The polymerization of acrylamide initiated by ceric nitrate and 3‐chloro‐1‐propanol was studied in aqueous solution at 25°C. At constant hydrogen ion and nitrate ion concentration, the rate of polymerization was found to be independent of the ceric ion concentration. The molecular weight of the polymer was very low. To explain the data, a kinetic scheme is proposed whereby ceric ions are responsible for both initiation and termination. The rate constant for oxidative termination was found to be of the order of 105 l. mole−1 sec.−1 and varied with the hydrogen ion and the nitrate ion concentrations.

The rate of reaction of ceric nitrate with the 1,2‐glycol units and the alcohol units of polyvinyl alcohol was determined at 20°C. It was found that the glycol units are oxidized much faster than the alcohol units even though they are outnumbered about one hundred to one in the polymer chain. Under the conditions studied, at least 83 glycol units reacted per 100 hours oxidized. Since the oxidation of the glycol units is accompanied by chain splitting, the free radicals are produced predominantly at the fragments end.

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The spotted wolffish Anarhichas minor is a promising new species for cold-water aquaculture. The broad host-range of piscine nodavirus (NV) and infectious pancreatic necrosis virus (IPNV) makes them potentially pathogenic to new fish species in aquaculture. IPNV and NV strains highly pathogenic in farmed Atlantic salmon Salmo salar and halibut Hippoglossus hippoglassus, respectively, in Norway were used for the challenge of spotted wolffish. In general, water-borne infection with IPNV and NV resulted in significant mortality among juveniles <1 g. Cumulative mortality after bath-challenge and cohabitation was 60 to 75% in the smallest juveniles (0.3 g). Intramuscular and intraperitoneal injection of NV was 100% lethal to wolffish of 10 g, and the groups at 12°C died before those at 7°C. No cohabitants of this size died, but NV was still detectable in these individuals after 10 wk. A persistent IPNV infection with low mortality developed in bath-challenged juveniles of 0.7 g, in which IPNV was still detectable 4 mo later. This study comprises a demonstration of experimental viral infections in cultured spotted wolffish, although to date no natural outbreaks of viral diseases have been reported in this species. KEY WORDS: Viral nervous necrosis · VNN · Viral encephalopathy and retinopathy · VER · Nodavirus · Infectious pancreatic necrosis · IPN · IPN virus · Spotted wolffish Resale or republication not permitted without written consent of the publisherDis Aquat Org 59: [101][102][103][104][105][106][107][108] 2004 Nakai 1997), and recently in the USA (Curtis et al. 2001) and Atlantic Canada (Johnson et al. 2002). Like IPN, VNN has caused high mortality in fry of Atlantic halibut (Grotmol et al. 1995), and in Atlantic cod (Starkey et al 2001, Johnson et al. 2002. Recently a persistent infection of NV was reported in halibut juveniles (Johansen et al 2002).The broad host-range of NV and IPNV makes these viruses potentially pathogenic to new fish species in aquaculture. The aim of the present study was to investigate the susceptibility of spotted wolffish juveniles to NV and IPNV strains highly pathogenic to farmed Atlantic salmon and halibut in Norway, and proactively study the possibility of VNN or IPN outbreak in this species. Some factors known to affect the outcome of these viral infections in fishes, such as host size, water temperature and infection route, were examined in 3 separate challenge experiments. However, the virulence of NV and IPNV was not compared. MATERIALS AND METHODSInitially, production of farmed spotted wolffish was small and limited the number of fish available for experimental studies. The present study was performed over a 4 yr period, using 3 different generations of spotted wolffish progeny (P) produced in 1998, 2000 and 2001. Attempts at viral detection were done on all batches of non-challenged wolffish: in 2 pools of 5 juveniles sampled at the start and the end of the trials, as well as in dead individuals. Due to the low number of control fish in Expt 1, these were only...

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