Description of Paeon asymboli n. sp. (Copepoda : Sphyriidae), parasitic on Asymbolus spp. (catsharks) and a new host record for P-australis Kabata, 1993.

Paeon asymboli n. sp. ( Copepoda: Sphyriidae) is described and illustrated from two female specimens taken from the gills of a grey spotted catshark Asymbolus analis ( Ogilby) and an orange spotted catshark A. rubiginosus ( Last, Gomon & Gledhill) ( Scyliorhinidae) from off southeastern Queensland, Australia. The key features for identification are: a pear- shaped trunk, longer than it is wide, along with a cephalothorax characterised by two large ventral papillae, projecting laterally and supporting a number of secondary lobes; a single mid- line, subconical papilla located antero- dorsal to the ventral papillae; an anterior surface bearing two prominent stalked papillae; and an absence of posterolateral lobular processes. P. australis Kabata, 1993 is recorded for the first time from the eastern shovelnose ray Aptychotrema rostrata ( Shaw & Nodder) ( Rhinobatidae).

Quantification of Listeria spp. contamination on shell and flesh of cooked black tiger prawns (Penaeus monodon)

Aims: To quantify Listeria levels on the shell and flesh of artificially contaminated cooked prawns after peeling, and determine the efficacy of Listeria innocua as a model for L. monocytogenes in this system. Methods and Results: A L. monocytogenes and L. innocua strain were inoculated separately onto cooked black tiger prawns using two protocols ( immersion or swabbing with incubation). Prawns were peeled by two methods ( gloved hand or scalpel and forceps) and numbers of Listeria on shells, flesh and whole prawn controls were determined. Prawns were exposed to crystal violet dye to assess the penetration of liquids. Regardless of preparation method or bacterial strain there were ca 1log(10) CFU more Listeria per shell than per peeled prawn. Dye was able to penetrate to the flesh in all cases. Conclusions: Shell-on prawns may be only slightly safer than shell-off prawns. Listeria innocua is an acceptable model for L. monocytogenes in this system. Significance and Impact of the Study: Reduced risk from L. monocytogenes on prawns can only be assured by adequate hygiene or heating.