marine SYMBIOSIS exam 1

Pea aphid + Buchnera aphidicola — Describe this relationship.

Partners: Acyrthosiphon pisum (pea aphid) and Buchnera aphidicola. | Habitat: Terrestrial; aphids feed on plant phloem sap. | Anatomy / location: Intracellular endosymbionts in specialized host bacteriocytes; bacteria are enclosed by host-derived symbiosomal membranes. | Transmission: Vertical, maternal transmission to offspring. | Interaction type: Obligate mutualism: both partners depend on the association. | Effect on host / recipient: Buchnera synthesizes essential amino acids missing or insufficient in the phloem diet, allowing the aphid to use this food source. | Effect on symbiont / other partner: The aphid provides a protected cellular environment and access to nutrients. Long-term host dependence is associated with extensive bacterial genome reduction. | Age: Ancestral acquisition about 160–280 million years ago; the roughly 50-million-year divergence of pea-aphid and greenbug lineages is a separate date. | Key distinction: Buchnera lost about 86% of its ancestral genome; this is a nutritional intracellular association, unlike bacteria merely living in a gut lumen.

Multispecies dental biofilm: bacteria with bacteria — Describe this relationship.

Partners: Multiple oral bacteria, including early Streptococcus colonizers and the bridging species Fusobacterium nucleatum. | Habitat: The oral cavity, on tooth surfaces. | Anatomy / location: Extracellular surface biofilm on the acquired tooth pellicle. Early colonizers attach first; coaggregation allows later species to join. F. nucleatum links different groups. | Transmission: Community assembly involves colonization and attachment of bacteria from the oral environment; an inherited transmission mechanism is not specified. | Interaction type: Cooperation among bacterial species; the lecture treats this as non-obligatory. | Effect on host / recipient: The human supplies the tooth surface and oral habitat. Bacterial cooperation does not by itself establish a benefit to the human. | Effect on symbiont / other partner: Community members gain expanded habitat, metabolic opportunities, genetic exchange, protection from predation, and increased resistance to antimicrobial challenges. | Age: Not specified in the provided sources. | Key distinction: The interaction being classified is bacteria–bacteria. Do not automatically call the bacteria–human relationship mutualistic.

Proteus mirabilis + human gut — Describe this relationship.

Partners: Proteus mirabilis and a human (gut). | Habitat: Human-associated habitat, specifically the gut. | Anatomy / location: Extracellular association in the gut; no specialized intracellular compartment is described. | Transmission: Not established for this specific association in the provided sources. | Interaction type: Commensalism in the lecture’s gut example. | Effect on host / recipient: No appreciable benefit or harm is assigned to the human in this context. | Effect on symbiont / other partner: Access to a host-associated habitat and resources; the lecture does not quantify its fitness benefit at this site. | Age: Not specified in the provided sources. | Key distinction: The same bacterial species changes interaction type when its location changes.

Proteus mirabilis + human urethra — Describe this relationship.

Partners: Proteus mirabilis and a human (urethra). | Habitat: Human-associated habitat, specifically the urethra. | Anatomy / location: The urethral/urinary-tract site; the lecture does not establish an intracellular location. | Transmission: Not established for this specific association in the provided sources. | Interaction type: Parasitism / conditional pathogenicity. | Effect on host / recipient: Infection harms the human at this site. | Effect on symbiont / other partner: Access to a host-associated habitat and resources; the lecture does not quantify its fitness benefit at this site. | Age: Not specified in the provided sources. | Key distinction: Gut commensal status does not imply harmlessness after the bacterium reaches the urinary tract.

Proteus mirabilis + human wound — Describe this relationship.

Partners: Proteus mirabilis and a human (wound). | Habitat: Human-associated habitat, specifically the wound. | Anatomy / location: Damaged tissue at a wound; a specific cellular compartment is not given. | Transmission: Not established for this specific association in the provided sources. | Interaction type: Parasitism / conditional pathogenicity. | Effect on host / recipient: Infection harms the host at the wound. | Effect on symbiont / other partner: Access to a host-associated habitat and resources; the lecture does not quantify its fitness benefit at this site. | Age: Not specified in the provided sources. | Key distinction: This is a separate damaged-tissue context from both the gut and urethra.

Proteus mirabilis + marine filter feeder — Describe this relationship.

Partners: Proteus mirabilis and a marine filter feeder. | Habitat: Marine coastal environments, including human-impacted coasts; P. mirabilis is halotolerant. | Anatomy / location: Associated with marine filter feeders; precise tissue and cellular location are not specified. | Transmission: Not established for this specific association in the provided sources. | Interaction type: Possible commensalism; the lecture explicitly presents this with uncertainty. | Effect on host / recipient: A benefit or disease effect is not demonstrated for the filter feeder. | Effect on symbiont / other partner: Access to a host-associated habitat and resources; the lecture does not quantify its fitness benefit at this site. | Age: Not specified in the provided sources. | Key distinction: High bacterial abundance is evidence of association, not proof of either mutualism or disease.

Myxococcus xanthus + bacterial prey — Describe this relationship.

Partners: Myxococcus xanthus is the predator; other bacteria are prey. Bdellovibrio is a different predator, not its partner. | Habitat: Soil. | Anatomy / location: Extracellular attack: groups of Myxococcus release enzymes that digest prey from outside. | Transmission: Predators encounter prey in the environment; this is not presented as inherited host colonization. | Interaction type: Predation, described as “wolf-pack” predation. | Effect on host / recipient: Prey cells are damaged and digested. | Effect on symbiont / other partner: The predator gains nutrients from the digested prey. | Age: Not specified in the provided sources. | Key distinction: Contrast with Bdellovibrio: Myxococcus does not need to grow inside the prey periplasm.

Bdellovibrio + bacterial prey — Describe this relationship.

Partners: Bdellovibrio predator and susceptible bacterial prey. | Habitat: Aquatic environments, including marine systems. | Anatomy / location: The predator crosses the prey’s outer membrane and enters the periplasm, between the outer and cytoplasmic membranes. Peptidoglycan modification produces a rounded bdelloplast. | Transmission: Motile predators encounter and attack new prey cells; no inherited host transmission is described. | Interaction type: Predation involving growth within a prey cell, rather than a stable beneficial endosymbiosis. | Effect on host / recipient: The prey is consumed and ultimately lysed. | Effect on symbiont / other partner: Bdellovibrio elongates while consuming prey resources, produces progeny, and escapes when the prey lyses, about 2–4 hours after attack in the lecture example. | Age: Not specified in the provided sources. | Key distinction: Periplasm is not cytoplasm. Keep this mechanism separate from extracellular Myxococcus digestion.

