Dinoflagellate infections of Favella panamensis from two North American estuaries

Abstract

Favella panamensis Kofoid and Campbell, 1929 is seasonally abundant in meso-to polyhaline waters of Chesapeake Bay and Indian River, Florida, USA, where it reaches densities of 103 cells 1-1 . During the summers of 1986-1992, F. panamensis populations of the two estuaries were commonly infected by the parasitic dinoflagellate Duboscquella aspida Cachon, 1964. The intracellular phase of the parasite reached maturity in -21 h (30 ~ and consumed -35% of the host's biomass. Infections were not typically lethal to F. panamensis, but sometimes forced the host from its lorica. Several D. aspida were found in the cytoplasm of many hosts, and the number of parasites infection -1 was directly related to infection level. Parasite prevalence averaged 24.0 and 11.5% with mean number of parasites infection -1 being 1.5 and 1.3 for Chesapeake Bay and Indian River samples, respectively. D. aspida was estimated to remove up to 68% of host standing stock d -1 with a mean of ~ 10% for all samples. The average impact of parasitism on F. panamensis populations was somewhat less than would be expected from copepod grazing.

Tintinnophagus acutus n. g., n. sp. (Phylum Dinoflagellata), an Ectoparasite of the Ciliate Tintinnopsis cylindrica Daday 1887, and Its Relationship to Duboscquodinium collini Grassé 1952

“…Some specimens contained numerous intracellular sporocysts, similar to the report of Haeckel (1873), leading Duboscq and Collin (1910) to conclude that sporogenesis began inside the host and culminated in the extracellular release of dinospores. Because cell division of the parasite inside the host cytoplasm was not observed, it is probable that the numerous intracellular sporocysts seen by Duboscq and Collin (1910) in a single host actually represented multiple infections (see Coats et al 1994). Unlike the gymnodinoid macrospores observed by Laackmann (1908) and Lohmann (1908), the parasite studied by Duboscq and Collin (1910) produced Oxyrrhis ‐like macrospores that had a pointed anterior portion, a rounded posterior end, and a pair of laterally placed flagella, one extending anteriad and one wrapping loosely around the cell.…”

Responsibility of microzooplankton and parasite pressure for the demise of toxic dinoflagellate blooms

“…Ciliates such as tintinnids may also be parasitized by a species related to Amoebophrya sp. (Coats et al 1994). If this were to occur in our proposed food web (Fig.…”

“…Dinospores arẽ 10 µm long, biflagellate cells that attach to the host surface, penetrate the host pellicle, and develop into trophonts in the cytoplasm or in the host nucleus, depending on the infected species (Cachon 1964. The trophont grows in the host for ~2 d (Coats et al 1994, Yih & Coats 2000 and replicates to produce a multinucleate, multiflagellate stage. At maturity, the multiflagellated stage metamorphoses into the vermiform, which escapes from the host, killing it.…”

“…At maturity, the multiflagellated stage metamorphoses into the vermiform, which escapes from the host, killing it. Vermiforms are free living for a fraction of a day , and then undergo cytokinesis to produce hundreds to thousands of dinospores (Coats et al 1994). Survival of dinospores outside the host is on the order of 1 to 2 d .…”

Euduboscquella costata n. sp. (Dinoflagellata, Syndinea), an Intracellular Parasite of the Ciliate Schmidingerella arcuata: Morphology, Molecular Phylogeny, Life Cycle, Prevalence, and Infection Intensity

“…On average, parasite induced host mortality rivals grazing effects of dominant zooplankton and promotes recycling of material within the microbial loop (Coats ; Coats et al. ).…”