis and its bacterial symbionts. Mar Ecol Prog Ser 456:101-111. https://doi.org/10.3354/meps09716 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 456. Online publication date: June 07, 2012 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2012 Inter-Research.

Epidemic Mortality of the Sponge Ircinia variabilis (Schmidt, 1862) Associated to Proliferation of a Vibrio Bacterium

In recent years, several episodes of mass mortality of sessile epibenthic invertebrates, including sponges, have been recorded worldwide. In the present study, we report a disease event on Ircinia variabilis recorded in September 2009 along the southern Adriatic and Ionian seas (Apulian coast), with the aim to quantify the mortality incidence on the sponge population, to investigate the effect of the disease on the sponge tissues and to assess whether the disease is associated with vibrios proliferation. The injured sponges showed wide necrotic areas on the surface or disruption of the body in several portions. Necrotic areas were whitish and often were covered with a thin mucous coat formed by bacteria. In the most affected specimens, sponge organisation resulted partial or complete loss, with the final exposure of the dense skeletal network of spongine fibres to the environment. The results of microbiological cultural analysis using in parallel Marine Agar 2216 and thiosulphate/citrate/bile salts/sucrose agar demonstrated that, in affected specimens, vibrios represented 15.8% of the total I. variabilis surface culturable bacteria. Moreover, all the isolated vibrios, grown from the wide whitish areas that characterize the surface of the diseased sponges, were identified, and their assignment to the Vibrio rotiferianus was consistent with phylogenetic analysis and data of morphological, cultural and biochemical tests. Studies on V. rotiferianus have shown that its pathogenicity, with respect to various aquatic organisms, is higher than that of Vibrio harveyi. The factors triggering the disease outbreak in Ircinia variabilis populations remain unclear. At present, we can hypothesize the involvement in the disease of a synergetic mechanism that, under stressful physiological conditions (high temperature, elevated nutrients and reduced water flow), induces sponge pathogens, in our case V. rotiferanius, to become virulent, making sponges unable to control their proliferation. Additional studies are needed to understand the etiological processes as well as the factors involved in sponges recovering from this epidemic event allowing them to face mass mortality. A drastic reduction of sponge-specific representatives could have marked a negative impact on the environmental health on account of their role in the sea remediation processes as filter-feeding organisms.

Trade-Offs in Defensive Metabolite Production But Not Ecological Function in Healthy and Diseased Sponges

Diseases of marine organisms, and sponges in particular, are increasingly reported worldwide. Prior research indicates that the survival of sponges on reefs is due largely to their production of biologically active secondary metabolites that provide protection from a diversity of stressors. Aplysina Red Band Syndrome (ARBS) is an emerging disease affecting Caribbean rope sponges (Aplysina spp.), but it is not known whether secondary metabolites play a role in disease susceptibility and resistance. To investigate whether differences in secondary metabolites may explain variability in susceptibility to ARBS in Aplysina cauliformis, we used high performance liquid chromatography (HPLC) to generate chemical profiles from healthy tissue in both healthy and diseased sponges, and quantified peak areas for 15 metabolites. Analyses of healthy and diseased sponges revealed qualitative and quantitative differences in their chemical profiles. Aplysamine-1 and fistularin-3 were produced in significantly higher concentrations by healthy sponges, whereas aerothionin and 11-oxoaerothionin were found only in diseased sponges. At natural concentrations, extracts from both healthy and diseased sponges deterred feeding by an omnivorous reef fish. Fistularin-3 deterred feeding at concentrations found in healthy sponges, but not at concentrations found in diseased sponges. Aerothionin deterred feeding at concentrations found in diseased sponges, and may at least partially replace the loss of fistularin-3 as a feeding deterrent compound following pathogenesis, suggesting a trade-off in the production of feeding deterrent compounds. Extracts from healthy and diseased sponges inhibited bacterial growth, and both aplysamine-1 and fistularin-3 displayed selective antibacterial activity. Despite differences in secondary metabolite production between healthy and diseased sponges, the stress associated with ARBS does not appear to compromise the ability of A. cauliformis to maintain defenses against some of its natural enemies.