Toxoplasma gondii + rodents — Describe this relationship.

Partners: Toxoplasma gondii, a protozoan parasite, and mice/rats; cats are the next host in the illustrated cycle. | Habitat: Terrestrial mammal-associated cycle. | Anatomy / location: Internal infection with tissue cysts; the lecture illustrates intracellular parasites. | Transmission: Rodents acquire infection through the environmental oocyst route shown in the life cycle; cats acquire the parasite when they eat infected rodents. | Interaction type: Parasitism. | Effect on host / recipient: The lecture describes altered behavior: infected rodents become attracted to cues in cat urine, increasing their risk of being eaten. | Effect on symbiont / other partner: The parasite gains a tissue habitat and increased opportunity to move into a cat through predation. | Age: Not specified in the provided sources. | Key distinction: Behavioral manipulation links the rodent association to transmission into cats; it is not a benefit to the rodent.

Toxoplasma gondii + cats — Describe this relationship.

Partners: Toxoplasma gondii and cats. | Habitat: Terrestrial predator–prey and fecal–environmental cycle. | Anatomy / location: The illustrated cycle links infected prey entering the cat to oocysts leaving in feces; the slides do not detail the specific feline cellular compartment. | Transmission: Horizontal trophic transmission when cats eat infected prey. Fecal oocysts then contaminate the environment and infect other hosts. | Interaction type: Parasitism; absence of a detailed feline symptom description does not make this commensalism. | Effect on host / recipient: The cat is infected; specific disease effects in cats are not developed in these slides. | Effect on symbiont / other partner: The cat supports the parasite’s life cycle and environmental dissemination through fecal oocysts. | Age: Not specified in the provided sources. | Key distinction: Keep cat acquisition by eating prey separate from rodent exposure to environmental oocysts.

Toxoplasma gondii + humans — Describe this relationship.

Partners: Toxoplasma gondii and humans. | Habitat: Human exposure within the terrestrial animal–environment cycle. | Anatomy / location: Internal, intracellular infection; the life-cycle figure includes tissue cysts and a maternal–fetal route. | Transmission: The figure shows ingestion routes through infected meat and contaminated food/water or cat-litter exposure, plus maternal-to-fetal transmission. The latter is vertical; the ingestion routes are horizontal. | Interaction type: Parasitism; the associated disease is toxoplasmosis. | Effect on host / recipient: Infection can cause disease. The lecture does not establish its proposed psychiatric association as causal. | Effect on symbiont / other partner: The parasite obtains an internal habitat for infection and persistence; the slides do not measure a human-specific fitness gain. | Age: Not specified in the provided sources. | Key distinction: Do not transfer the rodent behavioral result directly to humans or treat a suggested disease link as proof.

Lichen fungus + photosynthetic partner — Describe this relationship.

Partners: A fungus and a photosynthetic alga or cyanobacterium. | Habitat: Terrestrial lichen habitat; the lecture emphasizes survival under desiccating conditions. | Anatomy / location: The fungus forms the lichen thallus; photosynthetic cells are associated with fungal hyphae. Being inside a thallus does not establish that the photobiont is inside a fungal cell. | Transmission: Not established for this specific association in the provided sources. | Interaction type: Mutualistic nutritional association in the lecture. | Effect on host / recipient: The fungal partner receives photosynthetically fixed carbon. | Effect on symbiont / other partner: The photosynthetic partner receives protection from desiccation within the fungal structure. | Age: Approximately 400 million years for the broad lichen association described in the lecture; not a date for every modern species pair. | Key distinction: The organized lichen structure is an emergent property of the partners together.

Bryoria lichens + associated yeast — Describe this relationship.

Partners: Bryoria fremontii and B. tortuosa include the principal fungal and photosynthetic partners plus associated yeast. | Habitat: Terrestrial lichens. | Anatomy / location: Yeast occurs in the outer fungal cortex of the lichen; it is not shown inside the photosynthetic cells. | Transmission: Not established for this specific association in the provided sources. | Interaction type: A more complex multi-partner association; the yeast’s precise causal contribution is unresolved. | Effect on host / recipient: The lecture compares an edible form with a toxic form. The toxic form has more yeast signal, but this does not prove which partner makes the toxin. | Effect on symbiont / other partner: Yeast occupies the lichen habitat; its specific reciprocal benefit is not demonstrated. | Age: Not specified in the provided sources. | Key distinction: Genomic comparisons of the original two partners did not explain the difference; transcripts and FISH implicated yeast abundance. Yeast making the toxin versus inducing another partner are alternative hypotheses.

Hawaiian bobtail squid + Vibrio fischeri — Describe this relationship.

Partners: Euprymna scolopes and Vibrio fischeri; the light organ contains this bacterial species, potentially multiple strains. | Habitat: Shallow marine waters around Hawaii. | Anatomy / location: Extracellular endosymbionts in the light-organ crypts beneath the ink sac. The organ has two lobes with three crypts each. Cilia and mucus help recruit bacteria, which move through pores and ducts into crypts. | Transmission: Horizontal from seawater: hatchlings start aposymbiotic. Roughly 90% of the bacterial population is vented at dawn; retained cells regrow, and vented cells replenish environmental bacteria. | Interaction type: Cooperation: a beneficial, non-obligatory association under the course terminology. | Effect on host / recipient: Bacterial luminescence provides counterillumination, reducing the squid’s visible silhouette. | Effect on symbiont / other partner: The squid supplies shelter and a steady source of carbon, amino acids, iron, and electron acceptors. | Age: Not specified in the provided sources. | Key distinction: A light-organ symbiont can benefit squid while causing harm in another host; the species name alone does not determine interaction type.

V. fischeri FQA001 + ES114 inside the squid light organ — Describe this relationship.

Partners: Two V. fischeri strains: the T6SS-capable competitor FQA001 and susceptible ES114. | Habitat: The Hawaiian bobtail squid light organ in the marine host model. | Anatomy / location: Competition occurs among extracellular bacteria within crypts. Different strains can occupy different crypts in the same organ. | Transmission: Both strains enter from environmental inocula during horizontal colonization; competition then influences their local distribution. | Interaction type: Interference competition between bacteria, nested inside the beneficial squid–bacterium association. | Effect on host / recipient: The experiment resolves bacterial spatial organization; a direct change in squid fitness from this competition is not established. | Effect on symbiont / other partner: FQA001 can kill susceptible competitors by contact-dependent T6SS activity and gain exclusive local access to habitat/resources; susceptible ES114 cells lose access or are killed. | Age: Not specified in the provided sources. | Key distinction: Wild-type FQA001 and ES114 segregate into separate crypts, whereas a T6SS-defective FQA001 mutant permits shared occupancy. Do not equate this interbacterial result with every animal-host T6SS1 result.

