The life-cycle of the flatfish nematode Cucullanus heterochrous.

摘要: Mature specimens of Cucullanus heterochrous Rudolphi, 1802 (Nematoda: Cucullanidae) were obtained from the intestine flounder, Platichthys flesus, Danish waters. Eggs embryonate in seawater but do not hatch. Fully developed larvae pressed out eggs are 430 microm long with amphids and dereids enclosed within cuticle a previous larval stage. Infective believed to be their third Experimental studies showed that polychaetes, Nereis spp., Scoloplos armiger, Brada villosa Capitella sp., may act as intermediate hosts. In N. diversicolor increase length 1 mm four weeks (15 degrees C) without moulting. infections larvated infective fish, whereas >550 polychaetes survived 4-24 cm flounders plaice, Pleuronectes platessa. Third-stage 550 1.1 found submucosa one week post infection. At about 800 1.4 they moult fourth-stage larvae. Fourth-stage larvae, immature mature worms occur rectum. adults experimental transfer flounder another. Similar developmental stages for two experimentally infected cod, Gadus morhua.