Exploring the Role of Microorganisms in the Disease-Like Syndrome Affecting the Sponge Ianthella basta

A disease-like syndrome is currently affecting a large percentage of the Ianthella basta populations from the Great Barrier Reef and central Torres Strait. Symptoms of the syndrome include discolored, necrotic spots leading to tissue degradation, exposure of the skeletal fibers, and disruption of the choanocyte chambers. To ascertain the role of microbes in the disease process, a comprehensive comparison of bacteria, viruses, fungi, and other eukaryotes was performed in healthy and diseased sponges using multiple techniques. A low diversity of microbes was observed in both healthy and diseased sponge communities, with all sponges dominated by an Alphaproteobacteria, a Gammaproteobacteria, and a group I crenarchaeota. Bacterial cultivation, community analysis by denaturing gradient gel electrophoresis (Bacteria and Eukarya), sequencing of 16S rRNA clone libraries (Bacteria and Archaea), and direct visual assessment by electron microscopy failed to reveal any putative pathogens. In addition, infection assays could not establish the syndrome in healthy sponges even after direct physical contact with affected tissue. These results suggest that microbes are not responsible for the formation of brown spot lesions and necrosis in I. basta.

Bacillus insecticides are not acutely harmful to corals and sponges

Bacillus thuringiensis is a Gram-positive bacterium that produces crystalline endotoxins and is widely considered an environmentally safe insecticide to control mosquitoes and a number of agriculture pests. Bacteria closely related to B. thuringiensis have recently been discovered in association with diseased sponges, which has raised concerns that Bacillus insecticides may be harm- ful to tropical marine invertebrates. We exposed coral larvae and juvenile corals to the insecticides VectoBac ® G (containing B. thuringiensis israelensis) and VectoLex ® G (containing B. sphaericus). VectoBac G and VectoLex G had no effect on the survival and metamorphosis of Acropora millepora and A. tenuis larvae at very high concentrations (5000 µg l -1 ). The juvenile corals of the same species were also unaffected after 4 sequential 48 h exposures to B. thuringiensis israelensis and B. sphaeri- cus at different stages of development. Adult corals (A. millepora) and sponges (Ianthella basta) were exposed to a single 6 h pulse of 1000 µg l -1 VectoBac G. Although B. thuringiensis israelensis was detected in the seawater using denaturing gradient gel electrophoresis, it was not detected in associ- ation with the corals or sponges. No evidence of coral or sponge disease was observed during the following 2 wk. These results indicate that insecticides containing endotoxin-producing Bacillus spp. are unlikely to be acutely pathogenic to corals and sponges. However, the effect on most tropical marine invertebrates remain untested and the risks of seed populations of alien Bacillus becoming established on reefs and horizontal transfer of toxin genes to native bacteria also need to be addressed.

Shifts in microbial and chemical patterns within the marine sponge Aplysina aerophoba during a disease outbreak

The microbial community composition in affected and unaffected portions of diseased sponges and healthy control sponges of Aplysina aerophoba was assessed to ascertain the role of microbes in the disease process. Sponge secondary metabolites were also examined to assess chemical shifts in response to infection. The microbial profile and aplysinimine levels in unaffected tissue near the lesions closely reflected those of healthy sponge tissue, indicating a highly localized disease process. DGGE detected multiple sequences that were exclusively present in diseased sponges. Most notably, a Deltaproteobacteria sequence with high homology to a coral black band disease strain was detected in all sponge lesions and was absent from all healthy and unaffected regions of diseased sponges. Other potential pathogens identified by DGGE include an environmental Cytophaga strain and a novel Epsilonproteobacteria strain with no known close relatives. The disease process also caused a major shift in prokaryote community structure at a very high taxonomic level. Using 16S rRNA gene sequence analysis, only the diseased sponges were found to contain sequences belonging to the Epsilonproteobacteria and Firmicutes, and there was a much greater number of Bacteroidetes sequences within the diseased sponges. In contrast, only the healthy sponges contained sequences corresponding to the cyanobacteria and 'OP1' candidate division, and the healthy sponges were dominated by Chloroflexi and Gammaproteobacteria sequences. Overall bacterial diversity was found to be considerably higher in diseased sponges than in healthy sponges. These results provide a platform for future cultivation-based experiments to isolate the putative pathogens from A. aerophoba and perform re-infection trials to define the disease aetiology.