V. fischeri ES114 + zebrafish embryos — Describe this relationship.

Partners: Vibrio fischeri strain ES114 and zebrafish embryos. | Habitat: Laboratory aquatic exposure model; this is not evidence for a naturally coevolved association. | Anatomy / location: Bacteria are associated with the embryo. Antibiotic-protection results in the lecture support predominantly surface-associated bacteria; they do not prove identical localization for every strain. | Transmission: Experimental acquisition by exposure in the surrounding water, rather than demonstrated parent-to-offspring transmission. The natural transmission route is not established. | Interaction type: Pathogenic / parasitic effect in this experimental host context. | Effect on host / recipient: The live-bacterium exposure produces mortality. T6SS1 contributes to killing: disrupting it improves host survival. | Effect on symbiont / other partner: Host association/exposure is studied, but a bacterial fitness benefit from killing this host is not directly measured. | Age: Not specified in the provided sources. | Key distinction: T6SS1 contributes to killing: disrupting it improves host survival. Live ES114 is needed for the effect: heat-killed cells and cell-free supernatant do not reproduce it. Developmental abnormalities are also reported; a biofilm-regulatory vpsR mutant reduces killing.

V. fischeri ES114 + Artemia larvae — Describe this relationship.

Partners: Vibrio fischeri strain ES114 and Artemia (brine-shrimp) larvae. | Habitat: Laboratory aquatic exposure model; this is not evidence for a naturally coevolved association. | Anatomy / location: Larval brine shrimp are exposed in the assay; the bacterial tissue/cellular location is not established. Do not transfer embryo surface-localization evidence to Artemia. | Transmission: Experimental acquisition by exposure in the surrounding water, rather than demonstrated parent-to-offspring transmission. The natural transmission route is not established. | Interaction type: Pathogenic / parasitic effect in this experimental host context. | Effect on host / recipient: The live-bacterium exposure produces mortality. Killing is not dependent on T6SS1 in this assay: disrupting it does not remove the killing phenotype. | Effect on symbiont / other partner: Host association/exposure is studied, but a bacterial fitness benefit from killing this host is not directly measured. | Age: Not specified in the provided sources. | Key distinction: Killing is not dependent on T6SS1 in this assay: disrupting it does not remove the killing phenotype.

V. fischeri ES213 + zebrafish embryos — Describe this relationship.

Partners: Vibrio fischeri strain ES213 and zebrafish embryos. | Habitat: Laboratory aquatic exposure model; this is not evidence for a naturally coevolved association. | Anatomy / location: Bacteria are associated with the embryo. Antibiotic-protection results in the lecture support predominantly surface-associated bacteria; they do not prove identical localization for every strain. | Transmission: Experimental acquisition by exposure in the surrounding water, rather than demonstrated parent-to-offspring transmission. The natural transmission route is not established. | Interaction type: Pathogenic / parasitic effect in this experimental host context. | Effect on host / recipient: The live-bacterium exposure produces mortality. Killing is not dependent on T6SS1 in this assay: disrupting it does not remove the killing phenotype. | Effect on symbiont / other partner: Host association/exposure is studied, but a bacterial fitness benefit from killing this host is not directly measured. | Age: Not specified in the provided sources. | Key distinction: Killing is not dependent on T6SS1 in this assay: disrupting it does not remove the killing phenotype.

V. fischeri ES213 + Artemia larvae — Describe this relationship.

Partners: Vibrio fischeri strain ES213 and Artemia (brine-shrimp) larvae. | Habitat: Laboratory aquatic exposure model; this is not evidence for a naturally coevolved association. | Anatomy / location: Larval brine shrimp are exposed in the assay; the bacterial tissue/cellular location is not established. Do not transfer embryo surface-localization evidence to Artemia. | Transmission: Experimental acquisition by exposure in the surrounding water, rather than demonstrated parent-to-offspring transmission. The natural transmission route is not established. | Interaction type: Pathogenic / parasitic effect in this experimental host context. | Effect on host / recipient: The live-bacterium exposure produces mortality. T6SS1 contributes to killing: disrupting it improves host survival. | Effect on symbiont / other partner: Host association/exposure is studied, but a bacterial fitness benefit from killing this host is not directly measured. | Age: Not specified in the provided sources. | Key distinction: T6SS1 contributes to killing: disrupting it improves host survival.

V. fischeri PP3 + zebrafish embryos — Describe this relationship.

Partners: Vibrio fischeri strain PP3 and zebrafish embryos. | Habitat: Laboratory aquatic exposure model; this is not evidence for a naturally coevolved association. | Anatomy / location: Bacteria are associated with the embryo. Antibiotic-protection results in the lecture support predominantly surface-associated bacteria; they do not prove identical localization for every strain. | Transmission: Experimental acquisition by exposure in the surrounding water, rather than demonstrated parent-to-offspring transmission. The natural transmission route is not established. | Interaction type: Pathogenic / parasitic effect in this experimental host context. | Effect on host / recipient: The live-bacterium exposure produces mortality. T6SS1 contributes to killing: disrupting it improves host survival. | Effect on symbiont / other partner: Host association/exposure is studied, but a bacterial fitness benefit from killing this host is not directly measured. | Age: Not specified in the provided sources. | Key distinction: T6SS1 contributes to killing: disrupting it improves host survival.

V. fischeri PP3 + Artemia larvae — Describe this relationship.

Partners: Vibrio fischeri strain PP3 and Artemia (brine-shrimp) larvae. | Habitat: Laboratory aquatic exposure model; this is not evidence for a naturally coevolved association. | Anatomy / location: Larval brine shrimp are exposed in the assay; the bacterial tissue/cellular location is not established. Do not transfer embryo surface-localization evidence to Artemia. | Transmission: Experimental acquisition by exposure in the surrounding water, rather than demonstrated parent-to-offspring transmission. The natural transmission route is not established. | Interaction type: Experimental association with little or no significant pathogenic effect; mutualism or commensalism is not demonstrated. | Effect on host / recipient: Little or no significant killing is detected in this host assay; a T6SS1-dependent killing phenotype is not established. | Effect on symbiont / other partner: Host association/exposure is studied, but a bacterial fitness benefit from killing this host is not directly measured. | Age: Not specified in the provided sources. | Key distinction: Little or no significant killing is detected in this host assay; a T6SS1-dependent killing phenotype is not established.

