Symbiosis and Parasitism in Marine Organisms

Flashcards covering terms, definitions, and examples from the lecture on Symbiosis and Parasitism in marine environments, including specific parasite life cycles and ecological interactions.

Symbiosis

A close, long-term association between two or more different species of organisms.

Symbionts

The organisms involved in a symbiotic relationship.

Mutualism

A form of symbiosis in which two species associate for their mutual benefit ($+/+$).

Commensalism

Association whereby there is a clear example of benefit to one member whilst not harming the other ($+/0$).

Inquilinism

A subdivision of commensalism in which one animal lives in the home of another, or in its digestive tract, without being parasitic.

Commensal

In commensal and inquiline relationships, the partner gaining an advantage.

Host

The partner in a symbiotic or parasitic relationship that is typically larger or provides resources/shelter without gaining an advantage (in commensalism) or being harmed (in parasitism).

Competition

An interspecific interaction characterized by a negative outcome for both species ($-/-$).

Predation

An interaction where one species benefits and the other is harmed through consumption ($+/-$).

Parasitism (Rohde 2005)

Close association of two organisms, in which one – the parasite – depends on the other – the host – deriving some benefit from it.

Parasite (Poulin 2006)

An organism living in or on another organism, the host – feeding on it, showing some degree of structural adaption to it, and causing it some harm.

Marine Phyla (Taxa)

According to Table 1.4, the marine environment contains $32b$ phyla of higher animal taxa.

Terrestrial Phyla (Taxa)

According to Table 1.4, the terrestrial environment contains $12$ phyla of higher animal taxa.

Freshwater Phyla (Taxa)

According to Table 1.4, the freshwater environment contains $16$ phyla of higher animal taxa.

Marine Classes (Taxa)

According to Table 1.4, the marine environment contains $73$ classes of higher animal taxa.

Zooxanthellae

Algal symbionts classified as brown, yellow, or golden cells.

Zoochlorellae

Algal symbionts classified as green cells.

Cyanellae

Algal symbionts classified as blue-green cells.

Cassiopeia Jellyfish

A jellyfish that lies upside-down on the seabed to expose oral tentacles containing algae.

Egg Transmission

Method used by Cnidaria to pass algal symbionts to the next generation via eggs.

Re-infection

Method where Gastropods and Porifera must replenish algal symbionts in each new generation.

Endozoites

Commensal organisms living inside other organisms.

Epizoites

Commensal organisms living on the outer surface of other organisms.

Pearlfish (Carapus sp.)

A fish that lives in association with Sea Cucumbers (Holothurians).

Portuguese man-of-war (Physalia sp.)

A colonial siphonophore that lives in association with the fish $Nomeus\,gronovii$.

Goby Fish and Blind Shrimp

An association between $Cryptocentrus\,lutheri$ and $Alpheus\,djiboutensis$.

Lybia tesselata

A crab that uses sea anemones on its claws for defense and feeding.

Prevalence

The proportion of infected hosts at a given time, often expressed as a percentage.

Intensity

The number of parasite individuals of a particular species in each infected host.

Mean Intensity

The total number of parasite individuals in a sample divided by the number of infected individual hosts.

Abundance

The total number of parasite individuals in a sample divided by the total number of individual hosts (infected and uninfected).

Direct Life Cycle

A lifecycle where the parasite passes from one definitive host to another without intermediate hosts.

Definitive Host

The host in which a parasite reaches the adult (reproductive) stage.

Intermediate Host

A host in which a parasite undergoes development or larval stages (labeled L1, L2, etc.).

Paratenic Host

A 'transport' host where the parasite survives but does not undergo developmental changes.

Cymothoa exigua

A crustacean parasite that infects the Spotted Snapper ($Lutjanus\,guttatus$).

Miracidium

The free-living larval stage of a trematode that infects its first intermediate host (molluscs).

Cercariae

The free-living stage of major trematodes that exits the molluscan host to find a second intermediate host.

Metacercariae

The parasitic stage of trematodes typically found in the second intermediate host; in cockles, these can prevent burial into sediment.

Acanthocephala

A phylum of thorny or spiny-headed worms characterized by a hook-bearing proboscis.

Phototactism

Behavioral movement in response to light, which can be modified by parasites like acanthocephalans in amphipods.

Serotonin

A neurotransmitter in the brain of hosts like $Gammarus$ whose activity is linked to phototactism.

Sacculina sp.

A rhizocephalan parasite of crabs ($Carcinus\,maenas$) that causes sterilization and feminization.

Externa

The external reproductive part of a rhizocephalan parasite like $Sacculina$.

Interna

The root-like system of a rhizocephalan parasite that damages host endocrine organs and the CNS.

Feminization

The process where parasites convert genetic males into phenotypic females to ensure vertical transmission.

Vertical Transmission

Transmission of a parasite from parent to offspring via gametes (usually maternal).

Microsporidia

A group of parasites (e.g., $Nosema\,granulosis$) known for feminizing their amphipod hosts.

Androgenic Gland

The gland in crabs responsible for male characteristics; it degenerates when infected by $Sacculina$.