The Effect of Aplysina Red Band Syndrome on Secondary Metabolite Production in the Sponge Aplysina cauliformis

Sponges on Caribbean reefs represent tremendous biomass and biodiversity, perform numerous critical ecological roles and produce an array of biologically active secondary metabolites. Thus, the health of sponges on coral reefs is important to the overall condition of these coral reef communities. In recent years, newly emerging diseases of sponges have been reported with increasing frequency. Aplysina Red Band Syndrome (ARBS) is a recently described disease affecting Caribbean rope sponges. Although the etiologic agent for this disease has not yet been characterized, it is believed to be a filamentous cyanobacterium, which forms a red band that progresses along the sponge, leaving necrotic tissue behind. Some sponges produce antimicrobial chemical defenses that may protect them from pathogens. To investigate whether differences in chemical defenses may explain why some individual sponges are susceptible to ARBS and others are not, we compared chemical profiles from healthy and diseased sponges. Several metabolites are produced in significantly different concentrations by healthy and diseased sponges. In addition, qualitative differences were observed. Since both healthy and diseased sponges were feeding deterrent, these compounds may represent antimicrobial chemical defenses that inhibit pathogenesis.

First Report of Gray Mold Disease of Sponge Gourd (Luffa cylindrica) Caused by Botrytis cinerea in Taiwan.

A disease of sponge gourd (Luffa cylindrica (L.) Roem., family Cucurbitaceae) has become a serious threat to sponge gourd production since 2003 in central Taiwan. Initially, symptoms appear as small, brown spots on the flower petals that spread to the entire flower and cause blossom blight within 2 to 3 days. Subsequently, the pathogen develops abundant mycelium and moves from the petals onto the fruits causing blossom end rot and fruit stem rot. Severely infected fruits become completely rotten and desiccate. Tissues were excised from diseased sponge gourd fruits (sampled from Fongyuan, located at 24.25°N, 120.72°E in Taichung County), immersed in a solution containing 3% sodium hypochlorite and 70% ethanol for 1 min, washed three times with sterile water, and then cultured on potato dextrose agar (PDA) medium. A fungus, identified as Botrytis cinerea, produced abundant mycelium on PDA medium when incubated under constant fluorescent light 185 ± 35 μE·m-2·s-1 at 24°C. The conidia were smooth, hyaline, and globoid or slightly ellipsoid. The conidia measured 9.5 to 19.3 μm (average 13.8 μm) long and 6.0 to 17.8 μm (average 10.1 μm) wide, dimensions that are similar to the descriptions of B. cinerea (11 × 11 to 15 μm) that causes gray mold of strawberry (2). The identity of B. cinerea was also confirmed by the production of numerous black sclerotia on PDA plates incubated either in the dark or under light at 20 to 24°C for 9 to 10 days. Koch's postulates were fulfilled by using 3-day-old mycelial agar discs of the fungus or a spore suspension containing 105 conidia per milliliter of distilled water as inoculum. Shallow (2 × 2 × 2 mm) incisions were made on fresh sponge gourd fruits with a sterile scalpel and inoculated with either a 5-mm mycelial disc or 0.5 ml of the spore suspension. Inoculated areas were covered with moist sterile cotton, and the fruits were enclosed in a plastic bag and incubated at 20 to 24°C for 3 days. Wounded fruits inoculated with PDA discs or sterile distilled water alone served as controls. Pathogenicity tests were performed three times using five fruits in each trial. Symptoms and signs of the disease similar to those described above were observed in all (100%) the inoculated fruits, while no symptoms developed in the control fruits. Reisolation from the inoculated fruits consistently yielded B. cinerea. Reciprocal inoculations on sponge gourd, guava, and strawberry with mycelial discs or spore suspensions of a B. cinerea isolate obtained from sponge gourd, guava, and strawberry showed cross pathogenicity among isolates and hosts. Important groups of plants that are attacked by B. cinerea are vegetables, small berry fruits, ornamentals, and bulbs (1). Though 80 species of host plants, mostly shrubs and nursery plants, were reported to be the host of B. cinerea in Taiwan (3), to our knowledge, this is the first report of gray mold disease affecting sponge gourd in Taiwan.