Marine sponge + resident microbial consortium — Describe this relationship.

Partners: A sponge and a diverse microbial community; the community can contain core, variable, and host-species-specific members. | Habitat: Marine habitats. | Anatomy / location: Water enters ostia, passes through channels and choanocyte chambers, and exits oscula. Many resident microbes occur extracellularly in the mesohyl, the matrix between host cell layers. Archaeocytes digest captured food. | Transmission: Both vertical and environmental acquisition are considered. Microbes in larvae, buds, eggs, or sperm support vertical transfer in some cases; environmental reservoirs may be difficult to detect. | Interaction type: A consortium can include cooperation, commensalism, pathogens, and microbial predation; not every member has the same interaction type. | Effect on host / recipient: Different members can contribute nutrition, nutrient cycling, or chemical functions, while other members can be harmful. Mere detection does not identify function. | Effect on symbiont / other partner: The sponge provides a structured habitat with water flow and host-associated resources. | Age: The lecture considers a possible ancient origin around 600 million years ago for sponge–microbe associations; this is not a verified age for every specific partner. | Key distinction: Capture of food bacteria is not equivalent to stable symbiosis. Do not assign one universal location or transmission mode to every sponge microbe.

Sponge + Poribacteria — Describe this relationship.

Partners: Marine sponges and Poribacteria, a sponge-associated bacterial group. | Habitat: Marine sponge habitat. | Anatomy / location: Associated with sponge tissue/community; this example does not establish a specific intracellular compartment for every Poribacterium. | Transmission: Potential inherited and environmental contributions are discussed in the sponge lectures; an exclusive route for this pair is not demonstrated. | Interaction type: Host-associated heterotrophy is supported by genomic potential; a specific reciprocal benefit to the sponge is not established. | Effect on host / recipient: The lecture does not directly demonstrate a Poribacteria-specific host benefit. | Effect on symbiont / other partner: Single-cell genomic evidence suggests the ability to use carbohydrates, including compounds associated with the sponge matrix. | Age: Not specified in the provided sources. | Key distinction: Genomic capacity predicts possible metabolism; it does not alone prove a nutrient exchange or an obligate mutualism. These organisms were studied without routine cultivation.

Rhopaloeides odorabile + pathogenic strain NW4327 — Describe this relationship.

Partners: The sponge Rhopaloeides odorabile and bacterial strain NW4327. | Habitat: Great Barrier Reef marine sponge system. | Anatomy / location: Disease affects sponge tissue, including damage to collagen-associated structure; a specific intracellular niche is not established. | Transmission: Experimental inoculation transfers the isolate to healthy sponges; the natural transmission route is not established. | Interaction type: Parasitism / pathogenic infection. | Effect on host / recipient: NW4327 causes disease and tissue damage. In the challenge experiment, the normally abundant culturable strain NW001 is no longer detected. | Effect on symbiont / other partner: The pathogen establishes in sponge tissue; the lecture does not quantify its nutritional or reproductive benefit. | Age: Not specified in the provided sources. | Key distinction: Inoculation of healthy hosts followed by disease and re-isolation supports causation, beyond finding a bacterium in a sick sponge.

Healthy Rhopaloeides odorabile + strain NW001 — Describe this relationship.

Partners: The sponge Rhopaloeides odorabile and associated alphaproteobacterial strain NW001. | Habitat: Healthy marine sponges in the Great Barrier Reef example. | Anatomy / location: Sponge-associated isolate; its precise tissue or cellular compartment is not specified in this case. | Transmission: Not established for this specific association in the provided sources. | Interaction type: Commensal association in the study-guide terminology; a protective function is not proven. | Effect on host / recipient: No specific host benefit or injury is demonstrated for NW001. | Effect on symbiont / other partner: NW001 occupies the healthy sponge habitat and makes up about 75–90% of the culturable bacterial community in the cited example. | Age: Not specified in the provided sources. | Key distinction: “Culturable community” is not the entire microbiome. NW001 disappears from detection after NW4327 challenge, but this alone does not prove that NW001 prevents disease.

Photosynthetic sponge + cyanobacterial symbionts — Describe this relationship.

Partners: A marine sponge and photosynthetic cyanobacteria; Synechococcus spongiarum is one sponge-associated example in the lecture. | Habitat: Illuminated marine habitats where photosynthesis can contribute to host nutrition. | Anatomy / location: Cyanobacteria are associated with sponge tissue; a universal intracellular location is not established. | Transmission: Sponge microbes can have vertical and environmental routes. The slides do not justify assigning one exclusive route to every photosynthetic pair. | Interaction type: Beneficial nutritional association; do not assume universal obligate dependence. | Effect on host / recipient: Photosynthetically fixed carbon, including glycerol, can be supplied to the sponge. In some examples photosymbionts provide more than half the host’s energy, supporting mixotrophy. | Effect on symbiont / other partner: The sponge provides a habitat and host-derived compounds, including nitrogenous waste that microbes can use. | Age: Not specified in the provided sources. | Key distinction: The >50% contribution is an example-dependent result, not a value for every sponge or specifically every S. spongiarum association.

Sponge + nutrient-cycling microbial partners — Describe this relationship.

Partners: A sponge and metabolically different members of its microbial consortium. | Habitat: Marine sponge habitat. | Anatomy / location: Microbial processes occur within the sponge-associated community, often in the mesohyl; a single common cellular location is not established for all functions. | Transmission: Mixed possibilities across sponge microbes; the nutrient-cycling examples do not establish one universal route. | Interaction type: Cooperative nutrient exchange where host and microbes each receive useful resources. | Effect on host / recipient: Microbial metabolism can recycle nutrients and provide compounds such as vitamins; bacterial phosphate storage also contributes to nutrient handling within the holobiont. | Effect on symbiont / other partner: Microbes can use sponge-released ammonia/urea and other host-associated resources. | Age: Not specified in the provided sources. | Key distinction: Different microbes perform different functions. Do not claim that one named strain carries out every exchange shown for the whole consortium.

Sponge-associated bacterial predators + microbial prey — Describe this relationship.

Partners: Predatory bacteria and their microbial prey within a sponge-associated community; the lecture includes putative interactions involving cyanobacteria. | Habitat: Marine sponge microbial habitat. | Anatomy / location: Microbial interactions within the sponge community; the example does not fully resolve the location or identity of every predator–prey pairing. | Transmission: Not established for this specific association in the provided sources. | Interaction type: Predation between microbes; the overall effect on the sponge is context-dependent. | Effect on host / recipient: The host’s outcome depends on which organisms are removed. Killing a beneficial member could hurt the sponge; removal of a harmful member could help. Neither outcome should be presumed from predator presence alone. | Effect on symbiont / other partner: Predators gain resources from prey; prey are harmed or killed. | Age: Not specified in the provided sources. | Key distinction: Keep the predator–prey effect separate from any proposed host-defense effect, which requires additional evidence.

