Parasitism: the possible cause of the collapse of a Volvox population in Mount Bold Reservoir, South Australia

Abstract

A V. ?tertius population in Mt Bold Reservoir was found to be heavily parasitized by the rotifer Ascomorphella volvocicola, which may have led to the collapse of the V. ?tertius population.

Epizoic and parasitic rotifers

“…Rotifer parasites are common among colonies of Volvox, especially V. globator (Williams, 1852;Gosse, 1852;Hood, 1895;Galliford, 1946), V. aureus (Rousselet, 1911;Sauer, 1978), and V. tertius (Ganf et al, 1983). These rotifers have been identified as Proales parasita (Ehr.)…”

“…(Williams, 1852;Thompson, 1892;Rousselet, 1911Rousselet, , 1914Harring & Myers, 1922;Rich & Pocock, 1933;Hollowday, 1949;Wulfert, 1960;Sauer, 1978), Ascomorphella volvocicola (Plate) (Gosse 1852;Hood, 1895;Murray, 1906;Galliford, 1946;Ganf et al, 1983) and, more rarely, Cephalodella catellina volvocicola (Zawadovsky) (Edmondson & Hutchinson, 1934). Parasitism in Ascomorphella volvocicola seems to be specific to Volvox species, as this rotifer has never been observed on other phytoplankton species, or living freely (Ganf et al, 1983). The mature rotifer enters the Volvox colony and feeds on the cells causing extensive damage (Hood, 1895;Hollowday, 1949;Ganf et al, 1983).…”

“…Parasitism in Ascomorphella volvocicola seems to be specific to Volvox species, as this rotifer has never been observed on other phytoplankton species, or living freely (Ganf et al, 1983). The mature rotifer enters the Volvox colony and feeds on the cells causing extensive damage (Hood, 1895;Hollowday, 1949;Ganf et al, 1983). Whether this actually causes the Volvox population to decline is uncertain (Ganf et al, 1983).…”

“…The mature rotifer enters the Volvox colony and feeds on the cells causing extensive damage (Hood, 1895;Hollowday, 1949;Ganf et al, 1983). Whether this actually causes the Volvox population to decline is uncertain (Ganf et al, 1983).…”

Tasmanian rotifera: Affinities with the Australian fauna

“…In recent years, there has been a substantial increase in information concerning the rotifer fauna of Australia [Ganf et al, 1983;Shiel & Koste, 1986;Koste & Shiel 1986a;., in press]. Six hundred and twenty taxa are now known from Australia [Shiel & Koste, 1985;Koste & Shiel, 1986bl. However, compared to the northern hemisphere, our knowledge of the Australian rotifer fauna is poor.…”