Amoebophrya leptodisci
Diagnosis
Diagnosis_Genus: Amoebophrya Koeppen 1984. Intracellular parasites. Smallest trophonts observed have 3 µm long, a gymnodiniales form, with a large hypocone and a small rudimentary epicone. The hypocone broadens at its base and forms a cup-shaped circumvallation, turning in spiral. The hypocone starts to cover the epicone (in other word, the epicone becomes progressively invaginated into the hypocone, forming a cavity, the mastigocoel, which is a characteristic of the genus Amoebophrya. This mastigocoel remains open by a small aperture at the apex of the trophont. Sporogenesis starts rapidly during this transformation. The inner surface of the mastigocoel is furnished with helically coiled ridges as a result of a continuous lengthening of the previous dinospore girdle during the trophic growth. Along these ridges countless flagella are inserted. Flagella of future dinospores (the free-living stage of the parasite) are produced inside the mastigocoel. At the end of the intracellular maturation, flagella started to beat, and what was the epicone at the origin, directed through the aperture of the mastigocoel, moved forward. This evagination make the flagella outside the structure, which is now called the vermiform. This action breacks out the host membrane, releasing the vermiform outside. This vermiform is closed forward (at the epicone side), but open in the back. When release, this part forms a large digestive vacuole that contains what remains from the host. This vermiform considerably strechs out with time. The spore chain forming the vermiform rapidly separates to produce spores (gymnodinial shape), generally of two different sizes (macrospores and microspores). These spores have a large epicone and a reduced hypocone (the reverse of what is observed during the first stage of the trophont).
Diagnosis_species: Amoebophrya leptodisci Cachon 1964. Parasite infecting the Peridiniales Leptodiscus medusoides. Resembling to Amoebophrya ceratii, with few differences. The trophont could be either plurinucleate or having a single voluminous nucleus, the sporogenesis can occur at any time of the trophont development, or during the vermiform stage. The mastigocoel is formed just before the first nuclear division, and could be considerably delayed. A cytopharynx is observed (as in Amoebophrya ceratii) , not longer than 7 µm.
Type species
The type species (lectotype) of the genus Amoebophrya is Amoebophrya acanthometrae Borgert 1897
Type illustration / Type locality / Type specimen
Type host: Leptodiscus medusoides
Ecology
Substrate_spores: planktonic
Substrate_trophont: endozoic
Sociability_spores: solitary
Sociability_trophont: solitary
Salinity: marine
pH: neutral
Feeding: parasitism (by phagotrophy)
Life cycle
Phases_alternance: haplontic
Generation: <1 month
Reproduction_mode: asexual
Symbiont: horizontal_active-penetration
Feeding behaviour
Mode of locomotion
Reference(s)
Observation site(s)
Observation site(s)
HOSTS
Association with... | Region origin | Name of site | In reference... |
---|---|---|---|
Leptodiscus medusoides |
Contribution à l’étude des péridiniens parasites. Cytologie, cycles évolutifs. Ann. Sci. Nat. Zool. 6:1-158. (1964) |
SYMBIONTS
Association with... | Region origin | Name of site | In reference... |
---|---|---|---|
Amoebophrya ceratii-species complex |
Contribution à l’étude des péridiniens parasites. Cytologie, cycles évolutifs. Ann. Sci. Nat. Zool. 6:1-158. (1964) |