Hymeniacidon perlevis + associated viruses and bacteria — Describe this relationship.

Partners: The sponge Hymeniacidon perlevis, associated viruses, and bacterial members of its microbiome. | Habitat: Marine sponge habitat. | Anatomy / location: Viruses are detected in the sponge-associated system; this does not establish that they all infect sponge cells rather than microbial cells. | Transmission: Bacterial DNA in viral particles suggests the potential for horizontal gene transfer by transduction. Host-to-offspring viral transmission is not established here. | Interaction type: Potential virus–bacterium interactions; a single beneficial or harmful classification for the sponge is unresolved. | Effect on host / recipient: A direct net effect on the sponge is not demonstrated. | Effect on symbiont / other partner: Viruses may mediate movement of bacterial genes; the effects on individual bacterial recipients depend on what is transferred. | Age: Not specified in the provided sources. | Key distinction: Detection of a sponge-associated virus is not proof of a sponge pathogen. Transduction concerns gene movement, not necessarily transmission of the entire symbiotic community.

Sponge + associated microbial eukaryotes — Describe this relationship.

Partners: Sponges and detected fungi, protists, ciliates, dinoflagellates, or other microalgae. | Habitat: Marine sponge habitat and surrounding seawater. | Anatomy / location: These groups occur in sponge-associated samples; their precise tissue or cellular locations are not resolved for every taxon. | Transmission: Occurrence in surrounding water makes environmental acquisition plausible for some. Absence from sampled water does not by itself prove vertical inheritance. | Interaction type: Association is documented; specific mutualistic, commensal, or parasitic roles require further evidence. | Effect on host / recipient: No single host effect is established for all these eukaryotic members. | Effect on symbiont / other partner: Host association provides a possible habitat, but taxon-specific benefits are not demonstrated in this example. | Age: Not specified in the provided sources. | Key distinction: Distinguish evidence of presence from evidence of transmission and function.

Captive sandbar shark + disease-associated Vibrio — Describe this relationship.

Partners: A captive sandbar shark and Vibrio isolates; the lecture does not identify these as V. fischeri. | Habitat: Aquarium case in Baltimore. | Anatomy / location: Bacteria were cultured from internal organs, including kidney and liver, after the shark died. | Transmission: The natural acquisition route in the captive shark is not established. | Interaction type: Disease-associated bacterial infection; subsequent challenge work provides supporting pathogenicity evidence. | Effect on host / recipient: The shark died with Vibrio recovered from internal tissues. | Effect on symbiont / other partner: The bacteria were present in internal host tissue; a specific fitness gain is not quantified. | Age: Not specified in the provided sources. | Key distinction: This is the original clinical case. The experimental spiny-dogfish challenge is a separate host relationship.

Spiny dogfish + experimentally inoculated Vibrio — Describe this relationship.

Partners: Spiny dogfish and Vibrio isolated from the diseased captive-shark case. | Habitat: Laboratory challenge of a marine shark. | Anatomy / location: Experimental injection bypasses natural surface barriers; the lecture does not establish the natural entry site. | Transmission: Artificial inoculation by injection; this is not proof of the natural transmission route. | Interaction type: Pathogenic infection / parasitism. | Effect on host / recipient: Inoculated dogfish died within approximately 18 hours, and bacteria were re-isolated. | Effect on symbiont / other partner: The isolate establishes a lethal infection; its fitness advantage is not directly measured. | Age: Not specified in the provided sources. | Key distinction: The challenge supports pathogenic potential of the isolate, but does not identify all shark-associated Vibrio as pathogens.

Shark ampullae of Lorenzini gel + Staphylococcus-associated community — Describe this relationship.

Partners: Sharks and bacteria cultured from ampullae of Lorenzini (AoL) gel, especially Staphylococcus warneri and S. pasteuri; other isolates also occur. | Habitat: Marine sharks sampled in the lecture’s field study. | Anatomy / location: The AoL are electroreceptive structures connected to external pores by gel-filled canals. The conductive, chitin-containing gel is a restricted-diffusion habitat; bacterial presence in gel does not establish intracellular residence. | Transmission: Environmental entry through exposed pores is plausible, but transmission is not demonstrated by the study. | Interaction type: Association is established; beneficial symbiosis remains a hypothesis. | Effect on host / recipient: The organ supports detection of weak electrical signals. A bacterial role in maintaining gel or defending the host is proposed, not confirmed. | Effect on symbiont / other partner: The gel provides a potential habitat; exact nutritional and fitness benefits remain unresolved. | Age: Not specified in the provided sources. | Key distinction: These are AoL-associated isolates, not the squid light-organ V. fischeri association. Predicted biosynthetic gene clusters are not direct proof of protective compound production.

Shark body surfaces + site-associated microbiomes — Describe this relationship.

Partners: Multiple shark species and microbial communities from mouth/teeth, skin, gills, cloaca, and—in a separate culture study—wounds. | Habitat: Marine sharks sampled off Florida; community studies include seawater and bait comparisons. | Anatomy / location: Different external or exposed body sites harbor different communities. These are not automatically intracellular infections. | Transmission: Environmental exposure is possible, but the surveys do not establish a single transmission mechanism. | Interaction type: A mixture of associations; sequencing or culturing alone does not establish mutualism, commensalism, or pathogenicity for each member. | Effect on host / recipient: Host effects are unresolved for many detected taxa. Wound enrichment by Vibrionaceae does not itself demonstrate that those bacteria caused the wound or disease. | Effect on symbiont / other partner: Different sites provide distinct habitats and possible resources; organism-specific benefits were not directly measured. | Age: Not specified in the provided sources. | Key distinction: Body site and host identity matter. Do not pool AoL gel, teeth, normal skin, and diseased internal organs as one interchangeable shark symbiosis.

Diatom + vitamin B12-associated bacteria — Describe this relationship.

