Nereidae are vital to the functioning of estuarine ecosystems and are major components in the diets of over-wintering birds and commercial fish. They use environmental cues to synchronize reproduction. Photoperiod is the proximate cue, initiating vitellogenesis in a temperature-compensated process. The prevailing paradigm in Nereidae is of a single 'juvenile' hormone controlling growth and repr...

Nereis diversicolor O.F. Müller and N. succinea Frey et Leuckart (Polychaeta, Nereidae) living in brackish shallow areas in Denmark are naturally infected with tetractinomyxon actinospores. Infected Nereis spp. were experimentally fed to various potential fish hosts, and the actinosporean stages developed into myxosporean stages of Ellipsomyxa gobii Køie, 2003 (Ceratomyxidae) in the gallbladder...