Infaunal Diversity

The variety of organisms living within sediment, which can be altered by parasites affecting host behavior (e.g., trematodes in cockles).

Proboscis

The anterior part of an acanthocephalan, often equipped with hooks for host attachment.

Anisakiasis

A parasitic infection caused by raw fish consumption resulting in sudden, severe abdominal pain.

Chlonorchiasis

A liver infection characterized by jaundice, tenderness, and enlargement.

Diphyllobothrium Symptoms

Includes irritability, numbness, tingling, weakness, and increased heart rate.

Egg Mimicry

A behavioral change in crabs infected by $Sacculina$ where the host cares for the parasite's externa as if it were its own eggs.

Kentrogon

A life stage of $Sacculina$ that uses a stylet to inject the vermigon into the host crab.

Cypris

The settlement stage of the rhizocephalan life cycle.

Vermigon

The internal stage of $Sacculina$ injected into the host by the kentrogon.

Urechis caupo

The Echiurid Worm species that creates U-shaped burrows often inhabited by commensals like fish, worms, and crabs.

Mesozoa

Considered as two separate phyla in the context of the Higher Animal Taxa table provided by Prof. Ford.

Pogonophora

Considered a polychaete for the classification in Table 1.4.

Pentastomida

Considered a class of arthropods in the biodiversity count provided in the lecture.

Interspecific Interactions

Relationships between different species, including competition, predation, mutualism, commensalism, and parasitism.

Facultative association

A symbiotic relationship that is optional for the survival of the organisms involved.

Obligatory association

A symbiotic relationship that is essential for the survival of at least one of the partners.

Autotrophic cells

Self-nourishing cells, such as algae, that often form symbiotic associations with marine invertebrates.

Upper Pelagic Realm

The surface layers of the open ocean where algal-invertebrate associations are primarily restricted.

Bursa copulatrix

An anatomical structure in male acanthocephalans used for reproduction.

Lemniscus

An anatomical structure found in the anterior section of an acanthocephalan worm.

Prevalence Calculation

$4\,INFECTED / 10\,TOTAL = 0.4$ or $40\%$.

Intensity (Example)

If a host contains exactly $5$ individual parasites, the intensity is $5$.

Mean Intensity (Example)

$(5 + 4 + 4 + 3) / 4 = 4$. This represents the average number of parasites per infected host.

Abundance (Example)

$(0 + 0 + 5 + 4 + 0 + 0 + 4 + 3) / 8 = 2$. This represents the average number of parasites across the whole sample.

Convergent Evolution

The process where different species evolve similar traits, noted in Slide 29 regarding commensal associations.

Clevelandia ios

A fish species found in the U-shaped burrow of the Echiurid Worm.

Hesporone adventor

A Scale Worm species found in the U-shaped burrow of the Echiurid Worm.

Scleroplax granulata

A Pinnotherid Crab species found in the U-shaped burrow of the Echiurid Worm.

Bataeus longidactylus

A Long-Fingered Shrimp species found in the U-shaped burrow of the Echiurid Worm.

Diademichthys lineatus

The scientific name for the Cling Fish mentioned in slide 28.

Stegopontonia commensalis

A commensal shrimp species shown in the lecture slides.

Nomeus gronovii

The fish that lives among the stinging tentacles of the Portuguese man-of-war.

Chelopeds

The front claws of a crab, modified in $Lybia\,tesselata$ for holding anemones.

Klaus Rohde

The author of the 2005 text 'Marine Parasitology'.

Robert Poulin

The author of the 2006 text 'Evolutionary Ecology of Parasites'.

Sporocyst

A parasitic stage in the typical life cycle of trematodes that follows the miracidium.

Redia

A parasitic larval stage of trematodes produced within the sporocyst.

Pseudoterranova decipiens

A species belonging to the families Ascaridida and Anisakidae, with a complex life cycle.

Gammarus pulex

A freshwater amphipod used in studies regarding parasite-induced phototactism.

Nosema granulosis

A specific microsporidian parasite that infects $Gammarus\,duebeni$.

Dictyocoela duebenum

A microsporidian parasite, also referred to as Microsporidium spA, that feminizes its host.

Transmission dead-end

The role of male hosts for vertically transmitted parasites, as they do not pass on the parasite via gametes.

Feminising parasites

Parasites that increase the relative frequency of the transmitting (female) sex by converting males.

Thorny-headed worms

The common name for organisms in the phylum Acanthocephala.

Saefftigen's pouch

A specialized organ found in the anatomy of male acanthocephalans.

Cilliate protists

Commensal symbionts found on the external surfaces or internal gills/digestive tracts of hosts.

Prof. Alex Ford

The lecturer for the course on Marine Organisms, Ecosystems, Symbiosis, and Parasitism.

Chloroplast symbiosis

A type of association where only the functioning chloroplasts from algal cells are incorporated into invertebrate tissues.

Entire cell association

Relationship where the whole autotrophic cell lives within vacuoles inside host tissue cells or inter-layer spaces.

Stylet

The structure used by the kentrogon stage of $Sacculina$ to penetrate host cuticle.

Trichogon males

Implanted dwarf males found in the mature female parasite of the $Sacculina$ life cycle.