Partners: A vitamin-requiring diatom and associated bacteria; the experiment does not supply a universally applicable named pair. | Habitat: Aquatic diatom habitat and the laboratory B12-limitation experiment. | Anatomy / location: Bacteria occur in the diatom-associated environment/phycosphere; intracellular residence is not established for this example. | Transmission: Environmental association is consistent with the model; a specific inherited route is not established. | Interaction type: Growth-promoting association, consistent with nutrient cooperation; the exact exchanged factor needs confirmation. | Effect on host / recipient: Many diatoms require B12 but cannot synthesize it. Live bacteria improve growth under B12 limitation more than dead bacteria in the illustrated experiment. | Effect on symbiont / other partner: Diatom-derived organic carbon is a possible resource, based on the broader lecture model; a reciprocal fitness benefit is not directly measured in this experiment. | Age: Not specified in the provided sources. | Key distinction: Growth rescue alone does not prove that bacteria supplied B12 rather than another helpful metabolite.

Diatom + iron-mobilizing bacteria — Describe this relationship.

Partners: Diatoms and associated bacteria capable of producing iron-binding siderophores. | Habitat: Aquatic habitats where iron availability can limit growth. | Anatomy / location: Extracellular chemical exchange in the phycosphere and surrounding water; the interaction does not require an intracellular bacterium. | Transmission: Partners associate through the shared environment; pair-specific inheritance is not established. | Interaction type: Potential cooperation through iron mobilization, with possible competition for the same limiting resource. | Effect on host / recipient: Diatoms can benefit from bacterial siderophore-associated iron acquisition. Diatom-released saccharides can also improve iron accessibility. | Effect on symbiont / other partner: Bacteria bind/access iron; diatom-associated carbon may support them. The outcome depends on resource access and the partner combination. | Age: Not specified in the provided sources. | Key distinction: An iron-binding molecule can facilitate another organism’s uptake or withhold iron from it. The lecture also treats domoic-acid metal binding as a proposed mechanism, not a universal demonstrated exchange.

Diatom + consumers of released organic carbon — Describe this relationship.

Partners: Diatoms and heterotrophic bacteria able to use their dissolved organic carbon, including glycolate-utilizing bacteria. | Habitat: The phycosphere and broader aquatic bloom environment. | Anatomy / location: Extracellular exchange: diatoms release dissolved organic compounds and extracellular polymeric substances that bacteria can use. | Transmission: Environmental encounter/association; inherited transmission is not demonstrated. | Interaction type: Carbon provisioning benefits bacteria. A mutualistic classification requires a demonstrated return benefit to the diatom. | Effect on host / recipient: The diatom releases organic carbon; a specific benefit from each bacterial consumer is not established. | Effect on symbiont / other partner: Bacteria gain carbon and energy. Only some community members carry relevant capabilities, such as glcD-associated glycolate use. | Age: Not specified in the provided sources. | Key distinction: Carbon release alone does not prove mutualism. Community competition determines which bacteria exploit the released material.

Diatom + nitrogen-fixing cyanobacteria — Describe this relationship.

Partners: Diatoms and nitrogen-fixing cyanobacteria; Richelia and Calothrix are associated examples named in the lecture. | Habitat: Aquatic diatom habitats where fixed nitrogen is valuable. | Anatomy / location: Cyanobacterial heterocysts allow nitrogen fixation to be separated from oxygen-producing photosynthesis. Exact placement relative to the diatom is not specified for every named association. | Transmission: Not established for this specific association in the provided sources. | Interaction type: Nutritional association providing fixed nitrogen; reciprocal details depend on the particular pair. | Effect on host / recipient: Cyanobacteria convert N2 into ammonia that the diatom can take up. | Effect on symbiont / other partner: The association provides a diatom-associated habitat; the specific reciprocal resource transfer is not directly established in these slides. | Age: Not specified in the provided sources. | Key distinction: Do not assign one host species or one intracellular/extracellular location to both Richelia and Calothrix without pair-specific evidence.

Diatom + bacteria releasing extracellular algicides — Describe this relationship.

Partners: A diatom and algicidal bacteria; a single universal bacterial species is not named for this mechanism. | Habitat: Aquatic diatom-associated habitat. | Anatomy / location: Bacteria release algicidal substances outside cells; the mechanism does not require invasion of the diatom. | Transmission: Environmental exposure to bacteria/their products; no inherited transmission is established. | Interaction type: predation/Antagonism, presented among parasitic/defensive diatom–bacterial interactions. | Effect on host / recipient: Algicidal products damage or kill diatoms. | Effect on symbiont / other partner: Bacteria may gain access to material released by damaged diatoms; the exact fitness gain is not quantified in the slide. | Age: Not specified in the provided sources. | Key distinction: Quorum sensing can regulate extracellular attack. Keep this mechanism separate from direct Saprospira invasion.

Diatom + directly invading Saprospira — Describe this relationship.

Partners: Diatoms and Saprospira bacteria. | Habitat: Aquatic diatom habitat. | Anatomy / location: Direct physical attack/invasion of the diatom is illustrated, contrasting with diffusible extracellular algicides. | Transmission: Environmental encounter and attack; inherited colonization is not established. | Interaction type: Antagonistic, predatory/parasitic bacterial interaction. | Effect on host / recipient: The diatom is damaged or killed. | Effect on symbiont / other partner: The attacking bacterium can exploit diatom material; a quantitative fitness benefit is not given. | Age: Not specified in the provided sources. | Key distinction: This is a distinct bacterial attack strategy. Diatom fatty-acid products, polyunsaturated aldehydes, and altered quorum-sensing signals are discussed as defenses in the following slide, not as proof of protection in every encounter.

Antarctic ice diatom + peroxide-removing epibionts — Describe this relationship.

Partners: Amphiprora kufferathii and bacterial epibionts; tested isolates include MH1 Sulfitobacter sp., MH2 Colwellia sp., and MH3 Pibocella sp. | Habitat: Antarctic sea ice, including Weddell Sea brine channels and the underside of ice. | Anatomy / location: Ectosymbionts on the diatom exterior; bacteria were removed experimentally to compare cultures with and without epibionts. | Transmission: The study manipulates bacterial presence; it does not establish the natural inheritance mechanism. | Interaction type: Cooperation / bacterial facilitation of host growth; the diatom can be maintained without bacteria, so this is not demonstrated obligate dependence. | Effect on host / recipient: Bacteria promote growth and faster hydrogen-peroxide removal. Without epibionts, high-light cultures accumulate more peroxide, linking the association to oxidative-stress relief. | Effect on symbiont / other partner: Diatom organic carbon is a plausible resource from the broader phycosphere model, but this experiment does not directly establish the reciprocal exchange. | Age: Not specified in the provided sources. | Key distinction: All three isolates showed catalase activity. Diatom catalase was not detected under the assay conditions, although superoxide dismutase was detected; do not claim the diatom lacks all antioxidant defenses.

Bloom-forming TW diatom + associated bacterial community — Describe this relationship.