Identification of bacteria associated with a disease affecting the marine sponge Ianthella basta in New Britain, Papua New Guinea

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 324:139-150 (2006) - doi:10.3354/meps324139 Identification of bacteria associated with a disease affecting the marine sponge Ianthella basta in New Britain, Papua New Guinea James M. Cervino1,*, Kathryn Winiarski-Cervino2, Shawn W. Polson3, Thomas Goreau4, Garriet W. Smith5 1Department of Biological Sciences, Pace University, 1 Pace Plaza, New York, 10038, USA 2The New York Academy of Medicine, New York, 10029–5293, USA 3Medical University of South Carolina, Charleston, South Carolina, 29425, USA 4Global Coral Reef Alliance, 37 Pleasant St., Cambridge, Massachusetts, 02139, USA 5Department of Biology and Geology, University of South Carolina, Aiken, South Carolina, 29801, USA *Email: cnidaria@earthlink.net ABSTRACT: Ianthella basta marine sponges in Kimbe Bay, west New Britain, Papua New Guinea were affected by a disease, and exhibited high mortality, between 1996 and 2000. These fan-shaped sponges were mottled with brown lesions, rotted tissue and large holes. The decayed tissue was surrounded by brown biofilm that smothered the ostia openings. Since 1996, I. basta suffered its highest mortality at 3 sites within 16–20 km of the shore of west New Britain. No mortality was observed at 3 other locations further from shore (between 27–41 km), nor at 10 sites located more than 41 km from shore outside of Kimbe Bay in deeper waters, nor at the site nearest to shore. Comparison of the carbon source utilization patterns of 99 bacterial isolates from all healthy and diseased sponges revealed 5 species of bacteria specifically present in diseased I. basta. These bacteria were not present in healthy sponge samples. Bacteria isolated from affected sponges and inoculated onto healthy sponges caused disease signs similar to those in field specimens. The 16S rRNA genes from these bacteria were sequenced and found to correspond with 2 species of Bacillus and 3 species of Pseudomonas. The closest relatives of these bacteria based on BLAST searches included many terrestrial pathogens and species that are used as pathogens against insects and fungi in integrated pest control management. The bacteria causing disease in I. basta may thus originate from pesticides applied to agricultural land, predominantly oil palm plantations, in west New Britain. The possibility that these bacteria can pass virulence factors to marine bacteria through horizontal gene transfer needs to be investigated, as this may have unexpected impacts on marine ecosystems. KEY WORDS: Sponge disease · 16S rRNA · Pseudomonas · Bacillus · Pesticide · Ianthella basta Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 324. Online publication date: October 23, 2006 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2006 Inter-Research.

THE FUNGUS LAGENIDIUM CALLINECTES COUCH (1942) ON EGGS OF THE BLUE CRAB IN CHESAPEAKE BAY

1. The fungus parasite Lagenidium callinectes Couch has been observed to be a peripheral parasite of egg masses of the blue crabs of Chesapeake Bay.2. Blue crab eggs are susceptible to infection in all stages of their development. Infected areas of a sponge are brown or gray in appearance, depending on the age of the eggs.3. While the fungus spreads rapidly over the surface of the sponge, it penetrates the egg mass very slowly. Usually the depth of infection is not over 3 mm.4. Infection is heavier in older sponges which are brown and black than in younger yellow ones, probably due to the longer exposure of older sponges.5. Peripheral infection does not seem to retard the development of crab eggs in the interior of the sponge, which far outnumber the peripheral eggs. Not over 25 per cent of the eggs of a heavily diseased sponge are infected and only about 14 per cent of the crabs were found to be heavily infected. However, it was not unusual to find 80 or 90 per cent of the crabs in a sample to have some degree of infection.6. Under laboratory conditions, transmission of infection from egg to egg of the same and different blue crabs is unexpectedly rapid.7. Development of the fungus was observed to be abnormal in fresh pond water. In salinities from 5 to 30 p.p.t. development proceeded rapidly and indicated a strong tolerance of changes in salt concentration.8. Frequently occurring on the peripheral eggs with Lagenidium callinectes are Carchesium sp., Ephelota sp., and Chlamydobacterium sp. Carcinonemertes carcinophila Kölliker is present and shows periodic fluctuations similar to the fungus.9. Eggs of the oyster crab and the mud crab became infected with L. callinectes under laboratory conditions.10. The Hampton Roads-Lynnhaven waters is the area in Chesapeake Bay where L. callinectes is most common. Only slight infection was observed north of Buckroe Beach.