TY - JOUR
T1 - Culture of the cladoceran Moina macrocopa
T2 - Mortality associated with flagellate infection
AU - Poynton, Sarah L.
AU - Dachsel, Philipp
AU - Lehmann, Maik J.
AU - Steinberg, Christian E.W.
PY - 2013/12/5
Y1 - 2013/12/5
N2 - Cladocerans are important food animals in aquaculture, key grazers in freshwater ecosystems, and model animals for ecotoxicological investigations. Their epibiont community, extensively studied in Daphnia, includes filamentous bacteria, fungi, algae, peritrich ciliates, and rotifers; although epibionts are usually benign, heavy infections can be detrimental. During our laboratory culture of female Moina macrocopa Straus, we observed a novel flagellate infection associated with mortality. At day 10, all M. macrocopa were alive in uninfected cultures, whereas in untreated infected cultures, the survival was significantly lower: only 26% of cladocerans were alive. In infected cultures treated with humic substances (as 25mgL-1 dissolved organic carbon), mortalities were comparable to those in the untreated infected cultures; in contrast, in the infected cultures treated with 4gL-1 sea salt, mortalities were arrested, and 76% of the M. macrocopa were alive at day 10. Moribund cladocerans were transparent, had empty digestive tracts, and greatly reduced motor activity. Free-swimming flagellates moved forward with a wobbling motion, rotating around their long axis; they also attached to cladoceran tissue, the Petri dish, and the glass slide, by the tip of their posterior flagellum. Flagellates preserved for scanning electron microscopy were 6.9±0.7μm long and 2.1±0.3μm wide, with a short anterior flagellum (6.8±1.1μm) and long posterior flagellum (14.1±1.5μm). Multi-functionality of a flagellum, for locomotion and adhesion, is relatively rare, and previously reported from genera within the Kinetoplastea, suggesting that the flagellate on M. macrocopa may belong to this group. To combat flagellate mass occurrence in Moina cultures, we recommend a treatment with 4gL-1 sea salt.
AB - Cladocerans are important food animals in aquaculture, key grazers in freshwater ecosystems, and model animals for ecotoxicological investigations. Their epibiont community, extensively studied in Daphnia, includes filamentous bacteria, fungi, algae, peritrich ciliates, and rotifers; although epibionts are usually benign, heavy infections can be detrimental. During our laboratory culture of female Moina macrocopa Straus, we observed a novel flagellate infection associated with mortality. At day 10, all M. macrocopa were alive in uninfected cultures, whereas in untreated infected cultures, the survival was significantly lower: only 26% of cladocerans were alive. In infected cultures treated with humic substances (as 25mgL-1 dissolved organic carbon), mortalities were comparable to those in the untreated infected cultures; in contrast, in the infected cultures treated with 4gL-1 sea salt, mortalities were arrested, and 76% of the M. macrocopa were alive at day 10. Moribund cladocerans were transparent, had empty digestive tracts, and greatly reduced motor activity. Free-swimming flagellates moved forward with a wobbling motion, rotating around their long axis; they also attached to cladoceran tissue, the Petri dish, and the glass slide, by the tip of their posterior flagellum. Flagellates preserved for scanning electron microscopy were 6.9±0.7μm long and 2.1±0.3μm wide, with a short anterior flagellum (6.8±1.1μm) and long posterior flagellum (14.1±1.5μm). Multi-functionality of a flagellum, for locomotion and adhesion, is relatively rare, and previously reported from genera within the Kinetoplastea, suggesting that the flagellate on M. macrocopa may belong to this group. To combat flagellate mass occurrence in Moina cultures, we recommend a treatment with 4gL-1 sea salt.
KW - Adhesive flagellum
KW - Bodoid flagellate
KW - Cladoceran
KW - Kinetoplastid
KW - Moina macrocopa
UR - http://www.scopus.com/inward/record.url?scp=84886210159&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84886210159&partnerID=8YFLogxK
U2 - 10.1016/j.aquaculture.2013.09.029
DO - 10.1016/j.aquaculture.2013.09.029
M3 - Article
AN - SCOPUS:84886210159
SN - 0044-8486
VL - 416-417
SP - 374
EP - 379
JO - Aquaculture
JF - Aquaculture
ER -