Partners: The diatom labeled TW in the lecture’s bloom experiments and a changing bacterial community; the comparison dinoflagellate is a different host. | Habitat: Hong Kong-area waters across an estuary-to-coastal gradient and simulated bloom experiments. | Anatomy / location: The study compares attached and free-living bacterial fractions; community association does not establish intracellular residence. | Transmission: Environmental community assembly during blooms; vertical transmission is not demonstrated. | Interaction type: Host-associated community shifts and possible growth-supporting functions, rather than a single proven obligate mutualism. | Effect on host / recipient: Bacterial communities may influence bloom growth and nutrient exchange, but community patterns alone do not establish the effect of each taxon. | Effect on symbiont / other partner: Bloom-derived organic matter can support bacteria; functional profiles include carbohydrate-processing and glycolate-use potential. | Age: No age for this specific association. The separate broad diatom lecture discusses diatom–bacterial coexistence over more than 200 million years, not the age of this TW community. | Key distinction: Host identity and sampling site both matter. Predicted metabolic functions are evidence of potential, not direct measurement of a specific metabolite transfer.

Riftia + Endoriftia persephone — Describe this relationship.

Partners: The giant tubeworm Riftia and its bacterial symbiont Endoriftia persephone. | Habitat: Deep-sea hydrothermal vents with access to sulfide and oxygen. | Anatomy / location: Intracellular endosymbionts in the trophosome, the specialized internal nutritional organ. The adult lacks a digestive tract; the plume and circulation deliver needed compounds. | Transmission: Horizontal acquisition by the young host from the environment, rather than strict maternal inheritance. | Interaction type: An essential nutritional chemosymbiosis for the adult worm; benefits flow in both directions. | Effect on host / recipient: Bacteria oxidize sulfide to obtain energy for fixing CO2 into organic carbon and release carbohydrates used by the worm. | Effect on symbiont / other partner: The host supplies sulfide, oxygen, and CO2 plus a protected internal habitat. | Age: Not specified in the provided sources. | Key distinction: Trophosome = symbiont-containing nutritional tissue; plume = exchange structure. Chemical energy drives bacterial carbon fixation, so this food source does not require sunlight.

Vent polychaete + ectosymbiotic bacteria — Describe this relationship.

Partners: A hydrothermal-vent polychaete and chemosynthetic bacteria; the illustrated slide does not specify a species pair. | Habitat: Deep-sea hydrothermal vents. | Anatomy / location: Ectosymbionts on the worm exterior; this is distinct from Riftia bacteria inside a trophosome. | Transmission: Not established for this specific association in the provided sources. | Interaction type: A chemosynthetic nutritional association in the lecture’s examples; pair-specific dependence is not established. | Effect on host / recipient: Chemosynthetic microbes provide an association with a source of organic nutrition; the transfer mechanism and amount are not detailed for this illustrated host. | Effect on symbiont / other partner: The host provides an attachment/tissue habitat at the chemical interface; pair-specific benefits are not measured. | Age: Not specified in the provided sources. | Key distinction: Know the illustrated host and symbiont location. Do not borrow Riftia’s trophosome, named bacterium, or transmission route for this different animal.

Vent shrimp + ectosymbiotic bacteria — Describe this relationship.

Partners: Hydrothermal-vent shrimp and chemosynthetic bacteria; the illustrated slide does not specify a species pair. | Habitat: Deep-sea hydrothermal vents. | Anatomy / location: Ectosymbionts associated with external/exposed surfaces; a precise cell-level placement is not supplied. | Transmission: Not established for this specific association in the provided sources. | Interaction type: A chemosynthetic nutritional association in the lecture’s examples; pair-specific dependence is not established. | Effect on host / recipient: Chemosynthetic microbes provide an association with a source of organic nutrition; the transfer mechanism and amount are not detailed for this illustrated host. | Effect on symbiont / other partner: The host provides an attachment/tissue habitat at the chemical interface; pair-specific benefits are not measured. | Age: Not specified in the provided sources. | Key distinction: Know the illustrated host and symbiont location. Do not borrow Riftia’s trophosome, named bacterium, or transmission route for this different animal.

Vent gastropod + gill-associated bacteria — Describe this relationship.

Partners: A hydrothermal-vent gastropod (snail) and bacterial symbionts; a species pair is not named. | Habitat: Deep-sea hydrothermal vents. | Anatomy / location: Bacteria occur in the gills. This slide alone does not resolve whether every illustrated bacterium is inside or outside individual host cells. | Transmission: Not established for this specific association in the provided sources. | Interaction type: A chemosynthetic nutritional association in the lecture’s examples; pair-specific dependence is not established. | Effect on host / recipient: Chemosynthetic microbes provide an association with a source of organic nutrition; the transfer mechanism and amount are not detailed for this illustrated host. | Effect on symbiont / other partner: The host provides an attachment/tissue habitat at the chemical interface; pair-specific benefits are not measured. | Age: Not specified in the provided sources. | Key distinction: Know the illustrated host and symbiont location. Do not borrow Riftia’s trophosome, named bacterium, or transmission route for this different animal.

Marine nematode + sulfur-oxidizing surface bacteria — Describe this relationship.

Partners: A marine nematode and sulfur-oxidizing bacterial symbionts; species are not named in this comparison. | Habitat: Marine sediments with access to reduced sulfur compounds and oxidants. | Anatomy / location: A single bacterial layer coats the worm surface: ectosymbiosis. | Transmission: Not established for this specific association in the provided sources. | Interaction type: Chemosynthetic nutritional association; specific dependence is not established in this comparison. | Effect on host / recipient: The association links the worm to bacterial carbon production from chemical energy; the precise nutritional transfer is not detailed here. | Effect on symbiont / other partner: Bacteria occupy the host surface at a habitat interface suitable for their metabolism. | Age: Not specified in the provided sources. | Key distinction: The surface coating distinguishes this example from bacteria under a cuticle and bacteria inside a mussel’s gill cells.

Marine worm + extracellular bacteria beneath the cuticle — Describe this relationship.

Partners: A marine worm and chemosynthetic bacterial symbionts; the comparison does not identify a species pair. | Habitat: Marine sediment-associated chemosynthetic habitat. | Anatomy / location: Bacteria lie under the cuticle but outside epidermal cells: extracellular endosymbiosis. | Transmission: Not established for this specific association in the provided sources. | Interaction type: Beneficial nutritional/waste-processing association. | Effect on host / recipient: Bacteria contribute nutrition and waste removal in the illustrated example. | Effect on symbiont / other partner: The host provides an internal but extracellular habitat and access to host-associated substrates. | Age: Not specified in the provided sources. | Key distinction: Inside the animal is not the same as inside an animal cell. This example is neither an external surface coat nor an intracellular bacteriocyte association.

Chemosymbiotic mussel + gill bacteria — Describe this relationship.

Partners: A mussel and chemosynthetic bacterial symbionts; species are not specified in the anatomical comparison. | Habitat: Marine habitats with chemical energy sources, including the deep-sea chemosynthetic settings discussed in the module. | Anatomy / location: Bacteria occur inside specialized gill bacteriocytes: intracellular endosymbiosis. | Transmission: The module discusses horizontal, vertical, and mixed modes among chemosymbioses; it does not assign an exclusive mode to this unnamed mussel example. | Interaction type: Chemosynthetic nutritional association. | Effect on host / recipient: Bacterial chemical-energy-driven carbon fixation contributes organic nutrition. | Effect on symbiont / other partner: Gill cells provide an internal habitat at an exchange surface; species-specific substrate delivery is not detailed in this comparison. | Age: Not specified in the provided sources. | Key distinction: The defining anatomical feature is bacteria inside gill cells, not merely somewhere within the gill structure.

Whale-fall bivalves + chemosynthetic symbionts — Describe this relationship.

Partners: Chemosymbiotic bivalves in whale-fall communities and their microbial symbionts; a single named pair is not supplied. | Habitat: Deep-sea whale falls during sulfide-rich decomposition stages. | Anatomy / location: Bivalve-associated bacteria exploit the chemical habitat; the whale-fall slides do not establish a cellular location for every animal shown. | Transmission: Not established for this specific association in the provided sources. | Interaction type: Chemosynthetic nutritional association supported indirectly by decomposition of the carcass. | Effect on host / recipient: Symbiotic microbes provide access to chemically powered organic nutrition after the initial scavenging stages. | Effect on symbiont / other partner: Microbial degradation and sulfate reduction around the carcass generate sulfide, providing an energy substrate for sulfur-oxidizing symbionts. | Age: Not specified in the provided sources. | Key distinction: The symbiosis is with a living bivalve; the whale carcass creates the surrounding chemical habitat. Association age is not the same as the duration of a whale-fall stage.

Wood-feeding shipworm + xylotrophic gill bacteria — Describe this relationship.

Partners: A wood-feeding shipworm, which is a bivalve mollusk, and wood-degrading bacterial symbionts. | Habitat: Submerged wood in marine environments. | Anatomy / location: The animal bores into wood using its modified shell. Symbionts occur in the gills; wood processing occurs in the digestive system with microbial enzyme contributions. | Transmission: Vertical transmission is described for the wood-feeding shipworm association in this lecture. | Interaction type: Nutritional symbiosis based on wood degradation. | Effect on host / recipient: Bacterial enzymes help make wood-derived material available as nutrition, including degradation of the cellulose/lignin components discussed in the lecture. | Effect on symbiont / other partner: The host provides a protected gill habitat and access to a system using wood-derived resources; exact exchange details are not fully resolved in the slides. | Age: Not specified in the provided sources. | Key distinction: A shipworm is not an annelid worm. Xylotrophy uses wood-derived organic material and must not be confused with sulfide-powered CO2 fixation.

Giant shipworm Kuphus polythalamia + sulfur-oxidizing gill bacteria — Describe this relationship.

Partners: Kuphus polythalamia and sulfur-oxidizing gill symbionts, including a strain labeled 2141T in the study. | Habitat: Organic-rich marine sediment, rather than boring through wood as the principal food habitat. | Anatomy / location: An elongated bivalve in a calcareous tube, with a reduced wood-processing digestive region. Gill microscopy shows bacteria in host vacuolar compartments: intracellular endosymbionts. | Transmission: The natural transmission route is not established in this case. Do not automatically transfer the wood-feeding shipworm’s vertical mode. | Interaction type: Chemosynthetic nutritional symbiosis. | Effect on host / recipient: Sulfide-oxidizing bacteria use chemical energy to fix carbon that supports host nutrition, reducing reliance on direct wood feeding. | Effect on symbiont / other partner: The gills provide a protected host habitat with access to compounds needed for bacterial metabolism. | Age: Not specified in the provided sources. | Key distinction: The study finds sulfur-oxidizing symbiont genomes and cultured residual wood-associated bacteria; culture detection alone does not show that wood degraders dominate the living gill community.

Theonella swinhoei + Entotheonella — Describe this relationship.

Partners: The marine sponge Theonella swinhoei and filamentous Entotheonella bacteria. | Habitat: Indo-Pacific sponge habitats; the lecture names Indonesia, the Philippines, Japan, and northern Australia. | Anatomy / location: Filamentous bacterial symbionts occur extracellularly in the sponge mesohyl. | Transmission: Detection beyond the host and sporulation-related genes are consistent with an environmental phase, but an exclusively horizontal route is not proven. | Interaction type: An association with demonstrated microbial natural-product biosynthesis; ecological protection of the sponge remains a proposed benefit. | Effect on host / recipient: Entotheonella makes many of the bioactive compounds associated with Theonella. These could contribute chemical defense, but biomedical activity alone does not prove a protective effect in nature. | Effect on symbiont / other partner: The sponge provides a habitat; the precise reciprocal nutritional/fitness benefit to Entotheonella is not established. | Age: Not specified in the provided sources. | Key distinction: Two phylotypes with large genomes were resolved; one accounted for nearly all tested bioactive products in the example. This is a case with evidence identifying a microbial producer.

Discodermia dissoluta + discodermolide-producing system — Describe this relationship.

Partners: The sponge Discodermia dissoluta and its associated biological system. Discodermolide is the compound; the lecture does not identify a definitive microbial producer. | Habitat: Caribbean deep-sea sponge; the discovery collection discussed in the lecture occurred in 1987. | Anatomy / location: The compound was obtained from sponge material; the exact producing organism and its cellular/tissue location are not established in these slides. | Transmission: Unknown because a specific producing symbiont and transmission route are not established. | Interaction type: Natural-product association; a particular host–microbe mutualism cannot be assigned from these materials alone. | Effect on host / recipient: An ecological defensive role is proposed. Discodermolide stabilizes microtubules and interferes with cell division, explaining its biomedical interest. | Effect on symbiont / other partner: An identified producer’s reciprocal benefit cannot be stated from the lecture. | Age: Association age not specified. The 1987 collection is a discovery date, not an evolutionary age. | Key distinction: Discodermia = sponge; discodermolide = molecule. Do not import the Entotheonella producer identification from Theonella. Supply limitations motivated synthesis and cultivation approaches.